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Merge pull request #151 from benbjohnson/remove-c 

Remove the c package
master
Ben Johnson 2014-05-05 07:44:54 -06:00
parent 84570ee67e 376ce6858a
commit f860b35c4e
3 changed files with 0 additions and 732 deletions
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381
c/cursor.go
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@ -1,381 +0,0 @@
package c
/*
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <inttypes.h>
//------------------------------------------------------------------------------
// Constants
//------------------------------------------------------------------------------
// This represents the maximum number of levels that a cursor can traverse.
#define MAX_DEPTH 64
// These flags mark the type of page and are set in the page.flags.
#define PAGE_BRANCH 0x01
#define PAGE_LEAF 0x02
#define PAGE_META 0x04
#define PAGE_FREELIST 0x10
//------------------------------------------------------------------------------
// Typedefs
//------------------------------------------------------------------------------
// These types MUST have the same layout as their corresponding Go types
typedef int64_t pgid;
// Page represents a header struct of a block in the mmap.
typedef struct page {
pgid id;
uint16_t flags;
uint16_t count;
uint32_t overflow;
} page;
// The branch element represents an a item in a branch page
// that points to a child page.
typedef struct branch_element {
uint32_t pos;
uint32_t ksize;
pgid pgid;
} branch_element;
// The leaf element represents an a item in a leaf page
// that points to a key/value pair.
typedef struct leaf_element {
uint32_t flags;
uint32_t pos;
uint32_t ksize;
uint32_t vsize;
} leaf_element;
// elem_ref represents a pointer to an element inside of a page.
// It is used by the cursor stack to track the position at each level.
typedef struct elem_ref {
page *page;
uint16_t index;
} elem_ref;
// bolt_val represents a pointer to a fixed-length series of bytes.
// It is used to represent keys and values returned by the cursor.
typedef struct bolt_val {
uint32_t size;
void *data;
} bolt_val;
// bolt_cursor represents a cursor attached to a bucket.
typedef struct bolt_cursor {
void *data;
pgid root;
size_t pgsz;
int top;
elem_ref stack[MAX_DEPTH];
} bolt_cursor;
//------------------------------------------------------------------------------
// Forward Declarations
//------------------------------------------------------------------------------
elem_ref *cursor_push(bolt_cursor *c, pgid id);
elem_ref *cursor_current(bolt_cursor *c);
elem_ref *cursor_pop(bolt_cursor *c);
void cursor_key_value(bolt_cursor *c, bolt_val *key, bolt_val *value, uint32_t *flags);
void cursor_search(bolt_cursor *c, bolt_val key, pgid id);
void cursor_search_branch(bolt_cursor *c, bolt_val key);
void cursor_search_leaf(bolt_cursor *c, bolt_val key);
//------------------------------------------------------------------------------
// Public Functions
//------------------------------------------------------------------------------
// Initializes a cursor.
void bolt_cursor_init(bolt_cursor *c, void *data, size_t pgsz, pgid root) {
c->data = data;
c->root = root;
c->pgsz = pgsz;
c->top = -1;
}
// Positions the cursor to the first leaf element and returns the key/value pair.
void bolt_cursor_first(bolt_cursor *c, bolt_val *key, bolt_val *value, uint32_t *flags) {
// reset stack to initial state
elem_ref *ref = cursor_push(c, c->root);
// Find first leaf and return key/value.
cursor_key_value(c, key, value, flags);
}
// Positions the cursor to the next leaf element and returns the key/value pair.
void bolt_cursor_next(bolt_cursor *c, bolt_val *key, bolt_val *value, uint32_t *flags) {
int i;
elem_ref *ref;
// Attempt to move over one element until we're successful.
// Move up the stack as we hit the end of each page in our stack.
for (ref = cursor_current(c); ref != NULL; ref = cursor_current(c)) {
ref->index++;
if (ref->index < ref->page->count) break;
cursor_pop(c);
};
// Find first leaf and return key/value.
cursor_key_value(c, key, value, flags);
}
// Positions the cursor first leaf element starting from a given key.
