tracing: update to otelhttp roundtripper

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

go.mod

@@ -55,6 +55,8 @@ require (
 	github.com/urfave/cli v1.22.2
 	go.etcd.io/bbolt v1.3.5
 	go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.21.0
+	go.opentelemetry.io/contrib/instrumentation/net/http/httptrace/otelhttptrace v0.21.0
+	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.21.0
 	go.opentelemetry.io/otel v1.0.0-RC1
 	go.opentelemetry.io/otel/exporters/jaeger v1.0.0-RC1
 	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.0.0-RC1
@@ -73,3 +75,9 @@ require (
 )
 
 replace github.com/docker/docker => github.com/docker/docker v20.10.3-0.20210609100121-ef4d47340142+incompatible
+
+replace go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc => github.com/tonistiigi/opentelemetry-go-contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.0.0-20210714055410-d010b05b4939
+
+replace go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp => github.com/tonistiigi/opentelemetry-go-contrib/instrumentation/net/http/otelhttp v0.0.0-20210714055410-d010b05b4939
+
+replace go.opentelemetry.io/contrib/instrumentation/net/http/httptrace/otelhttptrace => github.com/tonistiigi/opentelemetry-go-contrib/instrumentation/net/http/httptrace/otelhttptrace v0.0.0-20210714055410-d010b05b4939

go.sum

@@ -419,6 +419,8 @@ github.com/evanphx/json-patch v4.2.0+incompatible/go.mod h1:50XU6AFN0ol/bzJsmQLi
 github.com/evanphx/json-patch v4.9.0+incompatible/go.mod h1:50XU6AFN0ol/bzJsmQLiYLvXMP4fmwYFNcr97nuDLSk=
 github.com/fatih/color v1.7.0/go.mod h1:Zm6kSWBoL9eyXnKyktHP6abPY2pDugNf5KwzbycvMj4=
 github.com/fatih/color v1.9.0/go.mod h1:eQcE1qtQxscV5RaZvpXrrb8Drkc3/DdQ+uUYCNjL+zU=
+github.com/felixge/httpsnoop v1.0.2 h1:+nS9g82KMXccJ/wp0zyRW9ZBHFETmMGtkk+2CTTrW4o=
+github.com/felixge/httpsnoop v1.0.2/go.mod h1:m8KPJKqk1gH5J9DgRY2ASl2lWCfGKXixSwevea8zH2U=
 github.com/flynn/go-shlex v0.0.0-20150515145356-3f9db97f8568/go.mod h1:xEzjJPgXI435gkrCt3MPfRiAkVrwSbHsst4LCFVfpJc=
 github.com/form3tech-oss/jwt-go v3.2.2+incompatible/go.mod h1:pbq4aXjuKjdthFRnoDwaVPLA+WlJuPGy+QneDUgJi2k=
 github.com/fortytw2/leaktest v1.2.0/go.mod h1:jDsjWgpAGjm2CA7WthBh/CdZYEPF31XHquHwclZch5g=
@@ -1071,6 +1073,12 @@ github.com/tonistiigi/fsutil v0.0.0-20210609172227-d72af97c0eaf h1:L0ixhsTk9j+dV
 github.com/tonistiigi/fsutil v0.0.0-20210609172227-d72af97c0eaf/go.mod h1:lJAxK//iyZ3yGbQswdrPTxugZIDM7sd4bEsD0x3XMHk=
 github.com/tonistiigi/go-actions-cache v0.0.0-20210714033416-b93d7f1b2e70 h1:+ZlFs3Tl5qYZJvX2PxfZxGlVXz847LsOJGyNVU5pCHo=
 github.com/tonistiigi/go-actions-cache v0.0.0-20210714033416-b93d7f1b2e70/go.mod h1:dNS+PPTqGnSl80x3wEyWWCHeON5xiBGtcM0uD6CgHNU=
+github.com/tonistiigi/opentelemetry-go-contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.0.0-20210714055410-d010b05b4939 h1:s6wDMZYNyWt8KvkjhrMpOthFPgI3JB8ipJS+eCV/psg=
+github.com/tonistiigi/opentelemetry-go-contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.0.0-20210714055410-d010b05b4939/go.mod h1:Vm5u/mtkj1OMhtao0v+BGo2LUoLCgHYXvRmj0jWITlE=
+github.com/tonistiigi/opentelemetry-go-contrib/instrumentation/net/http/httptrace/otelhttptrace v0.0.0-20210714055410-d010b05b4939 h1:ZZ1KHKvs97BcRoblbm6RhrDzs/OejFv7miYSIcZI7Ds=
+github.com/tonistiigi/opentelemetry-go-contrib/instrumentation/net/http/httptrace/otelhttptrace v0.0.0-20210714055410-d010b05b4939/go.mod h1:a9cocRplhIBkUAJmak+BPDx+LVL7cTmqUPB0uBcTA4k=
+github.com/tonistiigi/opentelemetry-go-contrib/instrumentation/net/http/otelhttp v0.0.0-20210714055410-d010b05b4939 h1:iYUjYA5PwiJjvlY1PkCjFZIoDFOlL4g/AqSrcd5lJtE=
+github.com/tonistiigi/opentelemetry-go-contrib/instrumentation/net/http/otelhttp v0.0.0-20210714055410-d010b05b4939/go.mod h1:JQAtechjxLEL81EjmbRwxBq/XEzGaHcsPuDHAx54hg4=
 github.com/tonistiigi/units v0.0.0-20180711220420-6950e57a87ea h1:SXhTLE6pb6eld/v/cCndK0AMpt1wiVFb/YYmqB3/QG0=
 github.com/tonistiigi/units v0.0.0-20180711220420-6950e57a87ea/go.mod h1:WPnis/6cRcDZSUvVmezrxJPkiO87ThFYsoUiMwWNDJk=
 github.com/tonistiigi/vt100 v0.0.0-20210615222946-8066bb97264f h1:DLpt6B5oaaS8jyXHa9VA4rrZloBVPVXeCtrOsrFauxc=
@@ -1139,8 +1147,6 @@ go.opencensus.io v0.22.3 h1:8sGtKOrtQqkN1bp2AtX+misvLIlOmsEsNd+9NIcPEm8=
 go.opencensus.io v0.22.3/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
 go.opentelemetry.io/contrib v0.21.0 h1:RMJ6GlUVzLYp/zmItxTTdAmr1gnpO/HHMFmvjAhvJQM=
 go.opentelemetry.io/contrib v0.21.0/go.mod h1:EH4yDYeNoaTqn/8yCWQmfNB78VHfGX2Jt2bvnvzBlGM=
-go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.21.0 h1:68WZYF6CrnsXIVDYc51cR9VmTX2IM7y0svo7s4lu5kQ=
-go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.21.0/go.mod h1:Vm5u/mtkj1OMhtao0v+BGo2LUoLCgHYXvRmj0jWITlE=
 go.opentelemetry.io/otel v1.0.0-RC1 h1:4CeoX93DNTWt8awGK9JmNXzF9j7TyOu9upscEdtcdXc=
 go.opentelemetry.io/otel v1.0.0-RC1/go.mod h1:x9tRa9HK4hSSq7jf2TKbqFbtt58/TGk0f9XiEYISI1I=
 go.opentelemetry.io/otel/exporters/jaeger v1.0.0-RC1 h1:tVhw2BMSAk248rhdeirOe9hlXKwGHDvVtF7P8F+H2DU=
@@ -1151,6 +1157,10 @@ go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.0.0-RC1 h1:ZO
 go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.0.0-RC1/go.mod h1:cDwRc2Jrh5Gku1peGK8p9rRuX/Uq2OtVmLicjlw2WYU=
 go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.0.0-RC1 h1:zoRUmPIQOAhkiXjoZ/BJUd6A9Ug1M/sEJgrEI68m3dU=
 go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.0.0-RC1/go.mod h1:OYKzEoxgXFvehW7X12WYT4/a2BlASJK9l7RtG4A91fg=
+go.opentelemetry.io/otel/internal/metric v0.21.0 h1:gZlIBo5O51hZOOZz8vEcuRx/l5dnADadKfpT70AELoo=
+go.opentelemetry.io/otel/internal/metric v0.21.0/go.mod h1:iOfAaY2YycsXfYD4kaRSbLx2LKmfpKObWBEv9QK5zFo=
+go.opentelemetry.io/otel/metric v0.21.0 h1:ZtcJlHqVE4l8Su0WOLOd9fEPheJuYEiQ0wr9wv2p25I=
+go.opentelemetry.io/otel/metric v0.21.0/go.mod h1:JWCt1bjivC4iCrz/aCrM1GSw+ZcvY44KCbaeeRhzHnc=
 go.opentelemetry.io/otel/oteltest v1.0.0-RC1 h1:G685iP3XiskCwk/z0eIabL55XUl2gk0cljhGk9sB0Yk=
 go.opentelemetry.io/otel/oteltest v1.0.0-RC1/go.mod h1:+eoIG0gdEOaPNftuy1YScLr1Gb4mL/9lpDkZ0JjMRq4=
 go.opentelemetry.io/otel/sdk v1.0.0-RC1 h1:Sy2VLOOg24bipyC29PhuMXYNJrLsxkie8hyI7kUlG9Q=

util/tracing/tracing.go

@@ -3,10 +3,12 @@ package tracing
 import (
 	"context"
 	"fmt"
-	"io"
 	"net/http"
+	"net/http/httptrace"
 
 	"github.com/moby/buildkit/util/bklog"
+	"go.opentelemetry.io/contrib/instrumentation/net/http/httptrace/otelhttptrace"
+	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
 	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/codes"
 	"go.opentelemetry.io/otel/propagation"
@@ -55,81 +57,17 @@ func ContextWithSpanFromContext(ctx, ctx2 context.Context) context.Context {
 	return ctx
 }
 
-var DefaultTransport http.RoundTripper = &Transport{
+var DefaultTransport http.RoundTripper = NewTransport(http.DefaultTransport)
-	RoundTripper: NewTransport(http.DefaultTransport),
-}
 
 var DefaultClient = &http.Client{
 	Transport: DefaultTransport,
 }
 
-var propagators = propagation.NewCompositeTextMapPropagator(propagation.TraceContext{}, propagation.Baggage{})
-
-type Transport struct {
-	http.RoundTripper
-}
-
 func NewTransport(rt http.RoundTripper) http.RoundTripper {
-	// TODO: switch to otelhttp. needs upstream updates to avoid transport-global tracer
+	return otelhttp.NewTransport(rt,
-	return &Transport{
+		otelhttp.WithPropagators(propagation.NewCompositeTextMapPropagator(propagation.TraceContext{}, propagation.Baggage{})),
-		RoundTripper: rt,
+		otelhttp.WithClientTrace(func(ctx context.Context) *httptrace.ClientTrace {
-	}
+			return otelhttptrace.NewClientTrace(ctx, otelhttptrace.WithoutSubSpans())
-}
+		}),
-
+	)
-func (t *Transport) RoundTrip(req *http.Request) (*http.Response, error) {
-	span := trace.SpanFromContext(req.Context())
-	if !span.SpanContext().IsValid() { // no tracer connected with either request or transport
-		return t.RoundTripper.RoundTrip(req)
-	}
-
-	ctx, span := span.TracerProvider().Tracer("").Start(req.Context(), req.Method)
-
-	req = req.WithContext(ctx)
-	span.SetAttributes(semconv.HTTPClientAttributesFromHTTPRequest(req)...)
-	propagators.Inject(ctx, propagation.HeaderCarrier(req.Header))
-
-	resp, err := t.RoundTripper.RoundTrip(req)
-	if err != nil {
-		span.RecordError(err)
-		span.End()
-		return resp, err
-	}
-
-	span.SetAttributes(semconv.HTTPAttributesFromHTTPStatusCode(resp.StatusCode)...)
-	span.SetStatus(semconv.SpanStatusFromHTTPStatusCode(resp.StatusCode))
-
-	if req.Method == "HEAD" {
-		span.End()
-	} else {
-		resp.Body = &wrappedBody{ctx: ctx, span: span, body: resp.Body}
-	}
-
-	return resp, err
-}
-
-type wrappedBody struct {
-	ctx  context.Context
-	span trace.Span
-	body io.ReadCloser
-}
-
-var _ io.ReadCloser = &wrappedBody{}
-
-func (wb *wrappedBody) Read(b []byte) (int, error) {
-	n, err := wb.body.Read(b)
-
-	switch err {
-	case nil:
-		// nothing to do here but fall through to the return
-	case io.EOF:
-		wb.span.End()
-	default:
-		wb.span.RecordError(err)
-	}
-	return n, err
-}
-
-func (wb *wrappedBody) Close() error {
-	wb.span.End()
-	return wb.body.Close()
 }

vendor/github.com/felixge/httpsnoop/.travis.yml

@@ -0,0 +1,6 @@
+language: go
+
+go:
+  - 1.6
+  - 1.7
+  - 1.8

vendor/github.com/felixge/httpsnoop/LICENSE.txt

@@ -0,0 +1,19 @@
+Copyright (c) 2016 Felix Geisendörfer (felix@debuggable.com)
+
+ Permission is hereby granted, free of charge, to any person obtaining a copy
+ of this software and associated documentation files (the "Software"), to deal
+ in the Software without restriction, including without limitation the rights
+ to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ copies of the Software, and to permit persons to whom the Software is
+ furnished to do so, subject to the following conditions:
+
+ The above copyright notice and this permission notice shall be included in
+ all copies or substantial portions of the Software.
+
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ THE SOFTWARE.

vendor/github.com/felixge/httpsnoop/Makefile

@@ -0,0 +1,10 @@
+.PHONY: ci generate clean
+
+ci: clean generate
+	go test -v ./...
+
+generate:
+	go generate .
+
+clean:
+	rm -rf *_generated*.go

vendor/github.com/felixge/httpsnoop/README.md

@@ -0,0 +1,95 @@
+# httpsnoop
+
+Package httpsnoop provides an easy way to capture http related metrics (i.e.
+response time, bytes written, and http status code) from your application's
+http.Handlers.
+
+Doing this requires non-trivial wrapping of the http.ResponseWriter interface,
+which is also exposed for users interested in a more low-level API.
+
+[![GoDoc](https://godoc.org/github.com/felixge/httpsnoop?status.svg)](https://godoc.org/github.com/felixge/httpsnoop)
+[![Build Status](https://travis-ci.org/felixge/httpsnoop.svg?branch=master)](https://travis-ci.org/felixge/httpsnoop)
+
+## Usage Example
+
+```go
+// myH is your app's http handler, perhaps a http.ServeMux or similar.
+var myH http.Handler
+// wrappedH wraps myH in order to log every request.
+wrappedH := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+	m := httpsnoop.CaptureMetrics(myH, w, r)
+	log.Printf(
+		"%s %s (code=%d dt=%s written=%d)",
+		r.Method,
+		r.URL,
+		m.Code,
+		m.Duration,
+		m.Written,
+	)
+})
+http.ListenAndServe(":8080", wrappedH)
+```
+
+## Why this package exists
+
+Instrumenting an application's http.Handler is surprisingly difficult.
+
+However if you google for e.g. "capture ResponseWriter status code" you'll find
+lots of advise and code examples that suggest it to be a fairly trivial
+undertaking. Unfortunately everything I've seen so far has a high chance of
+breaking your application.
+
+The main problem is that a `http.ResponseWriter` often implements additional
+interfaces such as `http.Flusher`, `http.CloseNotifier`, `http.Hijacker`, `http.Pusher`, and
+`io.ReaderFrom`. So the naive approach of just wrapping `http.ResponseWriter`
+in your own struct that also implements the `http.ResponseWriter` interface
+will hide the additional interfaces mentioned above. This has a high change of
+introducing subtle bugs into any non-trivial application.
+
+Another approach I've seen people take is to return a struct that implements
+all of the interfaces above. However, that's also problematic, because it's
+difficult to fake some of these interfaces behaviors when the underlying
+`http.ResponseWriter` doesn't have an implementation. It's also dangerous,
+because an application may choose to operate differently, merely because it
+detects the presence of these additional interfaces.
+
+This package solves this problem by checking which additional interfaces a
+`http.ResponseWriter` implements, returning a wrapped version implementing the
+exact same set of interfaces.
+
+Additionally this package properly handles edge cases such as `WriteHeader` not
+being called, or called more than once, as well as concurrent calls to
+`http.ResponseWriter` methods, and even calls happening after the wrapped
+`ServeHTTP` has already returned.
+
+Unfortunately this package is not perfect either. It's possible that it is
+still missing some interfaces provided by the go core (let me know if you find
+one), and it won't work for applications adding their own interfaces into the
+mix. You can however use `httpsnoop.Unwrap(w)` to access the underlying
+`http.ResponseWriter` and type-assert the result to its other interfaces.
+
+However, hopefully the explanation above has sufficiently scared you of rolling
+your own solution to this problem. httpsnoop may still break your application,
+but at least it tries to avoid it as much as possible.
+
+Anyway, the real problem here is that smuggling additional interfaces inside
+`http.ResponseWriter` is a problematic design choice, but it probably goes as
+deep as the Go language specification itself. But that's okay, I still prefer
+Go over the alternatives ;).
+
+## Performance
+
+```
+BenchmarkBaseline-8      	   20000	     94912 ns/op
+BenchmarkCaptureMetrics-8	   20000	     95461 ns/op
+```
+
+As you can see, using `CaptureMetrics` on a vanilla http.Handler introduces an
+overhead of ~500 ns per http request on my machine. However, the margin of
+error appears to be larger than that, therefor it should be reasonable to
+assume that the overhead introduced by `CaptureMetrics` is absolutely
+negligible.
+
+## License
+
+MIT

vendor/github.com/felixge/httpsnoop/capture_metrics.go

@@ -0,0 +1,79 @@
+package httpsnoop
+
+import (
+	"io"
+	"net/http"
+	"time"
+)
+
+// Metrics holds metrics captured from CaptureMetrics.
+type Metrics struct {
+	// Code is the first http response code passed to the WriteHeader func of
+	// the ResponseWriter. If no such call is made, a default code of 200 is
+	// assumed instead.
+	Code int
+	// Duration is the time it took to execute the handler.
+	Duration time.Duration
+	// Written is the number of bytes successfully written by the Write or
+	// ReadFrom function of the ResponseWriter. ResponseWriters may also write
+	// data to their underlaying connection directly (e.g. headers), but those
+	// are not tracked. Therefor the number of Written bytes will usually match
+	// the size of the response body.
+	Written int64
+}
+
+// CaptureMetrics wraps the given hnd, executes it with the given w and r, and
+// returns the metrics it captured from it.
+func CaptureMetrics(hnd http.Handler, w http.ResponseWriter, r *http.Request) Metrics {
+	return CaptureMetricsFn(w, func(ww http.ResponseWriter) {
+		hnd.ServeHTTP(ww, r)
+	})
+}
+
+// CaptureMetricsFn wraps w and calls fn with the wrapped w and returns the
+// resulting metrics. This is very similar to CaptureMetrics (which is just
+// sugar on top of this func), but is a more usable interface if your
+// application doesn't use the Go http.Handler interface.
+func CaptureMetricsFn(w http.ResponseWriter, fn func(http.ResponseWriter)) Metrics {
+	var (
+		start         = time.Now()
+		m             = Metrics{Code: http.StatusOK}
+		headerWritten bool
+		hooks         = Hooks{
+			WriteHeader: func(next WriteHeaderFunc) WriteHeaderFunc {
+				return func(code int) {
+					next(code)
+
+					if !headerWritten {
+						m.Code = code
+						headerWritten = true
+					}
+				}
+			},
+
+			Write: func(next WriteFunc) WriteFunc {
+				return func(p []byte) (int, error) {
+					n, err := next(p)
+
+					m.Written += int64(n)
+					headerWritten = true
+					return n, err
+				}
+			},
+
+			ReadFrom: func(next ReadFromFunc) ReadFromFunc {
+				return func(src io.Reader) (int64, error) {
+					n, err := next(src)
+
+					headerWritten = true
+					m.Written += n
+					return n, err
+				}
+			},
+		}
+	)
+
+	fn(Wrap(w, hooks))
+	m.Duration = time.Since(start)
+	return m
+}

vendor/github.com/felixge/httpsnoop/docs.go

@@ -0,0 +1,10 @@
+// Package httpsnoop provides an easy way to capture http related metrics (i.e.
+// response time, bytes written, and http status code) from your application's
+// http.Handlers.
+//
+// Doing this requires non-trivial wrapping of the http.ResponseWriter
+// interface, which is also exposed for users interested in a more low-level
+// API.
+package httpsnoop
+
+//go:generate go run codegen/main.go

