GOMODULES
/
bbolt
mirror of https://github.com/etcd-io/bbolt.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Intermediate commit.

pull/34/head
Ben Johnson 2014-01-21 14:37:55 -07:00
parent 153372abd4
commit bce3e667df
9 changed files with 505 additions and 559 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

34
README.md
View File

@ -1,4 +1,38 @@
bolt
====
## Overview
A low-level key/value database for Go.
## API
### DB
### Creating a database
```
db := DB()
err := db.Open("/path/to/db", 0666)
...
err := db.Close()
```
### Creating a bucket
* Cursor
```
DB
Bucket
Transaction / RWTransaction
Cursor / RWCursor
page
meta
branchNode
leafNode
```

79
branch_node.go
View File

@ -10,86 +10,7 @@ const (
dupNode = 0x04
)
// branchNode represents a node on a branch page.
type branchNode struct {
pgno uint32
flags uint16
keySize uint16
data uintptr // Pointer to the beginning of the data.
}
// key returns a byte slice that of the key data.
func (n *branchNode) key() []byte {
return (*[MaxKeySize]byte)(unsafe.Pointer(&n.data))[:n.keySize]
}
func (n *branchNode) size() int {
return 0 // TODO: offsetof(MDB_node, mn_data)
}
// TODO: #define INDXSIZE(k) (NODESIZE + ((k) == NULL ? 0 : (k)->mv_size))
// TODO: #define LEAFSIZE(k, d) (NODESIZE + (k)->mv_size + (d)->mv_size)
// TODO: #define NODEPTR(p, i) ((MDB_node *)((char *)(p) + (p)->mp_ptrs[i]))
// TODO: #define NODEKEY(node) (void *)((node)->mn_data)
// TODO: #define NODEDATA(node) (void *)((char *)(node)->mn_data + (node)->mn_ksize)
// TODO: #define NODEPGNO(node) ((node)->mn_lo | ((pgno_t) (node)->mn_hi << 16) | (PGNO_TOPWORD ? ((pgno_t) (node)->mn_flags << PGNO_TOPWORD) : 0))
// TODO: #define SETPGNO(node,pgno) do { (node)->mn_lo = (pgno) & 0xffff; (node)->mn_hi = (pgno) >> 16; if (PGNO_TOPWORD) (node)->mn_flags = (pgno) >> PGNO_TOPWORD; } while(0)
// TODO: #define NODEDSZ(node) ((node)->mn_lo | ((unsigned)(node)->mn_hi << 16))
// TODO: #define SETDSZ(node,size) do { (node)->mn_lo = (size) & 0xffff; (node)->mn_hi = (size) >> 16;} while(0)
// TODO: #define NODEKSZ(node) ((node)->mn_ksize)
// TODO: #define LEAF2KEY(p, i, ks) ((char *)(p) + PAGEHDRSZ + ((i)*(ks)))
// TODO: #define MDB_GET_KEY(node, keyptr) { if ((keyptr) != NULL) { (keyptr)->mv_size = NODEKSZ(node); (keyptr)->mv_data = NODEKEY(node); } }
// TODO: #define MDB_GET_KEY2(node, key) { key.mv_size = NODEKSZ(node); key.mv_data = NODEKEY(node); }
// Compact the main page after deleting a node on a subpage.
// @param[in] mp The main page to operate on.
// @param[in] indx The index of the subpage on the main page.
func (n *node) shrink(index int) {
/*
MDB_node *node;
MDB_page *sp, *xp;
char *base;
int nsize, delta;
indx_t i, numkeys, ptr;
node = NODEPTR(mp, indx);
sp = (MDB_page *)NODEDATA(node);
delta = SIZELEFT(sp);
xp = (MDB_page *)((char *)sp + delta);
// shift subpage upward
if (IS_LEAF2(sp)) {
nsize = NUMKEYS(sp) * sp->mp_pad;
if (nsize & 1)
return; // do not make the node uneven-sized
memmove(METADATA(xp), METADATA(sp), nsize);
} else {
int i;
numkeys = NUMKEYS(sp);
for (i=numkeys-1; i>=0; i--)
xp->mp_ptrs[i] = sp->mp_ptrs[i] - delta;
}
xp->mp_upper = sp->mp_lower;
xp->mp_lower = sp->mp_lower;
xp->mp_flags = sp->mp_flags;
xp->mp_pad = sp->mp_pad;
COPY_PGNO(xp->mp_pgno, mp->mp_pgno);
nsize = NODEDSZ(node) - delta;
SETDSZ(node, nsize);
// shift lower nodes upward
ptr = mp->mp_ptrs[indx];
numkeys = NUMKEYS(mp);
for (i = 0; i < numkeys; i++) {
if (mp->mp_ptrs[i] <= ptr)
mp->mp_ptrs[i] += delta;
}
base = (char *)mp + mp->mp_upper;
memmove(base + delta, base, ptr - mp->mp_upper + NODESIZE + NODEKSZ(node));
mp->mp_upper += delta;
*/
}

