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glibc/db2/btree/bt_put.c

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/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1996, 1997, 1998
* Sleepycat Software. All rights reserved.
*/
/*
* Copyright (c) 1990, 1993, 1994, 1995, 1996
* Keith Bostic. All rights reserved.
*/
/*
* Copyright (c) 1990, 1993, 1994, 1995
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Mike Olson.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "config.h"
#ifndef lint
static const char sccsid[] = "@(#)bt_put.c 10.45 (Sleepycat) 5/25/98";
#endif /* not lint */
#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>
#include <errno.h>
#include <string.h>
#endif
#include "db_int.h"
#include "db_page.h"
#include "btree.h"
static int __bam_fixed __P((BTREE *, DBT *));
static int __bam_isdeleted __P((DB *, PAGE *, u_int32_t, int *));
static int __bam_lookup __P((DB *, DBT *, int *));
static int __bam_ndup __P((DB *, PAGE *, u_int32_t));
static int __bam_ovput __P((DB *, PAGE *, u_int32_t, DBT *));
static int __bam_partial __P((DB *, DBT *, PAGE *, u_int32_t, u_int32_t));
static u_int32_t __bam_partsize __P((DBT *, PAGE *, u_int32_t));
/*
* __bam_put --
* Add a new key/data pair or replace an existing pair (btree).
*
* PUBLIC: int __bam_put __P((DB *, DB_TXN *, DBT *, DBT *, u_int32_t));
*/
int
__bam_put(argdbp, txn, key, data, flags)
DB *argdbp;
DB_TXN *txn;
DBT *key, *data;
u_int32_t flags;
{
BTREE *t;
CURSOR c;
DB *dbp;
PAGE *h;
db_indx_t indx;
u_int32_t iitem_flags, insert_flags;
int exact, isdeleted, newkey, ret, stack;
DEBUG_LWRITE(argdbp, txn, "bam_put", key, data, flags);
/* Check flags. */
if ((ret = __db_putchk(argdbp, key, data, flags,
F_ISSET(argdbp, DB_AM_RDONLY), F_ISSET(argdbp, DB_AM_DUP))) != 0)
return (ret);
GETHANDLE(argdbp, txn, &dbp, ret);
t = dbp->internal;
retry: /*
* Find the location at which to insert. The call to __bam_lookup
* leaves the returned page pinned.
*/
if ((ret = __bam_lookup(dbp, key, &exact)) != 0) {
PUTHANDLE(dbp);
return (ret);
}
h = t->bt_csp->page;
indx = t->bt_csp->indx;
stack = 1;
/*
* If DB_NOOVERWRITE is set and there's an identical key in the tree,
* return an error unless the data item has already been marked for
* deletion, or, all the remaining data items have already been marked
* for deletion in the case of duplicates. If all the data items have
* been marked for deletion, we do a replace, otherwise, it has to be
* a set of duplicates, and we simply append a new one to the set.
*/
isdeleted = 0;
if (exact) {
if ((ret = __bam_isdeleted(dbp, h, indx, &isdeleted)) != 0)
goto err;
if (isdeleted)
__bam_ca_replace(dbp, h->pgno, indx, REPLACE_SETUP);
else
if (flags == DB_NOOVERWRITE) {
ret = DB_KEYEXIST;
goto err;
}
}
/*
* If we're inserting into the first or last page of the tree,
* remember where we did it so we can do fast lookup next time.
*
* XXX
* Does reverse order still work (did it ever!?!?)
*/
t->bt_lpgno =
h->next_pgno == PGNO_INVALID || h->prev_pgno == PGNO_INVALID ?
h->pgno : PGNO_INVALID;
/*
* Select the arguments for __bam_iitem() and do the insert. If the
* key is an exact match, we're either adding a new duplicate at the
* end of the duplicate set, or we're replacing the data item with a
* new data item. If the key isn't an exact match, we're inserting
* a new key/data pair, before the search location.
*/
newkey = dbp->type == DB_BTREE && !exact;
if (exact) {
if (!isdeleted && F_ISSET(dbp, DB_AM_DUP)) {
/*
* Make sure that we're not looking at a page of
* duplicates -- if so, move to the last entry on
* that page.