// If there is a matching key then the cursor will be place on that key.
// If there not a match then the cursor will be placed on the next key, if available.
void bolt_cursor_seek(bolt_cursor *c, bolt_val seek, bolt_val *key, bolt_val *value, uint32_t *flags) {
// Start from root page/node and traverse to correct page.
cursor_push(c, c->root);
if (seek.size > 0) cursor_search(c, seek, c->root);
// Find first leaf and return key/value.
cursor_key_value(c, key, value, flags);
}
//------------------------------------------------------------------------------
// Private Functions
//------------------------------------------------------------------------------
// Push ref to the first element of the page onto the cursor stack
// If the page is the root page reset the stack to initial state
elem_ref *cursor_push(bolt_cursor *c, pgid id) {
elem_ref *ref;
if (id == c->root)
c->top = 0;
else
c->top++;
ref = &(c->stack[c->top]);
ref->page = (page *)(c->data + (c->pgsz * id));
ref->index = 0;
return ref;
}
// Return current element ref from the cursor stack
// If stack is empty return null
elem_ref *cursor_current(bolt_cursor *c) {
if (c->top < 0) return NULL;
return &c->stack[c->top];
}
// Pop current element ref off the cursor stack
// If stack is empty return null
elem_ref *cursor_pop(bolt_cursor *c) {
elem_ref *ref = cursor_current(c);
if (ref != NULL) c->top--;
return ref;
}
// Returns the branch element at a given index on a given page.
branch_element *page_branch_element(page *p, uint16_t index) {
branch_element *elements = (branch_element*)((void*)(p) + sizeof(page));
return &elements[index];
}
// Returns the leaf element at a given index on a given page.
leaf_element *page_leaf_element(page *p, uint16_t index) {
leaf_element *elements = (leaf_element*)((void*)(p) + sizeof(page));
return &elements[index];
}
// Returns the key/value pair for the current position of the cursor.
void cursor_key_value(bolt_cursor *c, bolt_val *key, bolt_val *value, uint32_t *flags) {
elem_ref *ref = cursor_current(c);
// If stack or current page is empty return null.
if (ref == NULL || ref->page->count == 0) {
key->size = value->size = 0;
key->data = value->data = NULL;
*flags = 0;
return;
};
// Descend to the current leaf page if we're on branch page.
while (ref->page->flags & PAGE_BRANCH) {
branch_element *elem = page_branch_element(ref->page,ref->index);
ref = cursor_push(c, elem->pgid);
};
leaf_element *elem = page_leaf_element(ref->page,ref->index);
// Assign key pointer.
key->size = elem->ksize;
key->data = ((void*)elem) + elem->pos;
// Assign value pointer.
value->size = elem->vsize;
value->data = key->data + key->size;
// Return the element flags.
*flags = elem->flags;
}
// Recursively performs a binary search against a given page/node until it finds a given key.
void cursor_search(bolt_cursor *c, bolt_val key, pgid id) {
// Push page onto the cursor stack.
elem_ref *ref = cursor_push(c, id);
// int len = key.size > 10 ? 10 : key.size;
// printf("\npage=%d, depth=%d, seek=...%.*s[%d]", (int)id, c->top, len, ((char*)(key.data)) + key.size - len, key.size);
// If we're on a leaf page/node then find the specific node.
if (ref->page->flags & PAGE_LEAF) {
cursor_search_leaf(c, key);
return;
}
// Otherwise search the branch page.
cursor_search_branch(c, key);
}
// Recursively search over a leaf page for a key.
void cursor_search_leaf(bolt_cursor *c, bolt_val key) {
elem_ref *ref = cursor_current(c);
int i;
// HACK: Simply loop over elements to find the right one. Replace with a binary search.
leaf_element *elems = (leaf_element*)((void*)(ref->page) + sizeof(page));
for (i=0; i<ref->page->count; i++) {
leaf_element *elem = &elems[i];
int rc = memcmp(key.data, ((void*)elem) + elem->pos, (elem->ksize < key.size ? elem->ksize : key.size));
// int len = key.size > 10 ? 10 : key.size;
// printf("\n?L rc=%d; elem=...%.*s[%d]", rc, len, ((char*)elem) + elem->pos + elem->ksize - len, elem->ksize);
if ((rc == 0 && key.size <= elem->ksize) || rc < 0) {
ref->index = i;
return;
}
}
// If nothing was greater than the key then pop the current page off the stack.