1
bucket.go
View File

@ -29,4 +29,3 @@ type bucket struct {
entries uint64
root pgno
}

48
cursor.go
View File

@ -5,31 +5,19 @@ package bolt
const (
c_initialized = 0x01 /**< cursor has been initialized and is valid */
c_eof = 0x02 /**< No more data */
c_sub = 0x04 /**< Cursor is a sub-cursor */
c_del = 0x08 /**< last op was a cursor_del */
c_splitting = 0x20 /**< Cursor is in page_split */
c_untrack = 0x40 /**< Un-track cursor when closing */
)
// TODO: #define MDB_NOSPILL 0x8000 /** Do not spill pages to disk if txn is getting full, may fail instead */
/*
type Cursor interface {
First() error
FirstDup() error
Get() ([]byte, []byte, error)
GetRange() ([]byte, []byte, error)
Current() ([]byte, []byte, error)
Last()
LastDup()
Last() error
Next() ([]byte, []byte, error)
NextDup() ([]byte, []byte, error)
NextNoDup() ([]byte, []byte, error)
Prev() ([]byte, []byte, error)
PrevDup() ([]byte, []byte, error)
PrevNoDup() ([]byte, []byte, error)
Set() ([]byte, []byte, error)
SetRange() ([]byte, []byte, error)
Current() ([]byte, []byte, error)
Get([]byte) ([]byte, error)
}
*/
@ -37,13 +25,11 @@ type Cursor struct {
flags int
next *Cursor
backup *Cursor
subcursor *Cursor
transaction *Transaction
bucket *Bucket
subbucket *Bucket
top int
pages []*page
indices []int /* the index of the node for the page at the same level */
indices []int /* the index of the node for the page at the same level */
}
// , data []byte, op int
@ -53,12 +39,6 @@ func (c *Cursor) Get(key []byte) ([]byte, error) {
int exact = 0;
int (*mfunc)(MDB_cursor *mc, MDB_val *key, MDB_val *data);
if (mc == NULL)
return EINVAL;
if (mc->mc_txn->mt_flags & MDB_TXN_ERROR)
return MDB_BAD_TXN;
switch (op) {
case MDB_GET_CURRENT:
if (!(mc->mc_flags & C_INITIALIZED)) {
@ -222,14 +202,14 @@ func (c *Cursor) page(key []byte, flags int) (*page, error) {
if (flags & ps_first) != 0 {
index = 0
} else if (flags & ps_last) != 0 {
index = indx(p.numkeys()) - 1;
index = indx(p.numkeys()) - 1
} else {
node, i, exact := p.find(key, c.transaction.db.pageSize);
node, i, exact := p.find(key, c.transaction.db.pageSize)
if exact {
c.indices[c.top] = i
}
if node == nil {
index = indx(p.numkeys()) - 1;
index = indx(p.numkeys()) - 1
} else {
index = indx(c.indices[c.top])
if !exact {
@ -255,7 +235,7 @@ func (c *Cursor) page(key []byte, flags int) (*page, error) {
}
// If we ended up with a non-leaf page by the end then something is wrong.
if p.flags & p_leaf == 0 {
if p.flags&p_leaf == 0 {
return nil, CorruptedError
}
@ -267,7 +247,7 @@ func (c *Cursor) page(key []byte, flags int) (*page, error) {
// pop moves the last page off the cursor's page stack.
func (c *Cursor) pop() {
top := len(c.pages)-1
top := len(c.pages) - 1
c.pages = c.pages[0:c.top]
c.indices = c.indices[0:c.top]
}
@ -279,8 +259,8 @@ func (c *Cursor) push(p *page) {
c.top = len(c.pages) - 1
}
// page retrieves the last page on the page stack.
func (c *Cursor) page() *page {
// currentPage retrieves the last page on the page stack.
func (c *Cursor) currentPage() *page {
top := len(c.pages)
if top > 0 {
return c.pages[top]
@ -306,7 +286,6 @@ func (c *Cursor) currentLeafNode() *node {
return nil
}
// //
// //
// //
@ -642,9 +621,6 @@ func (c *Cursor) page_touch() int {
return 0
}
// Search for the lowest key under the current branch page.
// This just bypasses a NUMKEYS check in the current page
// before calling mdb_page_search_root(), because the callers
@ -1262,7 +1238,7 @@ func (c *Cursor) touch() error {
}
return rc;
}
*/
*/
return nil
}

10
db.go
View File

@ -46,11 +46,11 @@ type DB struct {
size int /**< current file size */
pbuf []byte
transaction *RWTransaction /**< current write transaction */
maxPageNumber int /**< me_mapsize / me_psize */
dpages []*page /**< list of malloc'd blocks for re-use */
freePages []int /** IDL of pages that became unused in a write txn */
dirtyPages []int /** ID2L of pages written during a write txn. Length MDB_IDL_UM_SIZE. */
maxFreeOnePage int /** Max number of freelist items that can fit in a single overflow page */
maxPageNumber int /**< me_mapsize / me_psize */
dpages []*page /**< list of malloc'd blocks for re-use */
freePages []int /** IDL of pages that became unused in a write txn */
dirtyPages []int /** ID2L of pages written during a write txn. Length MDB_IDL_UM_SIZE. */
maxFreeOnePage int /** Max number of freelist items that can fit in a single overflow page */
maxPageDataSize int
maxNodeSize int /** Max size of a node on a page */
maxKeySize int /**< max size of a key */

16
leaf_node.go → node.go
View File

@ -4,14 +4,26 @@ import (
"unsafe"
)
// node represents a node on a page.
type node struct {
flags uint16
keySize uint16
}
// leafNode represents a node on a leaf page.
type leafNode struct {
flags uint16
keySize uint16
node
dataSize uint32
data uintptr // Pointer to the beginning of the data.
}
// branchNode represents a node on a branch page.
type branchNode struct {
node
pgno uint32
data uintptr // Pointer to the beginning of the data.
}
// key returns a byte slice that of the key data.
func (n *leafNode) key() []byte {
return (*[MaxKeySize]byte)(unsafe.Pointer(&n.data))[:n.keySize]