*/
c.page = h;
c.pgno = h->pgno;
c.indx = indx;
c.dpgno = PGNO_INVALID;
c.dindx = 0;
if ((ret =
__bam_ovfl_chk(dbp, &c, indx + O_INDX, 1)) != 0)
goto err;
if (c.dpgno != PGNO_INVALID) {
/*
* XXX
* The __bam_ovfl_chk() routine memp_fput() the
* current page and acquired a new one, but did
* not do anything about the lock we're holding.
*/
t->bt_csp->page = h = c.page;
indx = c.dindx;
}
insert_flags = DB_AFTER;
} else
insert_flags = DB_CURRENT;
} else
insert_flags = DB_BEFORE;
/*
* The pages we're using may be modified by __bam_iitem(), so make
* sure we reset the stack.
*/
iitem_flags = 0;
if (newkey)
iitem_flags |= BI_NEWKEY;
if (isdeleted)
iitem_flags |= BI_DOINCR;
ret = __bam_iitem(dbp, &h, &indx, key, data, insert_flags, iitem_flags);
t->bt_csp->page = h;
t->bt_csp->indx = indx;
switch (ret) {
case 0:
/* Done. Clean up the cursor. */
if (isdeleted)
__bam_ca_replace(dbp, h->pgno, indx, REPLACE_SUCCESS);
break;
case DB_NEEDSPLIT:
/*
* We have to split the page. Back out the cursor setup,
* discard the stack of pages, and do the split.
*/
if (isdeleted)
__bam_ca_replace(dbp, h->pgno, indx, REPLACE_FAILED);
(void)__bam_stkrel(dbp);
stack = 0;
if ((ret = __bam_split(dbp, key)) != 0)
break;
goto retry;
/* NOTREACHED */
default:
if (isdeleted)
__bam_ca_replace(dbp, h->pgno, indx, REPLACE_FAILED);
break;
}
err: if (stack)
(void)__bam_stkrel(dbp);
PUTHANDLE(dbp);
return (ret);
}
/*
* __bam_isdeleted --
* Return if the only remaining data item for the element has been
* deleted.
*/
static int
__bam_isdeleted(dbp, h, indx, isdeletedp)
DB *dbp;
PAGE *h;
u_int32_t indx;
int *isdeletedp;
{
BKEYDATA *bk;
db_pgno_t pgno;
int ret;
*isdeletedp = 1;
for (;;) {
bk = GET_BKEYDATA(h, indx + O_INDX);
switch (B_TYPE(bk->type)) {
case B_KEYDATA:
case B_OVERFLOW:
if (!B_DISSET(bk->type)) {
*isdeletedp = 0;
return (0);
}
break;
case B_DUPLICATE:
/*
* If the data item referencing the off-page duplicates
* is flagged as deleted, we're done. Else, we have to
* walk the chain of duplicate pages.
*/
if (B_DISSET(bk->type))
return (0);
goto dupchk;
default:
return (__db_pgfmt(dbp, h->pgno));
}
/*
* If there are no more on-page duplicate items, then every
* data item for this key must have been deleted.
*/
if (indx + P_INDX >= (u_int32_t)NUM_ENT(h))
return (0);
if (h->inp[indx] != h->inp[indx + P_INDX])
return (0);
/* Check the next item. */
indx += P_INDX;
}
/* NOTREACHED */
dupchk: /* Check a chain of duplicate pages. */
pgno = ((BOVERFLOW *)bk)->pgno;
for (;;) {
/* Acquire the next page in the duplicate chain. */
if ((ret = memp_fget(dbp->mpf, &pgno, 0, &h)) != 0)
return (ret);
/* Check each item for a delete flag. */
for (indx = 0; indx < NUM_ENT(h); ++indx)
if (!B_DISSET(GET_BKEYDATA(h, indx)->type)) {
*isdeletedp = 0;
goto done;
}
/*
* If we reach the end of the duplicate pages, then every
* item we reviewed must have been deleted.
*/
if ((pgno = NEXT_PGNO(h)) == PGNO_INVALID)
goto done;
(void)memp_fput(dbp->mpf, h, 0);
}
/* NOTREACHED */
done: (void)memp_fput(dbp->mpf, h, 0);
return (0);
}
/*
* __bam_lookup --
* Find the right location in the tree for the key.