cursor_pop(c);
}
// Recursively search over a branch page for a key.
void cursor_search_branch(bolt_cursor *c, bolt_val key) {
elem_ref *ref = cursor_current(c);
int i;
// HACK: Simply loop over elements to find the right one. Replace with a binary search.
branch_element *elems = (branch_element*)((void*)(ref->page) + sizeof(page));
for (i=0; i<ref->page->count; i++) {
branch_element *elem = &elems[i];
int rc = memcmp(key.data, ((void*)elem) + elem->pos, (elem->ksize < key.size ? elem->ksize : key.size));
// int len = key.size > 10 ? 10 : key.size;
// printf("\n?B rc=%d; elem=...%.*s[%d]", rc, len, ((char*)elem) + elem->pos + elem->ksize - len, elem->ksize);
if (rc == 0 && key.size == elem->ksize) {
// Exact match, done.
ref->index = i;
return;
} else if ((rc == 0 && key.size < elem->ksize) || rc < 0) {
// If key is less than anything in this subtree we are done.
// This should really only happen for key that's less than anything in the tree.
if (i == 0) return;
// Otherwise search the previous subtree.
cursor_search(c, key, elems[i-1].pgid);
// Didn't find anything greater than key?
if (cursor_current(c) == ref)
ref->index = i;
else
ref->index = i-1;
return;
}
}
// If nothing was greater than the key then search the last child.
cursor_search(c, key, elems[ref->page->count-1].pgid);
// If still didn't find anything greater than key, then pop the page off the stack.
if (cursor_current(c) == ref)
cursor_pop(c);
else
ref->index = ref->page->count-1;
}
*/
import "C"
import (
"fmt"
"os"
"unsafe"
"github.com/boltdb/bolt"
)
// Cursor represents a wrapper around a Bolt C cursor.
type Cursor struct {
C *C.bolt_cursor
}
// NewCursor creates a C cursor from a Bucket.
func NewCursor(b *bolt.Bucket) *Cursor {
info := b.Tx().DB().Info()
root := b.Root()
c := &Cursor{C: new(C.bolt_cursor)}
C.bolt_cursor_init(c.C, unsafe.Pointer(&info.Data[0]), C.size_t(info.PageSize), C.pgid(root))
return c
}
// Next moves the cursor to the first element and returns the key and value.
// Returns a nil key if there are no elements.
func (c *Cursor) First() (key, value []byte) {
var k, v C.bolt_val
var flags C.uint32_t
C.bolt_cursor_first(c.C, &k, &v, &flags)
if k.data == nil {
return nil, nil
}
return C.GoBytes(k.data, C.int(k.size)), C.GoBytes(v.data, C.int(v.size))
}
// Next moves the cursor to the next element and returns the key and value.
// Returns a nil key if there are no more key/value pairs.
func (c *Cursor) Next() (key, value []byte) {
var k, v C.bolt_val
var flags C.uint32_t
C.bolt_cursor_next(c.C, &k, &v, &flags)
if k.data == nil {
return nil, nil
}
return C.GoBytes(k.data, C.int(k.size)), C.GoBytes(v.data, C.int(v.size))
}
// Seek moves the cursor to a given key and returns it.
// If the key does not exist then the next key is used. If no keys
// follow, an empty value is returned.
func (c *Cursor) Seek(seek []byte) (key, value []byte, flags int) {
var _flags C.uint32_t
var _seek, k, v C.bolt_val
if len(seek) > 0 {
_seek.size = C.uint32_t(len(seek))
_seek.data = unsafe.Pointer(&seek[0])
}
C.bolt_cursor_seek(c.C, _seek, &k, &v, &_flags)
if k.data == nil {
return nil, nil, 0
}
return C.GoBytes(k.data, C.int(k.size)), C.GoBytes(v.data, C.int(v.size)), int(_flags)
}
func warn(v ...interface{}) {
fmt.Fprintln(os.Stderr, v...)