13
page.go
View File

@ -20,8 +20,7 @@ const (
p_leaf = 0x02
p_overflow = 0x04
p_meta = 0x08
p_dirty = 0x10 /**< dirty page, also set for #P_SUBP pages */
p_sub = 0x40
p_dirty = 0x10 /**< dirty page, also set for #P_SUBP pages */
p_keep = 0x8000 /**< leave this page alone during spill */
p_invalid = ^pgno(0)
@ -91,13 +90,13 @@ func (p *page) init(pageSize int) {
// branchNode retrieves the branch node at the given index within the page.
func (p *page) branchNode(index indx) *branchNode {
b := (*[maxPageSize]byte)(unsafe.Pointer(&p.ptr))
return (*branchNode)(unsafe.Pointer(&b[index * indx(unsafe.Sizeof(index))]))
return (*branchNode)(unsafe.Pointer(&b[index*indx(unsafe.Sizeof(index))]))
}
// leafNode retrieves the leaf node at the given index within the page.
func (p *page) leafNode(index indx) *leafNode {
b := (*[maxPageSize]byte)(unsafe.Pointer(&p.ptr))
return (*leafNode)(unsafe.Pointer(&b[index * indx(unsafe.Sizeof(index))]))
return (*leafNode)(unsafe.Pointer(&b[index*indx(unsafe.Sizeof(index))]))
}
// numkeys returns the number of nodes in the page.
@ -117,20 +116,20 @@ func (p *page) find(key []byte, pageSize int) (*node, int, bool) {
var node *node
nkeys := p.numkeys()
low, high := 1, nkeys - 1
low, high := 1, nkeys-1
if (p.flags & p_leaf) != 0 {
low = 0
}
// Perform a binary search to find the correct node.
var i, rc int
for ; low <= high; {
for low <= high {
i = (low + high) / 2
node = p.node(indx(i))
rc = bytes.Compare(key, node.key())
if rc == 0 {
break;
break
} else if rc > 0 {
low = i + 1
} else {