vendor/github.com/felixge/httpsnoop/go.mod

@@ -0,0 +1,3 @@
+module github.com/felixge/httpsnoop
+
+go 1.13

vendor/github.com/felixge/httpsnoop/wrap_generated_gteq_1.8.go

@@ -0,0 +1,436 @@
+// +build go1.8
+// Code generated by "httpsnoop/codegen"; DO NOT EDIT
+
+package httpsnoop
+
+import (
+	"bufio"
+	"io"
+	"net"
+	"net/http"
+)
+
+// HeaderFunc is part of the http.ResponseWriter interface.
+type HeaderFunc func() http.Header
+
+// WriteHeaderFunc is part of the http.ResponseWriter interface.
+type WriteHeaderFunc func(code int)
+
+// WriteFunc is part of the http.ResponseWriter interface.
+type WriteFunc func(b []byte) (int, error)
+
+// FlushFunc is part of the http.Flusher interface.
+type FlushFunc func()
+
+// CloseNotifyFunc is part of the http.CloseNotifier interface.
+type CloseNotifyFunc func() <-chan bool
+
+// HijackFunc is part of the http.Hijacker interface.
+type HijackFunc func() (net.Conn, *bufio.ReadWriter, error)
+
+// ReadFromFunc is part of the io.ReaderFrom interface.
+type ReadFromFunc func(src io.Reader) (int64, error)
+
+// PushFunc is part of the http.Pusher interface.
+type PushFunc func(target string, opts *http.PushOptions) error
+
+// Hooks defines a set of method interceptors for methods included in
+// http.ResponseWriter as well as some others. You can think of them as
+// middleware for the function calls they target. See Wrap for more details.
+type Hooks struct {
+	Header      func(HeaderFunc) HeaderFunc
+	WriteHeader func(WriteHeaderFunc) WriteHeaderFunc
+	Write       func(WriteFunc) WriteFunc
+	Flush       func(FlushFunc) FlushFunc
+	CloseNotify func(CloseNotifyFunc) CloseNotifyFunc
+	Hijack      func(HijackFunc) HijackFunc
+	ReadFrom    func(ReadFromFunc) ReadFromFunc
+	Push        func(PushFunc) PushFunc
+}
+
+// Wrap returns a wrapped version of w that provides the exact same interface
+// as w. Specifically if w implements any combination of:
+//
+// - http.Flusher
+// - http.CloseNotifier
+// - http.Hijacker
+// - io.ReaderFrom
+// - http.Pusher
+//
+// The wrapped version will implement the exact same combination. If no hooks
+// are set, the wrapped version also behaves exactly as w. Hooks targeting
+// methods not supported by w are ignored. Any other hooks will intercept the
+// method they target and may modify the call's arguments and/or return values.
+// The CaptureMetrics implementation serves as a working example for how the
+// hooks can be used.
+func Wrap(w http.ResponseWriter, hooks Hooks) http.ResponseWriter {
+	rw := &rw{w: w, h: hooks}
+	_, i0 := w.(http.Flusher)
+	_, i1 := w.(http.CloseNotifier)
+	_, i2 := w.(http.Hijacker)
+	_, i3 := w.(io.ReaderFrom)
+	_, i4 := w.(http.Pusher)
+	switch {
+	// combination 1/32
+	case !i0 && !i1 && !i2 && !i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+		}{rw, rw}
+	// combination 2/32
+	case !i0 && !i1 && !i2 && !i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Pusher
+		}{rw, rw, rw}
+	// combination 3/32
+	case !i0 && !i1 && !i2 && i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			io.ReaderFrom
+		}{rw, rw, rw}
+	// combination 4/32
+	case !i0 && !i1 && !i2 && i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			io.ReaderFrom
+			http.Pusher
+		}{rw, rw, rw, rw}
+	// combination 5/32
+	case !i0 && !i1 && i2 && !i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Hijacker
+		}{rw, rw, rw}
+	// combination 6/32
+	case !i0 && !i1 && i2 && !i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Hijacker
+			http.Pusher
+		}{rw, rw, rw, rw}
+	// combination 7/32
+	case !i0 && !i1 && i2 && i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Hijacker
+			io.ReaderFrom
+		}{rw, rw, rw, rw}
+	// combination 8/32
+	case !i0 && !i1 && i2 && i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Hijacker
+			io.ReaderFrom
+			http.Pusher
+		}{rw, rw, rw, rw, rw}
+	// combination 9/32
+	case !i0 && i1 && !i2 && !i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.CloseNotifier
+		}{rw, rw, rw}
+	// combination 10/32
+	case !i0 && i1 && !i2 && !i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.CloseNotifier
+			http.Pusher
+		}{rw, rw, rw, rw}
+	// combination 11/32
+	case !i0 && i1 && !i2 && i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.CloseNotifier
+			io.ReaderFrom
+		}{rw, rw, rw, rw}
+	// combination 12/32
+	case !i0 && i1 && !i2 && i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.CloseNotifier
+			io.ReaderFrom
+			http.Pusher
+		}{rw, rw, rw, rw, rw}
+	// combination 13/32
+	case !i0 && i1 && i2 && !i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.CloseNotifier
+			http.Hijacker
+		}{rw, rw, rw, rw}
+	// combination 14/32
+	case !i0 && i1 && i2 && !i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.CloseNotifier
+			http.Hijacker
+			http.Pusher
+		}{rw, rw, rw, rw, rw}
+	// combination 15/32
+	case !i0 && i1 && i2 && i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.CloseNotifier
+			http.Hijacker
+			io.ReaderFrom
+		}{rw, rw, rw, rw, rw}
+	// combination 16/32
+	case !i0 && i1 && i2 && i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.CloseNotifier
+			http.Hijacker
+			io.ReaderFrom
+			http.Pusher
+		}{rw, rw, rw, rw, rw, rw}
+	// combination 17/32
+	case i0 && !i1 && !i2 && !i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+		}{rw, rw, rw}
+	// combination 18/32
+	case i0 && !i1 && !i2 && !i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.Pusher
+		}{rw, rw, rw, rw}
+	// combination 19/32
+	case i0 && !i1 && !i2 && i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			io.ReaderFrom
+		}{rw, rw, rw, rw}
+	// combination 20/32
+	case i0 && !i1 && !i2 && i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			io.ReaderFrom
+			http.Pusher
+		}{rw, rw, rw, rw, rw}
+	// combination 21/32
+	case i0 && !i1 && i2 && !i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.Hijacker
+		}{rw, rw, rw, rw}
+	// combination 22/32
+	case i0 && !i1 && i2 && !i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.Hijacker
+			http.Pusher
+		}{rw, rw, rw, rw, rw}
+	// combination 23/32
+	case i0 && !i1 && i2 && i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.Hijacker
+			io.ReaderFrom
+		}{rw, rw, rw, rw, rw}
+	// combination 24/32
+	case i0 && !i1 && i2 && i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.Hijacker
+			io.ReaderFrom
+			http.Pusher
+		}{rw, rw, rw, rw, rw, rw}
+	// combination 25/32
+	case i0 && i1 && !i2 && !i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.CloseNotifier
+		}{rw, rw, rw, rw}
+	// combination 26/32
+	case i0 && i1 && !i2 && !i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.CloseNotifier
+			http.Pusher
+		}{rw, rw, rw, rw, rw}
+	// combination 27/32
+	case i0 && i1 && !i2 && i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.CloseNotifier
+			io.ReaderFrom
+		}{rw, rw, rw, rw, rw}
+	// combination 28/32
+	case i0 && i1 && !i2 && i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.CloseNotifier
+			io.ReaderFrom
+			http.Pusher
+		}{rw, rw, rw, rw, rw, rw}
+	// combination 29/32
+	case i0 && i1 && i2 && !i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.CloseNotifier
+			http.Hijacker
+		}{rw, rw, rw, rw, rw}
+	// combination 30/32
+	case i0 && i1 && i2 && !i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.CloseNotifier
+			http.Hijacker
+			http.Pusher
+		}{rw, rw, rw, rw, rw, rw}
+	// combination 31/32
+	case i0 && i1 && i2 && i3 && !i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.CloseNotifier
+			http.Hijacker
+			io.ReaderFrom
+		}{rw, rw, rw, rw, rw, rw}
+	// combination 32/32
+	case i0 && i1 && i2 && i3 && i4:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.CloseNotifier
+			http.Hijacker
+			io.ReaderFrom
+			http.Pusher
+		}{rw, rw, rw, rw, rw, rw, rw}
+	}
+	panic("unreachable")
+}
+
+type rw struct {
+	w http.ResponseWriter
+	h Hooks
+}
+
+func (w *rw) Unwrap() http.ResponseWriter {
+	return w.w
+}
+
+func (w *rw) Header() http.Header {
+	f := w.w.(http.ResponseWriter).Header
+	if w.h.Header != nil {
+		f = w.h.Header(f)
+	}
+	return f()
+}
+
+func (w *rw) WriteHeader(code int) {
+	f := w.w.(http.ResponseWriter).WriteHeader
+	if w.h.WriteHeader != nil {
+		f = w.h.WriteHeader(f)
+	}
+	f(code)
+}
+
+func (w *rw) Write(b []byte) (int, error) {
+	f := w.w.(http.ResponseWriter).Write
+	if w.h.Write != nil {
+		f = w.h.Write(f)
+	}
+	return f(b)
+}
+
+func (w *rw) Flush() {
+	f := w.w.(http.Flusher).Flush
+	if w.h.Flush != nil {
+		f = w.h.Flush(f)
+	}
+	f()
+}
+
+func (w *rw) CloseNotify() <-chan bool {
+	f := w.w.(http.CloseNotifier).CloseNotify
+	if w.h.CloseNotify != nil {
+		f = w.h.CloseNotify(f)
+	}
+	return f()
+}
+
+func (w *rw) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+	f := w.w.(http.Hijacker).Hijack
+	if w.h.Hijack != nil {
+		f = w.h.Hijack(f)
+	}
+	return f()
+}
+
+func (w *rw) ReadFrom(src io.Reader) (int64, error) {
+	f := w.w.(io.ReaderFrom).ReadFrom
+	if w.h.ReadFrom != nil {
+		f = w.h.ReadFrom(f)
+	}
+	return f(src)
+}
+
+func (w *rw) Push(target string, opts *http.PushOptions) error {
+	f := w.w.(http.Pusher).Push
+	if w.h.Push != nil {
+		f = w.h.Push(f)
+	}
+	return f(target, opts)
+}
+
+type Unwrapper interface {
+	Unwrap() http.ResponseWriter
+}
+
+// Unwrap returns the underlying http.ResponseWriter from within zero or more
+// layers of httpsnoop wrappers.
+func Unwrap(w http.ResponseWriter) http.ResponseWriter {
+	if rw, ok := w.(Unwrapper); ok {
+		// recurse until rw.Unwrap() returns a non-Unwrapper
+		return Unwrap(rw.Unwrap())
+	} else {
+		return w
+	}
+}

vendor/github.com/felixge/httpsnoop/wrap_generated_lt_1.8.go

@@ -0,0 +1,278 @@
+// +build !go1.8
+// Code generated by "httpsnoop/codegen"; DO NOT EDIT
+
+package httpsnoop
+
+import (
+	"bufio"
+	"io"
+	"net"
+	"net/http"
+)
+
+// HeaderFunc is part of the http.ResponseWriter interface.
+type HeaderFunc func() http.Header
+
+// WriteHeaderFunc is part of the http.ResponseWriter interface.
+type WriteHeaderFunc func(code int)
+
+// WriteFunc is part of the http.ResponseWriter interface.
+type WriteFunc func(b []byte) (int, error)
+
+// FlushFunc is part of the http.Flusher interface.
+type FlushFunc func()
+
+// CloseNotifyFunc is part of the http.CloseNotifier interface.
+type CloseNotifyFunc func() <-chan bool
+
+// HijackFunc is part of the http.Hijacker interface.
+type HijackFunc func() (net.Conn, *bufio.ReadWriter, error)
+
+// ReadFromFunc is part of the io.ReaderFrom interface.
+type ReadFromFunc func(src io.Reader) (int64, error)
+
+// Hooks defines a set of method interceptors for methods included in
+// http.ResponseWriter as well as some others. You can think of them as
+// middleware for the function calls they target. See Wrap for more details.
+type Hooks struct {
+	Header      func(HeaderFunc) HeaderFunc
+	WriteHeader func(WriteHeaderFunc) WriteHeaderFunc
+	Write       func(WriteFunc) WriteFunc
+	Flush       func(FlushFunc) FlushFunc
+	CloseNotify func(CloseNotifyFunc) CloseNotifyFunc
+	Hijack      func(HijackFunc) HijackFunc
+	ReadFrom    func(ReadFromFunc) ReadFromFunc
+}
+
+// Wrap returns a wrapped version of w that provides the exact same interface
+// as w. Specifically if w implements any combination of:
+//
+// - http.Flusher
+// - http.CloseNotifier
+// - http.Hijacker
+// - io.ReaderFrom
+//
+// The wrapped version will implement the exact same combination. If no hooks
+// are set, the wrapped version also behaves exactly as w. Hooks targeting
+// methods not supported by w are ignored. Any other hooks will intercept the
+// method they target and may modify the call's arguments and/or return values.
+// The CaptureMetrics implementation serves as a working example for how the
+// hooks can be used.
+func Wrap(w http.ResponseWriter, hooks Hooks) http.ResponseWriter {
+	rw := &rw{w: w, h: hooks}
+	_, i0 := w.(http.Flusher)
+	_, i1 := w.(http.CloseNotifier)
+	_, i2 := w.(http.Hijacker)
+	_, i3 := w.(io.ReaderFrom)
+	switch {
+	// combination 1/16
+	case !i0 && !i1 && !i2 && !i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+		}{rw, rw}
+	// combination 2/16
+	case !i0 && !i1 && !i2 && i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			io.ReaderFrom
+		}{rw, rw, rw}
+	// combination 3/16
+	case !i0 && !i1 && i2 && !i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Hijacker
+		}{rw, rw, rw}
+	// combination 4/16
+	case !i0 && !i1 && i2 && i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Hijacker
+			io.ReaderFrom
+		}{rw, rw, rw, rw}
+	// combination 5/16
+	case !i0 && i1 && !i2 && !i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.CloseNotifier
+		}{rw, rw, rw}
+	// combination 6/16
+	case !i0 && i1 && !i2 && i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.CloseNotifier
+			io.ReaderFrom
+		}{rw, rw, rw, rw}
+	// combination 7/16
+	case !i0 && i1 && i2 && !i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.CloseNotifier
+			http.Hijacker
+		}{rw, rw, rw, rw}
+	// combination 8/16
+	case !i0 && i1 && i2 && i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.CloseNotifier
+			http.Hijacker
+			io.ReaderFrom
+		}{rw, rw, rw, rw, rw}
+	// combination 9/16
+	case i0 && !i1 && !i2 && !i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+		}{rw, rw, rw}
+	// combination 10/16
+	case i0 && !i1 && !i2 && i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			io.ReaderFrom
+		}{rw, rw, rw, rw}
+	// combination 11/16
+	case i0 && !i1 && i2 && !i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.Hijacker
+		}{rw, rw, rw, rw}
+	// combination 12/16
+	case i0 && !i1 && i2 && i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.Hijacker
+			io.ReaderFrom
+		}{rw, rw, rw, rw, rw}
+	// combination 13/16
+	case i0 && i1 && !i2 && !i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.CloseNotifier
+		}{rw, rw, rw, rw}
+	// combination 14/16
+	case i0 && i1 && !i2 && i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.CloseNotifier
+			io.ReaderFrom
+		}{rw, rw, rw, rw, rw}
+	// combination 15/16
+	case i0 && i1 && i2 && !i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.CloseNotifier
+			http.Hijacker
+		}{rw, rw, rw, rw, rw}
+	// combination 16/16
+	case i0 && i1 && i2 && i3:
+		return struct {
+			Unwrapper
+			http.ResponseWriter
+			http.Flusher
+			http.CloseNotifier
+			http.Hijacker
+			io.ReaderFrom
+		}{rw, rw, rw, rw, rw, rw}
+	}
+	panic("unreachable")
+}
+
+type rw struct {
+	w http.ResponseWriter
+	h Hooks
+}
+
+func (w *rw) Unwrap() http.ResponseWriter {
+	return w.w
+}
+
+func (w *rw) Header() http.Header {
+	f := w.w.(http.ResponseWriter).Header
+	if w.h.Header != nil {
+		f = w.h.Header(f)
+	}
+	return f()
+}
+
+func (w *rw) WriteHeader(code int) {
+	f := w.w.(http.ResponseWriter).WriteHeader
+	if w.h.WriteHeader != nil {
+		f = w.h.WriteHeader(f)
+	}
+	f(code)
+}
+
+func (w *rw) Write(b []byte) (int, error) {
+	f := w.w.(http.ResponseWriter).Write
+	if w.h.Write != nil {
+		f = w.h.Write(f)
+	}
+	return f(b)
+}
+
+func (w *rw) Flush() {
+	f := w.w.(http.Flusher).Flush
+	if w.h.Flush != nil {
+		f = w.h.Flush(f)
+	}
+	f()
+}
+
+func (w *rw) CloseNotify() <-chan bool {
+	f := w.w.(http.CloseNotifier).CloseNotify
+	if w.h.CloseNotify != nil {
+		f = w.h.CloseNotify(f)
+	}
+	return f()
+}
+
+func (w *rw) Hijack() (net.Conn, *bufio.ReadWriter, error) {
+	f := w.w.(http.Hijacker).Hijack
+	if w.h.Hijack != nil {
+		f = w.h.Hijack(f)
+	}
+	return f()
+}
+
+func (w *rw) ReadFrom(src io.Reader) (int64, error) {
+	f := w.w.(io.ReaderFrom).ReadFrom
+	if w.h.ReadFrom != nil {
+		f = w.h.ReadFrom(f)
+	}
+	return f(src)
+}
+
+type Unwrapper interface {
+	Unwrap() http.ResponseWriter
+}
+
+// Unwrap returns the underlying http.ResponseWriter from within zero or more
+// layers of httpsnoop wrappers.
+func Unwrap(w http.ResponseWriter) http.ResponseWriter {
+	if rw, ok := w.(Unwrapper); ok {
+		// recurse until rw.Unwrap() returns a non-Unwrapper
+		return Unwrap(rw.Unwrap())
+	} else {
+		return w
+	}
+}

vendor/go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc/interceptor.go

@@ -122,8 +122,7 @@ type streamEvent struct {
 }
 
 const (
-	closeEvent streamEventType = iota
+	receiveEndEvent streamEventType = iota
-	receiveEndEvent
 	errorEvent
 )
 
@@ -188,19 +187,12 @@ func (w *clientStream) CloseSend() error {
 
 	if err != nil {
 		w.sendStreamEvent(errorEvent, err)
-	} else {
-		w.sendStreamEvent(closeEvent, nil)
 	}
 
 	return err
 }
 
-const (
+func wrapClientStream(ctx context.Context, s grpc.ClientStream, desc *grpc.StreamDesc) *clientStream {
-	clientClosedState byte = 1 << iota
-	receiveEndedState
-)
-
-func wrapClientStream(s grpc.ClientStream, desc *grpc.StreamDesc) *clientStream {
 	events := make(chan streamEvent)
 	eventsDone := make(chan struct{})
 	finished := make(chan error)
@@ -208,23 +200,20 @@ func wrapClientStream(s grpc.ClientStream, desc *grpc.StreamDesc) *clientStream
 	go func() {
 		defer close(eventsDone)
 
-		// Both streams have to be closed
+		for {
-		state := byte(0)
+			select {
-
+			case <-ctx.Done():
-		for event := range events {
+				finished <- ctx.Err()
-			switch event.Type {
-			case closeEvent:
-				state |= clientClosedState
-			case receiveEndEvent:
-				state |= receiveEndedState
-			case errorEvent:
-				finished <- event.Err
-				return
-			}
-
-			if state == clientClosedState|receiveEndedState {
-				finished <- nil
 				return
+			case event := <-events:
+				switch event.Type {
+				case receiveEndEvent:
+					finished <- nil
+					return
+				case errorEvent:
+					finished <- event.Err
+					return
+				}
 			}
 		}
 	}()
@@ -284,7 +273,7 @@ func StreamClientInterceptor(opts ...Option) grpc.StreamClientInterceptor {
 			span.End()
 			return s, err
 		}
-		stream := wrapClientStream(s, desc)
+		stream := wrapClientStream(ctx, s, desc)
 
 		go func() {
 			err := <-stream.finished

vendor/go.opentelemetry.io/contrib/instrumentation/net/http/httptrace/otelhttptrace/LICENSE

@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
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+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
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+      including but not limited to software source code, documentation
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+
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+      transformation or translation of a Source form, including but
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+
+      "Work" shall mean the work of authorship, whether in Source or
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+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
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+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
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+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
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+      on Your own behalf and on Your sole responsibility, not on behalf
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+
+   Unless required by applicable law or agreed to in writing, software
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+   limitations under the License.

vendor/go.opentelemetry.io/contrib/instrumentation/net/http/httptrace/otelhttptrace/api.go

@@ -0,0 +1,28 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package otelhttptrace
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptrace"
+)
+
+// W3C client.
+func W3C(ctx context.Context, req *http.Request) (context.Context, *http.Request) {
+	ctx = httptrace.WithClientTrace(ctx, NewClientTrace(ctx))
+	req = req.WithContext(ctx)
+	return ctx, req
+}

vendor/go.opentelemetry.io/contrib/instrumentation/net/http/httptrace/otelhttptrace/clienttrace.go

@@ -0,0 +1,370 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package otelhttptrace
+
+import (
+	"context"
+	"crypto/tls"
+	"net/http/httptrace"
+	"net/textproto"
+	"strings"
+	"sync"
+
+	"go.opentelemetry.io/contrib"
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/codes"
+	semconv "go.opentelemetry.io/otel/semconv/v1.4.0"
+	"go.opentelemetry.io/otel/trace"
+)
+
+// HTTP attributes.
+var (
+	HTTPStatus                 = attribute.Key("http.status")
+	HTTPHeaderMIME             = attribute.Key("http.mime")
+	HTTPRemoteAddr             = attribute.Key("http.remote")
+	HTTPLocalAddr              = attribute.Key("http.local")
+	HTTPConnectionReused       = attribute.Key("http.conn.reused")
+	HTTPConnectionWasIdle      = attribute.Key("http.conn.wasidle")
+	HTTPConnectionIdleTime     = attribute.Key("http.conn.idletime")
+	HTTPConnectionStartNetwork = attribute.Key("http.conn.start.network")
+	HTTPConnectionDoneNetwork  = attribute.Key("http.conn.done.network")
+	HTTPConnectionDoneAddr     = attribute.Key("http.conn.done.addr")
+	HTTPDNSAddrs               = attribute.Key("http.dns.addrs")
+)
+
+var (
+	hookMap = map[string]string{
+		"http.dns":     "http.getconn",
+		"http.connect": "http.getconn",
+		"http.tls":     "http.getconn",
+	}
+)
+
+func parentHook(hook string) string {
+	if strings.HasPrefix(hook, "http.connect") {
+		return hookMap["http.connect"]
+	}
+	return hookMap[hook]
+}
+
+// ClientTraceOption allows customizations to how the httptrace.Client
+// collects information.
+type ClientTraceOption func(*clientTracer)
+
+// WithoutSubSpans will modify the httptrace.Client to only collect data
+// as Events and Attributes on a span found in the context.  By default
+// sub-spans will be generated.
+func WithoutSubSpans() ClientTraceOption {
+	return func(ct *clientTracer) {
+		ct.useSpans = false
+	}
+}
+
+// WithRedactedHeaders will be replaced by fixed '****' values for the header
+// names provided.  These are in addition to the sensitive headers already
+// redacted by default: Authorization, WWW-Authenticate, Proxy-Authenticate
+// Proxy-Authorization, Cookie, Set-Cookie
+func WithRedactedHeaders(headers ...string) ClientTraceOption {
+	return func(ct *clientTracer) {
+		for _, header := range headers {
+			ct.redactedHeaders[strings.ToLower(header)] = struct{}{}
+		}
+	}
+}
+
+// WithoutHeaders will disable adding span annotations for the http headers
+// and values.
+func WithoutHeaders() ClientTraceOption {
+	return func(ct *clientTracer) {
+		ct.addHeaders = false
+	}
+}
+
+type clientTracer struct {
+	context.Context
+
+	tr trace.Tracer
+
+	activeHooks     map[string]context.Context
+	root            trace.Span
+	mtx             sync.Mutex
+	redactedHeaders map[string]struct{}
+	addHeaders      bool
+	useSpans        bool
+}
+
+func NewClientTrace(ctx context.Context, opts ...ClientTraceOption) *httptrace.ClientTrace {
+	ct := &clientTracer{
+		Context:     ctx,
+		activeHooks: make(map[string]context.Context),
+		redactedHeaders: map[string]struct{}{
+			"authorization":       {},
+			"www-authenticate":    {},
+			"proxy-authenticate":  {},
+			"proxy-authorization": {},
+			"cookie":              {},
+			"set-cookie":          {},
+		},
+		addHeaders: true,
+		useSpans:   true,
+	}
+	for _, opt := range opts {
+		opt(ct)
+	}
+
+	var tp trace.TracerProvider
+	if span := trace.SpanFromContext(ctx); span.SpanContext().IsValid() {
+		tp = span.TracerProvider()
+	} else {
+		tp = otel.GetTracerProvider()
+	}
+
+	ct.tr = tp.Tracer(
+		"go.opentelemetry.io/otel/instrumentation/httptrace",
+		trace.WithInstrumentationVersion(contrib.SemVersion()),
+	)
+
+	return &httptrace.ClientTrace{
+		GetConn:              ct.getConn,
+		GotConn:              ct.gotConn,
+		PutIdleConn:          ct.putIdleConn,
+		GotFirstResponseByte: ct.gotFirstResponseByte,
+		Got100Continue:       ct.got100Continue,
+		Got1xxResponse:       ct.got1xxResponse,
+		DNSStart:             ct.dnsStart,
+		DNSDone:              ct.dnsDone,
+		ConnectStart:         ct.connectStart,
+		ConnectDone:          ct.connectDone,
+		TLSHandshakeStart:    ct.tlsHandshakeStart,
+		TLSHandshakeDone:     ct.tlsHandshakeDone,
+		WroteHeaderField:     ct.wroteHeaderField,
+		WroteHeaders:         ct.wroteHeaders,
+		Wait100Continue:      ct.wait100Continue,
+		WroteRequest:         ct.wroteRequest,
+	}
+}
+
+func (ct *clientTracer) start(hook, spanName string, attrs ...attribute.KeyValue) {
+	if !ct.useSpans {
+		if ct.root == nil {
+			ct.root = trace.SpanFromContext(ct.Context)
+		}
+		ct.root.AddEvent(hook+".start", trace.WithAttributes(attrs...))
+		return
+	}
+
+	ct.mtx.Lock()
+	defer ct.mtx.Unlock()
+
+	if hookCtx, found := ct.activeHooks[hook]; !found {
+		var sp trace.Span
+		ct.activeHooks[hook], sp = ct.tr.Start(ct.getParentContext(hook), spanName, trace.WithAttributes(attrs...), trace.WithSpanKind(trace.SpanKindClient))
+		if ct.root == nil {
+			ct.root = sp
+		}
+	} else {
+		// end was called before start finished, add the start attributes and end the span here
+		span := trace.SpanFromContext(hookCtx)
+		span.SetAttributes(attrs...)
+		span.End()
+
+		delete(ct.activeHooks, hook)
+	}
+}
+
+func (ct *clientTracer) end(hook string, err error, attrs ...attribute.KeyValue) {
+	if !ct.useSpans {
+		if err != nil {
+			attrs = append(attrs, attribute.String(hook+".error", err.Error()))
+		}
+		ct.root.AddEvent(hook+".done", trace.WithAttributes(attrs...))
+		return
+	}
+
+	ct.mtx.Lock()
+	defer ct.mtx.Unlock()
+	if ctx, ok := ct.activeHooks[hook]; ok {
+		span := trace.SpanFromContext(ctx)
+		if err != nil {
+			span.SetStatus(codes.Error, err.Error())
+		}
+		span.SetAttributes(attrs...)
+		span.End()
+		delete(ct.activeHooks, hook)
+	} else {
+		// start is not finished before end is called.
+		// Start a span here with the ending attributes that will be finished when start finishes.
+		// Yes, it's backwards. v0v
+		ctx, span := ct.tr.Start(ct.getParentContext(hook), hook, trace.WithAttributes(attrs...), trace.WithSpanKind(trace.SpanKindClient))
+		if err != nil {
+			span.SetStatus(codes.Error, err.Error())
+		}
+		ct.activeHooks[hook] = ctx
+	}
+}
+
+func (ct *clientTracer) getParentContext(hook string) context.Context {
+	ctx, ok := ct.activeHooks[parentHook(hook)]
+	if !ok {
+		return ct.Context
+	}
+	return ctx
+}
+
+func (ct *clientTracer) span(hook string) trace.Span {
+	ct.mtx.Lock()
+	defer ct.mtx.Unlock()
+	if ctx, ok := ct.activeHooks[hook]; ok {
+		return trace.SpanFromContext(ctx)
+	}
+	return nil
+}
+
+func (ct *clientTracer) getConn(host string) {
+	ct.start("http.getconn", "http.getconn", semconv.HTTPHostKey.String(host))
+}
+
+func (ct *clientTracer) gotConn(info httptrace.GotConnInfo) {
+	attrs := []attribute.KeyValue{
+		HTTPRemoteAddr.String(info.Conn.RemoteAddr().String()),
+		HTTPLocalAddr.String(info.Conn.LocalAddr().String()),
+		HTTPConnectionReused.Bool(info.Reused),
+		HTTPConnectionWasIdle.Bool(info.WasIdle),
+	}
+	if info.WasIdle {
+		attrs = append(attrs, HTTPConnectionIdleTime.String(info.IdleTime.String()))
+	}
+	ct.end("http.getconn", nil, attrs...)
+}
+
+func (ct *clientTracer) putIdleConn(err error) {
+	ct.end("http.receive", err)
+}
+
+func (ct *clientTracer) gotFirstResponseByte() {
+	ct.start("http.receive", "http.receive")
+}
+
+func (ct *clientTracer) dnsStart(info httptrace.DNSStartInfo) {
+	ct.start("http.dns", "http.dns", semconv.HTTPHostKey.String(info.Host))
+}
+
+func (ct *clientTracer) dnsDone(info httptrace.DNSDoneInfo) {
+	var addrs []string
+	for _, netAddr := range info.Addrs {
+		addrs = append(addrs, netAddr.String())
+	}
+	ct.end("http.dns", info.Err, HTTPDNSAddrs.String(sliceToString(addrs)))
+}
+
+func (ct *clientTracer) connectStart(network, addr string) {
+	ct.start("http.connect."+addr, "http.connect",
+		HTTPRemoteAddr.String(addr),
+		HTTPConnectionStartNetwork.String(network),
+	)
+}
+
+func (ct *clientTracer) connectDone(network, addr string, err error) {
+	ct.end("http.connect."+addr, err,
+		HTTPConnectionDoneAddr.String(addr),
+		HTTPConnectionDoneNetwork.String(network),
+	)
+}
+
+func (ct *clientTracer) tlsHandshakeStart() {
+	ct.start("http.tls", "http.tls")
+}
+
+func (ct *clientTracer) tlsHandshakeDone(_ tls.ConnectionState, err error) {
+	ct.end("http.tls", err)
+}
+
+func (ct *clientTracer) wroteHeaderField(k string, v []string) {
+	if ct.useSpans && ct.span("http.headers") == nil {
+		ct.start("http.headers", "http.headers")
+	}
+	if !ct.addHeaders {
+		return
+	}
+	k = strings.ToLower(k)
+	value := sliceToString(v)
+	if _, ok := ct.redactedHeaders[k]; ok {
+		value = "****"
+	}
+	ct.root.SetAttributes(attribute.String("http."+k, value))
+}
+
+func (ct *clientTracer) wroteHeaders() {
+	if ct.useSpans && ct.span("http.headers") != nil {
+		ct.end("http.headers", nil)
+	}
+	ct.start("http.send", "http.send")
+}
+
+func (ct *clientTracer) wroteRequest(info httptrace.WroteRequestInfo) {
+	if info.Err != nil {
+		ct.root.SetStatus(codes.Error, info.Err.Error())
+	}
+	ct.end("http.send", info.Err)
+}
+
+func (ct *clientTracer) got100Continue() {
+	span := ct.root
+	if ct.useSpans {
+		span = ct.span("http.receive")
+	}
+	span.AddEvent("GOT 100 - Continue")
+}
+
+func (ct *clientTracer) wait100Continue() {
+	span := ct.root
+	if ct.useSpans {
+		span = ct.span("http.receive")
+	}
+	span.AddEvent("GOT 100 - Wait")
+}
+
+func (ct *clientTracer) got1xxResponse(code int, header textproto.MIMEHeader) error {
+	span := ct.root
+	if ct.useSpans {
+		span = ct.span("http.receive")
+	}
+	span.AddEvent("GOT 1xx", trace.WithAttributes(
+		HTTPStatus.Int(code),
+		HTTPHeaderMIME.String(sm2s(header)),
+	))
+	return nil
+}
+
+func sliceToString(value []string) string {
+	if len(value) == 0 {
+		return "undefined"
+	}
+	return strings.Join(value, ",")
+}
+
+func sm2s(value map[string][]string) string {
+	var buf strings.Builder
+	for k, v := range value {
+		if buf.Len() != 0 {
+			buf.WriteString(",")
+		}
+		buf.WriteString(k)
+		buf.WriteString("=")
+		buf.WriteString(sliceToString(v))
+	}
+	return buf.String()
+}