*/
static int
__bam_lookup(dbp, key, exactp)
DB *dbp;
DBT *key;
int *exactp;
{
BTREE *t;
DB_LOCK lock;
EPG e;
PAGE *h;
db_indx_t indx;
int cmp, ret;
t = dbp->internal;
h = NULL;
/*
* Record numbers can't be fast-tracked, we have to lock the entire
* tree.
*/
if (F_ISSET(dbp, DB_BT_RECNUM))
goto slow;
/* Check to see if we've been seeing sorted input. */
if (t->bt_lpgno == PGNO_INVALID)
goto slow;
/*
* Retrieve the page on which we did the last insert. It's okay if
* it doesn't exist, or if it's not the page type we expect, it just
* means that the world changed.
*/
if (__bam_lget(dbp, 0, t->bt_lpgno, DB_LOCK_WRITE, &lock))
goto miss;
if (__bam_pget(dbp, &h, &t->bt_lpgno, 0)) {
(void)__BT_LPUT(dbp, lock);
goto miss;
}
if (TYPE(h) != P_LBTREE)
goto miss;
if (NUM_ENT(h) == 0)
goto miss;
/*
* We have to be at the end or beginning of the tree to know that
* we're inserting in a sort order. If that's the case and we're
* in the right order in comparison to the first/last key/data pair,
* we have the right position.
*/
if (h->next_pgno == PGNO_INVALID) {
e.page = h;
e.indx = NUM_ENT(h) - P_INDX;
if ((cmp = __bam_cmp(dbp, key, &e)) >= 0) {
if (cmp > 0)
e.indx += P_INDX;
goto fast;
}
}
if (h->prev_pgno == PGNO_INVALID) {
e.page = h;
e.indx = 0;
if ((cmp = __bam_cmp(dbp, key, &e)) <= 0) {
/*
* We're doing a put, so we want to insert as the last
* of any set of duplicates.
*/
if (cmp == 0) {
for (indx = 0;
indx < (db_indx_t)(NUM_ENT(h) - P_INDX) &&
h->inp[indx] == h->inp[indx + P_INDX];
indx += P_INDX)
;
e.indx = indx;
}
goto fast;
}
}
goto miss;
/* Set the exact match flag in case we've already inserted this key. */
fast: *exactp = cmp == 0;
/* Enter the entry in the stack. */
BT_STK_CLR(t);
BT_STK_ENTER(t, e.page, e.indx, lock, ret);
if (ret != 0)
return (ret);
++t->lstat.bt_cache_hit;
return (0);
miss: ++t->lstat.bt_cache_miss;
if (h != NULL) {
(void)memp_fput(dbp->mpf, h, 0);
(void)__BT_LPUT(dbp, lock);
}
slow: return (__bam_search(dbp, key, S_INSERT, 1, NULL, exactp));
}
/*
* __bam_iitem --
* Insert an item into the tree.
*
* PUBLIC: int __bam_iitem __P((DB *,
* PUBLIC: PAGE **, db_indx_t *, DBT *, DBT *, u_int32_t, u_int32_t));
*/
int
__bam_iitem(dbp, hp, indxp, key, data, op, flags)
DB *dbp;
PAGE **hp;
db_indx_t *indxp;
DBT *key, *data;
u_int32_t op, flags;
{
BTREE *t;
BKEYDATA *bk;
DBT tdbt;
PAGE *h;
db_indx_t indx, nbytes;
u_int32_t data_size, have_bytes, need_bytes, needed;
int bigkey, bigdata, dupadjust, replace, ret;
COMPQUIET(bk, NULL);
t = dbp->internal;
h = *hp;
indx = *indxp;
dupadjust = replace = 0;
/*
* If it's a page of duplicates, call the common code to do the work.
*
* !!!
* Here's where the hp and indxp are important. The duplicate code
* may decide to rework/rearrange the pages and indices we're using,
* so the caller must understand that the page stack may change.