861
rwcursor.go
View File

@ -1,11 +1,18 @@
package bolt
/*
type RWCursor interface {
Put([]byte, []byte) (error)
Delete([]byte) (error)
}
*/
// RWCursor represents a cursor that can read and write data for a bucket.
type RWCursor struct {
Cursor
transaction *RWTransaction
reclaimed []pgno /**< Reclaimed freeDB pages, or NULL before use (was me_pghead) */
last txnid /**< ID of last used record, or 0 if len(reclaimed) == 0 */
reclaimed []pgno /**< Reclaimed freeDB pages, or NULL before use (was me_pghead) */
last txnid /**< ID of last used record, or 0 if len(reclaimed) == 0 */
}
func (c *RWCursor) Put(key []byte, value []byte) error {
@ -61,339 +68,339 @@ func (c *RWCursor) Put(key []byte, value []byte) error {
// If key does not exist the
if exists {
node := c.currentNode()
}
/*
insert = rc;
if (insert) {
// The key does not exist
DPRINTF(("inserting key at index %i", mc->mc_ki[mc->mc_top]));
if ((mc->mc_db->md_flags & MDB_DUPSORT) &&
LEAFSIZE(key, data) > env->me_nodemax)
{
// Too big for a node, insert in sub-DB
fp_flags = P_LEAF|P_DIRTY;
fp = env->me_pbuf;
fp->mp_pad = data->mv_size; // used if MDB_DUPFIXED
fp->mp_lower = fp->mp_upper = olddata.mv_size = PAGEHDRSZ;
goto prep_subDB;
}
} else {
more:
leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
olddata.mv_size = NODEDSZ(leaf);
olddata.mv_data = NODEDATA(leaf);
// DB has dups?
if (F_ISSET(mc->mc_db->md_flags, MDB_DUPSORT)) {
// Prepare (sub-)page/sub-DB to accept the new item,
// if needed. fp: old sub-page or a header faking
// it. mp: new (sub-)page. offset: growth in page
// size. xdata: node data with new page or DB.
ssize_t i, offset = 0;
mp = fp = xdata.mv_data = env->me_pbuf;
mp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno;
// Was a single item before, must convert now
if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
// Just overwrite the current item
if (flags == MDB_CURRENT)
goto current;
#if UINT_MAX < SIZE_MAX
if (mc->mc_dbx->md_dcmp == mdb_cmp_int && olddata.mv_size == sizeof(size_t))
#ifdef MISALIGNED_OK
mc->mc_dbx->md_dcmp = mdb_cmp_long;
#else
mc->mc_dbx->md_dcmp = mdb_cmp_cint;
#endif
#endif
// if data matches, skip it
if (!mc->mc_dbx->md_dcmp(data, &olddata)) {
if (flags & MDB_NODUPDATA)
rc = MDB_KEYEXIST;
else if (flags & MDB_MULTIPLE)
goto next_mult;
else
rc = MDB_SUCCESS;
return rc;
}
// Back up original data item
dkey.mv_size = olddata.mv_size;
dkey.mv_data = memcpy(fp+1, olddata.mv_data, olddata.mv_size);
// Make sub-page header for the dup items, with dummy body
fp->mp_flags = P_LEAF|P_DIRTY|P_SUBP;
fp->mp_lower = PAGEHDRSZ;
xdata.mv_size = PAGEHDRSZ + dkey.mv_size + data->mv_size;
if (mc->mc_db->md_flags & MDB_DUPFIXED) {
fp->mp_flags |= P_LEAF2;
fp->mp_pad = data->mv_size;
xdata.mv_size += 2 * data->mv_size; // leave space for 2 more
} else {
xdata.mv_size += 2 * (sizeof(indx_t) + NODESIZE) +
(dkey.mv_size & 1) + (data->mv_size & 1);
}
fp->mp_upper = xdata.mv_size;
olddata.mv_size = fp->mp_upper; // pretend olddata is fp
} else if (leaf->mn_flags & F_SUBDATA) {
// Data is on sub-DB, just store it
flags |= F_DUPDATA|F_SUBDATA;
goto put_sub;
} else {
// Data is on sub-page
fp = olddata.mv_data;
switch (flags) {
default:
i = -(ssize_t)SIZELEFT(fp);
if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
offset = i += (ssize_t) EVEN(
sizeof(indx_t) + NODESIZE + data->mv_size);
} else {
i += offset = fp->mp_pad;
offset *= 4; // space for 4 more
}
if (i > 0)
break;
// FALLTHRU: Sub-page is big enough
case MDB_CURRENT:
fp->mp_flags |= P_DIRTY;
COPY_PGNO(fp->mp_pgno, mp->mp_pgno);
mc->mc_xcursor->mx_cursor.mc_pg[0] = fp;
flags |= F_DUPDATA;
goto put_sub;
}
xdata.mv_size = olddata.mv_size + offset;
insert = rc;
if (insert) {
// The key does not exist
DPRINTF(("inserting key at index %i", mc->mc_ki[mc->mc_top]));
if ((mc->mc_db->md_flags & MDB_DUPSORT) &&
LEAFSIZE(key, data) > env->me_nodemax)
{
// Too big for a node, insert in sub-DB
fp_flags = P_LEAF|P_DIRTY;
fp = env->me_pbuf;
fp->mp_pad = data->mv_size; // used if MDB_DUPFIXED
fp->mp_lower = fp->mp_upper = olddata.mv_size = PAGEHDRSZ;
goto prep_subDB;
}
} else {
fp_flags = fp->mp_flags;
if (NODESIZE + NODEKSZ(leaf) + xdata.mv_size > env->me_nodemax) {
// Too big for a sub-page, convert to sub-DB
fp_flags &= ~P_SUBP;
prep_subDB:
dummy.md_pad = 0;
dummy.md_flags = 0;
dummy.md_depth = 1;
dummy.md_branch_pages = 0;
dummy.md_leaf_pages = 1;
dummy.md_overflow_pages = 0;
dummy.md_entries = NUMKEYS(fp);
xdata.mv_size = sizeof(MDB_db);
xdata.mv_data = &dummy;
if ((rc = mdb_page_alloc(mc, 1, &mp)))
return rc;
offset = env->me_psize - olddata.mv_size;
flags |= F_DUPDATA|F_SUBDATA;
dummy.md_root = mp->mp_pgno;
}
if (mp != fp) {
mp->mp_flags = fp_flags | P_DIRTY;