vendor/go.opentelemetry.io/contrib/instrumentation/net/http/httptrace/otelhttptrace/go.mod

@@ -0,0 +1,14 @@
+module go.opentelemetry.io/contrib/instrumentation/net/http/httptrace/otelhttptrace
+
+go 1.15
+
+replace go.opentelemetry.io/contrib => ../../../../..
+
+require (
+	github.com/google/go-cmp v0.5.6
+	github.com/stretchr/testify v1.7.0
+	go.opentelemetry.io/contrib v0.21.0
+	go.opentelemetry.io/otel v1.0.0-RC1
+	go.opentelemetry.io/otel/oteltest v1.0.0-RC1
+	go.opentelemetry.io/otel/trace v1.0.0-RC1
+)

vendor/go.opentelemetry.io/contrib/instrumentation/net/http/httptrace/otelhttptrace/go.sum

@@ -0,0 +1,21 @@
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/google/go-cmp v0.5.6 h1:BKbKCqvP6I+rmFHt06ZmyQtvB8xAkWdhFyr0ZUNZcxQ=
+github.com/google/go-cmp v0.5.6/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+go.opentelemetry.io/otel v1.0.0-RC1 h1:4CeoX93DNTWt8awGK9JmNXzF9j7TyOu9upscEdtcdXc=
+go.opentelemetry.io/otel v1.0.0-RC1/go.mod h1:x9tRa9HK4hSSq7jf2TKbqFbtt58/TGk0f9XiEYISI1I=
+go.opentelemetry.io/otel/oteltest v1.0.0-RC1 h1:G685iP3XiskCwk/z0eIabL55XUl2gk0cljhGk9sB0Yk=
+go.opentelemetry.io/otel/oteltest v1.0.0-RC1/go.mod h1:+eoIG0gdEOaPNftuy1YScLr1Gb4mL/9lpDkZ0JjMRq4=
+go.opentelemetry.io/otel/trace v1.0.0-RC1 h1:jrjqKJZEibFrDz+umEASeU3LvdVyWKlnTh7XEfwrT58=
+go.opentelemetry.io/otel/trace v1.0.0-RC1/go.mod h1:86UHmyHWFEtWjfWPSbu0+d0Pf9Q6e1U+3ViBOc+NXAg=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

vendor/go.opentelemetry.io/contrib/instrumentation/net/http/httptrace/otelhttptrace/httptrace.go

@@ -0,0 +1,68 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package otelhttptrace
+
+import (
+	"context"
+	"net/http"
+
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/baggage"
+	"go.opentelemetry.io/otel/propagation"
+	semconv "go.opentelemetry.io/otel/semconv/v1.4.0"
+	"go.opentelemetry.io/otel/trace"
+)
+
+// Option is a function that allows configuration of the httptrace Extract()
+// and Inject() functions
+type Option func(*config)
+
+type config struct {
+	propagators propagation.TextMapPropagator
+}
+
+func newConfig(opts []Option) *config {
+	c := &config{propagators: otel.GetTextMapPropagator()}
+	for _, o := range opts {
+		o(c)
+	}
+	return c
+}
+
+// WithPropagators sets the propagators to use for Extraction and Injection
+func WithPropagators(props propagation.TextMapPropagator) Option {
+	return func(c *config) {
+		c.propagators = props
+	}
+}
+
+// Extract returns the Attributes, Context Entries, and SpanContext that were encoded by Inject.
+func Extract(ctx context.Context, req *http.Request, opts ...Option) ([]attribute.KeyValue, baggage.Baggage, trace.SpanContext) {
+	c := newConfig(opts)
+	ctx = c.propagators.Extract(ctx, propagation.HeaderCarrier(req.Header))
+
+	attrs := append(
+		semconv.HTTPServerAttributesFromHTTPRequest("", "", req),
+		semconv.NetAttributesFromHTTPRequest("tcp", req)...,
+	)
+
+	return attrs, baggage.FromContext(ctx), trace.SpanContextFromContext(ctx)
+}
+
+func Inject(ctx context.Context, req *http.Request, opts ...Option) {
+	c := newConfig(opts)
+	c.propagators.Inject(ctx, propagation.HeaderCarrier(req.Header))
+}

vendor/go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp/LICENSE

@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
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+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
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+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
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+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
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+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
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+   3. Grant of Patent License. Subject to the terms and conditions of
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+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
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+      (d) If the Work includes a "NOTICE" text file as part of its
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+          notices within Derivative Works that You distribute, alongside
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+          that such additional attribution notices cannot be construed
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+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
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+      file or class name and description of purpose be included on the
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+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

vendor/go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp/client.go

@@ -0,0 +1,61 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package otelhttp
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"net/url"
+	"strings"
+)
+
+// DefaultClient is the default Client and is used by Get, Head, Post and PostForm.
+// Please be careful of intitialization order - for example, if you change
+// the global propagator, the DefaultClient might still be using the old one
+var DefaultClient = &http.Client{Transport: NewTransport(http.DefaultTransport)}
+
+// Get is a convenient replacement for http.Get that adds a span around the request.
+func Get(ctx context.Context, url string) (resp *http.Response, err error) {
+	req, err := http.NewRequestWithContext(ctx, "GET", url, nil)
+	if err != nil {
+		return nil, err
+	}
+	return DefaultClient.Do(req)
+}
+
+// Head is a convenient replacement for http.Head that adds a span around the request.
+func Head(ctx context.Context, url string) (resp *http.Response, err error) {
+	req, err := http.NewRequestWithContext(ctx, "HEAD", url, nil)
+	if err != nil {
+		return nil, err
+	}
+	return DefaultClient.Do(req)
+}
+
+// Post is a convenient replacement for http.Post that adds a span around the request.
+func Post(ctx context.Context, url, contentType string, body io.Reader) (resp *http.Response, err error) {
+	req, err := http.NewRequestWithContext(ctx, "POST", url, body)
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Content-Type", contentType)
+	return DefaultClient.Do(req)
+}
+
+// PostForm is a convenient replacement for http.PostForm that adds a span around the request.
+func PostForm(ctx context.Context, url string, data url.Values) (resp *http.Response, err error) {
+	return Post(ctx, url, "application/x-www-form-urlencoded", strings.NewReader(data.Encode()))
+}

vendor/go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp/common.go

@@ -0,0 +1,47 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package otelhttp
+
+import (
+	"net/http"
+
+	"go.opentelemetry.io/contrib"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/trace"
+)
+
+// Attribute keys that can be added to a span.
+const (
+	ReadBytesKey  = attribute.Key("http.read_bytes")  // if anything was read from the request body, the total number of bytes read
+	ReadErrorKey  = attribute.Key("http.read_error")  // If an error occurred while reading a request, the string of the error (io.EOF is not recorded)
+	WroteBytesKey = attribute.Key("http.wrote_bytes") // if anything was written to the response writer, the total number of bytes written
+	WriteErrorKey = attribute.Key("http.write_error") // if an error occurred while writing a reply, the string of the error (io.EOF is not recorded)
+)
+
+// Server HTTP metrics
+const (
+	RequestCount          = "http.server.request_count"           // Incoming request count total
+	RequestContentLength  = "http.server.request_content_length"  // Incoming request bytes total
+	ResponseContentLength = "http.server.response_content_length" // Incoming response bytes total
+	ServerLatency         = "http.server.duration"                // Incoming end to end duration, microseconds
+)
+
+// Filter is a predicate used to determine whether a given http.request should
+// be traced. A Filter must return true if the request should be traced.
+type Filter func(*http.Request) bool
+
+func newTracer(tp trace.TracerProvider) trace.Tracer {
+	return tp.Tracer(instrumentationName, trace.WithInstrumentationVersion(contrib.SemVersion()))
+}

vendor/go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp/config.go

@@ -0,0 +1,181 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package otelhttp
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptrace"
+
+	"go.opentelemetry.io/contrib"
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/metric"
+	"go.opentelemetry.io/otel/metric/global"
+	"go.opentelemetry.io/otel/propagation"
+	"go.opentelemetry.io/otel/trace"
+)
+
+const (
+	instrumentationName = "go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
+)
+
+// config represents the configuration options available for the http.Handler
+// and http.Transport types.
+type config struct {
+	Tracer            trace.Tracer
+	Meter             metric.Meter
+	Propagators       propagation.TextMapPropagator
+	SpanStartOptions  []trace.SpanStartOption
+	ReadEvent         bool
+	WriteEvent        bool
+	Filters           []Filter
+	SpanNameFormatter func(string, *http.Request) string
+	ClientTrace       func(context.Context) *httptrace.ClientTrace
+
+	TracerProvider trace.TracerProvider
+	MeterProvider  metric.MeterProvider
+}
+
+// Option interface used for setting optional config properties.
+type Option interface {
+	apply(*config)
+}
+
+type optionFunc func(*config)
+
+func (o optionFunc) apply(c *config) {
+	o(c)
+}
+
+// newConfig creates a new config struct and applies opts to it.
+func newConfig(opts ...Option) *config {
+	c := &config{
+		Propagators:   otel.GetTextMapPropagator(),
+		MeterProvider: global.GetMeterProvider(),
+	}
+	for _, opt := range opts {
+		opt.apply(c)
+	}
+
+	// Tracer is only initialized if manually specified. Otherwise, can be passed with the tracing context.
+	if c.TracerProvider != nil {
+		c.Tracer = newTracer(c.TracerProvider)
+	}
+	c.Meter = c.MeterProvider.Meter(
+		instrumentationName,
+		metric.WithInstrumentationVersion(contrib.SemVersion()),
+	)
+
+	return c
+}
+
+// WithTracerProvider specifies a tracer provider to use for creating a tracer.
+// If none is specified, the global provider is used.
+func WithTracerProvider(provider trace.TracerProvider) Option {
+	return optionFunc(func(cfg *config) {
+		cfg.TracerProvider = provider
+	})
+}
+
+// WithMeterProvider specifies a meter provider to use for creating a meter.
+// If none is specified, the global provider is used.
+func WithMeterProvider(provider metric.MeterProvider) Option {
+	return optionFunc(func(cfg *config) {
+		cfg.MeterProvider = provider
+	})
+}
+
+// WithPublicEndpoint configures the Handler to link the span with an incoming
+// span context. If this option is not provided, then the association is a child
+// association instead of a link.
+func WithPublicEndpoint() Option {
+	return optionFunc(func(c *config) {
+		c.SpanStartOptions = append(c.SpanStartOptions, trace.WithNewRoot())
+	})
+}
+
+// WithPropagators configures specific propagators. If this
+// option isn't specified then
+func WithPropagators(ps propagation.TextMapPropagator) Option {
+	return optionFunc(func(c *config) {
+		c.Propagators = ps
+	})
+}
+
+// WithSpanOptions configures an additional set of
+// trace.SpanOptions, which are applied to each new span.
+func WithSpanOptions(opts ...trace.SpanStartOption) Option {
+	return optionFunc(func(c *config) {
+		c.SpanStartOptions = append(c.SpanStartOptions, opts...)
+	})
+}
+
+// WithFilter adds a filter to the list of filters used by the handler.
+// If any filter indicates to exclude a request then the request will not be
+// traced. All filters must allow a request to be traced for a Span to be created.
+// If no filters are provided then all requests are traced.
+// Filters will be invoked for each processed request, it is advised to make them
+// simple and fast.
+func WithFilter(f Filter) Option {
+	return optionFunc(func(c *config) {
+		c.Filters = append(c.Filters, f)
+	})
+}
+
+type event int
+
+// Different types of events that can be recorded, see WithMessageEvents
+const (
+	ReadEvents event = iota
+	WriteEvents
+)
+
+// WithMessageEvents configures the Handler to record the specified events
+// (span.AddEvent) on spans. By default only summary attributes are added at the
+// end of the request.
+//
+// Valid events are:
+//     * ReadEvents: Record the number of bytes read after every http.Request.Body.Read
+//       using the ReadBytesKey
+//     * WriteEvents: Record the number of bytes written after every http.ResponeWriter.Write
+//       using the WriteBytesKey
+func WithMessageEvents(events ...event) Option {
+	return optionFunc(func(c *config) {
+		for _, e := range events {
+			switch e {
+			case ReadEvents:
+				c.ReadEvent = true
+			case WriteEvents:
+				c.WriteEvent = true
+			}
+		}
+	})
+}
+
+// WithSpanNameFormatter takes a function that will be called on every
+// request and the returned string will become the Span Name
+func WithSpanNameFormatter(f func(operation string, r *http.Request) string) Option {
+	return optionFunc(func(c *config) {
+		c.SpanNameFormatter = f
+	})
+}
+
+// WithClientTrace takes a function that returns client trace instance that will be
+// applied to the requests sent through the otelhttp Transport.
+func WithClientTrace(f func(context.Context) *httptrace.ClientTrace) Option {
+	return optionFunc(func(c *config) {
+		c.ClientTrace = f
+	})
+}

vendor/go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp/doc.go

@@ -0,0 +1,18 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package otelhttp provides an http.Handler and functions that are intended
+// to be used to add tracing by wrapping existing handlers (with Handler) and
+// routes WithRouteTag.
+package otelhttp // import "go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"

vendor/go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp/go.mod

@@ -0,0 +1,15 @@
+module go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp
+
+go 1.15
+
+replace go.opentelemetry.io/contrib => ../../../..
+
+require (
+	github.com/felixge/httpsnoop v1.0.2
+	github.com/stretchr/testify v1.7.0
+	go.opentelemetry.io/contrib v0.21.0
+	go.opentelemetry.io/otel v1.0.0-RC1
+	go.opentelemetry.io/otel/metric v0.21.0
+	go.opentelemetry.io/otel/oteltest v1.0.0-RC1
+	go.opentelemetry.io/otel/trace v1.0.0-RC1
+)

vendor/go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp/go.sum

@@ -0,0 +1,27 @@
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/felixge/httpsnoop v1.0.2 h1:+nS9g82KMXccJ/wp0zyRW9ZBHFETmMGtkk+2CTTrW4o=
+github.com/felixge/httpsnoop v1.0.2/go.mod h1:m8KPJKqk1gH5J9DgRY2ASl2lWCfGKXixSwevea8zH2U=
+github.com/google/go-cmp v0.5.6 h1:BKbKCqvP6I+rmFHt06ZmyQtvB8xAkWdhFyr0ZUNZcxQ=
+github.com/google/go-cmp v0.5.6/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+go.opentelemetry.io/otel v1.0.0-RC1 h1:4CeoX93DNTWt8awGK9JmNXzF9j7TyOu9upscEdtcdXc=
+go.opentelemetry.io/otel v1.0.0-RC1/go.mod h1:x9tRa9HK4hSSq7jf2TKbqFbtt58/TGk0f9XiEYISI1I=
+go.opentelemetry.io/otel/internal/metric v0.21.0 h1:gZlIBo5O51hZOOZz8vEcuRx/l5dnADadKfpT70AELoo=
+go.opentelemetry.io/otel/internal/metric v0.21.0/go.mod h1:iOfAaY2YycsXfYD4kaRSbLx2LKmfpKObWBEv9QK5zFo=
+go.opentelemetry.io/otel/metric v0.21.0 h1:ZtcJlHqVE4l8Su0WOLOd9fEPheJuYEiQ0wr9wv2p25I=
+go.opentelemetry.io/otel/metric v0.21.0/go.mod h1:JWCt1bjivC4iCrz/aCrM1GSw+ZcvY44KCbaeeRhzHnc=
+go.opentelemetry.io/otel/oteltest v1.0.0-RC1 h1:G685iP3XiskCwk/z0eIabL55XUl2gk0cljhGk9sB0Yk=
+go.opentelemetry.io/otel/oteltest v1.0.0-RC1/go.mod h1:+eoIG0gdEOaPNftuy1YScLr1Gb4mL/9lpDkZ0JjMRq4=
+go.opentelemetry.io/otel/trace v1.0.0-RC1 h1:jrjqKJZEibFrDz+umEASeU3LvdVyWKlnTh7XEfwrT58=
+go.opentelemetry.io/otel/trace v1.0.0-RC1/go.mod h1:86UHmyHWFEtWjfWPSbu0+d0Pf9Q6e1U+3ViBOc+NXAg=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