*/
if (TYPE(h) == P_DUPLICATE) {
/* Adjust the index for the new item if it's a DB_AFTER op. */
if (op == DB_AFTER)
++*indxp;
/* Remove the current item if it's a DB_CURRENT op. */
if (op == DB_CURRENT) {
bk = GET_BKEYDATA(*hp, *indxp);
switch (B_TYPE(bk->type)) {
case B_KEYDATA:
nbytes = BKEYDATA_SIZE(bk->len);
break;
case B_OVERFLOW:
nbytes = BOVERFLOW_SIZE;
break;
default:
return (__db_pgfmt(dbp, h->pgno));
}
if ((ret = __db_ditem(dbp, *hp, *indxp, nbytes)) != 0)
return (ret);
}
/* Put the new/replacement item onto the page. */
if ((ret = __db_dput(dbp, data, hp, indxp, __bam_new)) != 0)
return (ret);
goto done;
}
/* Handle fixed-length records: build the real record. */
if (F_ISSET(dbp, DB_RE_FIXEDLEN) && data->size != t->bt_recno->re_len) {
tdbt = *data;
if ((ret = __bam_fixed(t, &tdbt)) != 0)
return (ret);
data = &tdbt;
}
/*
* Figure out how much space the data will take, including if it's a
* partial record. If either of the key or data items won't fit on
* a page, we'll have to store them on overflow pages.
*/
bigkey = LF_ISSET(BI_NEWKEY) && key->size > t->bt_ovflsize;
data_size = F_ISSET(data, DB_DBT_PARTIAL) ?
__bam_partsize(data, h, indx) : data->size;
bigdata = data_size > t->bt_ovflsize;
needed = 0;
if (LF_ISSET(BI_NEWKEY)) {
/* If BI_NEWKEY is set we're adding a new key and data pair. */
if (bigkey)
needed += BOVERFLOW_PSIZE;
else
needed += BKEYDATA_PSIZE(key->size);
if (bigdata)
needed += BOVERFLOW_PSIZE;
else
needed += BKEYDATA_PSIZE(data_size);
} else {
/*
* We're either overwriting the data item of a key/data pair
* or we're adding the data item only, i.e. a new duplicate.
*/
if (op == DB_CURRENT) {
bk = GET_BKEYDATA(h,
indx + (TYPE(h) == P_LBTREE ? O_INDX : 0));
if (B_TYPE(bk->type) == B_KEYDATA)
have_bytes = BKEYDATA_PSIZE(bk->len);
else
have_bytes = BOVERFLOW_PSIZE;
need_bytes = 0;
} else {
have_bytes = 0;
need_bytes = sizeof(db_indx_t);
}
if (bigdata)
need_bytes += BOVERFLOW_PSIZE;
else
need_bytes += BKEYDATA_PSIZE(data_size);
if (have_bytes < need_bytes)
needed += need_bytes - have_bytes;
}
/*
* If there's not enough room, or the user has put a ceiling on the
* number of keys permitted in the page, split the page.
*
* XXX
* The t->bt_maxkey test here may be insufficient -- do we have to
* check in the btree split code, so we don't undo it there!?!?
*/
if (P_FREESPACE(h) < needed ||
(t->bt_maxkey != 0 && NUM_ENT(h) > t->bt_maxkey))
return (DB_NEEDSPLIT);
/* Handle partial puts: build the real record. */
if (F_ISSET(data, DB_DBT_PARTIAL)) {
tdbt = *data;
if ((ret = __bam_partial(dbp, &tdbt, h, indx, data_size)) != 0)
return (ret);
data = &tdbt;
}
/*
* The code breaks it up into six cases:
*
* 1. Append a new key/data pair.
* 2. Insert a new key/data pair.
* 3. Append a new data item (a new duplicate).
* 4. Insert a new data item (a new duplicate).
* 5. Overflow item: delete and re-add the data item.
* 6. Replace the data item.
*/
if (LF_ISSET(BI_NEWKEY)) {
switch (op) {
case DB_AFTER: /* 1. Append a new key/data pair. */
indx += 2;
*indxp += 2;
break;
case DB_BEFORE: /* 2. Insert a new key/data pair. */
break;
default:
return (EINVAL);
}
/* Add the key. */
if (bigkey) {
if ((ret = __bam_ovput(dbp, h, indx, key)) != 0)
return (ret);
} else
if ((ret = __db_pitem(dbp, h, indx,
BKEYDATA_SIZE(key->size), NULL, key)) != 0)
return (ret);
++indx;
} else {
switch (op) {
case DB_AFTER: /* 3. Append a new data item. */
if (TYPE(h) == P_LBTREE) {
/*
* Adjust the cursor and copy in the key for
* the duplicate.