mp->mp_pad = fp->mp_pad;
mp->mp_lower = fp->mp_lower;
mp->mp_upper = fp->mp_upper + offset;
if (fp_flags & P_LEAF2) {
memcpy(METADATA(mp), METADATA(fp), NUMKEYS(fp) * fp->mp_pad);
} else {
memcpy((char *)mp + mp->mp_upper, (char *)fp + fp->mp_upper,
olddata.mv_size - fp->mp_upper);
for (i = NUMKEYS(fp); --i >= 0; )
mp->mp_ptrs[i] = fp->mp_ptrs[i] + offset;
}
}
rdata = &xdata;
flags |= F_DUPDATA;
do_sub = 1;
if (!insert)
mdb_node_del(mc, 0);
goto new_sub;
}
current:
// overflow page overwrites need special handling
if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
MDB_page *omp;
pgno_t pg;
int level, ovpages, dpages = OVPAGES(data->mv_size, env->me_psize);
memcpy(&pg, olddata.mv_data, sizeof(pg));
if ((rc2 = mdb_page_get(mc->mc_txn, pg, &omp, &level)) != 0)
return rc2;
ovpages = omp->mp_pages;
// Is the ov page large enough?
if (ovpages >= dpages) {
if (!(omp->mp_flags & P_DIRTY) &&
(level || (env->me_flags & MDB_WRITEMAP)))
{
rc = mdb_page_unspill(mc->mc_txn, omp, &omp);
if (rc)
return rc;
level = 0; // dirty in this txn or clean
}
// Is it dirty?
if (omp->mp_flags & P_DIRTY) {
// yes, overwrite it. Note in this case we don't
// bother to try shrinking the page if the new data
// is smaller than the overflow threshold.
if (level > 1) {
// It is writable only in a parent txn
size_t sz = (size_t) env->me_psize * ovpages, off;
MDB_page *np = mdb_page_malloc(mc->mc_txn, ovpages);
MDB_ID2 id2;
if (!np)
return ENOMEM;
id2.mid = pg;
id2.mptr = np;
rc = mdb_mid2l_insert(mc->mc_txn->mt_u.dirty_list, &id2);
mdb_cassert(mc, rc == 0);
if (!(flags & MDB_RESERVE)) {
// Copy end of page, adjusting alignment so
// compiler may copy words instead of bytes.
off = (PAGEHDRSZ + data->mv_size) & -sizeof(size_t);
memcpy((size_t *)((char *)np + off),
(size_t *)((char *)omp + off), sz - off);
sz = PAGEHDRSZ;
}
memcpy(np, omp, sz); // Copy beginning of page
omp = np;
}
SETDSZ(leaf, data->mv_size);
if (F_ISSET(flags, MDB_RESERVE))
data->mv_data = METADATA(omp);
else
memcpy(METADATA(omp), data->mv_data, data->mv_size);
goto done;
}
}
if ((rc2 = mdb_ovpage_free(mc, omp)) != MDB_SUCCESS)
return rc2;
} else if (data->mv_size == olddata.mv_size) {
// same size, just replace it. Note that we could
// also reuse this node if the new data is smaller,
// but instead we opt to shrink the node in that case.
if (F_ISSET(flags, MDB_RESERVE))
data->mv_data = olddata.mv_data;
else if (data->mv_size)
memcpy(olddata.mv_data, data->mv_data, data->mv_size);
else
memcpy(NODEKEY(leaf), key->mv_data, key->mv_size);
goto done;
}
mdb_node_del(mc, 0);
mc->mc_db->md_entries--;
}
rdata = data;
new_sub:
nflags = flags & NODE_ADD_FLAGS;
nsize = IS_LEAF2(mc->mc_pg[mc->mc_top]) ? key->mv_size : mdb_leaf_size(env, key, rdata);
if (SIZELEFT(mc->mc_pg[mc->mc_top]) < nsize) {
if (( flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA )
nflags &= ~MDB_APPEND;
if (!insert)
nflags |= MDB_SPLIT_REPLACE;
rc = mdb_page_split(mc, key, rdata, P_INVALID, nflags);
} else {
// There is room already in this leaf page.
rc = mdb_node_add(mc, mc->mc_ki[mc->mc_top], key, rdata, 0, nflags);
if (rc == 0 && !do_sub && insert) {
// Adjust other cursors pointing to mp
MDB_cursor *m2, *m3;
MDB_dbi dbi = mc->mc_dbi;
unsigned i = mc->mc_top;
MDB_page *mp = mc->mc_pg[i];
for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
if (mc->mc_flags & C_SUB)
m3 = &m2->mc_xcursor->mx_cursor;
else
m3 = m2;
if (m3 == mc || m3->mc_snum < mc->mc_snum) continue;
if (m3->mc_pg[i] == mp && m3->mc_ki[i] >= mc->mc_ki[i]) {
m3->mc_ki[i]++;
}
}
}
}
if (rc != MDB_SUCCESS)
mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
else {
// Now store the actual data in the child DB. Note that we're
// storing the user data in the keys field, so there are strict
// size limits on dupdata. The actual data fields of the child
// DB are all zero size.
if (do_sub) {
int xflags;
put_sub:
xdata.mv_size = 0;
xdata.mv_data = "";
more:
leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
if (flags & MDB_CURRENT) {
xflags = MDB_CURRENT|MDB_NOSPILL;
} else {
mdb_xcursor_init1(mc, leaf);
xflags = (flags & MDB_NODUPDATA) ?
MDB_NOOVERWRITE|MDB_NOSPILL : MDB_NOSPILL;
}
// converted, write the original data first
if (dkey.mv_size) {
rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, &dkey, &xdata, xflags);
if (rc)
return rc;
{
// Adjust other cursors pointing to mp
MDB_cursor *m2;
unsigned i = mc->mc_top;
MDB_page *mp = mc->mc_pg[i];
olddata.mv_size = NODEDSZ(leaf);
olddata.mv_data = NODEDATA(leaf);
for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
if (!(m2->mc_flags & C_INITIALIZED)) continue;
if (m2->mc_pg[i] == mp && m2->mc_ki[i] == mc->mc_ki[i]) {
mdb_xcursor_init1(m2, leaf);
// DB has dups?
