buildkit/util/contentutil/fetcher_test.go

106 lines
2.3 KiB
Go

package contentutil
import (
"bytes"
"context"
"io"
"testing"
"time"
"github.com/containerd/containerd/content"
digest "github.com/opencontainers/go-digest"
ocispec "github.com/opencontainers/image-spec/specs-go/v1"
"github.com/stretchr/testify/require"
)
func TestFetcher(t *testing.T) {
t.Parallel()
ctx := context.TODO()
b0 := NewBuffer()
err := content.WriteBlob(ctx, b0, "foo", bytes.NewBuffer([]byte("foobar")), ocispec.Descriptor{Size: -1})
require.NoError(t, err)
f := &localFetcher{b0}
p := FromFetcher(f)
b1 := NewBuffer()
err = Copy(ctx, b1, p, ocispec.Descriptor{Digest: digest.FromBytes([]byte("foobar")), Size: -1})
require.NoError(t, err)
dt, err := content.ReadBlob(ctx, b1, ocispec.Descriptor{Digest: digest.FromBytes([]byte("foobar"))})
require.NoError(t, err)
require.Equal(t, string(dt), "foobar")
rdr, err := p.ReaderAt(ctx, ocispec.Descriptor{Digest: digest.FromBytes([]byte("foobar"))})
require.NoError(t, err)
buf := make([]byte, 3)
n, err := rdr.ReadAt(buf, 1)
require.NoError(t, err)
require.Equal(t, "oob", string(buf[:n]))
n, err = rdr.ReadAt(buf, 5)
require.Error(t, err)
require.Equal(t, err, io.EOF)
require.Equal(t, "r", string(buf[:n]))
}
func TestSlowFetch(t *testing.T) {
t.Parallel()
ctx := context.TODO()
f := &dummySlowFetcher{}
p := FromFetcher(f)
rdr, err := p.ReaderAt(ctx, ocispec.Descriptor{Digest: digest.FromBytes([]byte("foobar"))})
require.NoError(t, err)
buf := make([]byte, 3)
n, err := rdr.ReadAt(buf, 1)
require.NoError(t, err)
require.Equal(t, "oob", string(buf[:n]))
n, err = rdr.ReadAt(buf, 5)
require.Error(t, err)
require.Equal(t, err, io.EOF)
require.Equal(t, "r", string(buf[:n]))
}
type dummySlowFetcher struct{}
func (f *dummySlowFetcher) Fetch(ctx context.Context, desc ocispec.Descriptor) (io.ReadCloser, error) {
return newSlowBuffer([]byte("foobar")), nil
}
func newSlowBuffer(dt []byte) io.ReadCloser {
return &slowBuffer{dt: dt}
}
type slowBuffer struct {
dt []byte
off int
}
func (sb *slowBuffer) Seek(offset int64, _ int) (int64, error) {
sb.off = int(offset)
return offset, nil
}
func (sb *slowBuffer) Read(b []byte) (int, error) {
time.Sleep(5 * time.Millisecond)
if sb.off >= len(sb.dt) {
return 0, io.EOF
}
b[0] = sb.dt[sb.off]
sb.off++
return 1, nil
}
func (sb *slowBuffer) Close() error {
return nil
}