*/
if ((ret = __bam_adjindx(dbp,
h, indx + P_INDX, indx, 1)) != 0)
return (ret);
indx += 3;
dupadjust = 1;
*indxp += 2;
} else {
++indx;
__bam_ca_di(dbp, h->pgno, indx, 1);
*indxp += 1;
}
break;
case DB_BEFORE: /* 4. Insert a new data item. */
if (TYPE(h) == P_LBTREE) {
/*
* Adjust the cursor and copy in the key for
* the duplicate.
*/
if ((ret =
__bam_adjindx(dbp, h, indx, indx, 1)) != 0)
return (ret);
++indx;
dupadjust = 1;
} else
__bam_ca_di(dbp, h->pgno, indx, 1);
break;
case DB_CURRENT:
if (TYPE(h) == P_LBTREE)
++indx;
/*
* 5. Delete/re-add the data item.
*
* If we're dealing with offpage items, we have to
* delete and then re-add the item.
*/
if (bigdata || B_TYPE(bk->type) != B_KEYDATA) {
if ((ret = __bam_ditem(dbp, h, indx)) != 0)
return (ret);
break;
}
/* 6. Replace the data item. */
replace = 1;
break;
default:
return (EINVAL);
}
}
/* Add the data. */
if (bigdata) {
if ((ret = __bam_ovput(dbp, h, indx, data)) != 0)
return (ret);
} else {
BKEYDATA __bk;
DBT __hdr;
if (LF_ISSET(BI_DELETED)) {
B_TSET(__bk.type, B_KEYDATA, 1);
__bk.len = data->size;
__hdr.data = &__bk;
__hdr.size = SSZA(BKEYDATA, data);
ret = __db_pitem(dbp, h, indx,
BKEYDATA_SIZE(data->size), &__hdr, data);
} else if (replace)
ret = __bam_ritem(dbp, h, indx, data);
else
ret = __db_pitem(dbp, h, indx,
BKEYDATA_SIZE(data->size), NULL, data);
if (ret != 0)
return (ret);
}
if ((ret = memp_fset(dbp->mpf, h, DB_MPOOL_DIRTY)) != 0)
return (ret);
/*
* If the page is at least 50% full, and we added a duplicate, see if
* that set of duplicates takes up at least 25% of the space. If it
* does, move it off onto its own page.
*/
if (dupadjust && P_FREESPACE(h) <= dbp->pgsize / 2) {
--indx;
if ((ret = __bam_ndup(dbp, h, indx)) != 0)
return (ret);
}
/*
* If we've changed the record count, update the tree. Record counts
* need to be updated in recno databases and in btree databases where
* we are supporting records. In both cases, adjust the count if the
* operation wasn't performed on the current record or when the caller
* overrides and wants the adjustment made regardless.
*/
done: if (LF_ISSET(BI_DOINCR) ||
(op != DB_CURRENT &&
(F_ISSET(dbp, DB_BT_RECNUM) || dbp->type == DB_RECNO)))
if ((ret = __bam_adjust(dbp, t, 1)) != 0)
return (ret);
/* If we've modified a recno file, set the flag */
if (t->bt_recno != NULL)
F_SET(t->bt_recno, RECNO_MODIFIED);
++t->lstat.bt_added;
return (ret);
}
/*
* __bam_partsize --
* Figure out how much space a partial data item is in total.
*/
static u_int32_t
__bam_partsize(data, h, indx)
DBT *data;
PAGE *h;
u_int32_t indx;
{
BKEYDATA *bk;
u_int32_t nbytes;
/*
* Figure out how much total space we'll need. If the record doesn't
* already exist, it's simply the data we're provided.
*/
if (indx >= NUM_ENT(h))
return (data->doff + data->size);
/*
* Otherwise, it's the data provided plus any already existing data
* that we're not replacing.
*/
bk = GET_BKEYDATA(h, indx + (TYPE(h) == P_LBTREE ? O_INDX : 0));
nbytes =
B_TYPE(bk->type) == B_OVERFLOW ? ((BOVERFLOW *)bk)->tlen : bk->len;
/*
* There are really two cases here:
*
* Case 1: We are replacing some bytes that do not exist (i.e., they
* are past the end of the record). In this case the number of bytes
* we are replacing is irrelevant and all we care about is how many
* bytes we are going to add from offset. So, the new record length
* is going to be the size of the new bytes (size) plus wherever those
* new bytes begin (doff).