if (F_ISSET(mc->mc_db->md_flags, MDB_DUPSORT)) {
// Prepare (sub-)page/sub-DB to accept the new item,
// if needed. fp: old sub-page or a header faking
// it. mp: new (sub-)page. offset: growth in page
// size. xdata: node data with new page or DB.
ssize_t i, offset = 0;
mp = fp = xdata.mv_data = env->me_pbuf;
mp->mp_pgno = mc->mc_pg[mc->mc_top]->mp_pgno;
// Was a single item before, must convert now
if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
// Just overwrite the current item
if (flags == MDB_CURRENT)
goto current;
#if UINT_MAX < SIZE_MAX
if (mc->mc_dbx->md_dcmp == mdb_cmp_int && olddata.mv_size == sizeof(size_t))
#ifdef MISALIGNED_OK
mc->mc_dbx->md_dcmp = mdb_cmp_long;
#else
mc->mc_dbx->md_dcmp = mdb_cmp_cint;
#endif
#endif
// if data matches, skip it
if (!mc->mc_dbx->md_dcmp(data, &olddata)) {
if (flags & MDB_NODUPDATA)
rc = MDB_KEYEXIST;
else if (flags & MDB_MULTIPLE)
goto next_mult;
else
rc = MDB_SUCCESS;
return rc;
}
// Back up original data item
dkey.mv_size = olddata.mv_size;
dkey.mv_data = memcpy(fp+1, olddata.mv_data, olddata.mv_size);
// Make sub-page header for the dup items, with dummy body
fp->mp_flags = P_LEAF|P_DIRTY|P_SUBP;
fp->mp_lower = PAGEHDRSZ;
xdata.mv_size = PAGEHDRSZ + dkey.mv_size + data->mv_size;
if (mc->mc_db->md_flags & MDB_DUPFIXED) {
fp->mp_flags |= P_LEAF2;
fp->mp_pad = data->mv_size;
xdata.mv_size += 2 * data->mv_size; // leave space for 2 more
} else {
xdata.mv_size += 2 * (sizeof(indx_t) + NODESIZE) +
(dkey.mv_size & 1) + (data->mv_size & 1);
}
fp->mp_upper = xdata.mv_size;
olddata.mv_size = fp->mp_upper; // pretend olddata is fp
} else if (leaf->mn_flags & F_SUBDATA) {
// Data is on sub-DB, just store it
flags |= F_DUPDATA|F_SUBDATA;
goto put_sub;
} else {
// Data is on sub-page
fp = olddata.mv_data;
switch (flags) {
default:
i = -(ssize_t)SIZELEFT(fp);
if (!(mc->mc_db->md_flags & MDB_DUPFIXED)) {
offset = i += (ssize_t) EVEN(
sizeof(indx_t) + NODESIZE + data->mv_size);
} else {
i += offset = fp->mp_pad;
offset *= 4; // space for 4 more
}
if (i > 0)
break;
// FALLTHRU: Sub-page is big enough
case MDB_CURRENT:
fp->mp_flags |= P_DIRTY;
COPY_PGNO(fp->mp_pgno, mp->mp_pgno);
mc->mc_xcursor->mx_cursor.mc_pg[0] = fp;
flags |= F_DUPDATA;
goto put_sub;
}
xdata.mv_size = olddata.mv_size + offset;
}
fp_flags = fp->mp_flags;
if (NODESIZE + NODEKSZ(leaf) + xdata.mv_size > env->me_nodemax) {
// Too big for a sub-page, convert to sub-DB
fp_flags &= ~P_SUBP;
prep_subDB:
dummy.md_pad = 0;
dummy.md_flags = 0;
dummy.md_depth = 1;
dummy.md_branch_pages = 0;
dummy.md_leaf_pages = 1;
dummy.md_overflow_pages = 0;
dummy.md_entries = NUMKEYS(fp);
xdata.mv_size = sizeof(MDB_db);
xdata.mv_data = &dummy;
if ((rc = mdb_page_alloc(mc, 1, &mp)))
return rc;
offset = env->me_psize - olddata.mv_size;
flags |= F_DUPDATA|F_SUBDATA;
dummy.md_root = mp->mp_pgno;
}
if (mp != fp) {
mp->mp_flags = fp_flags | P_DIRTY;
mp->mp_pad = fp->mp_pad;
mp->mp_lower = fp->mp_lower;
mp->mp_upper = fp->mp_upper + offset;
if (fp_flags & P_LEAF2) {
memcpy(METADATA(mp), METADATA(fp), NUMKEYS(fp) * fp->mp_pad);
} else {
memcpy((char *)mp + mp->mp_upper, (char *)fp + fp->mp_upper,
olddata.mv_size - fp->mp_upper);
for (i = NUMKEYS(fp); --i >= 0; )
mp->mp_ptrs[i] = fp->mp_ptrs[i] + offset;
}
}
rdata = &xdata;
flags |= F_DUPDATA;
do_sub = 1;
if (!insert)
mdb_node_del(mc, 0);
goto new_sub;
}
current:
// overflow page overwrites need special handling
if (F_ISSET(leaf->mn_flags, F_BIGDATA)) {
MDB_page *omp;
pgno_t pg;
int level, ovpages, dpages = OVPAGES(data->mv_size, env->me_psize);
memcpy(&pg, olddata.mv_data, sizeof(pg));
if ((rc2 = mdb_page_get(mc->mc_txn, pg, &omp, &level)) != 0)
return rc2;
ovpages = omp->mp_pages;
// Is the ov page large enough?
if (ovpages >= dpages) {
if (!(omp->mp_flags & P_DIRTY) &&
(level || (env->me_flags & MDB_WRITEMAP)))
{
rc = mdb_page_unspill(mc->mc_txn, omp, &omp);
if (rc)
return rc;
level = 0; // dirty in this txn or clean
}
// Is it dirty?
if (omp->mp_flags & P_DIRTY) {
// yes, overwrite it. Note in this case we don't
// bother to try shrinking the page if the new data
// is smaller than the overflow threshold.
if (level > 1) {
// It is writable only in a parent txn
size_t sz = (size_t) env->me_psize * ovpages, off;
MDB_page *np = mdb_page_malloc(mc->mc_txn, ovpages);
MDB_ID2 id2;
if (!np)
return ENOMEM;
id2.mid = pg;
id2.mptr = np;
rc = mdb_mid2l_insert(mc->mc_txn->mt_u.dirty_list, &id2);
mdb_cassert(mc, rc == 0);
if (!(flags & MDB_RESERVE)) {
// Copy end of page, adjusting alignment so
// compiler may copy words instead of bytes.
off = (PAGEHDRSZ + data->mv_size) & -sizeof(size_t);
memcpy((size_t *)((char *)np + off),
(size_t *)((char *)omp + off), sz - off);
sz = PAGEHDRSZ;
}