vendor/go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp/handler.go

@@ -0,0 +1,235 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package otelhttp
+
+import (
+	"io"
+	"net/http"
+	"time"
+
+	"github.com/felixge/httpsnoop"
+
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/metric"
+	"go.opentelemetry.io/otel/propagation"
+	semconv "go.opentelemetry.io/otel/semconv/v1.4.0"
+	"go.opentelemetry.io/otel/trace"
+)
+
+var _ http.Handler = &Handler{}
+
+// Handler is http middleware that corresponds to the http.Handler interface and
+// is designed to wrap a http.Mux (or equivalent), while individual routes on
+// the mux are wrapped with WithRouteTag. A Handler will add various attributes
+// to the span using the attribute.Keys defined in this package.
+type Handler struct {
+	operation string
+	handler   http.Handler
+
+	tracer            trace.Tracer
+	meter             metric.Meter
+	propagators       propagation.TextMapPropagator
+	spanStartOptions  []trace.SpanStartOption
+	readEvent         bool
+	writeEvent        bool
+	filters           []Filter
+	spanNameFormatter func(string, *http.Request) string
+	counters          map[string]metric.Int64Counter
+	valueRecorders    map[string]metric.Int64ValueRecorder
+}
+
+func defaultHandlerFormatter(operation string, _ *http.Request) string {
+	return operation
+}
+
+// NewHandler wraps the passed handler, functioning like middleware, in a span
+// named after the operation and with any provided Options.
+func NewHandler(handler http.Handler, operation string, opts ...Option) http.Handler {
+	h := Handler{
+		handler:   handler,
+		operation: operation,
+	}
+
+	defaultOpts := []Option{
+		WithSpanOptions(trace.WithSpanKind(trace.SpanKindServer)),
+		WithSpanNameFormatter(defaultHandlerFormatter),
+	}
+
+	c := newConfig(append(defaultOpts, opts...)...)
+	h.configure(c)
+	h.createMeasures()
+
+	return &h
+}
+
+func (h *Handler) configure(c *config) {
+	h.tracer = c.Tracer
+	h.meter = c.Meter
+	h.propagators = c.Propagators
+	h.spanStartOptions = c.SpanStartOptions
+	h.readEvent = c.ReadEvent
+	h.writeEvent = c.WriteEvent
+	h.filters = c.Filters
+	h.spanNameFormatter = c.SpanNameFormatter
+}
+
+func handleErr(err error) {
+	if err != nil {
+		otel.Handle(err)
+	}
+}
+
+func (h *Handler) createMeasures() {
+	h.counters = make(map[string]metric.Int64Counter)
+	h.valueRecorders = make(map[string]metric.Int64ValueRecorder)
+
+	requestBytesCounter, err := h.meter.NewInt64Counter(RequestContentLength)
+	handleErr(err)
+
+	responseBytesCounter, err := h.meter.NewInt64Counter(ResponseContentLength)
+	handleErr(err)
+
+	serverLatencyMeasure, err := h.meter.NewInt64ValueRecorder(ServerLatency)
+	handleErr(err)
+
+	h.counters[RequestContentLength] = requestBytesCounter
+	h.counters[ResponseContentLength] = responseBytesCounter
+	h.valueRecorders[ServerLatency] = serverLatencyMeasure
+}
+
+// ServeHTTP serves HTTP requests (http.Handler)
+func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	requestStartTime := time.Now()
+	for _, f := range h.filters {
+		if !f(r) {
+			// Simply pass through to the handler if a filter rejects the request
+			h.handler.ServeHTTP(w, r)
+			return
+		}
+	}
+
+	opts := append([]trace.SpanStartOption{
+		trace.WithAttributes(semconv.NetAttributesFromHTTPRequest("tcp", r)...),
+		trace.WithAttributes(semconv.EndUserAttributesFromHTTPRequest(r)...),
+		trace.WithAttributes(semconv.HTTPServerAttributesFromHTTPRequest(h.operation, "", r)...),
+	}, h.spanStartOptions...) // start with the configured options
+
+	tracer := h.tracer
+
+	if tracer == nil {
+		if span := trace.SpanFromContext(r.Context()); span.SpanContext().IsValid() {
+			tracer = newTracer(span.TracerProvider())
+		} else {
+			tracer = newTracer(otel.GetTracerProvider())
+		}
+	}
+
+	ctx := h.propagators.Extract(r.Context(), propagation.HeaderCarrier(r.Header))
+	ctx, span := tracer.Start(ctx, h.spanNameFormatter(h.operation, r), opts...)
+	defer span.End()
+
+	readRecordFunc := func(int64) {}
+	if h.readEvent {
+		readRecordFunc = func(n int64) {
+			span.AddEvent("read", trace.WithAttributes(ReadBytesKey.Int64(n)))
+		}
+	}
+
+	var bw bodyWrapper
+	// if request body is nil we don't want to mutate the body as it will affect
+	// the identity of it in a unforeseeable way because we assert ReadCloser
+	// fullfills a certain interface and it is indeed nil.
+	if r.Body != nil {
+		bw.ReadCloser = r.Body
+		bw.record = readRecordFunc
+		r.Body = &bw
+	}
+
+	writeRecordFunc := func(int64) {}
+	if h.writeEvent {
+		writeRecordFunc = func(n int64) {
+			span.AddEvent("write", trace.WithAttributes(WroteBytesKey.Int64(n)))
+		}
+	}
+
+	rww := &respWriterWrapper{ResponseWriter: w, record: writeRecordFunc, ctx: ctx, props: h.propagators}
+
+	// Wrap w to use our ResponseWriter methods while also exposing
+	// other interfaces that w may implement (http.CloseNotifier,
+	// http.Flusher, http.Hijacker, http.Pusher, io.ReaderFrom).
+
+	w = httpsnoop.Wrap(w, httpsnoop.Hooks{
+		Header: func(httpsnoop.HeaderFunc) httpsnoop.HeaderFunc {
+			return rww.Header
+		},
+		Write: func(httpsnoop.WriteFunc) httpsnoop.WriteFunc {
+			return rww.Write
+		},
+		WriteHeader: func(httpsnoop.WriteHeaderFunc) httpsnoop.WriteHeaderFunc {
+			return rww.WriteHeader
+		},
+	})
+
+	labeler := &Labeler{}
+	ctx = injectLabeler(ctx, labeler)
+
+	h.handler.ServeHTTP(w, r.WithContext(ctx))
+
+	setAfterServeAttributes(span, bw.read, rww.written, rww.statusCode, bw.err, rww.err)
+
+	// Add metrics
+	attributes := append(labeler.Get(), semconv.HTTPServerMetricAttributesFromHTTPRequest(h.operation, r)...)
+	h.counters[RequestContentLength].Add(ctx, bw.read, attributes...)
+	h.counters[ResponseContentLength].Add(ctx, rww.written, attributes...)
+
+	elapsedTime := time.Since(requestStartTime).Microseconds()
+
+	h.valueRecorders[ServerLatency].Record(ctx, elapsedTime, attributes...)
+}
+
+func setAfterServeAttributes(span trace.Span, read, wrote int64, statusCode int, rerr, werr error) {
+	attributes := []attribute.KeyValue{}
+
+	// TODO: Consider adding an event after each read and write, possibly as an
+	// option (defaulting to off), so as to not create needlessly verbose spans.
+	if read > 0 {
+		attributes = append(attributes, ReadBytesKey.Int64(read))
+	}
+	if rerr != nil && rerr != io.EOF {
+		attributes = append(attributes, ReadErrorKey.String(rerr.Error()))
+	}
+	if wrote > 0 {
+		attributes = append(attributes, WroteBytesKey.Int64(wrote))
+	}
+	if statusCode > 0 {
+		attributes = append(attributes, semconv.HTTPAttributesFromHTTPStatusCode(statusCode)...)
+		span.SetStatus(semconv.SpanStatusFromHTTPStatusCode(statusCode))
+	}
+	if werr != nil && werr != io.EOF {
+		attributes = append(attributes, WriteErrorKey.String(werr.Error()))
+	}
+	span.SetAttributes(attributes...)
+}
+
+// WithRouteTag annotates a span with the provided route name using the
+// RouteKey Tag.
+func WithRouteTag(route string, h http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		span := trace.SpanFromContext(r.Context())
+		span.SetAttributes(semconv.HTTPRouteKey.String(route))
+		h.ServeHTTP(w, r)
+	})
+}

vendor/go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp/labeler.go

@@ -0,0 +1,65 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package otelhttp
+
+import (
+	"context"
+	"sync"
+
+	"go.opentelemetry.io/otel/attribute"
+)
+
+// Labeler is used to allow instrumented HTTP handlers to add custom attributes to
+// the metrics recorded by the net/http instrumentation.
+type Labeler struct {
+	mu         sync.Mutex
+	attributes []attribute.KeyValue
+}
+
+// Add attributes to a Labeler.
+func (l *Labeler) Add(ls ...attribute.KeyValue) {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	l.attributes = append(l.attributes, ls...)
+}
+
+// Get returns a copy of the attributes added to the Labeler.
+func (l *Labeler) Get() []attribute.KeyValue {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	ret := make([]attribute.KeyValue, len(l.attributes))
+	copy(ret, l.attributes)
+	return ret
+}
+
+type labelerContextKeyType int
+
+const lablelerContextKey labelerContextKeyType = 0
+
+func injectLabeler(ctx context.Context, l *Labeler) context.Context {
+	return context.WithValue(ctx, lablelerContextKey, l)
+}
+
+// LabelerFromContext retrieves a Labeler instance from the provided context if
+// one is available.  If no Labeler was found in the provided context a new, empty
+// Labeler is returned and the second return value is false.  In this case it is
+// safe to use the Labeler but any attributes added to it will not be used.
+func LabelerFromContext(ctx context.Context) (*Labeler, bool) {
+	l, ok := ctx.Value(lablelerContextKey).(*Labeler)
+	if !ok {
+		l = &Labeler{}
+	}
+	return l, ok
+}

vendor/go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp/transport.go

@@ -0,0 +1,154 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package otelhttp
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"net/http/httptrace"
+
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/propagation"
+	semconv "go.opentelemetry.io/otel/semconv/v1.4.0"
+	"go.opentelemetry.io/otel/trace"
+)
+
+// Transport implements the http.RoundTripper interface and wraps
+// outbound HTTP(S) requests with a span.
+type Transport struct {
+	rt http.RoundTripper
+
+	tracer            trace.Tracer
+	propagators       propagation.TextMapPropagator
+	spanStartOptions  []trace.SpanStartOption
+	filters           []Filter
+	spanNameFormatter func(string, *http.Request) string
+	clientTrace       func(context.Context) *httptrace.ClientTrace
+}
+
+var _ http.RoundTripper = &Transport{}
+
+// NewTransport wraps the provided http.RoundTripper with one that
+// starts a span and injects the span context into the outbound request headers.
+//
+// If the provided http.RoundTripper is nil, http.DefaultTransport will be used
+// as the base http.RoundTripper
+func NewTransport(base http.RoundTripper, opts ...Option) *Transport {
+	if base == nil {
+		base = http.DefaultTransport
+	}
+
+	t := Transport{
+		rt: base,
+	}
+
+	defaultOpts := []Option{
+		WithSpanOptions(trace.WithSpanKind(trace.SpanKindClient)),
+		WithSpanNameFormatter(defaultTransportFormatter),
+	}
+
+	c := newConfig(append(defaultOpts, opts...)...)
+	t.applyConfig(c)
+
+	return &t
+}
+
+func (t *Transport) applyConfig(c *config) {
+	t.tracer = c.Tracer
+	t.propagators = c.Propagators
+	t.spanStartOptions = c.SpanStartOptions
+	t.filters = c.Filters
+	t.spanNameFormatter = c.SpanNameFormatter
+	t.clientTrace = c.ClientTrace
+}
+
+func defaultTransportFormatter(_ string, r *http.Request) string {
+	return "HTTP " + r.Method
+}
+
+// RoundTrip creates a Span and propagates its context via the provided request's headers
+// before handing the request to the configured base RoundTripper. The created span will
+// end when the response body is closed or when a read from the body returns io.EOF.
+func (t *Transport) RoundTrip(r *http.Request) (*http.Response, error) {
+	for _, f := range t.filters {
+		if !f(r) {
+			// Simply pass through to the base RoundTripper if a filter rejects the request
+			return t.rt.RoundTrip(r)
+		}
+	}
+
+	tracer := t.tracer
+
+	if tracer == nil {
+		if span := trace.SpanFromContext(r.Context()); span.SpanContext().IsValid() {
+			tracer = newTracer(span.TracerProvider())
+		} else {
+			tracer = newTracer(otel.GetTracerProvider())
+		}
+	}
+
+	opts := append([]trace.SpanStartOption{}, t.spanStartOptions...) // start with the configured options
+
+	ctx, span := tracer.Start(r.Context(), t.spanNameFormatter("", r), opts...)
+
+	if t.clientTrace != nil {
+		ctx = httptrace.WithClientTrace(ctx, t.clientTrace(ctx))
+	}
+
+	r = r.WithContext(ctx)
+	span.SetAttributes(semconv.HTTPClientAttributesFromHTTPRequest(r)...)
+	t.propagators.Inject(ctx, propagation.HeaderCarrier(r.Header))
+
+	res, err := t.rt.RoundTrip(r)
+	if err != nil {
+		span.RecordError(err)
+		span.End()
+		return res, err
+	}
+
+	span.SetAttributes(semconv.HTTPAttributesFromHTTPStatusCode(res.StatusCode)...)
+	span.SetStatus(semconv.SpanStatusFromHTTPStatusCode(res.StatusCode))
+	res.Body = &wrappedBody{ctx: ctx, span: span, body: res.Body}
+
+	return res, err
+}
+
+type wrappedBody struct {
+	ctx  context.Context
+	span trace.Span
+	body io.ReadCloser
+}
+
+var _ io.ReadCloser = &wrappedBody{}
+
+func (wb *wrappedBody) Read(b []byte) (int, error) {
+	n, err := wb.body.Read(b)
+
+	switch err {
+	case nil:
+		// nothing to do here but fall through to the return
+	case io.EOF:
+		wb.span.End()
+	default:
+		wb.span.RecordError(err)
+	}
+	return n, err
+}
+
+func (wb *wrappedBody) Close() error {
+	wb.span.End()
+	return wb.body.Close()
+}

vendor/go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp/wrap.go

@@ -0,0 +1,96 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package otelhttp
+
+import (
+	"context"
+	"io"
+	"net/http"
+
+	"go.opentelemetry.io/otel/propagation"
+)
+
+var _ io.ReadCloser = &bodyWrapper{}
+
+// bodyWrapper wraps a http.Request.Body (an io.ReadCloser) to track the number
+// of bytes read and the last error
+type bodyWrapper struct {
+	io.ReadCloser
+	record func(n int64) // must not be nil
+
+	read int64
+	err  error
+}
+
+func (w *bodyWrapper) Read(b []byte) (int, error) {
+	n, err := w.ReadCloser.Read(b)
+	n1 := int64(n)
+	w.read += n1
+	w.err = err
+	w.record(n1)
+	return n, err
+}
+
+func (w *bodyWrapper) Close() error {
+	return w.ReadCloser.Close()
+}
+
+var _ http.ResponseWriter = &respWriterWrapper{}
+
+// respWriterWrapper wraps a http.ResponseWriter in order to track the number of
+// bytes written, the last error, and to catch the returned statusCode
+// TODO: The wrapped http.ResponseWriter doesn't implement any of the optional
+// types (http.Hijacker, http.Pusher, http.CloseNotifier, http.Flusher, etc)
+// that may be useful when using it in real life situations.
+type respWriterWrapper struct {
+	http.ResponseWriter
+	record func(n int64) // must not be nil
+
+	// used to inject the header
+	ctx context.Context
+
+	props propagation.TextMapPropagator
+
+	written     int64
+	statusCode  int
+	err         error
+	wroteHeader bool
+}
+
+func (w *respWriterWrapper) Header() http.Header {
+	return w.ResponseWriter.Header()
+}
+
+func (w *respWriterWrapper) Write(p []byte) (int, error) {
+	if !w.wroteHeader {
+		w.WriteHeader(http.StatusOK)
+	}
+	n, err := w.ResponseWriter.Write(p)
+	n1 := int64(n)
+	w.record(n1)
+	w.written += n1
+	w.err = err
+	return n, err
+}
+
+func (w *respWriterWrapper) WriteHeader(statusCode int) {
+	if w.wroteHeader {
+		return
+	}
+	w.wroteHeader = true
+	w.statusCode = statusCode
+	w.props.Inject(w.ctx, propagation.HeaderCarrier(w.Header()))
+	w.ResponseWriter.WriteHeader(statusCode)
+}

vendor/go.opentelemetry.io/otel/internal/metric/LICENSE

@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
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+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
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+      including but not limited to software source code, documentation
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+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
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+      or a Contribution incorporated within the Work constitutes direct
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+
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+
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+
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+          or as an addendum to the NOTICE text from the Work, provided
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+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
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+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
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+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

vendor/go.opentelemetry.io/otel/internal/metric/global/meter.go

@@ -0,0 +1,348 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package global
+
+import (
+	"context"
+	"sync"
+	"sync/atomic"
+	"unsafe"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/metric"
+	"go.opentelemetry.io/otel/metric/number"
+	"go.opentelemetry.io/otel/metric/registry"
+)
+
+// This file contains the forwarding implementation of MeterProvider used as
+// the default global instance.  Metric events using instruments provided by
+// this implementation are no-ops until the first Meter implementation is set
+// as the global provider.
+//
+// The implementation here uses Mutexes to maintain a list of active Meters in
+// the MeterProvider and Instruments in each Meter, under the assumption that
+// these interfaces are not performance-critical.
+//
+// We have the invariant that setDelegate() will be called before a new
+// MeterProvider implementation is registered as the global provider.  Mutexes
+// in the MeterProvider and Meters ensure that each instrument has a delegate
+// before the global provider is set.
+//
+// Bound instrument operations are implemented by delegating to the
+// instrument after it is registered, with a sync.Once initializer to
+// protect against races with Release().
+//
+// Metric uniqueness checking is implemented by calling the exported
+// methods of the api/metric/registry package.
+
+type meterKey struct {
+	Name, Version string
+}
+
+type meterProvider struct {
+	delegate metric.MeterProvider
+
+	// lock protects `delegate` and `meters`.
+	lock sync.Mutex
+
+	// meters maintains a unique entry for every named Meter
+	// that has been registered through the global instance.
+	meters map[meterKey]*meterEntry
+}
+
+type meterImpl struct {
+	delegate unsafe.Pointer // (*metric.MeterImpl)
+
+	lock       sync.Mutex
+	syncInsts  []*syncImpl
+	asyncInsts []*asyncImpl
+}
+
+type meterEntry struct {
+	unique metric.MeterImpl
+	impl   meterImpl
+}
+
+type instrument struct {
+	descriptor metric.Descriptor
+}
+
+type syncImpl struct {
+	delegate unsafe.Pointer // (*metric.SyncImpl)
+
+	instrument
+}
+
+type asyncImpl struct {
+	delegate unsafe.Pointer // (*metric.AsyncImpl)
+
+	instrument
+
+	runner metric.AsyncRunner
+}
+
+// SyncImpler is implemented by all of the sync metric
+// instruments.
+type SyncImpler interface {
+	SyncImpl() metric.SyncImpl
+}
+
+// AsyncImpler is implemented by all of the async
+// metric instruments.
+type AsyncImpler interface {
+	AsyncImpl() metric.AsyncImpl
+}
+
+type syncHandle struct {
+	delegate unsafe.Pointer // (*metric.BoundInstrumentImpl)
+
+	inst   *syncImpl
+	labels []attribute.KeyValue
+
+	initialize sync.Once
+}
+
+var _ metric.MeterProvider = &meterProvider{}
+var _ metric.MeterImpl = &meterImpl{}
+var _ metric.InstrumentImpl = &syncImpl{}
+var _ metric.BoundSyncImpl = &syncHandle{}
+var _ metric.AsyncImpl = &asyncImpl{}
+
+func (inst *instrument) Descriptor() metric.Descriptor {
+	return inst.descriptor
+}
+
+// MeterProvider interface and delegation
+
+func newMeterProvider() *meterProvider {
+	return &meterProvider{
+		meters: map[meterKey]*meterEntry{},
+	}
+}
+
+func (p *meterProvider) setDelegate(provider metric.MeterProvider) {
+	p.lock.Lock()
+	defer p.lock.Unlock()
+
+	p.delegate = provider
+	for key, entry := range p.meters {
+		entry.impl.setDelegate(key.Name, key.Version, provider)
+	}
+	p.meters = nil
+}
+
+func (p *meterProvider) Meter(instrumentationName string, opts ...metric.MeterOption) metric.Meter {
+	p.lock.Lock()
+	defer p.lock.Unlock()
+
+	if p.delegate != nil {
+		return p.delegate.Meter(instrumentationName, opts...)
+	}
+
+	key := meterKey{
+		Name:    instrumentationName,
+		Version: metric.NewMeterConfig(opts...).InstrumentationVersion(),
+	}
+	entry, ok := p.meters[key]
+	if !ok {
+		entry = &meterEntry{}
+		entry.unique = registry.NewUniqueInstrumentMeterImpl(&entry.impl)
+		p.meters[key] = entry
+
+	}
+	return metric.WrapMeterImpl(entry.unique, key.Name, metric.WithInstrumentationVersion(key.Version))
+}
+
+// Meter interface and delegation
+
+func (m *meterImpl) setDelegate(name, version string, provider metric.MeterProvider) {
+	m.lock.Lock()
+	defer m.lock.Unlock()
+
+	d := new(metric.MeterImpl)
+	*d = provider.Meter(name, metric.WithInstrumentationVersion(version)).MeterImpl()
+	m.delegate = unsafe.Pointer(d)
+
+	for _, inst := range m.syncInsts {
+		inst.setDelegate(*d)
+	}
+	m.syncInsts = nil
+	for _, obs := range m.asyncInsts {
+		obs.setDelegate(*d)
+	}
+	m.asyncInsts = nil
+}
+
+func (m *meterImpl) NewSyncInstrument(desc metric.Descriptor) (metric.SyncImpl, error) {
+	m.lock.Lock()
+	defer m.lock.Unlock()
+
+	if meterPtr := (*metric.MeterImpl)(atomic.LoadPointer(&m.delegate)); meterPtr != nil {
+		return (*meterPtr).NewSyncInstrument(desc)
+	}
+
+	inst := &syncImpl{
+		instrument: instrument{
+			descriptor: desc,
+		},
+	}
+	m.syncInsts = append(m.syncInsts, inst)
+	return inst, nil
+}
+
+// Synchronous delegation
+
+func (inst *syncImpl) setDelegate(d metric.MeterImpl) {
+	implPtr := new(metric.SyncImpl)
+
+	var err error
+	*implPtr, err = d.NewSyncInstrument(inst.descriptor)
+
+	if err != nil {
+		// TODO: There is no standard way to deliver this error to the user.
+		// See https://github.com/open-telemetry/opentelemetry-go/issues/514
+		// Note that the default SDK will not generate any errors yet, this is
+		// only for added safety.
+		panic(err)
+	}
+
+	atomic.StorePointer(&inst.delegate, unsafe.Pointer(implPtr))
+}
+
+func (inst *syncImpl) Implementation() interface{} {
+	if implPtr := (*metric.SyncImpl)(atomic.LoadPointer(&inst.delegate)); implPtr != nil {
+		return (*implPtr).Implementation()
+	}
+	return inst
+}
+
+func (inst *syncImpl) Bind(labels []attribute.KeyValue) metric.BoundSyncImpl {
+	if implPtr := (*metric.SyncImpl)(atomic.LoadPointer(&inst.delegate)); implPtr != nil {
+		return (*implPtr).Bind(labels)
+	}
+	return &syncHandle{
+		inst:   inst,
+		labels: labels,
+	}
+}
+
+func (bound *syncHandle) Unbind() {
+	bound.initialize.Do(func() {})
+
+	implPtr := (*metric.BoundSyncImpl)(atomic.LoadPointer(&bound.delegate))
+
+	if implPtr == nil {
+		return
+	}
+
+	(*implPtr).Unbind()
+}
+
+// Async delegation
+
+func (m *meterImpl) NewAsyncInstrument(
+	desc metric.Descriptor,
+	runner metric.AsyncRunner,
+) (metric.AsyncImpl, error) {
+
+	m.lock.Lock()
+	defer m.lock.Unlock()
+
+	if meterPtr := (*metric.MeterImpl)(atomic.LoadPointer(&m.delegate)); meterPtr != nil {
+		return (*meterPtr).NewAsyncInstrument(desc, runner)
+	}
+
+	inst := &asyncImpl{
+		instrument: instrument{
+			descriptor: desc,
+		},
+		runner: runner,
+	}
+	m.asyncInsts = append(m.asyncInsts, inst)
+	return inst, nil
+}
+
+func (obs *asyncImpl) Implementation() interface{} {
+	if implPtr := (*metric.AsyncImpl)(atomic.LoadPointer(&obs.delegate)); implPtr != nil {
+		return (*implPtr).Implementation()
+	}
+	return obs
+}
+
+func (obs *asyncImpl) setDelegate(d metric.MeterImpl) {
+	implPtr := new(metric.AsyncImpl)
+
+	var err error
+	*implPtr, err = d.NewAsyncInstrument(obs.descriptor, obs.runner)
+
+	if err != nil {
+		// TODO: There is no standard way to deliver this error to the user.
+		// See https://github.com/open-telemetry/opentelemetry-go/issues/514
+		// Note that the default SDK will not generate any errors yet, this is
+		// only for added safety.
+		panic(err)
+	}
+
+	atomic.StorePointer(&obs.delegate, unsafe.Pointer(implPtr))
+}
+
+// Metric updates
+
+func (m *meterImpl) RecordBatch(ctx context.Context, labels []attribute.KeyValue, measurements ...metric.Measurement) {
+	if delegatePtr := (*metric.MeterImpl)(atomic.LoadPointer(&m.delegate)); delegatePtr != nil {
+		(*delegatePtr).RecordBatch(ctx, labels, measurements...)
+	}
+}
+
+func (inst *syncImpl) RecordOne(ctx context.Context, number number.Number, labels []attribute.KeyValue) {
+	if instPtr := (*metric.SyncImpl)(atomic.LoadPointer(&inst.delegate)); instPtr != nil {
+		(*instPtr).RecordOne(ctx, number, labels)
+	}
+}
+
+// Bound instrument initialization
+
+func (bound *syncHandle) RecordOne(ctx context.Context, number number.Number) {
+	instPtr := (*metric.SyncImpl)(atomic.LoadPointer(&bound.inst.delegate))
+	if instPtr == nil {
+		return
+	}
+	var implPtr *metric.BoundSyncImpl
+	bound.initialize.Do(func() {
+		implPtr = new(metric.BoundSyncImpl)
+		*implPtr = (*instPtr).Bind(bound.labels)
+		atomic.StorePointer(&bound.delegate, unsafe.Pointer(implPtr))
+	})
+	if implPtr == nil {
+		implPtr = (*metric.BoundSyncImpl)(atomic.LoadPointer(&bound.delegate))
+	}
+	// This may still be nil if instrument was created and bound
+	// without a delegate, then the instrument was set to have a
+	// delegate and unbound.
+	if implPtr == nil {
+		return
+	}
+	(*implPtr).RecordOne(ctx, number)
+}
+
+func AtomicFieldOffsets() map[string]uintptr {
+	return map[string]uintptr{
+		"meterProvider.delegate": unsafe.Offsetof(meterProvider{}.delegate),
+		"meterImpl.delegate":     unsafe.Offsetof(meterImpl{}.delegate),
+		"syncImpl.delegate":      unsafe.Offsetof(syncImpl{}.delegate),
+		"asyncImpl.delegate":     unsafe.Offsetof(asyncImpl{}.delegate),
+		"syncHandle.delegate":    unsafe.Offsetof(syncHandle{}.delegate),
+	}
+}