*
* Case 2: All the bytes we are replacing exist. Therefore, the new
* size is the oldsize (nbytes) minus the bytes we are replacing (dlen)
* plus the bytes we are adding (size).
*/
if (nbytes < data->doff + data->dlen) /* Case 1 */
return (data->doff + data->size);
return (nbytes + data->size - data->dlen); /* Case 2 */
}
/*
* OVPUT --
* Copy an overflow item onto a page.
*/
#undef OVPUT
#define OVPUT(h, indx, bo) do { \
DBT __hdr; \
memset(&__hdr, 0, sizeof(__hdr)); \
__hdr.data = &bo; \
__hdr.size = BOVERFLOW_SIZE; \
if ((ret = __db_pitem(dbp, \
h, indx, BOVERFLOW_SIZE, &__hdr, NULL)) != 0) \
return (ret); \
} while (0)
/*
* __bam_ovput --
* Build an overflow item and put it on the page.
*/
static int
__bam_ovput(dbp, h, indx, item)
DB *dbp;
PAGE *h;
u_int32_t indx;
DBT *item;
{
BOVERFLOW bo;
int ret;
B_TSET(bo.type, B_OVERFLOW, 0);
bo.tlen = item->size;
if ((ret = __db_poff(dbp, item, &bo.pgno, __bam_new)) != 0)
return (ret);
OVPUT(h, indx, bo);
return (0);
}
/*
* __bam_ritem --
* Replace an item on a page.
*
* PUBLIC: int __bam_ritem __P((DB *, PAGE *, u_int32_t, DBT *));
*/
int
__bam_ritem(dbp, h, indx, data)
DB *dbp;
PAGE *h;
u_int32_t indx;
DBT *data;
{
BKEYDATA *bk;
DBT orig, repl;
db_indx_t cnt, lo, ln, min, off, prefix, suffix;
int32_t nbytes;
int ret;
u_int8_t *p, *t;
/*
* Replace a single item onto a page. The logic figuring out where
* to insert and whether it fits is handled in the caller. All we do
* here is manage the page shuffling.
*/
bk = GET_BKEYDATA(h, indx);
/* Log the change. */
if (DB_LOGGING(dbp)) {
/*
* We might as well check to see if the two data items share
* a common prefix and suffix -- it can save us a lot of log
* message if they're large.
*/
min = data->size < bk->len ? data->size : bk->len;
for (prefix = 0,
p = bk->data, t = data->data;
prefix < min && *p == *t; ++prefix, ++p, ++t)
;
min -= prefix;
for (suffix = 0,
p = (u_int8_t *)bk->data + bk->len - 1,
t = (u_int8_t *)data->data + data->size - 1;
suffix < min && *p == *t; ++suffix, --p, --t)
;
/* We only log the parts of the keys that have changed. */
orig.data = (u_int8_t *)bk->data + prefix;
orig.size = bk->len - (prefix + suffix);
repl.data = (u_int8_t *)data->data + prefix;
repl.size = data->size - (prefix + suffix);
if ((ret = __bam_repl_log(dbp->dbenv->lg_info, dbp->txn,
&LSN(h), 0, dbp->log_fileid, PGNO(h), &LSN(h),
(u_int32_t)indx, (u_int32_t)B_DISSET(bk->type),
&orig, &repl, (u_int32_t)prefix, (u_int32_t)suffix)) != 0)
return (ret);
}
/*
* Set references to the first in-use byte on the page and the
* first byte of the item being replaced.
*/
p = (u_int8_t *)h + HOFFSET(h);
t = (u_int8_t *)bk;
/*
* If the entry is growing in size, shift the beginning of the data
* part of the page down. If the entry is shrinking in size, shift
* the beginning of the data part of the page up. Use memmove(3),
* the regions overlap.
*/
lo = BKEYDATA_SIZE(bk->len);
ln = BKEYDATA_SIZE(data->size);
if (lo != ln) {
nbytes = lo - ln; /* Signed difference. */
if (p == t) /* First index is fast. */
h->inp[indx] += nbytes;
else { /* Else, shift the page. */
memmove(p + nbytes, p, t - p);
/* Adjust the indices' offsets. */
off = h->inp[indx];
for (cnt = 0; cnt < NUM_ENT(h); ++cnt)
if (h->inp[cnt] <= off)
h->inp[cnt] += nbytes;
}
/* Clean up the page and adjust the item's reference. */
HOFFSET(h) += nbytes;
t += nbytes;
}
/* Copy the new item onto the page. */
bk = (BKEYDATA *)t;
B_TSET(bk->type, B_KEYDATA, 0);
bk->len = data->size;
memcpy(bk->data, data->data, data->size);
return (0);
}
/*
* __bam_ndup --
* Check to see if the duplicate set at indx should have its own page.