memcpy(np, omp, sz); // Copy beginning of page
omp = np;
}
SETDSZ(leaf, data->mv_size);
if (F_ISSET(flags, MDB_RESERVE))
data->mv_data = METADATA(omp);
else
memcpy(METADATA(omp), data->mv_data, data->mv_size);
goto done;
}
}
if ((rc2 = mdb_ovpage_free(mc, omp)) != MDB_SUCCESS)
return rc2;
} else if (data->mv_size == olddata.mv_size) {
// same size, just replace it. Note that we could
// also reuse this node if the new data is smaller,
// but instead we opt to shrink the node in that case.
if (F_ISSET(flags, MDB_RESERVE))
data->mv_data = olddata.mv_data;
else if (data->mv_size)
memcpy(olddata.mv_data, data->mv_data, data->mv_size);
else
memcpy(NODEKEY(leaf), key->mv_data, key->mv_size);
goto done;
}
mdb_node_del(mc, 0);
mc->mc_db->md_entries--;
}
rdata = data;
new_sub:
nflags = flags & NODE_ADD_FLAGS;
nsize = IS_LEAF2(mc->mc_pg[mc->mc_top]) ? key->mv_size : mdb_leaf_size(env, key, rdata);
if (SIZELEFT(mc->mc_pg[mc->mc_top]) < nsize) {
if (( flags & (F_DUPDATA|F_SUBDATA)) == F_DUPDATA )
nflags &= ~MDB_APPEND;
if (!insert)
nflags |= MDB_SPLIT_REPLACE;
rc = mdb_page_split(mc, key, rdata, P_INVALID, nflags);
} else {
// There is room already in this leaf page.
rc = mdb_node_add(mc, mc->mc_ki[mc->mc_top], key, rdata, 0, nflags);
if (rc == 0 && !do_sub && insert) {
// Adjust other cursors pointing to mp
MDB_cursor *m2, *m3;
MDB_dbi dbi = mc->mc_dbi;
unsigned i = mc->mc_top;
MDB_page *mp = mc->mc_pg[i];
for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
if (mc->mc_flags & C_SUB)
m3 = &m2->mc_xcursor->mx_cursor;
else
m3 = m2;
if (m3 == mc || m3->mc_snum < mc->mc_snum) continue;
if (m3->mc_pg[i] == mp && m3->mc_ki[i] >= mc->mc_ki[i]) {
m3->mc_ki[i]++;
}
}
}
}
if (rc != MDB_SUCCESS)
mc->mc_txn->mt_flags |= MDB_TXN_ERROR;
else {
// Now store the actual data in the child DB. Note that we're
// storing the user data in the keys field, so there are strict
// size limits on dupdata. The actual data fields of the child
// DB are all zero size.
if (do_sub) {
int xflags;
put_sub:
xdata.mv_size = 0;
xdata.mv_data = "";
leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
if (flags & MDB_CURRENT) {
xflags = MDB_CURRENT|MDB_NOSPILL;
} else {
mdb_xcursor_init1(mc, leaf);
xflags = (flags & MDB_NODUPDATA) ?
MDB_NOOVERWRITE|MDB_NOSPILL : MDB_NOSPILL;
}
// converted, write the original data first
if (dkey.mv_size) {
rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, &dkey, &xdata, xflags);
if (rc)
return rc;
{
// Adjust other cursors pointing to mp
MDB_cursor *m2;
unsigned i = mc->mc_top;
MDB_page *mp = mc->mc_pg[i];
for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
if (!(m2->mc_flags & C_INITIALIZED)) continue;
if (m2->mc_pg[i] == mp && m2->mc_ki[i] == mc->mc_ki[i]) {
mdb_xcursor_init1(m2, leaf);
}
}
}
// we've done our job
dkey.mv_size = 0;
}
if (flags & MDB_APPENDDUP)
xflags |= MDB_APPEND;
rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, data, &xdata, xflags);
if (flags & F_SUBDATA) {
void *db = NODEDATA(leaf);
memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
}
// we've done our job
dkey.mv_size = 0;
}
if (flags & MDB_APPENDDUP)
xflags |= MDB_APPEND;
rc = mdb_cursor_put(&mc->mc_xcursor->mx_cursor, data, &xdata, xflags);
if (flags & F_SUBDATA) {
void *db = NODEDATA(leaf);
memcpy(db, &mc->mc_xcursor->mx_db, sizeof(MDB_db));
}
}
// sub-writes might have failed so check rc again.
// Don't increment count if we just replaced an existing item.
if (!rc && !(flags & MDB_CURRENT))
mc->mc_db->md_entries++;
if (flags & MDB_MULTIPLE) {
if (!rc) {
next_mult:
mcount++;
// let caller know how many succeeded, if any
data[1].mv_size = mcount;
if (mcount < dcount) {
data[0].mv_data = (char *)data[0].mv_data + data[0].mv_size;
goto more;
// sub-writes might have failed so check rc again.
// Don't increment count if we just replaced an existing item.
if (!rc && !(flags & MDB_CURRENT))
mc->mc_db->md_entries++;
if (flags & MDB_MULTIPLE) {
if (!rc) {
next_mult:
mcount++;
// let caller know how many succeeded, if any
data[1].mv_size = mcount;
if (mcount < dcount) {
data[0].mv_data = (char *)data[0].mv_data + data[0].mv_size;
goto more;
}
}
}
}
}
done:
// If we succeeded and the key didn't exist before, make sure
// the cursor is marked valid.
if (!rc && insert)
mc->mc_flags |= C_INITIALIZED;
return rc;
done:
// If we succeeded and the key didn't exist before, make sure
// the cursor is marked valid.
if (!rc && insert)
mc->mc_flags |= C_INITIALIZED;
return rc;
*/
return nil
}
@ -476,126 +483,126 @@ func (c *RWCursor) allocatePage(count int) (*page, error) {
// }
/*
int rc, retry = INT_MAX;
MDB_txn *txn = mc->mc_txn;
MDB_env *env = txn->mt_env;
pgno_t pgno, *mop = env->me_pghead;
unsigned i, j, k, mop_len = mop ? mop[0] : 0, n2 = num-1;