vendor/go.opentelemetry.io/otel/internal/metric/global/metric.go

@@ -0,0 +1,66 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package global
+
+import (
+	"sync"
+	"sync/atomic"
+
+	"go.opentelemetry.io/otel/metric"
+)
+
+type meterProviderHolder struct {
+	mp metric.MeterProvider
+}
+
+var (
+	globalMeter = defaultMeterValue()
+
+	delegateMeterOnce sync.Once
+)
+
+// MeterProvider is the internal implementation for global.MeterProvider.
+func MeterProvider() metric.MeterProvider {
+	return globalMeter.Load().(meterProviderHolder).mp
+}
+
+// SetMeterProvider is the internal implementation for global.SetMeterProvider.
+func SetMeterProvider(mp metric.MeterProvider) {
+	delegateMeterOnce.Do(func() {
+		current := MeterProvider()
+
+		if current == mp {
+			// Setting the provider to the prior default is nonsense, panic.
+			// Panic is acceptable because we are likely still early in the
+			// process lifetime.
+			panic("invalid MeterProvider, the global instance cannot be reinstalled")
+		} else if def, ok := current.(*meterProvider); ok {
+			def.setDelegate(mp)
+		}
+	})
+	globalMeter.Store(meterProviderHolder{mp: mp})
+}
+
+func defaultMeterValue() *atomic.Value {
+	v := &atomic.Value{}
+	v.Store(meterProviderHolder{mp: newMeterProvider()})
+	return v
+}
+
+// ResetForTest restores the initial global state, for testing purposes.
+func ResetForTest() {
+	globalMeter = defaultMeterValue()
+	delegateMeterOnce = sync.Once{}
+}

vendor/go.opentelemetry.io/otel/metric/LICENSE

@@ -0,0 +1,201 @@
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
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+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
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+      direction or management of such entity, whether by contract or
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+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
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+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
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+      "Contribution" shall mean any work of authorship, including
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+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
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+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
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+
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+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

vendor/go.opentelemetry.io/otel/metric/config.go

@@ -0,0 +1,141 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package metric // import "go.opentelemetry.io/otel/metric"
+
+import (
+	"go.opentelemetry.io/otel/metric/unit"
+)
+
+// InstrumentConfig contains options for metric instrument descriptors.
+type InstrumentConfig struct {
+	description            string
+	unit                   unit.Unit
+	instrumentationName    string
+	instrumentationVersion string
+}
+
+// Description describes the instrument in human-readable terms.
+func (cfg InstrumentConfig) Description() string {
+	return cfg.description
+}
+
+// Unit describes the measurement unit for a instrument.
+func (cfg InstrumentConfig) Unit() unit.Unit {
+	return cfg.unit
+}
+
+// InstrumentationName is the name of the library providing
+// instrumentation.
+func (cfg InstrumentConfig) InstrumentationName() string {
+	return cfg.instrumentationName
+}
+
+// InstrumentationVersion is the version of the library providing
+// instrumentation.
+func (cfg InstrumentConfig) InstrumentationVersion() string {
+	return cfg.instrumentationVersion
+}
+
+// InstrumentOption is an interface for applying metric instrument options.
+type InstrumentOption interface {
+	// ApplyMeter is used to set a InstrumentOption value of a
+	// InstrumentConfig.
+	applyInstrument(*InstrumentConfig)
+}
+
+// NewInstrumentConfig creates a new InstrumentConfig
+// and applies all the given options.
+func NewInstrumentConfig(opts ...InstrumentOption) InstrumentConfig {
+	var config InstrumentConfig
+	for _, o := range opts {
+		o.applyInstrument(&config)
+	}
+	return config
+}
+
+type instrumentOptionFunc func(*InstrumentConfig)
+
+func (fn instrumentOptionFunc) applyInstrument(cfg *InstrumentConfig) {
+	fn(cfg)
+}
+
+// WithDescription applies provided description.
+func WithDescription(desc string) InstrumentOption {
+	return instrumentOptionFunc(func(cfg *InstrumentConfig) {
+		cfg.description = desc
+	})
+}
+
+// WithUnit applies provided unit.
+func WithUnit(unit unit.Unit) InstrumentOption {
+	return instrumentOptionFunc(func(cfg *InstrumentConfig) {
+		cfg.unit = unit
+	})
+}
+
+// WithInstrumentationName sets the instrumentation name.
+func WithInstrumentationName(name string) InstrumentOption {
+	return instrumentOptionFunc(func(cfg *InstrumentConfig) {
+		cfg.instrumentationName = name
+	})
+}
+
+// MeterConfig contains options for Meters.
+type MeterConfig struct {
+	instrumentationVersion string
+}
+
+// InstrumentationVersion is the version of the library providing instrumentation.
+func (cfg MeterConfig) InstrumentationVersion() string {
+	return cfg.instrumentationVersion
+}
+
+// MeterOption is an interface for applying Meter options.
+type MeterOption interface {
+	// ApplyMeter is used to set a MeterOption value of a MeterConfig.
+	applyMeter(*MeterConfig)
+}
+
+// NewMeterConfig creates a new MeterConfig and applies
+// all the given options.
+func NewMeterConfig(opts ...MeterOption) MeterConfig {
+	var config MeterConfig
+	for _, o := range opts {
+		o.applyMeter(&config)
+	}
+	return config
+}
+
+// InstrumentMeterOption are options that can be used as both an InstrumentOption
+// and MeterOption
+type InstrumentMeterOption interface {
+	InstrumentOption
+	MeterOption
+}
+
+// WithInstrumentationVersion sets the instrumentation version.
+func WithInstrumentationVersion(version string) InstrumentMeterOption {
+	return instrumentationVersionOption(version)
+}
+
+type instrumentationVersionOption string
+
+func (i instrumentationVersionOption) applyMeter(config *MeterConfig) {
+	config.instrumentationVersion = string(i)
+}
+
+func (i instrumentationVersionOption) applyInstrument(config *InstrumentConfig) {
+	config.instrumentationVersion = string(i)
+}

vendor/go.opentelemetry.io/otel/metric/doc.go

@@ -0,0 +1,67 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/*
+Package metric provides an implementation of the metrics part of the
+OpenTelemetry API.
+
+This package is currently in a pre-GA phase. Backwards incompatible changes
+may be introduced in subsequent minor version releases as we work to track the
+evolving OpenTelemetry specification and user feedback.
+
+Measurements can be made about an operation being performed or the state of a
+system in general. These measurements can be crucial to the reliable operation
+of code and provide valuable insights about the inner workings of a system.
+
+Measurements are made using instruments provided by this package. The type of
+instrument used will depend on the type of measurement being made and of what
+part of a system is being measured.
+
+Instruments are categorized as Synchronous or Asynchronous and independently
+as Adding or Grouping. Synchronous instruments are called by the user with a
+Context. Asynchronous instruments are called by the SDK during collection.
+Additive instruments are semantically intended for capturing a sum. Grouping
+instruments are intended for capturing a distribution.
+
+Additive instruments may be monotonic, in which case they are non-decreasing
+and naturally define a rate.
+
+The synchronous instrument names are:
+
+  Counter:           additive, monotonic
+  UpDownCounter:     additive
+  ValueRecorder:     grouping
+
+and the asynchronous instruments are:
+
+  SumObserver:       additive, monotonic
+  UpDownSumObserver: additive
+  ValueObserver:     grouping
+
+All instruments are provided with support for either float64 or int64 input
+values.
+
+An instrument is created using a Meter. Additionally, a Meter is used to
+record batches of synchronous measurements or asynchronous observations. A
+Meter is obtained using a MeterProvider. A Meter, like a Tracer, is unique to
+the instrumentation it instruments and must be named and versioned when
+created with a MeterProvider with the name and version of the instrumentation
+library.
+
+Instrumentation should be designed to accept a MeterProvider from which it can
+create its own unique Meter. Alternatively, the registered global
+MeterProvider from the go.opentelemetry.io/otel package can be used as a
+default.
+*/
+package metric // import "go.opentelemetry.io/otel/metric"

vendor/go.opentelemetry.io/otel/metric/global/metric.go

@@ -0,0 +1,49 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package global // import "go.opentelemetry.io/otel/metric/global"
+
+import (
+	"go.opentelemetry.io/otel/internal/metric/global"
+	"go.opentelemetry.io/otel/metric"
+)
+
+// Meter creates an implementation of the Meter interface from the global
+// MeterProvider. The instrumentationName must be the name of the library
+// providing instrumentation. This name may be the same as the instrumented
+// code only if that code provides built-in instrumentation. If the
+// instrumentationName is empty, then a implementation defined default name
+// will be used instead.
+//
+// This is short for MeterProvider().Meter(name)
+func Meter(instrumentationName string, opts ...metric.MeterOption) metric.Meter {
+	return GetMeterProvider().Meter(instrumentationName, opts...)
+}
+
+// GetMeterProvider returns the registered global meter provider.  If
+// none is registered then a default meter provider is returned that
+// forwards the Meter interface to the first registered Meter.
+//
+// Use the meter provider to create a named meter. E.g.
+//     meter := global.MeterProvider().Meter("example.com/foo")
+// or
+//     meter := global.Meter("example.com/foo")
+func GetMeterProvider() metric.MeterProvider {
+	return global.MeterProvider()
+}
+
+// SetMeterProvider registers `mp` as the global meter provider.
+func SetMeterProvider(mp metric.MeterProvider) {
+	global.SetMeterProvider(mp)
+}

vendor/go.opentelemetry.io/otel/metric/go.mod

@@ -0,0 +1,74 @@
+module go.opentelemetry.io/otel/metric
+
+go 1.15
+
+replace go.opentelemetry.io/otel => ../
+
+replace go.opentelemetry.io/otel/bridge/opencensus => ../bridge/opencensus
+
+replace go.opentelemetry.io/otel/bridge/opentracing => ../bridge/opentracing
+
+replace go.opentelemetry.io/otel/example/jaeger => ../example/jaeger
+
+replace go.opentelemetry.io/otel/example/namedtracer => ../example/namedtracer
+
+replace go.opentelemetry.io/otel/example/opencensus => ../example/opencensus
+
+replace go.opentelemetry.io/otel/example/otel-collector => ../example/otel-collector
+
+replace go.opentelemetry.io/otel/example/prom-collector => ../example/prom-collector
+
+replace go.opentelemetry.io/otel/example/prometheus => ../example/prometheus
+
+replace go.opentelemetry.io/otel/example/zipkin => ../example/zipkin
+
+replace go.opentelemetry.io/otel/exporters/prometheus => ../exporters/prometheus
+
+replace go.opentelemetry.io/otel/exporters/jaeger => ../exporters/jaeger
+
+replace go.opentelemetry.io/otel/exporters/zipkin => ../exporters/zipkin
+
+replace go.opentelemetry.io/otel/internal/tools => ../internal/tools
+
+replace go.opentelemetry.io/otel/metric => ./
+
+replace go.opentelemetry.io/otel/oteltest => ../oteltest
+
+replace go.opentelemetry.io/otel/sdk => ../sdk
+
+replace go.opentelemetry.io/otel/sdk/export/metric => ../sdk/export/metric
+
+replace go.opentelemetry.io/otel/sdk/metric => ../sdk/metric
+
+replace go.opentelemetry.io/otel/trace => ../trace
+
+require (
+	github.com/google/go-cmp v0.5.6
+	github.com/stretchr/testify v1.7.0
+	go.opentelemetry.io/otel v1.0.0-RC1
+	go.opentelemetry.io/otel/internal/metric v0.21.0
+)
+
+replace go.opentelemetry.io/otel/example/passthrough => ../example/passthrough
+
+replace go.opentelemetry.io/otel/exporters/otlp/otlptrace => ../exporters/otlp/otlptrace
+
+replace go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc => ../exporters/otlp/otlptrace/otlptracegrpc
+
+replace go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp => ../exporters/otlp/otlptrace/otlptracehttp
+
+replace go.opentelemetry.io/otel/internal/metric => ../internal/metric
+
+replace go.opentelemetry.io/otel/exporters/metric/prometheus => ../exporters/metric/prometheus
+
+replace go.opentelemetry.io/otel/exporters/trace/jaeger => ../exporters/trace/jaeger
+
+replace go.opentelemetry.io/otel/exporters/trace/zipkin => ../exporters/trace/zipkin
+
+replace go.opentelemetry.io/otel/exporters/otlp/otlpmetric => ../exporters/otlp/otlpmetric
+
+replace go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc => ../exporters/otlp/otlpmetric/otlpmetricgrpc
+
+replace go.opentelemetry.io/otel/exporters/stdout/stdoutmetric => ../exporters/stdout/stdoutmetric
+
+replace go.opentelemetry.io/otel/exporters/stdout/stdouttrace => ../exporters/stdout/stdouttrace

vendor/go.opentelemetry.io/otel/metric/go.sum

@@ -0,0 +1,15 @@
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/google/go-cmp v0.5.6 h1:BKbKCqvP6I+rmFHt06ZmyQtvB8xAkWdhFyr0ZUNZcxQ=
+github.com/google/go-cmp v0.5.6/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
+github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
+golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

vendor/go.opentelemetry.io/otel/metric/instrumentkind_string.go

@@ -0,0 +1,28 @@
+// Code generated by "stringer -type=InstrumentKind"; DO NOT EDIT.
+
+package metric
+
+import "strconv"
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[ValueRecorderInstrumentKind-0]
+	_ = x[ValueObserverInstrumentKind-1]
+	_ = x[CounterInstrumentKind-2]
+	_ = x[UpDownCounterInstrumentKind-3]
+	_ = x[SumObserverInstrumentKind-4]
+	_ = x[UpDownSumObserverInstrumentKind-5]
+}
+
+const _InstrumentKind_name = "ValueRecorderInstrumentKindValueObserverInstrumentKindCounterInstrumentKindUpDownCounterInstrumentKindSumObserverInstrumentKindUpDownSumObserverInstrumentKind"
+
+var _InstrumentKind_index = [...]uint8{0, 27, 54, 75, 102, 127, 158}
+
+func (i InstrumentKind) String() string {
+	if i < 0 || i >= InstrumentKind(len(_InstrumentKind_index)-1) {
+		return "InstrumentKind(" + strconv.FormatInt(int64(i), 10) + ")"
+	}
+	return _InstrumentKind_name[_InstrumentKind_index[i]:_InstrumentKind_index[i+1]]
+}