* If it should, create it.
*/
static int
__bam_ndup(dbp, h, indx)
DB *dbp;
PAGE *h;
u_int32_t indx;
{
BKEYDATA *bk;
BOVERFLOW bo;
DBT hdr;
PAGE *cp;
db_indx_t cnt, cpindx, first, sz;
int ret;
while (indx > 0 && h->inp[indx] == h->inp[indx - P_INDX])
indx -= P_INDX;
for (cnt = 0, sz = 0, first = indx;; ++cnt, indx += P_INDX) {
if (indx >= NUM_ENT(h) || h->inp[first] != h->inp[indx])
break;
bk = GET_BKEYDATA(h, indx);
sz += B_TYPE(bk->type) == B_KEYDATA ?
BKEYDATA_PSIZE(bk->len) : BOVERFLOW_PSIZE;
bk = GET_BKEYDATA(h, indx + O_INDX);
sz += B_TYPE(bk->type) == B_KEYDATA ?
BKEYDATA_PSIZE(bk->len) : BOVERFLOW_PSIZE;
}
/*
* If this set of duplicates is using more than 25% of the page, move
* them off. The choice of 25% is a WAG, but it has to be small enough
* that we can always split regardless of the presence of duplicates.
*/
if (sz < dbp->pgsize / 4)
return (0);
/* Get a new page. */
if ((ret = __bam_new(dbp, P_DUPLICATE, &cp)) != 0)
return (ret);
/*
* Move this set of duplicates off the page. First points to the first
* key of the first duplicate key/data pair, cnt is the number of pairs
* we're dealing with.
*/
memset(&hdr, 0, sizeof(hdr));
for (indx = first + O_INDX, cpindx = 0;; ++cpindx) {
/* Copy the entry to the new page. */
bk = GET_BKEYDATA(h, indx);
hdr.data = bk;
hdr.size = B_TYPE(bk->type) == B_KEYDATA ?
BKEYDATA_SIZE(bk->len) : BOVERFLOW_SIZE;
if ((ret =
__db_pitem(dbp, cp, cpindx, hdr.size, &hdr, NULL)) != 0)
goto err;
/*
* Move cursors referencing the old entry to the new entry.
* Done after the page put because __db_pitem() adjusts
* cursors on the new page, and before the delete because
* __db_ditem adjusts cursors on the old page.
*/
__bam_ca_dup(dbp,
PGNO(h), first, indx - O_INDX, PGNO(cp), cpindx);
/* Delete the data item. */
if ((ret = __db_ditem(dbp, h, indx, hdr.size)) != 0)
goto err;
/* Delete all but the first reference to the key. */
if (--cnt == 0)
break;
if ((ret = __bam_adjindx(dbp, h, indx, first, 0)) != 0)
goto err;
}
/* Put in a new data item that points to the duplicates page. */
B_TSET(bo.type, B_DUPLICATE, 0);
bo.pgno = cp->pgno;
bo.tlen = 0;
OVPUT(h, indx, bo);
return (memp_fput(dbp->mpf, cp, DB_MPOOL_DIRTY));
err: (void)__bam_free(dbp, cp);
return (ret);
}
/*
* __bam_fixed --
* Build the real record for a fixed length put.
*/
static int
__bam_fixed(t, dbt)
BTREE *t;
DBT *dbt;
{
RECNO *rp;
rp = t->bt_recno;
/*
* If database contains fixed-length records, and the record is long,
* return EINVAL.
*/
if (dbt->size > rp->re_len)
return (EINVAL);
/*
* The caller checked to see if it was just right, so we know it's
* short. Pad it out. We use the record data return memory, it's
* only a short-term use.
*/
if (t->bt_rdata.ulen < rp->re_len) {
t->bt_rdata.data = t->bt_rdata.data == NULL ?