MDB_page *np;
txnid_t oldest = 0, last;
MDB_cursor_op op;
MDB_cursor m2;
int rc, retry = INT_MAX;
MDB_txn *txn = mc->mc_txn;
MDB_env *env = txn->mt_env;
pgno_t pgno, *mop = env->me_pghead;
unsigned i, j, k, mop_len = mop ? mop[0] : 0, n2 = num-1;
MDB_page *np;
txnid_t oldest = 0, last;
MDB_cursor_op op;
MDB_cursor m2;
*mp = NULL;
*mp = NULL;
for (op = MDB_FIRST;; op = MDB_NEXT) {
MDB_val key, data;
MDB_node *leaf;
pgno_t *idl, old_id, new_id;
for (op = MDB_FIRST;; op = MDB_NEXT) {
MDB_val key, data;
MDB_node *leaf;
pgno_t *idl, old_id, new_id;
// Seek a big enough contiguous page range. Prefer
// pages at the tail, just truncating the list.
if (mop_len > n2) {
i = mop_len;
do {
pgno = mop[i];
if (mop[i-n2] == pgno+n2)
goto search_done;
} while (--i > n2);
if (Max_retries < INT_MAX && --retry < 0)
break;
}
if (op == MDB_FIRST) { // 1st iteration
// Prepare to fetch more and coalesce
oldest = mdb_find_oldest(txn);
last = env->me_pglast;
mdb_cursor_init(&m2, txn, FREE_DBI, NULL);
if (last) {
op = MDB_SET_RANGE;
key.mv_data = &last; // will look up last+1
key.mv_size = sizeof(last);
// Seek a big enough contiguous page range. Prefer
// pages at the tail, just truncating the list.
if (mop_len > n2) {
i = mop_len;
do {
pgno = mop[i];
if (mop[i-n2] == pgno+n2)
goto search_done;
} while (--i > n2);
if (Max_retries < INT_MAX && --retry < 0)
break;
}
}
last++;
// Do not fetch more if the record will be too recent
if (oldest <= last)
break;
rc = mdb_cursor_get(&m2, &key, NULL, op);
if (rc) {
if (rc == MDB_NOTFOUND)
if (op == MDB_FIRST) { // 1st iteration
// Prepare to fetch more and coalesce
oldest = mdb_find_oldest(txn);
last = env->me_pglast;
mdb_cursor_init(&m2, txn, FREE_DBI, NULL);
if (last) {
op = MDB_SET_RANGE;
key.mv_data = &last; // will look up last+1
key.mv_size = sizeof(last);
}
}
last++;
// Do not fetch more if the record will be too recent
if (oldest <= last)
break;
goto fail;
}
last = *(txnid_t*)key.mv_data;
if (oldest <= last)
break;
np = m2.mc_pg[m2.mc_top];
leaf = NODEPTR(np, m2.mc_ki[m2.mc_top]);
if ((rc = mdb_node_read(txn, leaf, &data)) != MDB_SUCCESS)
return rc;
idl = (MDB_ID *) data.mv_data;
i = idl[0];
if (!mop) {
if (!(env->me_pghead = mop = mdb_midl_alloc(i))) {
rc = ENOMEM;
rc = mdb_cursor_get(&m2, &key, NULL, op);
if (rc) {
if (rc == MDB_NOTFOUND)
break;
goto fail;
}
last = *(txnid_t*)key.mv_data;
if (oldest <= last)
break;
np = m2.mc_pg[m2.mc_top];
leaf = NODEPTR(np, m2.mc_ki[m2.mc_top]);
if ((rc = mdb_node_read(txn, leaf, &data)) != MDB_SUCCESS)
return rc;
idl = (MDB_ID *) data.mv_data;
i = idl[0];
if (!mop) {
if (!(env->me_pghead = mop = mdb_midl_alloc(i))) {
rc = ENOMEM;
goto fail;
}
} else {
if ((rc = mdb_midl_need(&env->me_pghead, i)) != 0)
goto fail;
mop = env->me_pghead;
}
env->me_pglast = last;
// Merge in descending sorted order
j = mop_len;
k = mop_len += i;
mop[0] = (pgno_t)-1;
old_id = mop[j];
while (i) {
new_id = idl[i--];
for (; old_id < new_id; old_id = mop[--j])
mop[k--] = old_id;
mop[k--] = new_id;
}
mop[0] = mop_len;
}
// Use new pages from the map when nothing suitable in the freeDB
i = 0;
pgno = txn->mt_next_pgno;
if (pgno + num >= env->me_maxpg) {
DPUTS("DB size maxed out");
rc = MDB_MAP_FULL;
goto fail;
}
search_done:
if (!(np = mdb_page_malloc(txn, num))) {
rc = ENOMEM;
goto fail;
}
if (i) {
mop[0] = mop_len -= num;
// Move any stragglers down
for (j = i-num; j < mop_len; )
mop[++j] = mop[++i];
} else {
if ((rc = mdb_midl_need(&env->me_pghead, i)) != 0)
goto fail;
mop = env->me_pghead;
txn->mt_next_pgno = pgno + num;
}
env->me_pglast = last;
np->mp_pgno = pgno;
mdb_page_dirty(txn, np);
*mp = np;
// Merge in descending sorted order
j = mop_len;
k = mop_len += i;
mop[0] = (pgno_t)-1;
old_id = mop[j];
while (i) {
new_id = idl[i--];
for (; old_id < new_id; old_id = mop[--j])
mop[k--] = old_id;
mop[k--] = new_id;
}
mop[0] = mop_len;
}
return MDB_SUCCESS;
// Use new pages from the map when nothing suitable in the freeDB
i = 0;
pgno = txn->mt_next_pgno;
if (pgno + num >= env->me_maxpg) {
DPUTS("DB size maxed out");
rc = MDB_MAP_FULL;
goto fail;
}
search_done:
if (!(np = mdb_page_malloc(txn, num))) {
rc = ENOMEM;
goto fail;
}
if (i) {
mop[0] = mop_len -= num;
// Move any stragglers down
for (j = i-num; j < mop_len; )
mop[++j] = mop[++i];
} else {
txn->mt_next_pgno = pgno + num;
}
np->mp_pgno = pgno;
mdb_page_dirty(txn, np);
*mp = np;
return MDB_SUCCESS;
fail:
txn->mt_flags |= MDB_TXN_ERROR;
return rc;
fail:
txn->mt_flags |= MDB_TXN_ERROR;
return rc;
*/
return nil
}

2
rwtransaction.go
View File

@ -4,6 +4,4 @@ package bolt
// Only one read/write transaction can be active for a DB at a time.
type RWTransaction struct {
Transaction
pagestate pagestate
}