}
func warnf(msg string, v ...interface{}) {
fmt.Fprintf(os.Stderr, msg+"\n", v...)
}

347
c/cursor_test.go
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@ -1,347 +0,0 @@
package c_test
import (
"fmt"
"io/ioutil"
"os"
"testing"
"github.com/boltdb/bolt"
. "github.com/boltdb/bolt/c"
"github.com/stretchr/testify/assert"
)
// Ensure that the C cursor can seek to first element.
func TestCursor_First(t *testing.T) {
withDB(func(db *bolt.DB) {
db.Update(func(tx *bolt.Tx) error {
b, _ := tx.CreateBucket([]byte("widgets"))
return b.Put([]byte("foo"), []byte("barz"))
})
db.View(func(tx *bolt.Tx) error {
c := NewCursor(tx.Bucket([]byte("widgets")))
key, value := c.First()
assert.Equal(t, []byte("foo"), key)
assert.Equal(t, []byte("barz"), value)
return nil
})
})
}
// Ensure that a C cursor handles empty bucket properly
func TestCursor_Empty(t *testing.T) {
withDB(func(db *bolt.DB) {
db.Update(func(tx *bolt.Tx) error {
tx.CreateBucket([]byte("widgets"))
return nil
})
db.View(func(tx *bolt.Tx) error {
c := NewCursor(tx.Bucket([]byte("widgets")))
key, value := c.First()
assert.Nil(t, key)
assert.Nil(t, value)
key, value = c.Next()
assert.Nil(t, key)
assert.Nil(t, value)
key, value, flags := c.Seek([]byte("bar"))
assert.Nil(t, key)
assert.Nil(t, value)
assert.Equal(t, 0, flags)
return nil
})
})
}
// Ensure that a C cursor can seek to the appropriate keys.
func TestCursor_Seek(t *testing.T) {
withDB(func(db *bolt.DB) {
db.Update(func(tx *bolt.Tx) error {
b, err := tx.CreateBucket([]byte("widgets"))
assert.NoError(t, err)
assert.NoError(t, b.Put([]byte("foo"), []byte("0001")))
assert.NoError(t, b.Put([]byte("bar"), []byte("0002")))
assert.NoError(t, b.Put([]byte("baz"), []byte("0003")))
_, err = b.CreateBucket([]byte("bkt"))
assert.NoError(t, err)
return nil
})
db.View(func(tx *bolt.Tx) error {
c := NewCursor(tx.Bucket([]byte("widgets")))
// Exact match should go to the key.
k, v, flags := c.Seek([]byte("bar"))
assert.Equal(t, "bar", string(k))
assert.Equal(t, "0002", string(v))
assert.Equal(t, 0, flags)
// Inexact match should go to the next key.
k, v, flags = c.Seek([]byte("bas"))
assert.Equal(t, "baz", string(k))
assert.Equal(t, "0003", string(v))
assert.Equal(t, 0, flags)
// Inexact match with smaller db key should go to the next key.
k, v, flags = c.Seek([]byte("barrrr"))
assert.Equal(t, "baz", string(k))
assert.Equal(t, "0003", string(v))
assert.Equal(t, 0, flags)
// Inexact match with smaller seek key should go to the next key.
k, v, flags = c.Seek([]byte("ba"))
assert.Equal(t, "bar", string(k))
assert.Equal(t, "0002", string(v))
assert.Equal(t, 0, flags)
// Low key should go to the first key.
k, v, flags = c.Seek([]byte(""))
assert.Equal(t, "bar", string(k))
assert.Equal(t, "0002", string(v))
assert.Equal(t, 0, flags)
// High key should return no key.
k, v, flags = c.Seek([]byte("zzz"))
assert.Equal(t, "", string(k))
assert.Equal(t, "", string(v))
assert.Equal(t, 0, flags)
// Buckets should return their key but no value.