vendor/go.opentelemetry.io/otel/metric/metric.go

@@ -0,0 +1,577 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package metric // import "go.opentelemetry.io/otel/metric"
+
+import (
+	"context"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/metric/number"
+	"go.opentelemetry.io/otel/metric/unit"
+)
+
+// MeterProvider supports named Meter instances.
+type MeterProvider interface {
+	// Meter creates an implementation of the Meter interface.
+	// The instrumentationName must be the name of the library providing
+	// instrumentation. This name may be the same as the instrumented code
+	// only if that code provides built-in instrumentation. If the
+	// instrumentationName is empty, then a implementation defined default
+	// name will be used instead.
+	Meter(instrumentationName string, opts ...MeterOption) Meter
+}
+
+// Meter is the creator of metric instruments.
+//
+// An uninitialized Meter is a no-op implementation.
+type Meter struct {
+	impl          MeterImpl
+	name, version string
+}
+
+// RecordBatch atomically records a batch of measurements.
+func (m Meter) RecordBatch(ctx context.Context, ls []attribute.KeyValue, ms ...Measurement) {
+	if m.impl == nil {
+		return
+	}
+	m.impl.RecordBatch(ctx, ls, ms...)
+}
+
+// NewBatchObserver creates a new BatchObserver that supports
+// making batches of observations for multiple instruments.
+func (m Meter) NewBatchObserver(callback BatchObserverFunc) BatchObserver {
+	return BatchObserver{
+		meter:  m,
+		runner: newBatchAsyncRunner(callback),
+	}
+}
+
+// NewInt64Counter creates a new integer Counter instrument with the
+// given name, customized with options.  May return an error if the
+// name is invalid (e.g., empty) or improperly registered (e.g.,
+// duplicate registration).
+func (m Meter) NewInt64Counter(name string, options ...InstrumentOption) (Int64Counter, error) {
+	return wrapInt64CounterInstrument(
+		m.newSync(name, CounterInstrumentKind, number.Int64Kind, options))
+}
+
+// NewFloat64Counter creates a new floating point Counter with the
+// given name, customized with options.  May return an error if the
+// name is invalid (e.g., empty) or improperly registered (e.g.,
+// duplicate registration).
+func (m Meter) NewFloat64Counter(name string, options ...InstrumentOption) (Float64Counter, error) {
+	return wrapFloat64CounterInstrument(
+		m.newSync(name, CounterInstrumentKind, number.Float64Kind, options))
+}
+
+// NewInt64UpDownCounter creates a new integer UpDownCounter instrument with the
+// given name, customized with options.  May return an error if the
+// name is invalid (e.g., empty) or improperly registered (e.g.,
+// duplicate registration).
+func (m Meter) NewInt64UpDownCounter(name string, options ...InstrumentOption) (Int64UpDownCounter, error) {
+	return wrapInt64UpDownCounterInstrument(
+		m.newSync(name, UpDownCounterInstrumentKind, number.Int64Kind, options))
+}
+
+// NewFloat64UpDownCounter creates a new floating point UpDownCounter with the
+// given name, customized with options.  May return an error if the
+// name is invalid (e.g., empty) or improperly registered (e.g.,
+// duplicate registration).
+func (m Meter) NewFloat64UpDownCounter(name string, options ...InstrumentOption) (Float64UpDownCounter, error) {
+	return wrapFloat64UpDownCounterInstrument(
+		m.newSync(name, UpDownCounterInstrumentKind, number.Float64Kind, options))
+}
+
+// NewInt64ValueRecorder creates a new integer ValueRecorder instrument with the
+// given name, customized with options.  May return an error if the
+// name is invalid (e.g., empty) or improperly registered (e.g.,
+// duplicate registration).
+func (m Meter) NewInt64ValueRecorder(name string, opts ...InstrumentOption) (Int64ValueRecorder, error) {
+	return wrapInt64ValueRecorderInstrument(
+		m.newSync(name, ValueRecorderInstrumentKind, number.Int64Kind, opts))
+}
+
+// NewFloat64ValueRecorder creates a new floating point ValueRecorder with the
+// given name, customized with options.  May return an error if the
+// name is invalid (e.g., empty) or improperly registered (e.g.,
+// duplicate registration).
+func (m Meter) NewFloat64ValueRecorder(name string, opts ...InstrumentOption) (Float64ValueRecorder, error) {
+	return wrapFloat64ValueRecorderInstrument(
+		m.newSync(name, ValueRecorderInstrumentKind, number.Float64Kind, opts))
+}
+
+// NewInt64ValueObserver creates a new integer ValueObserver instrument
+// with the given name, running a given callback, and customized with
+// options.  May return an error if the name is invalid (e.g., empty)
+// or improperly registered (e.g., duplicate registration).
+func (m Meter) NewInt64ValueObserver(name string, callback Int64ObserverFunc, opts ...InstrumentOption) (Int64ValueObserver, error) {
+	if callback == nil {
+		return wrapInt64ValueObserverInstrument(NoopAsync{}, nil)
+	}
+	return wrapInt64ValueObserverInstrument(
+		m.newAsync(name, ValueObserverInstrumentKind, number.Int64Kind, opts,
+			newInt64AsyncRunner(callback)))
+}
+
+// NewFloat64ValueObserver creates a new floating point ValueObserver with
+// the given name, running a given callback, and customized with
+// options.  May return an error if the name is invalid (e.g., empty)
+// or improperly registered (e.g., duplicate registration).
+func (m Meter) NewFloat64ValueObserver(name string, callback Float64ObserverFunc, opts ...InstrumentOption) (Float64ValueObserver, error) {
+	if callback == nil {
+		return wrapFloat64ValueObserverInstrument(NoopAsync{}, nil)
+	}
+	return wrapFloat64ValueObserverInstrument(
+		m.newAsync(name, ValueObserverInstrumentKind, number.Float64Kind, opts,
+			newFloat64AsyncRunner(callback)))
+}
+
+// NewInt64SumObserver creates a new integer SumObserver instrument
+// with the given name, running a given callback, and customized with
+// options.  May return an error if the name is invalid (e.g., empty)
+// or improperly registered (e.g., duplicate registration).
+func (m Meter) NewInt64SumObserver(name string, callback Int64ObserverFunc, opts ...InstrumentOption) (Int64SumObserver, error) {
+	if callback == nil {
+		return wrapInt64SumObserverInstrument(NoopAsync{}, nil)
+	}
+	return wrapInt64SumObserverInstrument(
+		m.newAsync(name, SumObserverInstrumentKind, number.Int64Kind, opts,
+			newInt64AsyncRunner(callback)))
+}
+
+// NewFloat64SumObserver creates a new floating point SumObserver with
+// the given name, running a given callback, and customized with
+// options.  May return an error if the name is invalid (e.g., empty)
+// or improperly registered (e.g., duplicate registration).
+func (m Meter) NewFloat64SumObserver(name string, callback Float64ObserverFunc, opts ...InstrumentOption) (Float64SumObserver, error) {
+	if callback == nil {
+		return wrapFloat64SumObserverInstrument(NoopAsync{}, nil)
+	}
+	return wrapFloat64SumObserverInstrument(
+		m.newAsync(name, SumObserverInstrumentKind, number.Float64Kind, opts,
+			newFloat64AsyncRunner(callback)))
+}
+
+// NewInt64UpDownSumObserver creates a new integer UpDownSumObserver instrument
+// with the given name, running a given callback, and customized with
+// options.  May return an error if the name is invalid (e.g., empty)
+// or improperly registered (e.g., duplicate registration).
+func (m Meter) NewInt64UpDownSumObserver(name string, callback Int64ObserverFunc, opts ...InstrumentOption) (Int64UpDownSumObserver, error) {
+	if callback == nil {
+		return wrapInt64UpDownSumObserverInstrument(NoopAsync{}, nil)
+	}
+	return wrapInt64UpDownSumObserverInstrument(
+		m.newAsync(name, UpDownSumObserverInstrumentKind, number.Int64Kind, opts,
+			newInt64AsyncRunner(callback)))
+}
+
+// NewFloat64UpDownSumObserver creates a new floating point UpDownSumObserver with
+// the given name, running a given callback, and customized with
+// options.  May return an error if the name is invalid (e.g., empty)
+// or improperly registered (e.g., duplicate registration).
+func (m Meter) NewFloat64UpDownSumObserver(name string, callback Float64ObserverFunc, opts ...InstrumentOption) (Float64UpDownSumObserver, error) {
+	if callback == nil {
+		return wrapFloat64UpDownSumObserverInstrument(NoopAsync{}, nil)
+	}
+	return wrapFloat64UpDownSumObserverInstrument(
+		m.newAsync(name, UpDownSumObserverInstrumentKind, number.Float64Kind, opts,
+			newFloat64AsyncRunner(callback)))
+}
+
+// NewInt64ValueObserver creates a new integer ValueObserver instrument
+// with the given name, running in a batch callback, and customized with
+// options.  May return an error if the name is invalid (e.g., empty)
+// or improperly registered (e.g., duplicate registration).
+func (b BatchObserver) NewInt64ValueObserver(name string, opts ...InstrumentOption) (Int64ValueObserver, error) {
+	if b.runner == nil {
+		return wrapInt64ValueObserverInstrument(NoopAsync{}, nil)
+	}
+	return wrapInt64ValueObserverInstrument(
+		b.meter.newAsync(name, ValueObserverInstrumentKind, number.Int64Kind, opts, b.runner))
+}
+
+// NewFloat64ValueObserver creates a new floating point ValueObserver with
+// the given name, running in a batch callback, and customized with
+// options.  May return an error if the name is invalid (e.g., empty)
+// or improperly registered (e.g., duplicate registration).
+func (b BatchObserver) NewFloat64ValueObserver(name string, opts ...InstrumentOption) (Float64ValueObserver, error) {
+	if b.runner == nil {
+		return wrapFloat64ValueObserverInstrument(NoopAsync{}, nil)
+	}
+	return wrapFloat64ValueObserverInstrument(
+		b.meter.newAsync(name, ValueObserverInstrumentKind, number.Float64Kind, opts,
+			b.runner))
+}
+
+// NewInt64SumObserver creates a new integer SumObserver instrument
+// with the given name, running in a batch callback, and customized with
+// options.  May return an error if the name is invalid (e.g., empty)
+// or improperly registered (e.g., duplicate registration).
+func (b BatchObserver) NewInt64SumObserver(name string, opts ...InstrumentOption) (Int64SumObserver, error) {
+	if b.runner == nil {
+		return wrapInt64SumObserverInstrument(NoopAsync{}, nil)
+	}
+	return wrapInt64SumObserverInstrument(
+		b.meter.newAsync(name, SumObserverInstrumentKind, number.Int64Kind, opts, b.runner))
+}
+
+// NewFloat64SumObserver creates a new floating point SumObserver with
+// the given name, running in a batch callback, and customized with
+// options.  May return an error if the name is invalid (e.g., empty)
+// or improperly registered (e.g., duplicate registration).
+func (b BatchObserver) NewFloat64SumObserver(name string, opts ...InstrumentOption) (Float64SumObserver, error) {
+	if b.runner == nil {
+		return wrapFloat64SumObserverInstrument(NoopAsync{}, nil)
+	}
+	return wrapFloat64SumObserverInstrument(
+		b.meter.newAsync(name, SumObserverInstrumentKind, number.Float64Kind, opts,
+			b.runner))
+}
+
+// NewInt64UpDownSumObserver creates a new integer UpDownSumObserver instrument
+// with the given name, running in a batch callback, and customized with
+// options.  May return an error if the name is invalid (e.g., empty)
+// or improperly registered (e.g., duplicate registration).
+func (b BatchObserver) NewInt64UpDownSumObserver(name string, opts ...InstrumentOption) (Int64UpDownSumObserver, error) {
+	if b.runner == nil {
+		return wrapInt64UpDownSumObserverInstrument(NoopAsync{}, nil)
+	}
+	return wrapInt64UpDownSumObserverInstrument(
+		b.meter.newAsync(name, UpDownSumObserverInstrumentKind, number.Int64Kind, opts, b.runner))
+}
+
+// NewFloat64UpDownSumObserver creates a new floating point UpDownSumObserver with
+// the given name, running in a batch callback, and customized with
+// options.  May return an error if the name is invalid (e.g., empty)
+// or improperly registered (e.g., duplicate registration).
+func (b BatchObserver) NewFloat64UpDownSumObserver(name string, opts ...InstrumentOption) (Float64UpDownSumObserver, error) {
+	if b.runner == nil {
+		return wrapFloat64UpDownSumObserverInstrument(NoopAsync{}, nil)
+	}
+	return wrapFloat64UpDownSumObserverInstrument(
+		b.meter.newAsync(name, UpDownSumObserverInstrumentKind, number.Float64Kind, opts,
+			b.runner))
+}
+
+// MeterImpl returns the underlying MeterImpl of this Meter.
+func (m Meter) MeterImpl() MeterImpl {
+	return m.impl
+}
+
+// newAsync constructs one new asynchronous instrument.
+func (m Meter) newAsync(
+	name string,
+	mkind InstrumentKind,
+	nkind number.Kind,
+	opts []InstrumentOption,
+	runner AsyncRunner,
+) (
+	AsyncImpl,
+	error,
+) {
+	if m.impl == nil {
+		return NoopAsync{}, nil
+	}
+	desc := NewDescriptor(name, mkind, nkind, opts...)
+	desc.config.instrumentationName = m.name
+	desc.config.instrumentationVersion = m.version
+	return m.impl.NewAsyncInstrument(desc, runner)
+}
+
+// newSync constructs one new synchronous instrument.
+func (m Meter) newSync(
+	name string,
+	metricKind InstrumentKind,
+	numberKind number.Kind,
+	opts []InstrumentOption,
+) (
+	SyncImpl,
+	error,
+) {
+	if m.impl == nil {
+		return NoopSync{}, nil
+	}
+	desc := NewDescriptor(name, metricKind, numberKind, opts...)
+	desc.config.instrumentationName = m.name
+	desc.config.instrumentationVersion = m.version
+	return m.impl.NewSyncInstrument(desc)
+}
+
+// MeterMust is a wrapper for Meter interfaces that panics when any
+// instrument constructor encounters an error.
+type MeterMust struct {
+	meter Meter
+}
+
+// BatchObserverMust is a wrapper for BatchObserver that panics when
+// any instrument constructor encounters an error.
+type BatchObserverMust struct {
+	batch BatchObserver
+}
+
+// Must constructs a MeterMust implementation from a Meter, allowing
+// the application to panic when any instrument constructor yields an
+// error.
+func Must(meter Meter) MeterMust {
+	return MeterMust{meter: meter}
+}
+
+// NewInt64Counter calls `Meter.NewInt64Counter` and returns the
+// instrument, panicking if it encounters an error.
+func (mm MeterMust) NewInt64Counter(name string, cos ...InstrumentOption) Int64Counter {
+	if inst, err := mm.meter.NewInt64Counter(name, cos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewFloat64Counter calls `Meter.NewFloat64Counter` and returns the
+// instrument, panicking if it encounters an error.
+func (mm MeterMust) NewFloat64Counter(name string, cos ...InstrumentOption) Float64Counter {
+	if inst, err := mm.meter.NewFloat64Counter(name, cos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewInt64UpDownCounter calls `Meter.NewInt64UpDownCounter` and returns the
+// instrument, panicking if it encounters an error.
+func (mm MeterMust) NewInt64UpDownCounter(name string, cos ...InstrumentOption) Int64UpDownCounter {
+	if inst, err := mm.meter.NewInt64UpDownCounter(name, cos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewFloat64UpDownCounter calls `Meter.NewFloat64UpDownCounter` and returns the
+// instrument, panicking if it encounters an error.
+func (mm MeterMust) NewFloat64UpDownCounter(name string, cos ...InstrumentOption) Float64UpDownCounter {
+	if inst, err := mm.meter.NewFloat64UpDownCounter(name, cos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewInt64ValueRecorder calls `Meter.NewInt64ValueRecorder` and returns the
+// instrument, panicking if it encounters an error.
+func (mm MeterMust) NewInt64ValueRecorder(name string, mos ...InstrumentOption) Int64ValueRecorder {
+	if inst, err := mm.meter.NewInt64ValueRecorder(name, mos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewFloat64ValueRecorder calls `Meter.NewFloat64ValueRecorder` and returns the
+// instrument, panicking if it encounters an error.
+func (mm MeterMust) NewFloat64ValueRecorder(name string, mos ...InstrumentOption) Float64ValueRecorder {
+	if inst, err := mm.meter.NewFloat64ValueRecorder(name, mos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewInt64ValueObserver calls `Meter.NewInt64ValueObserver` and
+// returns the instrument, panicking if it encounters an error.
+func (mm MeterMust) NewInt64ValueObserver(name string, callback Int64ObserverFunc, oos ...InstrumentOption) Int64ValueObserver {
+	if inst, err := mm.meter.NewInt64ValueObserver(name, callback, oos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewFloat64ValueObserver calls `Meter.NewFloat64ValueObserver` and
+// returns the instrument, panicking if it encounters an error.
+func (mm MeterMust) NewFloat64ValueObserver(name string, callback Float64ObserverFunc, oos ...InstrumentOption) Float64ValueObserver {
+	if inst, err := mm.meter.NewFloat64ValueObserver(name, callback, oos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewInt64SumObserver calls `Meter.NewInt64SumObserver` and
+// returns the instrument, panicking if it encounters an error.
+func (mm MeterMust) NewInt64SumObserver(name string, callback Int64ObserverFunc, oos ...InstrumentOption) Int64SumObserver {
+	if inst, err := mm.meter.NewInt64SumObserver(name, callback, oos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewFloat64SumObserver calls `Meter.NewFloat64SumObserver` and
+// returns the instrument, panicking if it encounters an error.
+func (mm MeterMust) NewFloat64SumObserver(name string, callback Float64ObserverFunc, oos ...InstrumentOption) Float64SumObserver {
+	if inst, err := mm.meter.NewFloat64SumObserver(name, callback, oos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewInt64UpDownSumObserver calls `Meter.NewInt64UpDownSumObserver` and
+// returns the instrument, panicking if it encounters an error.
+func (mm MeterMust) NewInt64UpDownSumObserver(name string, callback Int64ObserverFunc, oos ...InstrumentOption) Int64UpDownSumObserver {
+	if inst, err := mm.meter.NewInt64UpDownSumObserver(name, callback, oos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewFloat64UpDownSumObserver calls `Meter.NewFloat64UpDownSumObserver` and
+// returns the instrument, panicking if it encounters an error.
+func (mm MeterMust) NewFloat64UpDownSumObserver(name string, callback Float64ObserverFunc, oos ...InstrumentOption) Float64UpDownSumObserver {
+	if inst, err := mm.meter.NewFloat64UpDownSumObserver(name, callback, oos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewBatchObserver returns a wrapper around BatchObserver that panics
+// when any instrument constructor returns an error.
+func (mm MeterMust) NewBatchObserver(callback BatchObserverFunc) BatchObserverMust {
+	return BatchObserverMust{
+		batch: mm.meter.NewBatchObserver(callback),
+	}
+}
+
+// NewInt64ValueObserver calls `BatchObserver.NewInt64ValueObserver` and
+// returns the instrument, panicking if it encounters an error.
+func (bm BatchObserverMust) NewInt64ValueObserver(name string, oos ...InstrumentOption) Int64ValueObserver {
+	if inst, err := bm.batch.NewInt64ValueObserver(name, oos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewFloat64ValueObserver calls `BatchObserver.NewFloat64ValueObserver` and
+// returns the instrument, panicking if it encounters an error.
+func (bm BatchObserverMust) NewFloat64ValueObserver(name string, oos ...InstrumentOption) Float64ValueObserver {
+	if inst, err := bm.batch.NewFloat64ValueObserver(name, oos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewInt64SumObserver calls `BatchObserver.NewInt64SumObserver` and
+// returns the instrument, panicking if it encounters an error.
+func (bm BatchObserverMust) NewInt64SumObserver(name string, oos ...InstrumentOption) Int64SumObserver {
+	if inst, err := bm.batch.NewInt64SumObserver(name, oos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewFloat64SumObserver calls `BatchObserver.NewFloat64SumObserver` and
+// returns the instrument, panicking if it encounters an error.
+func (bm BatchObserverMust) NewFloat64SumObserver(name string, oos ...InstrumentOption) Float64SumObserver {
+	if inst, err := bm.batch.NewFloat64SumObserver(name, oos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewInt64UpDownSumObserver calls `BatchObserver.NewInt64UpDownSumObserver` and
+// returns the instrument, panicking if it encounters an error.
+func (bm BatchObserverMust) NewInt64UpDownSumObserver(name string, oos ...InstrumentOption) Int64UpDownSumObserver {
+	if inst, err := bm.batch.NewInt64UpDownSumObserver(name, oos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// NewFloat64UpDownSumObserver calls `BatchObserver.NewFloat64UpDownSumObserver` and
+// returns the instrument, panicking if it encounters an error.
+func (bm BatchObserverMust) NewFloat64UpDownSumObserver(name string, oos ...InstrumentOption) Float64UpDownSumObserver {
+	if inst, err := bm.batch.NewFloat64UpDownSumObserver(name, oos...); err != nil {
+		panic(err)
+	} else {
+		return inst
+	}
+}
+
+// Descriptor contains all the settings that describe an instrument,
+// including its name, metric kind, number kind, and the configurable
+// options.
+type Descriptor struct {
+	name           string
+	instrumentKind InstrumentKind
+	numberKind     number.Kind
+	config         InstrumentConfig
+}
+
+// NewDescriptor returns a Descriptor with the given contents.
+func NewDescriptor(name string, ikind InstrumentKind, nkind number.Kind, opts ...InstrumentOption) Descriptor {
+	return Descriptor{
+		name:           name,
+		instrumentKind: ikind,
+		numberKind:     nkind,
+		config:         NewInstrumentConfig(opts...),
+	}
+}
+
+// Name returns the metric instrument's name.
+func (d Descriptor) Name() string {
+	return d.name
+}
+
+// InstrumentKind returns the specific kind of instrument.
+func (d Descriptor) InstrumentKind() InstrumentKind {
+	return d.instrumentKind
+}
+
+// Description provides a human-readable description of the metric
+// instrument.
+func (d Descriptor) Description() string {
+	return d.config.Description()
+}
+
+// Unit describes the units of the metric instrument.  Unitless
+// metrics return the empty string.
+func (d Descriptor) Unit() unit.Unit {
+	return d.config.Unit()
+}
+
+// NumberKind returns whether this instrument is declared over int64,
+// float64, or uint64 values.
+func (d Descriptor) NumberKind() number.Kind {
+	return d.numberKind
+}
+
+// InstrumentationName returns the name of the library that provided
+// instrumentation for this instrument.
+func (d Descriptor) InstrumentationName() string {
+	return d.config.InstrumentationName()
+}
+
+// InstrumentationVersion returns the version of the library that provided
+// instrumentation for this instrument.
+func (d Descriptor) InstrumentationVersion() string {
+	return d.config.InstrumentationVersion()
+}