(void *)__db_malloc(rp->re_len) :
(void *)__db_realloc(t->bt_rdata.data, rp->re_len);
if (t->bt_rdata.data == NULL) {
t->bt_rdata.ulen = 0;
return (ENOMEM);
}
t->bt_rdata.ulen = rp->re_len;
}
memcpy(t->bt_rdata.data, dbt->data, dbt->size);
memset((u_int8_t *)t->bt_rdata.data + dbt->size,
rp->re_pad, rp->re_len - dbt->size);
/*
* Clean up our flags and other information just in case, and
* change the caller's DBT to reference our created record.
*/
t->bt_rdata.size = rp->re_len;
t->bt_rdata.dlen = 0;
t->bt_rdata.doff = 0;
t->bt_rdata.flags = 0;
*dbt = t->bt_rdata;
return (0);
}
/*
* __bam_partial --
* Build the real record for a partial put.
*/
static int
__bam_partial(dbp, dbt, h, indx, nbytes)
DB *dbp;
DBT *dbt;
PAGE *h;
u_int32_t indx, nbytes;
{
BTREE *t;
BKEYDATA *bk, tbk;
BOVERFLOW *bo;
DBT copy;
u_int32_t len, tlen;
u_int8_t *p;
int ret;
COMPQUIET(bo, NULL);
t = dbp->internal;
/* We use the record data return memory, it's only a short-term use. */
if (t->bt_rdata.ulen < nbytes) {
t->bt_rdata.data = t->bt_rdata.data == NULL ?
(void *)__db_malloc(nbytes) :
(void *)__db_realloc(t->bt_rdata.data, nbytes);
if (t->bt_rdata.data == NULL) {
t->bt_rdata.ulen = 0;
return (ENOMEM);
}
t->bt_rdata.ulen = nbytes;
}
/* Find the current record. */
if (indx < NUM_ENT(h)) {
bk = GET_BKEYDATA(h, indx + (TYPE(h) == P_LBTREE ? O_INDX : 0));
bo = (BOVERFLOW *)bk;
} else {
bk = &tbk;
B_TSET(bk->type, B_KEYDATA, 0);
bk->len = 0;
}
/*
* We use nul bytes for any part of the record that isn't specified,
* get it over with.
*/
memset(t->bt_rdata.data, 0, nbytes);
if (B_TYPE(bk->type) == B_OVERFLOW) {
/*
* In the case of an overflow record, we shift things around
* in the current record rather than allocate a separate copy.
*/
memset(&copy, 0, sizeof(copy));
if ((ret = __db_goff(dbp, &copy, bo->tlen,
bo->pgno, &t->bt_rdata.data, &t->bt_rdata.ulen)) != 0)
return (ret);
/* Skip any leading data from the original record. */
tlen = dbt->doff;
p = (u_int8_t *)t->bt_rdata.data + dbt->doff;
/*
* Copy in any trailing data from the original record.
*
* If the original record was larger than the original offset
* plus the bytes being deleted, there is trailing data in the
* original record we need to preserve. If we aren't deleting
* the same number of bytes as we're inserting, copy it up or
* down, into place.
*
* Use memmove(), the regions may overlap.
*/
if (bo->tlen > dbt->doff + dbt->dlen) {
len = bo->tlen - (dbt->doff + dbt->dlen);
if (dbt->dlen != dbt->size)
memmove(p + dbt->size, p + dbt->dlen, len);
tlen += len;
}
/* Copy in the application provided data. */
memcpy(p, dbt->data, dbt->size);
tlen += dbt->size;
} else {
/* Copy in any leading data from the original record. */
memcpy(t->bt_rdata.data,
bk->data, dbt->doff > bk->len ? bk->len : dbt->doff);
tlen = dbt->doff;
p = (u_int8_t *)t->bt_rdata.data + dbt->doff;
/* Copy in the application provided data. */
memcpy(p, dbt->data, dbt->size);
tlen += dbt->size;
/* Copy in any trailing data from the original record. */
len = dbt->doff + dbt->dlen;
if (bk->len > len) {
memcpy(p + dbt->size, bk->data + len, bk->len - len);
tlen += bk->len - len;
}
}
/* Set the DBT to reference our new record. */
t->bt_rdata.size = tlen;
t->bt_rdata.dlen = 0;
t->bt_rdata.doff = 0;
t->bt_rdata.flags = 0;
*dbt = t->bt_rdata;
return (0);
}
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