k, v, flags = c.Seek([]byte("bkt"))
assert.Equal(t, []byte("bkt"), k)
assert.True(t, len(v) > 0)
assert.Equal(t, 1, flags) // bucketLeafFlag
return nil
})
})
}
// Ensure that a C cursor can iterate over a single root with a couple elements.
func TestCursor_Iterate_Leaf(t *testing.T) {
withDB(func(db *bolt.DB) {
db.Update(func(tx *bolt.Tx) error {
tx.CreateBucket([]byte("widgets"))
tx.Bucket([]byte("widgets")).Put([]byte("baz"), []byte{})
tx.Bucket([]byte("widgets")).Put([]byte("foo"), []byte{0})
tx.Bucket([]byte("widgets")).Put([]byte("bar"), []byte{1})
return nil
})
db.View(func(tx *bolt.Tx) error {
c := NewCursor(tx.Bucket([]byte("widgets")))
k, v := c.First()
assert.Equal(t, string(k), "bar")
assert.Equal(t, []byte{1}, v)
k, v = c.Next()
assert.Equal(t, string(k), "baz")
assert.Equal(t, []byte{}, v)
k, v = c.Next()
assert.Equal(t, string(k), "foo")
assert.Equal(t, []byte{0}, v)
k, v = c.Next()
assert.Equal(t, []byte{}, k)
assert.Equal(t, []byte{}, v)
k, v = c.Next()
assert.Equal(t, []byte{}, k)
assert.Equal(t, []byte{}, v)
return nil
})
})
}
// Ensure that a C cursor can iterate over branches and leafs.
func TestCursor_Iterate_Large(t *testing.T) {
withDB(func(db *bolt.DB) {
db.Update(func(tx *bolt.Tx) error {
b, _ := tx.CreateBucket([]byte("widgets"))
for i := 0; i < 1000; i++ {
b.Put([]byte(fmt.Sprintf("%05d", i)), []byte(fmt.Sprintf("%020d", i)))
}
return nil
})
db.View(func(tx *bolt.Tx) error {
var index int
c := NewCursor(tx.Bucket([]byte("widgets")))
for k, v := c.First(); len(k) > 0; k, v = c.Next() {
assert.Equal(t, fmt.Sprintf("%05d", index), string(k))
assert.Equal(t, fmt.Sprintf("%020d", index), string(v))
index++
}
assert.Equal(t, 1000, index)
return nil
})
})
}
// Ensure that a C cursor can iterate over branches and leafs.
func TestCursor_Iterate_Deep(t *testing.T) {
withDB(func(db *bolt.DB) {
pgsz := db.Info().PageSize / 10
assert.True(t, pgsz > 100)
db.Update(func(tx *bolt.Tx) error {
b, _ := tx.CreateBucket([]byte("widgets"))
for i := 0; i < 1000; i++ {
kv := []byte(fmt.Sprintf("%0*d", pgsz, i))
b.Put(kv, kv)
}
return nil
})
db.View(func(tx *bolt.Tx) error {
b := tx.Bucket([]byte("widgets"))
s := b.Stats()
assert.True(t, s.Depth > 3)
var index int
c := NewCursor(b)
for k, v := c.First(); len(k) > 0; k, v = c.Next() {
kv := fmt.Sprintf("%0*d", pgsz, index)
assert.Equal(t, kv, string(k))
assert.Equal(t, kv, string(v))
index++
}
assert.Equal(t, 1000, index)
k, _ := c.Next()
assert.Nil(t, k)
return nil
})
})
}
// Ensure that a C cursor can seek over branches and leafs.
func TestCursor_Seek_Large(t *testing.T) {
withDB(func(db *bolt.DB) {
db.Update(func(tx *bolt.Tx) error {
b, _ := tx.CreateBucket([]byte("widgets"))
for i := 1; i < 1000; i++ {
b.Put([]byte(fmt.Sprintf("%05d\000", i*10)), []byte(fmt.Sprintf("%020d", i*10)))
}
return nil
})
db.View(func(tx *bolt.Tx) error {
c := NewCursor(tx.Bucket([]byte("widgets")))
// Exact match should go to the key.