vendor/go.opentelemetry.io/otel/metric/metric_instrument.go

@@ -0,0 +1,777 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:generate stringer -type=InstrumentKind
+
+package metric // import "go.opentelemetry.io/otel/metric"
+
+import (
+	"context"
+	"errors"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/metric/number"
+)
+
+// ErrSDKReturnedNilImpl is returned when a new `MeterImpl` returns nil.
+var ErrSDKReturnedNilImpl = errors.New("SDK returned a nil implementation")
+
+// InstrumentKind describes the kind of instrument.
+type InstrumentKind int8
+
+const (
+	// ValueRecorderInstrumentKind indicates a ValueRecorder instrument.
+	ValueRecorderInstrumentKind InstrumentKind = iota
+	// ValueObserverInstrumentKind indicates an ValueObserver instrument.
+	ValueObserverInstrumentKind
+
+	// CounterInstrumentKind indicates a Counter instrument.
+	CounterInstrumentKind
+	// UpDownCounterInstrumentKind indicates a UpDownCounter instrument.
+	UpDownCounterInstrumentKind
+
+	// SumObserverInstrumentKind indicates a SumObserver instrument.
+	SumObserverInstrumentKind
+	// UpDownSumObserverInstrumentKind indicates a UpDownSumObserver
+	// instrument.
+	UpDownSumObserverInstrumentKind
+)
+
+// Synchronous returns whether this is a synchronous kind of instrument.
+func (k InstrumentKind) Synchronous() bool {
+	switch k {
+	case CounterInstrumentKind, UpDownCounterInstrumentKind, ValueRecorderInstrumentKind:
+		return true
+	}
+	return false
+}
+
+// Asynchronous returns whether this is an asynchronous kind of instrument.
+func (k InstrumentKind) Asynchronous() bool {
+	return !k.Synchronous()
+}
+
+// Adding returns whether this kind of instrument adds its inputs (as opposed to Grouping).
+func (k InstrumentKind) Adding() bool {
+	switch k {
+	case CounterInstrumentKind, UpDownCounterInstrumentKind, SumObserverInstrumentKind, UpDownSumObserverInstrumentKind:
+		return true
+	}
+	return false
+}
+
+// Grouping returns whether this kind of instrument groups its inputs (as opposed to Adding).
+func (k InstrumentKind) Grouping() bool {
+	return !k.Adding()
+}
+
+// Monotonic returns whether this kind of instrument exposes a non-decreasing sum.
+func (k InstrumentKind) Monotonic() bool {
+	switch k {
+	case CounterInstrumentKind, SumObserverInstrumentKind:
+		return true
+	}
+	return false
+}
+
+// PrecomputedSum returns whether this kind of instrument receives precomputed sums.
+func (k InstrumentKind) PrecomputedSum() bool {
+	return k.Adding() && k.Asynchronous()
+}
+
+// Observation is used for reporting an asynchronous  batch of metric
+// values. Instances of this type should be created by asynchronous
+// instruments (e.g., Int64ValueObserver.Observation()).
+type Observation struct {
+	// number needs to be aligned for 64-bit atomic operations.
+	number     number.Number
+	instrument AsyncImpl
+}
+
+// Int64ObserverFunc is a type of callback that integral
+// observers run.
+type Int64ObserverFunc func(context.Context, Int64ObserverResult)
+
+// Float64ObserverFunc is a type of callback that floating point
+// observers run.
+type Float64ObserverFunc func(context.Context, Float64ObserverResult)
+
+// BatchObserverFunc is a callback argument for use with any
+// Observer instrument that will be reported as a batch of
+// observations.
+type BatchObserverFunc func(context.Context, BatchObserverResult)
+
+// Int64ObserverResult is passed to an observer callback to capture
+// observations for one asynchronous integer metric instrument.
+type Int64ObserverResult struct {
+	instrument AsyncImpl
+	function   func([]attribute.KeyValue, ...Observation)
+}
+
+// Float64ObserverResult is passed to an observer callback to capture
+// observations for one asynchronous floating point metric instrument.
+type Float64ObserverResult struct {
+	instrument AsyncImpl
+	function   func([]attribute.KeyValue, ...Observation)
+}
+
+// BatchObserverResult is passed to a batch observer callback to
+// capture observations for multiple asynchronous instruments.
+type BatchObserverResult struct {
+	function func([]attribute.KeyValue, ...Observation)
+}
+
+// Observe captures a single integer value from the associated
+// instrument callback, with the given labels.
+func (ir Int64ObserverResult) Observe(value int64, labels ...attribute.KeyValue) {
+	ir.function(labels, Observation{
+		instrument: ir.instrument,
+		number:     number.NewInt64Number(value),
+	})
+}
+
+// Observe captures a single floating point value from the associated
+// instrument callback, with the given labels.
+func (fr Float64ObserverResult) Observe(value float64, labels ...attribute.KeyValue) {
+	fr.function(labels, Observation{
+		instrument: fr.instrument,
+		number:     number.NewFloat64Number(value),
+	})
+}
+
+// Observe captures a multiple observations from the associated batch
+// instrument callback, with the given labels.
+func (br BatchObserverResult) Observe(labels []attribute.KeyValue, obs ...Observation) {
+	br.function(labels, obs...)
+}
+
+// AsyncRunner is expected to convert into an AsyncSingleRunner or an
+// AsyncBatchRunner.  SDKs will encounter an error if the AsyncRunner
+// does not satisfy one of these interfaces.
+type AsyncRunner interface {
+	// AnyRunner() is a non-exported method with no functional use
+	// other than to make this a non-empty interface.
+	AnyRunner()
+}
+
+// AsyncSingleRunner is an interface implemented by single-observer
+// callbacks.
+type AsyncSingleRunner interface {
+	// Run accepts a single instrument and function for capturing
+	// observations of that instrument.  Each call to the function
+	// receives one captured observation.  (The function accepts
+	// multiple observations so the same implementation can be
+	// used for batch runners.)
+	Run(ctx context.Context, single AsyncImpl, capture func([]attribute.KeyValue, ...Observation))
+
+	AsyncRunner
+}
+
+// AsyncBatchRunner is an interface implemented by batch-observer
+// callbacks.
+type AsyncBatchRunner interface {
+	// Run accepts a function for capturing observations of
+	// multiple instruments.
+	Run(ctx context.Context, capture func([]attribute.KeyValue, ...Observation))
+
+	AsyncRunner
+}
+
+var _ AsyncSingleRunner = (*Int64ObserverFunc)(nil)
+var _ AsyncSingleRunner = (*Float64ObserverFunc)(nil)
+var _ AsyncBatchRunner = (*BatchObserverFunc)(nil)
+
+// newInt64AsyncRunner returns a single-observer callback for integer Observer instruments.
+func newInt64AsyncRunner(c Int64ObserverFunc) AsyncSingleRunner {
+	return &c
+}
+
+// newFloat64AsyncRunner returns a single-observer callback for floating point Observer instruments.
+func newFloat64AsyncRunner(c Float64ObserverFunc) AsyncSingleRunner {
+	return &c
+}
+
+// newBatchAsyncRunner returns a batch-observer callback use with multiple Observer instruments.
+func newBatchAsyncRunner(c BatchObserverFunc) AsyncBatchRunner {
+	return &c
+}
+
+// AnyRunner implements AsyncRunner.
+func (*Int64ObserverFunc) AnyRunner() {}
+
+// AnyRunner implements AsyncRunner.
+func (*Float64ObserverFunc) AnyRunner() {}
+
+// AnyRunner implements AsyncRunner.
+func (*BatchObserverFunc) AnyRunner() {}
+
+// Run implements AsyncSingleRunner.
+func (i *Int64ObserverFunc) Run(ctx context.Context, impl AsyncImpl, function func([]attribute.KeyValue, ...Observation)) {
+	(*i)(ctx, Int64ObserverResult{
+		instrument: impl,
+		function:   function,
+	})
+}
+
+// Run implements AsyncSingleRunner.
+func (f *Float64ObserverFunc) Run(ctx context.Context, impl AsyncImpl, function func([]attribute.KeyValue, ...Observation)) {
+	(*f)(ctx, Float64ObserverResult{
+		instrument: impl,
+		function:   function,
+	})
+}
+
+// Run implements AsyncBatchRunner.
+func (b *BatchObserverFunc) Run(ctx context.Context, function func([]attribute.KeyValue, ...Observation)) {
+	(*b)(ctx, BatchObserverResult{
+		function: function,
+	})
+}
+
+// wrapInt64ValueObserverInstrument converts an AsyncImpl into Int64ValueObserver.
+func wrapInt64ValueObserverInstrument(asyncInst AsyncImpl, err error) (Int64ValueObserver, error) {
+	common, err := checkNewAsync(asyncInst, err)
+	return Int64ValueObserver{asyncInstrument: common}, err
+}
+
+// wrapFloat64ValueObserverInstrument converts an AsyncImpl into Float64ValueObserver.
+func wrapFloat64ValueObserverInstrument(asyncInst AsyncImpl, err error) (Float64ValueObserver, error) {
+	common, err := checkNewAsync(asyncInst, err)
+	return Float64ValueObserver{asyncInstrument: common}, err
+}
+
+// wrapInt64SumObserverInstrument converts an AsyncImpl into Int64SumObserver.
+func wrapInt64SumObserverInstrument(asyncInst AsyncImpl, err error) (Int64SumObserver, error) {
+	common, err := checkNewAsync(asyncInst, err)
+	return Int64SumObserver{asyncInstrument: common}, err
+}
+
+// wrapFloat64SumObserverInstrument converts an AsyncImpl into Float64SumObserver.
+func wrapFloat64SumObserverInstrument(asyncInst AsyncImpl, err error) (Float64SumObserver, error) {
+	common, err := checkNewAsync(asyncInst, err)
+	return Float64SumObserver{asyncInstrument: common}, err
+}
+
+// wrapInt64UpDownSumObserverInstrument converts an AsyncImpl into Int64UpDownSumObserver.
+func wrapInt64UpDownSumObserverInstrument(asyncInst AsyncImpl, err error) (Int64UpDownSumObserver, error) {
+	common, err := checkNewAsync(asyncInst, err)
+	return Int64UpDownSumObserver{asyncInstrument: common}, err
+}
+
+// wrapFloat64UpDownSumObserverInstrument converts an AsyncImpl into Float64UpDownSumObserver.
+func wrapFloat64UpDownSumObserverInstrument(asyncInst AsyncImpl, err error) (Float64UpDownSumObserver, error) {
+	common, err := checkNewAsync(asyncInst, err)
+	return Float64UpDownSumObserver{asyncInstrument: common}, err
+}
+
+// BatchObserver represents an Observer callback that can report
+// observations for multiple instruments.
+type BatchObserver struct {
+	meter  Meter
+	runner AsyncBatchRunner
+}
+
+// Int64ValueObserver is a metric that captures a set of int64 values at a
+// point in time.
+type Int64ValueObserver struct {
+	asyncInstrument
+}
+
+// Float64ValueObserver is a metric that captures a set of float64 values
+// at a point in time.
+type Float64ValueObserver struct {
+	asyncInstrument
+}
+
+// Int64SumObserver is a metric that captures a precomputed sum of
+// int64 values at a point in time.
+type Int64SumObserver struct {
+	asyncInstrument
+}
+
+// Float64SumObserver is a metric that captures a precomputed sum of
+// float64 values at a point in time.
+type Float64SumObserver struct {
+	asyncInstrument
+}
+
+// Int64UpDownSumObserver is a metric that captures a precomputed sum of
+// int64 values at a point in time.
+type Int64UpDownSumObserver struct {
+	asyncInstrument
+}
+
+// Float64UpDownSumObserver is a metric that captures a precomputed sum of
+// float64 values at a point in time.
+type Float64UpDownSumObserver struct {
+	asyncInstrument
+}
+
+// Observation returns an Observation, a BatchObserverFunc
+// argument, for an asynchronous integer instrument.
+// This returns an implementation-level object for use by the SDK,
+// users should not refer to this.
+func (i Int64ValueObserver) Observation(v int64) Observation {
+	return Observation{
+		number:     number.NewInt64Number(v),
+		instrument: i.instrument,
+	}
+}
+
+// Observation returns an Observation, a BatchObserverFunc
+// argument, for an asynchronous integer instrument.
+// This returns an implementation-level object for use by the SDK,
+// users should not refer to this.
+func (f Float64ValueObserver) Observation(v float64) Observation {
+	return Observation{
+		number:     number.NewFloat64Number(v),
+		instrument: f.instrument,
+	}
+}
+
+// Observation returns an Observation, a BatchObserverFunc
+// argument, for an asynchronous integer instrument.
+// This returns an implementation-level object for use by the SDK,
+// users should not refer to this.
+func (i Int64SumObserver) Observation(v int64) Observation {
+	return Observation{
+		number:     number.NewInt64Number(v),
+		instrument: i.instrument,
+	}
+}
+
+// Observation returns an Observation, a BatchObserverFunc
+// argument, for an asynchronous integer instrument.
+// This returns an implementation-level object for use by the SDK,
+// users should not refer to this.
+func (f Float64SumObserver) Observation(v float64) Observation {
+	return Observation{
+		number:     number.NewFloat64Number(v),
+		instrument: f.instrument,
+	}
+}
+
+// Observation returns an Observation, a BatchObserverFunc
+// argument, for an asynchronous integer instrument.
+// This returns an implementation-level object for use by the SDK,
+// users should not refer to this.
+func (i Int64UpDownSumObserver) Observation(v int64) Observation {
+	return Observation{
+		number:     number.NewInt64Number(v),
+		instrument: i.instrument,
+	}
+}
+
+// Observation returns an Observation, a BatchObserverFunc
+// argument, for an asynchronous integer instrument.
+// This returns an implementation-level object for use by the SDK,
+// users should not refer to this.
+func (f Float64UpDownSumObserver) Observation(v float64) Observation {
+	return Observation{
+		number:     number.NewFloat64Number(v),
+		instrument: f.instrument,
+	}
+}
+
+// Measurement is used for reporting a synchronous batch of metric
+// values. Instances of this type should be created by synchronous
+// instruments (e.g., Int64Counter.Measurement()).
+type Measurement struct {
+	// number needs to be aligned for 64-bit atomic operations.
+	number     number.Number
+	instrument SyncImpl
+}
+
+// syncInstrument contains a SyncImpl.
+type syncInstrument struct {
+	instrument SyncImpl
+}
+
+// syncBoundInstrument contains a BoundSyncImpl.
+type syncBoundInstrument struct {
+	boundInstrument BoundSyncImpl
+}
+
+// asyncInstrument contains a AsyncImpl.
+type asyncInstrument struct {
+	instrument AsyncImpl
+}
+
+// SyncImpl returns the instrument that created this measurement.
+// This returns an implementation-level object for use by the SDK,
+// users should not refer to this.
+func (m Measurement) SyncImpl() SyncImpl {
+	return m.instrument
+}
+
+// Number returns a number recorded in this measurement.
+func (m Measurement) Number() number.Number {
+	return m.number
+}
+
+// AsyncImpl returns the instrument that created this observation.
+// This returns an implementation-level object for use by the SDK,
+// users should not refer to this.
+func (m Observation) AsyncImpl() AsyncImpl {
+	return m.instrument
+}
+
+// Number returns a number recorded in this observation.
+func (m Observation) Number() number.Number {
+	return m.number
+}
+
+// AsyncImpl implements AsyncImpl.
+func (a asyncInstrument) AsyncImpl() AsyncImpl {
+	return a.instrument
+}
+
+// SyncImpl returns the implementation object for synchronous instruments.
+func (s syncInstrument) SyncImpl() SyncImpl {
+	return s.instrument
+}
+
+func (s syncInstrument) bind(labels []attribute.KeyValue) syncBoundInstrument {
+	return newSyncBoundInstrument(s.instrument.Bind(labels))
+}
+
+func (s syncInstrument) float64Measurement(value float64) Measurement {
+	return newMeasurement(s.instrument, number.NewFloat64Number(value))
+}
+
+func (s syncInstrument) int64Measurement(value int64) Measurement {
+	return newMeasurement(s.instrument, number.NewInt64Number(value))
+}
+
+func (s syncInstrument) directRecord(ctx context.Context, number number.Number, labels []attribute.KeyValue) {
+	s.instrument.RecordOne(ctx, number, labels)
+}
+
+func (h syncBoundInstrument) directRecord(ctx context.Context, number number.Number) {
+	h.boundInstrument.RecordOne(ctx, number)
+}
+
+// Unbind calls SyncImpl.Unbind.
+func (h syncBoundInstrument) Unbind() {
+	h.boundInstrument.Unbind()
+}
+
+// checkNewAsync receives an AsyncImpl and potential
+// error, and returns the same types, checking for and ensuring that
+// the returned interface is not nil.
+func checkNewAsync(instrument AsyncImpl, err error) (asyncInstrument, error) {
+	if instrument == nil {
+		if err == nil {
+			err = ErrSDKReturnedNilImpl
+		}
+		instrument = NoopAsync{}
+	}
+	return asyncInstrument{
+		instrument: instrument,
+	}, err
+}
+
+// checkNewSync receives an SyncImpl and potential
+// error, and returns the same types, checking for and ensuring that
+// the returned interface is not nil.
+func checkNewSync(instrument SyncImpl, err error) (syncInstrument, error) {
+	if instrument == nil {
+		if err == nil {
+			err = ErrSDKReturnedNilImpl
+		}
+		// Note: an alternate behavior would be to synthesize a new name
+		// or group all duplicately-named instruments of a certain type
+		// together and use a tag for the original name, e.g.,
+		//   name = 'invalid.counter.int64'
+		//   label = 'original-name=duplicate-counter-name'
+		instrument = NoopSync{}
+	}
+	return syncInstrument{
+		instrument: instrument,
+	}, err
+}
+
+func newSyncBoundInstrument(boundInstrument BoundSyncImpl) syncBoundInstrument {
+	return syncBoundInstrument{
+		boundInstrument: boundInstrument,
+	}
+}
+
+func newMeasurement(instrument SyncImpl, number number.Number) Measurement {
+	return Measurement{
+		instrument: instrument,
+		number:     number,
+	}
+}
+
+// wrapInt64CounterInstrument converts a SyncImpl into Int64Counter.
+func wrapInt64CounterInstrument(syncInst SyncImpl, err error) (Int64Counter, error) {
+	common, err := checkNewSync(syncInst, err)
+	return Int64Counter{syncInstrument: common}, err
+}
+
+// wrapFloat64CounterInstrument converts a SyncImpl into Float64Counter.
+func wrapFloat64CounterInstrument(syncInst SyncImpl, err error) (Float64Counter, error) {
+	common, err := checkNewSync(syncInst, err)
+	return Float64Counter{syncInstrument: common}, err
+}
+
+// wrapInt64UpDownCounterInstrument converts a SyncImpl into Int64UpDownCounter.
+func wrapInt64UpDownCounterInstrument(syncInst SyncImpl, err error) (Int64UpDownCounter, error) {
+	common, err := checkNewSync(syncInst, err)
+	return Int64UpDownCounter{syncInstrument: common}, err
+}
+
+// wrapFloat64UpDownCounterInstrument converts a SyncImpl into Float64UpDownCounter.
+func wrapFloat64UpDownCounterInstrument(syncInst SyncImpl, err error) (Float64UpDownCounter, error) {
+	common, err := checkNewSync(syncInst, err)
+	return Float64UpDownCounter{syncInstrument: common}, err
+}
+
+// wrapInt64ValueRecorderInstrument converts a SyncImpl into Int64ValueRecorder.
+func wrapInt64ValueRecorderInstrument(syncInst SyncImpl, err error) (Int64ValueRecorder, error) {
+	common, err := checkNewSync(syncInst, err)
+	return Int64ValueRecorder{syncInstrument: common}, err
+}
+
+// wrapFloat64ValueRecorderInstrument converts a SyncImpl into Float64ValueRecorder.
+func wrapFloat64ValueRecorderInstrument(syncInst SyncImpl, err error) (Float64ValueRecorder, error) {
+	common, err := checkNewSync(syncInst, err)
+	return Float64ValueRecorder{syncInstrument: common}, err
+}
+
+// Float64Counter is a metric that accumulates float64 values.
+type Float64Counter struct {
+	syncInstrument
+}
+
+// Int64Counter is a metric that accumulates int64 values.
+type Int64Counter struct {
+	syncInstrument
+}
+
+// BoundFloat64Counter is a bound instrument for Float64Counter.
+//
+// It inherits the Unbind function from syncBoundInstrument.
+type BoundFloat64Counter struct {
+	syncBoundInstrument
+}
+
+// BoundInt64Counter is a boundInstrument for Int64Counter.
+//
+// It inherits the Unbind function from syncBoundInstrument.
+type BoundInt64Counter struct {
+	syncBoundInstrument
+}
+
+// Bind creates a bound instrument for this counter. The labels are
+// associated with values recorded via subsequent calls to Record.
+func (c Float64Counter) Bind(labels ...attribute.KeyValue) (h BoundFloat64Counter) {
+	h.syncBoundInstrument = c.bind(labels)
+	return
+}
+
+// Bind creates a bound instrument for this counter. The labels are
+// associated with values recorded via subsequent calls to Record.
+func (c Int64Counter) Bind(labels ...attribute.KeyValue) (h BoundInt64Counter) {
+	h.syncBoundInstrument = c.bind(labels)
+	return
+}
+
+// Measurement creates a Measurement object to use with batch
+// recording.
+func (c Float64Counter) Measurement(value float64) Measurement {
+	return c.float64Measurement(value)
+}
+
+// Measurement creates a Measurement object to use with batch
+// recording.
+func (c Int64Counter) Measurement(value int64) Measurement {
+	return c.int64Measurement(value)
+}
+
+// Add adds the value to the counter's sum. The labels should contain
+// the keys and values to be associated with this value.
+func (c Float64Counter) Add(ctx context.Context, value float64, labels ...attribute.KeyValue) {
+	c.directRecord(ctx, number.NewFloat64Number(value), labels)
+}
+
+// Add adds the value to the counter's sum. The labels should contain
+// the keys and values to be associated with this value.
+func (c Int64Counter) Add(ctx context.Context, value int64, labels ...attribute.KeyValue) {
+	c.directRecord(ctx, number.NewInt64Number(value), labels)
+}
+
+// Add adds the value to the counter's sum using the labels
+// previously bound to this counter via Bind()
+func (b BoundFloat64Counter) Add(ctx context.Context, value float64) {
+	b.directRecord(ctx, number.NewFloat64Number(value))
+}
+
+// Add adds the value to the counter's sum using the labels
+// previously bound to this counter via Bind()
+func (b BoundInt64Counter) Add(ctx context.Context, value int64) {
+	b.directRecord(ctx, number.NewInt64Number(value))
+}
+
+// Float64UpDownCounter is a metric instrument that sums floating
+// point values.
+type Float64UpDownCounter struct {
+	syncInstrument
+}
+
+// Int64UpDownCounter is a metric instrument that sums integer values.
+type Int64UpDownCounter struct {
+	syncInstrument
+}
+
+// BoundFloat64UpDownCounter is a bound instrument for Float64UpDownCounter.
+//
+// It inherits the Unbind function from syncBoundInstrument.
+type BoundFloat64UpDownCounter struct {
+	syncBoundInstrument
+}
+
+// BoundInt64UpDownCounter is a boundInstrument for Int64UpDownCounter.
+//
+// It inherits the Unbind function from syncBoundInstrument.
+type BoundInt64UpDownCounter struct {
+	syncBoundInstrument
+}
+
+// Bind creates a bound instrument for this counter. The labels are
+// associated with values recorded via subsequent calls to Record.
+func (c Float64UpDownCounter) Bind(labels ...attribute.KeyValue) (h BoundFloat64UpDownCounter) {
+	h.syncBoundInstrument = c.bind(labels)
+	return
+}
+
+// Bind creates a bound instrument for this counter. The labels are
+// associated with values recorded via subsequent calls to Record.
+func (c Int64UpDownCounter) Bind(labels ...attribute.KeyValue) (h BoundInt64UpDownCounter) {
+	h.syncBoundInstrument = c.bind(labels)
+	return
+}
+
+// Measurement creates a Measurement object to use with batch
+// recording.
+func (c Float64UpDownCounter) Measurement(value float64) Measurement {
+	return c.float64Measurement(value)
+}
+
+// Measurement creates a Measurement object to use with batch
+// recording.
+func (c Int64UpDownCounter) Measurement(value int64) Measurement {
+	return c.int64Measurement(value)
+}
+
+// Add adds the value to the counter's sum. The labels should contain
+// the keys and values to be associated with this value.
+func (c Float64UpDownCounter) Add(ctx context.Context, value float64, labels ...attribute.KeyValue) {
+	c.directRecord(ctx, number.NewFloat64Number(value), labels)
+}
+
+// Add adds the value to the counter's sum. The labels should contain
+// the keys and values to be associated with this value.
+func (c Int64UpDownCounter) Add(ctx context.Context, value int64, labels ...attribute.KeyValue) {
+	c.directRecord(ctx, number.NewInt64Number(value), labels)
+}
+
+// Add adds the value to the counter's sum using the labels
+// previously bound to this counter via Bind()
+func (b BoundFloat64UpDownCounter) Add(ctx context.Context, value float64) {
+	b.directRecord(ctx, number.NewFloat64Number(value))
+}
+
+// Add adds the value to the counter's sum using the labels
+// previously bound to this counter via Bind()
+func (b BoundInt64UpDownCounter) Add(ctx context.Context, value int64) {
+	b.directRecord(ctx, number.NewInt64Number(value))
+}
+
+// Float64ValueRecorder is a metric that records float64 values.
+type Float64ValueRecorder struct {
+	syncInstrument
+}
+
+// Int64ValueRecorder is a metric that records int64 values.
+type Int64ValueRecorder struct {
+	syncInstrument
+}
+
+// BoundFloat64ValueRecorder is a bound instrument for Float64ValueRecorder.
+//
+// It inherits the Unbind function from syncBoundInstrument.
+type BoundFloat64ValueRecorder struct {
+	syncBoundInstrument
+}
+
+// BoundInt64ValueRecorder is a bound instrument for Int64ValueRecorder.
+//
+// It inherits the Unbind function from syncBoundInstrument.
+type BoundInt64ValueRecorder struct {
+	syncBoundInstrument
+}
+
+// Bind creates a bound instrument for this ValueRecorder. The labels are
+// associated with values recorded via subsequent calls to Record.
+func (c Float64ValueRecorder) Bind(labels ...attribute.KeyValue) (h BoundFloat64ValueRecorder) {
+	h.syncBoundInstrument = c.bind(labels)
+	return
+}
+
+// Bind creates a bound instrument for this ValueRecorder. The labels are
+// associated with values recorded via subsequent calls to Record.
+func (c Int64ValueRecorder) Bind(labels ...attribute.KeyValue) (h BoundInt64ValueRecorder) {
+	h.syncBoundInstrument = c.bind(labels)
+	return
+}
+
+// Measurement creates a Measurement object to use with batch
+// recording.
+func (c Float64ValueRecorder) Measurement(value float64) Measurement {
+	return c.float64Measurement(value)
+}
+
+// Measurement creates a Measurement object to use with batch
+// recording.
+func (c Int64ValueRecorder) Measurement(value int64) Measurement {
+	return c.int64Measurement(value)
+}
+
+// Record adds a new value to the list of ValueRecorder's records. The
+// labels should contain the keys and values to be associated with
+// this value.
+func (c Float64ValueRecorder) Record(ctx context.Context, value float64, labels ...attribute.KeyValue) {
+	c.directRecord(ctx, number.NewFloat64Number(value), labels)
+}
+
+// Record adds a new value to the ValueRecorder's distribution. The
+// labels should contain the keys and values to be associated with
+// this value.
+func (c Int64ValueRecorder) Record(ctx context.Context, value int64, labels ...attribute.KeyValue) {
+	c.directRecord(ctx, number.NewInt64Number(value), labels)
+}
+
+// Record adds a new value to the ValueRecorder's distribution using the labels
+// previously bound to the ValueRecorder via Bind().
+func (b BoundFloat64ValueRecorder) Record(ctx context.Context, value float64) {
+	b.directRecord(ctx, number.NewFloat64Number(value))
+}
+
+// Record adds a new value to the ValueRecorder's distribution using the labels
+// previously bound to the ValueRecorder via Bind().
+func (b BoundInt64ValueRecorder) Record(ctx context.Context, value int64) {
+	b.directRecord(ctx, number.NewInt64Number(value))
+}

vendor/go.opentelemetry.io/otel/metric/metric_noop.go

@@ -0,0 +1,59 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package metric // import "go.opentelemetry.io/otel/metric"
+
+import (
+	"context"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/metric/number"
+)
+
+type NoopMeterProvider struct{}
+
+type noopInstrument struct{}
+type noopBoundInstrument struct{}
+type NoopSync struct{ noopInstrument }
+type NoopAsync struct{ noopInstrument }
+
+var _ MeterProvider = NoopMeterProvider{}
+var _ SyncImpl = NoopSync{}
+var _ BoundSyncImpl = noopBoundInstrument{}
+var _ AsyncImpl = NoopAsync{}
+
+func (NoopMeterProvider) Meter(_ string, _ ...MeterOption) Meter {
+	return Meter{}
+}
+
+func (noopInstrument) Implementation() interface{} {
+	return nil
+}
+
+func (noopInstrument) Descriptor() Descriptor {
+	return Descriptor{}
+}
+
+func (noopBoundInstrument) RecordOne(context.Context, number.Number) {
+}
+
+func (noopBoundInstrument) Unbind() {
+}
+
+func (NoopSync) Bind([]attribute.KeyValue) BoundSyncImpl {
+	return noopBoundInstrument{}
+}
+
+func (NoopSync) RecordOne(context.Context, number.Number, []attribute.KeyValue) {
+}

vendor/go.opentelemetry.io/otel/metric/metric_sdkapi.go

@@ -0,0 +1,95 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package metric // import "go.opentelemetry.io/otel/metric"
+
+import (
+	"context"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/metric/number"
+)
+
+// MeterImpl is the interface an SDK must implement to supply a Meter
+// implementation.
+type MeterImpl interface {
+	// RecordBatch atomically records a batch of measurements.
+	RecordBatch(ctx context.Context, labels []attribute.KeyValue, measurement ...Measurement)
+
+	// NewSyncInstrument returns a newly constructed
+	// synchronous instrument implementation or an error, should
+	// one occur.
+	NewSyncInstrument(descriptor Descriptor) (SyncImpl, error)
+
+	// NewAsyncInstrument returns a newly constructed
+	// asynchronous instrument implementation or an error, should
+	// one occur.
+	NewAsyncInstrument(
+		descriptor Descriptor,
+		runner AsyncRunner,
+	) (AsyncImpl, error)
+}
+
+// InstrumentImpl is a common interface for synchronous and
+// asynchronous instruments.
+type InstrumentImpl interface {
+	// Implementation returns the underlying implementation of the
+	// instrument, which allows the implementation to gain access
+	// to its own representation especially from a `Measurement`.
+	Implementation() interface{}
+
+	// Descriptor returns a copy of the instrument's Descriptor.
+	Descriptor() Descriptor
+}
+
+// SyncImpl is the implementation-level interface to a generic
+// synchronous instrument (e.g., ValueRecorder and Counter instruments).
+type SyncImpl interface {
+	InstrumentImpl
+
+	// Bind creates an implementation-level bound instrument,
+	// binding a label set with this instrument implementation.
+	Bind(labels []attribute.KeyValue) BoundSyncImpl
+
+	// RecordOne captures a single synchronous metric event.
+	RecordOne(ctx context.Context, number number.Number, labels []attribute.KeyValue)
+}
+
+// BoundSyncImpl is the implementation-level interface to a
+// generic bound synchronous instrument
+type BoundSyncImpl interface {
+
+	// RecordOne captures a single synchronous metric event.
+	RecordOne(ctx context.Context, number number.Number)
+
+	// Unbind frees the resources associated with this bound instrument. It
+	// does not affect the metric this bound instrument was created through.
+	Unbind()
+}
+
+// AsyncImpl is an implementation-level interface to an
+// asynchronous instrument (e.g., Observer instruments).
+type AsyncImpl interface {
+	InstrumentImpl
+}
+
+// WrapMeterImpl constructs a `Meter` implementation from a
+// `MeterImpl` implementation.
+func WrapMeterImpl(impl MeterImpl, instrumentationName string, opts ...MeterOption) Meter {
+	return Meter{
+		impl:    impl,
+		name:    instrumentationName,
+		version: NewMeterConfig(opts...).InstrumentationVersion(),
+	}
+}

vendor/go.opentelemetry.io/otel/metric/number/doc.go

@@ -0,0 +1,23 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/*
+Package number provides a number abstraction for instruments that
+either support int64 or float64 input values.
+
+This package is currently in a pre-GA phase. Backwards incompatible changes
+may be introduced in subsequent minor version releases as we work to track the
+evolving OpenTelemetry specification and user feedback.
+*/
+package number // import "go.opentelemetry.io/otel/metric/number"

vendor/go.opentelemetry.io/otel/metric/number/kind_string.go

@@ -0,0 +1,24 @@
+// Code generated by "stringer -type=Kind"; DO NOT EDIT.
+
+package number
+
+import "strconv"
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[Int64Kind-0]
+	_ = x[Float64Kind-1]
+}
+
+const _Kind_name = "Int64KindFloat64Kind"
+
+var _Kind_index = [...]uint8{0, 9, 20}
+
+func (i Kind) String() string {
+	if i < 0 || i >= Kind(len(_Kind_index)-1) {
+		return "Kind(" + strconv.FormatInt(int64(i), 10) + ")"
+	}
+	return _Kind_name[_Kind_index[i]:_Kind_index[i+1]]
+}