k, v, _ := c.Seek([]byte("05000\000"))
assert.Equal(t, "05000\000", string(k))
assert.Equal(t, fmt.Sprintf("%020d", 5000), string(v))
// Inexact match should go to the next key.
k, v, _ = c.Seek([]byte("07495\000"))
assert.Equal(t, "07500\000", string(k))
assert.Equal(t, fmt.Sprintf("%020d", 7500), string(v))
// Low key should go to the first key.
k, v, _ = c.Seek([]byte("00000\000"))
assert.Equal(t, "00010\000", string(k))
assert.Equal(t, fmt.Sprintf("%020d", 10), string(v))
// High key should return no key.
k, v, _ = c.Seek([]byte("40000\000"))
assert.Equal(t, "", string(k))
assert.Equal(t, "", string(v))
return nil
})
})
}
// Ensure that a C cursor can seek over branches and leafs.
func TestCursor_Seek_Deep(t *testing.T) {
withDB(func(db *bolt.DB) {
pgsz := db.Info().PageSize / 10
assert.True(t, pgsz > 100)
db.Update(func(tx *bolt.Tx) error {
b, _ := tx.CreateBucket([]byte("widgets"))
for i := 1; i < 1000; i++ {
kv := []byte(fmt.Sprintf("%0*d", pgsz, i*10))
b.Put(kv, kv)
}
return nil
})
db.View(func(tx *bolt.Tx) error {
b := tx.Bucket([]byte("widgets"))
s := b.Stats()
assert.True(t, s.Depth > 3)
c := NewCursor(b)
// Exact match should go to the key.
seek := fmt.Sprintf("%0*d", pgsz, 5000)
k, v, _ := c.Seek([]byte(seek))
assert.Equal(t, seek, string(k))
assert.Equal(t, seek, string(v))
// Inexact match should go to the next key.
seek = fmt.Sprintf("%0*d", pgsz, 7495)
found := fmt.Sprintf("%0*d", pgsz, 7500)
k, v, _ = c.Seek([]byte(seek))
assert.Equal(t, found, string(k))
assert.Equal(t, found, string(v))
// Low key should go to the first key.
seek = fmt.Sprintf("%0*d", pgsz, 0)
found = fmt.Sprintf("%0*d", pgsz, 10)
k, v, _ = c.Seek([]byte(seek))
assert.Equal(t, found, string(k))
assert.Equal(t, found, string(v))
// High key should return no key.
seek = fmt.Sprintf("%0*d", pgsz, 40000)
k, v, _ = c.Seek([]byte(seek))
assert.Equal(t, "", string(k))
assert.Equal(t, "", string(v))
// Exact match in the middle of a branch page.
seek = fmt.Sprintf("%0*d", pgsz, 4170)
k, v, _ = c.Seek([]byte(seek))
assert.Equal(t, seek, string(k))
assert.Equal(t, seek, string(v))
return nil
})
})
}
// tempfile returns a temporary path.
func tempfile() string {
f, _ := ioutil.TempFile("", "bolt-c-")
f.Close()
os.Remove(f.Name())
return f.Name()
}
// withDB executes a function with an already opened database.
func withDB(fn func(*bolt.DB)) {
path := tempfile()
db, err := bolt.Open(path, 0666)
if err != nil {
panic("cannot open db: " + err.Error())
}
defer os.Remove(path)
defer db.Close()
fn(db)
// Check database consistency after every test.
mustCheck(db)
}
// mustCheck runs a consistency check on the database and panics if any errors are found.
func mustCheck(db *bolt.DB) {
if err := db.Check(); err != nil {
// Copy db off first.
var path = tempfile()
db.CopyFile(path, 0600)
if errors, ok := err.(bolt.ErrorList); ok {
for _, err := range errors {
fmt.Println(err)
}
}
fmt.Println(err)
panic("check failure: " + path)
}
}

4
c/doc.go
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@ -1,4 +0,0 @@
/*
Package c provides a C interface to Bolt.
*/
package c