vendor/go.opentelemetry.io/otel/metric/number/number.go

@@ -0,0 +1,538 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package number // import "go.opentelemetry.io/otel/metric/number"
+
+//go:generate stringer -type=Kind
+
+import (
+	"fmt"
+	"math"
+	"sync/atomic"
+
+	"go.opentelemetry.io/otel/internal"
+)
+
+// Kind describes the data type of the Number.
+type Kind int8
+
+const (
+	// Int64Kind means that the Number stores int64.
+	Int64Kind Kind = iota
+	// Float64Kind means that the Number stores float64.
+	Float64Kind
+)
+
+// Zero returns a zero value for a given Kind
+func (k Kind) Zero() Number {
+	switch k {
+	case Int64Kind:
+		return NewInt64Number(0)
+	case Float64Kind:
+		return NewFloat64Number(0.)
+	default:
+		return Number(0)
+	}
+}
+
+// Minimum returns the minimum representable value
+// for a given Kind
+func (k Kind) Minimum() Number {
+	switch k {
+	case Int64Kind:
+		return NewInt64Number(math.MinInt64)
+	case Float64Kind:
+		return NewFloat64Number(-1. * math.MaxFloat64)
+	default:
+		return Number(0)
+	}
+}
+
+// Maximum returns the maximum representable value
+// for a given Kind
+func (k Kind) Maximum() Number {
+	switch k {
+	case Int64Kind:
+		return NewInt64Number(math.MaxInt64)
+	case Float64Kind:
+		return NewFloat64Number(math.MaxFloat64)
+	default:
+		return Number(0)
+	}
+}
+
+// Number represents either an integral or a floating point value. It
+// needs to be accompanied with a source of Kind that describes
+// the actual type of the value stored within Number.
+type Number uint64
+
+// - constructors
+
+// NewNumberFromRaw creates a new Number from a raw value.
+func NewNumberFromRaw(r uint64) Number {
+	return Number(r)
+}
+
+// NewInt64Number creates an integral Number.
+func NewInt64Number(i int64) Number {
+	return NewNumberFromRaw(internal.Int64ToRaw(i))
+}
+
+// NewFloat64Number creates a floating point Number.
+func NewFloat64Number(f float64) Number {
+	return NewNumberFromRaw(internal.Float64ToRaw(f))
+}
+
+// NewNumberSignChange returns a number with the same magnitude and
+// the opposite sign.  `kind` must describe the kind of number in `nn`.
+func NewNumberSignChange(kind Kind, nn Number) Number {
+	switch kind {
+	case Int64Kind:
+		return NewInt64Number(-nn.AsInt64())
+	case Float64Kind:
+		return NewFloat64Number(-nn.AsFloat64())
+	}
+	return nn
+}
+
+// - as x
+
+// AsNumber gets the Number.
+func (n *Number) AsNumber() Number {
+	return *n
+}
+
+// AsRaw gets the uninterpreted raw value. Might be useful for some
+// atomic operations.
+func (n *Number) AsRaw() uint64 {
+	return uint64(*n)
+}
+
+// AsInt64 assumes that the value contains an int64 and returns it as
+// such.
+func (n *Number) AsInt64() int64 {
+	return internal.RawToInt64(n.AsRaw())
+}
+
+// AsFloat64 assumes that the measurement value contains a float64 and
+// returns it as such.
+func (n *Number) AsFloat64() float64 {
+	return internal.RawToFloat64(n.AsRaw())
+}
+
+// - as x atomic
+
+// AsNumberAtomic gets the Number atomically.
+func (n *Number) AsNumberAtomic() Number {
+	return NewNumberFromRaw(n.AsRawAtomic())
+}
+
+// AsRawAtomic gets the uninterpreted raw value atomically. Might be
+// useful for some atomic operations.
+func (n *Number) AsRawAtomic() uint64 {
+	return atomic.LoadUint64(n.AsRawPtr())
+}
+
+// AsInt64Atomic assumes that the number contains an int64 and returns
+// it as such atomically.
+func (n *Number) AsInt64Atomic() int64 {
+	return atomic.LoadInt64(n.AsInt64Ptr())
+}
+
+// AsFloat64Atomic assumes that the measurement value contains a
+// float64 and returns it as such atomically.
+func (n *Number) AsFloat64Atomic() float64 {
+	return internal.RawToFloat64(n.AsRawAtomic())
+}
+
+// - as x ptr
+
+// AsRawPtr gets the pointer to the raw, uninterpreted raw
+// value. Might be useful for some atomic operations.
+func (n *Number) AsRawPtr() *uint64 {
+	return (*uint64)(n)
+}
+
+// AsInt64Ptr assumes that the number contains an int64 and returns a
+// pointer to it.
+func (n *Number) AsInt64Ptr() *int64 {
+	return internal.RawPtrToInt64Ptr(n.AsRawPtr())
+}
+
+// AsFloat64Ptr assumes that the number contains a float64 and returns a
+// pointer to it.
+func (n *Number) AsFloat64Ptr() *float64 {
+	return internal.RawPtrToFloat64Ptr(n.AsRawPtr())
+}
+
+// - coerce
+
+// CoerceToInt64 casts the number to int64. May result in
+// data/precision loss.
+func (n *Number) CoerceToInt64(kind Kind) int64 {
+	switch kind {
+	case Int64Kind:
+		return n.AsInt64()
+	case Float64Kind:
+		return int64(n.AsFloat64())
+	default:
+		// you get what you deserve
+		return 0
+	}
+}
+
+// CoerceToFloat64 casts the number to float64. May result in
+// data/precision loss.
+func (n *Number) CoerceToFloat64(kind Kind) float64 {
+	switch kind {
+	case Int64Kind:
+		return float64(n.AsInt64())
+	case Float64Kind:
+		return n.AsFloat64()
+	default:
+		// you get what you deserve
+		return 0
+	}
+}
+
+// - set
+
+// SetNumber sets the number to the passed number. Both should be of
+// the same kind.
+func (n *Number) SetNumber(nn Number) {
+	*n.AsRawPtr() = nn.AsRaw()
+}
+
+// SetRaw sets the number to the passed raw value. Both number and the
+// raw number should represent the same kind.
+func (n *Number) SetRaw(r uint64) {
+	*n.AsRawPtr() = r
+}
+
+// SetInt64 assumes that the number contains an int64 and sets it to
+// the passed value.
+func (n *Number) SetInt64(i int64) {
+	*n.AsInt64Ptr() = i
+}
+
+// SetFloat64 assumes that the number contains a float64 and sets it
+// to the passed value.
+func (n *Number) SetFloat64(f float64) {
+	*n.AsFloat64Ptr() = f
+}
+
+// - set atomic
+
+// SetNumberAtomic sets the number to the passed number
+// atomically. Both should be of the same kind.
+func (n *Number) SetNumberAtomic(nn Number) {
+	atomic.StoreUint64(n.AsRawPtr(), nn.AsRaw())
+}
+
+// SetRawAtomic sets the number to the passed raw value
+// atomically. Both number and the raw number should represent the
+// same kind.
+func (n *Number) SetRawAtomic(r uint64) {
+	atomic.StoreUint64(n.AsRawPtr(), r)
+}
+
+// SetInt64Atomic assumes that the number contains an int64 and sets
+// it to the passed value atomically.
+func (n *Number) SetInt64Atomic(i int64) {
+	atomic.StoreInt64(n.AsInt64Ptr(), i)
+}
+
+// SetFloat64Atomic assumes that the number contains a float64 and
+// sets it to the passed value atomically.
+func (n *Number) SetFloat64Atomic(f float64) {
+	atomic.StoreUint64(n.AsRawPtr(), internal.Float64ToRaw(f))
+}
+
+// - swap
+
+// SwapNumber sets the number to the passed number and returns the old
+// number. Both this number and the passed number should be of the
+// same kind.
+func (n *Number) SwapNumber(nn Number) Number {
+	old := *n
+	n.SetNumber(nn)
+	return old
+}
+
+// SwapRaw sets the number to the passed raw value and returns the old
+// raw value. Both number and the raw number should represent the same
+// kind.
+func (n *Number) SwapRaw(r uint64) uint64 {
+	old := n.AsRaw()
+	n.SetRaw(r)
+	return old
+}
+
+// SwapInt64 assumes that the number contains an int64, sets it to the
+// passed value and returns the old int64 value.
+func (n *Number) SwapInt64(i int64) int64 {
+	old := n.AsInt64()
+	n.SetInt64(i)
+	return old
+}
+
+// SwapFloat64 assumes that the number contains an float64, sets it to
+// the passed value and returns the old float64 value.
+func (n *Number) SwapFloat64(f float64) float64 {
+	old := n.AsFloat64()
+	n.SetFloat64(f)
+	return old
+}
+
+// - swap atomic
+
+// SwapNumberAtomic sets the number to the passed number and returns
+// the old number atomically. Both this number and the passed number
+// should be of the same kind.
+func (n *Number) SwapNumberAtomic(nn Number) Number {
+	return NewNumberFromRaw(atomic.SwapUint64(n.AsRawPtr(), nn.AsRaw()))
+}
+
+// SwapRawAtomic sets the number to the passed raw value and returns
+// the old raw value atomically. Both number and the raw number should
+// represent the same kind.
+func (n *Number) SwapRawAtomic(r uint64) uint64 {
+	return atomic.SwapUint64(n.AsRawPtr(), r)
+}
+
+// SwapInt64Atomic assumes that the number contains an int64, sets it
+// to the passed value and returns the old int64 value atomically.
+func (n *Number) SwapInt64Atomic(i int64) int64 {
+	return atomic.SwapInt64(n.AsInt64Ptr(), i)
+}
+
+// SwapFloat64Atomic assumes that the number contains an float64, sets
+// it to the passed value and returns the old float64 value
+// atomically.
+func (n *Number) SwapFloat64Atomic(f float64) float64 {
+	return internal.RawToFloat64(atomic.SwapUint64(n.AsRawPtr(), internal.Float64ToRaw(f)))
+}
+
+// - add
+
+// AddNumber assumes that this and the passed number are of the passed
+// kind and adds the passed number to this number.
+func (n *Number) AddNumber(kind Kind, nn Number) {
+	switch kind {
+	case Int64Kind:
+		n.AddInt64(nn.AsInt64())
+	case Float64Kind:
+		n.AddFloat64(nn.AsFloat64())
+	}
+}
+
+// AddRaw assumes that this number and the passed raw value are of the
+// passed kind and adds the passed raw value to this number.
+func (n *Number) AddRaw(kind Kind, r uint64) {
+	n.AddNumber(kind, NewNumberFromRaw(r))
+}
+
+// AddInt64 assumes that the number contains an int64 and adds the
+// passed int64 to it.
+func (n *Number) AddInt64(i int64) {
+	*n.AsInt64Ptr() += i
+}
+
+// AddFloat64 assumes that the number contains a float64 and adds the
+// passed float64 to it.
+func (n *Number) AddFloat64(f float64) {
+	*n.AsFloat64Ptr() += f
+}
+
+// - add atomic
+
+// AddNumberAtomic assumes that this and the passed number are of the
+// passed kind and adds the passed number to this number atomically.
+func (n *Number) AddNumberAtomic(kind Kind, nn Number) {
+	switch kind {
+	case Int64Kind:
+		n.AddInt64Atomic(nn.AsInt64())
+	case Float64Kind:
+		n.AddFloat64Atomic(nn.AsFloat64())
+	}
+}
+
+// AddRawAtomic assumes that this number and the passed raw value are
+// of the passed kind and adds the passed raw value to this number
+// atomically.
+func (n *Number) AddRawAtomic(kind Kind, r uint64) {
+	n.AddNumberAtomic(kind, NewNumberFromRaw(r))
+}
+
+// AddInt64Atomic assumes that the number contains an int64 and adds
+// the passed int64 to it atomically.
+func (n *Number) AddInt64Atomic(i int64) {
+	atomic.AddInt64(n.AsInt64Ptr(), i)
+}
+
+// AddFloat64Atomic assumes that the number contains a float64 and
+// adds the passed float64 to it atomically.
+func (n *Number) AddFloat64Atomic(f float64) {
+	for {
+		o := n.AsFloat64Atomic()
+		if n.CompareAndSwapFloat64(o, o+f) {
+			break
+		}
+	}
+}
+
+// - compare and swap (atomic only)
+
+// CompareAndSwapNumber does the atomic CAS operation on this
+// number. This number and passed old and new numbers should be of the
+// same kind.
+func (n *Number) CompareAndSwapNumber(on, nn Number) bool {
+	return atomic.CompareAndSwapUint64(n.AsRawPtr(), on.AsRaw(), nn.AsRaw())
+}
+
+// CompareAndSwapRaw does the atomic CAS operation on this
+// number. This number and passed old and new raw values should be of
+// the same kind.
+func (n *Number) CompareAndSwapRaw(or, nr uint64) bool {
+	return atomic.CompareAndSwapUint64(n.AsRawPtr(), or, nr)
+}
+
+// CompareAndSwapInt64 assumes that this number contains an int64 and
+// does the atomic CAS operation on it.
+func (n *Number) CompareAndSwapInt64(oi, ni int64) bool {
+	return atomic.CompareAndSwapInt64(n.AsInt64Ptr(), oi, ni)
+}
+
+// CompareAndSwapFloat64 assumes that this number contains a float64 and
+// does the atomic CAS operation on it.
+func (n *Number) CompareAndSwapFloat64(of, nf float64) bool {
+	return atomic.CompareAndSwapUint64(n.AsRawPtr(), internal.Float64ToRaw(of), internal.Float64ToRaw(nf))
+}
+
+// - compare
+
+// CompareNumber compares two Numbers given their kind.  Both numbers
+// should have the same kind.  This returns:
+//    0 if the numbers are equal
+//    -1 if the subject `n` is less than the argument `nn`
+//    +1 if the subject `n` is greater than the argument `nn`
+func (n *Number) CompareNumber(kind Kind, nn Number) int {
+	switch kind {
+	case Int64Kind:
+		return n.CompareInt64(nn.AsInt64())
+	case Float64Kind:
+		return n.CompareFloat64(nn.AsFloat64())
+	default:
+		// you get what you deserve
+		return 0
+	}
+}
+
+// CompareRaw compares two numbers, where one is input as a raw
+// uint64, interpreting both values as a `kind` of number.
+func (n *Number) CompareRaw(kind Kind, r uint64) int {
+	return n.CompareNumber(kind, NewNumberFromRaw(r))
+}
+
+// CompareInt64 assumes that the Number contains an int64 and performs
+// a comparison between the value and the other value. It returns the
+// typical result of the compare function: -1 if the value is less
+// than the other, 0 if both are equal, 1 if the value is greater than
+// the other.
+func (n *Number) CompareInt64(i int64) int {
+	this := n.AsInt64()
+	if this < i {
+		return -1
+	} else if this > i {
+		return 1
+	}
+	return 0
+}
+
+// CompareFloat64 assumes that the Number contains a float64 and
+// performs a comparison between the value and the other value. It
+// returns the typical result of the compare function: -1 if the value
+// is less than the other, 0 if both are equal, 1 if the value is
+// greater than the other.
+//
+// Do not compare NaN values.
+func (n *Number) CompareFloat64(f float64) int {
+	this := n.AsFloat64()
+	if this < f {
+		return -1
+	} else if this > f {
+		return 1
+	}
+	return 0
+}
+
+// - relations to zero
+
+// IsPositive returns true if the actual value is greater than zero.
+func (n *Number) IsPositive(kind Kind) bool {
+	return n.compareWithZero(kind) > 0
+}
+
+// IsNegative returns true if the actual value is less than zero.
+func (n *Number) IsNegative(kind Kind) bool {
+	return n.compareWithZero(kind) < 0
+}
+
+// IsZero returns true if the actual value is equal to zero.
+func (n *Number) IsZero(kind Kind) bool {
+	return n.compareWithZero(kind) == 0
+}
+
+// - misc
+
+// Emit returns a string representation of the raw value of the
+// Number. A %d is used for integral values, %f for floating point
+// values.
+func (n *Number) Emit(kind Kind) string {
+	switch kind {
+	case Int64Kind:
+		return fmt.Sprintf("%d", n.AsInt64())
+	case Float64Kind:
+		return fmt.Sprintf("%f", n.AsFloat64())
+	default:
+		return ""
+	}
+}
+
+// AsInterface returns the number as an interface{}, typically used
+// for Kind-correct JSON conversion.
+func (n *Number) AsInterface(kind Kind) interface{} {
+	switch kind {
+	case Int64Kind:
+		return n.AsInt64()
+	case Float64Kind:
+		return n.AsFloat64()
+	default:
+		return math.NaN()
+	}
+}
+
+// - private stuff
+
+func (n *Number) compareWithZero(kind Kind) int {
+	switch kind {
+	case Int64Kind:
+		return n.CompareInt64(0)
+	case Float64Kind:
+		return n.CompareFloat64(0.)
+	default:
+		// you get what you deserve
+		return 0
+	}
+}

vendor/go.opentelemetry.io/otel/metric/registry/doc.go

@@ -0,0 +1,24 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/*
+Package registry provides a non-standalone implementation of
+MeterProvider that adds uniqueness checking for instrument descriptors
+on top of other MeterProvider it wraps.
+
+This package is currently in a pre-GA phase. Backwards incompatible changes
+may be introduced in subsequent minor version releases as we work to track the
+evolving OpenTelemetry specification and user feedback.
+*/
+package registry // import "go.opentelemetry.io/otel/metric/registry"

vendor/go.opentelemetry.io/otel/metric/registry/registry.go

@@ -0,0 +1,170 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package registry // import "go.opentelemetry.io/otel/metric/registry"
+
+import (
+	"context"
+	"fmt"
+	"sync"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/metric"
+)
+
+// MeterProvider is a standard MeterProvider for wrapping `MeterImpl`
+type MeterProvider struct {
+	impl metric.MeterImpl
+}
+
+var _ metric.MeterProvider = (*MeterProvider)(nil)
+
+// uniqueInstrumentMeterImpl implements the metric.MeterImpl interface, adding
+// uniqueness checking for instrument descriptors.  Use NewUniqueInstrumentMeter
+// to wrap an implementation with uniqueness checking.
+type uniqueInstrumentMeterImpl struct {
+	lock  sync.Mutex
+	impl  metric.MeterImpl
+	state map[key]metric.InstrumentImpl
+}
+
+var _ metric.MeterImpl = (*uniqueInstrumentMeterImpl)(nil)
+
+type key struct {
+	instrumentName         string
+	instrumentationName    string
+	InstrumentationVersion string
+}
+
+// NewMeterProvider returns a new provider that implements instrument
+// name-uniqueness checking.
+func NewMeterProvider(impl metric.MeterImpl) *MeterProvider {
+	return &MeterProvider{
+		impl: NewUniqueInstrumentMeterImpl(impl),
+	}
+}
+
+// Meter implements MeterProvider.
+func (p *MeterProvider) Meter(instrumentationName string, opts ...metric.MeterOption) metric.Meter {
+	return metric.WrapMeterImpl(p.impl, instrumentationName, opts...)
+}
+
+// ErrMetricKindMismatch is the standard error for mismatched metric
+// instrument definitions.
+var ErrMetricKindMismatch = fmt.Errorf(
+	"a metric was already registered by this name with another kind or number type")
+
+// NewUniqueInstrumentMeterImpl returns a wrapped metric.MeterImpl with
+// the addition of uniqueness checking.
+func NewUniqueInstrumentMeterImpl(impl metric.MeterImpl) metric.MeterImpl {
+	return &uniqueInstrumentMeterImpl{
+		impl:  impl,
+		state: map[key]metric.InstrumentImpl{},
+	}
+}
+
+// RecordBatch implements metric.MeterImpl.
+func (u *uniqueInstrumentMeterImpl) RecordBatch(ctx context.Context, labels []attribute.KeyValue, ms ...metric.Measurement) {
+	u.impl.RecordBatch(ctx, labels, ms...)
+}
+
+func keyOf(descriptor metric.Descriptor) key {
+	return key{
+		descriptor.Name(),
+		descriptor.InstrumentationName(),
+		descriptor.InstrumentationVersion(),
+	}
+}
+
+// NewMetricKindMismatchError formats an error that describes a
+// mismatched metric instrument definition.
+func NewMetricKindMismatchError(desc metric.Descriptor) error {
+	return fmt.Errorf("metric was %s (%s %s)registered as a %s %s: %w",
+		desc.Name(),
+		desc.InstrumentationName(),
+		desc.InstrumentationVersion(),
+		desc.NumberKind(),
+		desc.InstrumentKind(),
+		ErrMetricKindMismatch)
+}
+
+// Compatible determines whether two metric.Descriptors are considered
+// the same for the purpose of uniqueness checking.
+func Compatible(candidate, existing metric.Descriptor) bool {
+	return candidate.InstrumentKind() == existing.InstrumentKind() &&
+		candidate.NumberKind() == existing.NumberKind()
+}
+
+// checkUniqueness returns an ErrMetricKindMismatch error if there is
+// a conflict between a descriptor that was already registered and the
+// `descriptor` argument.  If there is an existing compatible
+// registration, this returns the already-registered instrument.  If
+// there is no conflict and no prior registration, returns (nil, nil).
+func (u *uniqueInstrumentMeterImpl) checkUniqueness(descriptor metric.Descriptor) (metric.InstrumentImpl, error) {
+	impl, ok := u.state[keyOf(descriptor)]
+	if !ok {
+		return nil, nil
+	}
+
+	if !Compatible(descriptor, impl.Descriptor()) {
+		return nil, NewMetricKindMismatchError(impl.Descriptor())
+	}
+
+	return impl, nil
+}
+
+// NewSyncInstrument implements metric.MeterImpl.
+func (u *uniqueInstrumentMeterImpl) NewSyncInstrument(descriptor metric.Descriptor) (metric.SyncImpl, error) {
+	u.lock.Lock()
+	defer u.lock.Unlock()
+
+	impl, err := u.checkUniqueness(descriptor)
+
+	if err != nil {
+		return nil, err
+	} else if impl != nil {
+		return impl.(metric.SyncImpl), nil
+	}
+
+	syncInst, err := u.impl.NewSyncInstrument(descriptor)
+	if err != nil {
+		return nil, err
+	}
+	u.state[keyOf(descriptor)] = syncInst
+	return syncInst, nil
+}
+
+// NewAsyncInstrument implements metric.MeterImpl.
+func (u *uniqueInstrumentMeterImpl) NewAsyncInstrument(
+	descriptor metric.Descriptor,
+	runner metric.AsyncRunner,
+) (metric.AsyncImpl, error) {
+	u.lock.Lock()
+	defer u.lock.Unlock()
+
+	impl, err := u.checkUniqueness(descriptor)
+
+	if err != nil {
+		return nil, err
+	} else if impl != nil {
+		return impl.(metric.AsyncImpl), nil
+	}
+
+	asyncInst, err := u.impl.NewAsyncInstrument(descriptor, runner)
+	if err != nil {
+		return nil, err
+	}
+	u.state[keyOf(descriptor)] = asyncInst
+	return asyncInst, nil
+}

vendor/go.opentelemetry.io/otel/metric/unit/doc.go

@@ -0,0 +1,20 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package unit provides units.
+//
+// This package is currently in a pre-GA phase. Backwards incompatible changes
+// may be introduced in subsequent minor version releases as we work to track
+// the evolving OpenTelemetry specification and user feedback.
+package unit // import "go.opentelemetry.io/otel/metric/unit"

vendor/go.opentelemetry.io/otel/metric/unit/unit.go

@@ -0,0 +1,24 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package unit // import "go.opentelemetry.io/otel/metric/unit"
+
+type Unit string
+
+// Units defined by OpenTelemetry.
+const (
+	Dimensionless Unit = "1"
+	Bytes         Unit = "By"
+	Milliseconds  Unit = "ms"
+)

vendor/modules.txt

@@ -239,6 +239,8 @@ github.com/docker/go-events
 github.com/docker/go-metrics
 # github.com/docker/go-units v0.4.0
 github.com/docker/go-units
+# github.com/felixge/httpsnoop v1.0.2
+github.com/felixge/httpsnoop
 # github.com/gofrs/flock v0.7.3
 github.com/gofrs/flock
 # github.com/gogo/googleapis v1.4.0
@@ -385,8 +387,12 @@ go.opencensus.io/trace/internal
 go.opencensus.io/trace/tracestate
 # go.opentelemetry.io/contrib v0.21.0
 go.opentelemetry.io/contrib
-# go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.21.0
+# go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.21.0 => github.com/tonistiigi/opentelemetry-go-contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.0.0-20210714055410-d010b05b4939
 go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc
+# go.opentelemetry.io/contrib/instrumentation/net/http/httptrace/otelhttptrace v0.21.0 => github.com/tonistiigi/opentelemetry-go-contrib/instrumentation/net/http/httptrace/otelhttptrace v0.0.0-20210714055410-d010b05b4939
+go.opentelemetry.io/contrib/instrumentation/net/http/httptrace/otelhttptrace
+# go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.21.0 => github.com/tonistiigi/opentelemetry-go-contrib/instrumentation/net/http/otelhttp v0.0.0-20210714055410-d010b05b4939
+go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp
 # go.opentelemetry.io/otel v1.0.0-RC1
 go.opentelemetry.io/otel
 go.opentelemetry.io/otel/attribute
@@ -412,6 +418,14 @@ go.opentelemetry.io/otel/exporters/otlp/otlptrace/internal/tracetransform
 go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc
 # go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.0.0-RC1
 go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp
+# go.opentelemetry.io/otel/internal/metric v0.21.0
+go.opentelemetry.io/otel/internal/metric/global
+# go.opentelemetry.io/otel/metric v0.21.0
+go.opentelemetry.io/otel/metric
+go.opentelemetry.io/otel/metric/global
+go.opentelemetry.io/otel/metric/number
+go.opentelemetry.io/otel/metric/registry
+go.opentelemetry.io/otel/metric/unit
 # go.opentelemetry.io/otel/sdk v1.0.0-RC1
 go.opentelemetry.io/otel/sdk/instrumentation
 go.opentelemetry.io/otel/sdk/internal