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glibc/db2/hash/hash.c
Ulrich Drepper ec239360d1 Update. 
* db2/Makefile (distribute): Remove files which do not exist
	anymore.
1999-06-13 13:36:34 +00:00

1338 lines
34 KiB
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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
* Margo Seltzer. All rights reserved.
*/
/*
* Copyright (c) 1990, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Margo Seltzer.
*
* 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[] = "@(#)hash.c 10.63 (Sleepycat) 12/11/98";
#endif /* not lint */
#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#endif
#include "db_int.h"
#include "shqueue.h"
#include "db_page.h"
#include "db_am.h"
#include "db_ext.h"
#include "hash.h"
#include "btree.h"
#include "log.h"
#include "db_shash.h"
#include "lock.h"
#include "lock_ext.h"
static int __ham_c_close __P((DBC *));
static int __ham_c_del __P((DBC *, u_int32_t));
static int __ham_c_destroy __P((DBC *));
static int __ham_c_get __P((DBC *, DBT *, DBT *, u_int32_t));
static int __ham_c_put __P((DBC *, DBT *, DBT *, u_int32_t));
static int __ham_delete __P((DB *, DB_TXN *, DBT *, u_int32_t));
static int __ham_dup_return __P((DBC *, DBT *, u_int32_t));
static int __ham_expand_table __P((DBC *));
static void __ham_init_htab __P((DBC *, u_int32_t, u_int32_t));
static int __ham_lookup __P((DBC *, const DBT *, u_int32_t, db_lockmode_t));
static int __ham_overwrite __P((DBC *, DBT *));
/************************** INTERFACE ROUTINES ***************************/
/* OPEN/CLOSE */
/*
* __ham_open --
*
* PUBLIC: int __ham_open __P((DB *, DB_INFO *));
*/
int
__ham_open(dbp, dbinfo)
DB *dbp;
DB_INFO *dbinfo;
{
DB_ENV *dbenv;
DBC *dbc;
HASH_CURSOR *hcp;
int file_existed, ret;
dbc = NULL;
dbenv = dbp->dbenv;
/* Set the hash function if specified by the user. */
if (dbinfo != NULL && dbinfo->h_hash != NULL)
dbp->h_hash = dbinfo->h_hash;
/*
* Initialize the remaining fields of the dbp. The only function
* that differs from the default set is __ham_stat().
*/
dbp->internal = NULL;
dbp->am_close = __ham_close;
dbp->del = __ham_delete;
dbp->stat = __ham_stat;
/* Get a cursor we can use for the rest of this function. */
if ((ret = dbp->cursor(dbp, NULL, &dbc, 0)) != 0)
goto out;
hcp = (HASH_CURSOR *)dbc->internal;
GET_META(dbp, hcp, ret);
if (ret != 0)
goto out;
/*
* If this is a new file, initialize it, and put it back dirty.
*/
/* Initialize the hdr structure */
if (hcp->hdr->magic == DB_HASHMAGIC) {
file_existed = 1;
/* File exists, verify the data in the header. */
if (dbp->h_hash == NULL)
dbp->h_hash =
hcp->hdr->version < 5 ? __ham_func4 : __ham_func5;
if (dbp->h_hash(CHARKEY, sizeof(CHARKEY)) !=
hcp->hdr->h_charkey) {
__db_err(dbp->dbenv, "hash: incompatible hash function");
ret = EINVAL;
goto out;
}
if (F_ISSET(hcp->hdr, DB_HASH_DUP))
F_SET(dbp, DB_AM_DUP);
} else {
/*
* File does not exist, we must initialize the header. If
* locking is enabled that means getting a write lock first.
*/
file_existed = 0;
if (F_ISSET(dbp, DB_AM_LOCKING) &&
((ret = lock_put(dbenv->lk_info, hcp->hlock)) != 0 ||
(ret = lock_get(dbenv->lk_info, dbc->locker, 0,
&dbc->lock_dbt, DB_LOCK_WRITE, &hcp->hlock)) != 0)) {
if (ret < 0)
ret = EAGAIN;
goto out;
}
__ham_init_htab(dbc, dbinfo != NULL ? dbinfo->h_nelem : 0,
dbinfo != NULL ? dbinfo->h_ffactor : 0);
if (F_ISSET(dbp, DB_AM_DUP))
F_SET(hcp->hdr, DB_HASH_DUP);
if ((ret = __ham_dirty_page(dbp, (PAGE *)hcp->hdr)) != 0)
goto out;
}
/* Release the meta data page */
RELEASE_META(dbp, hcp);
if ((ret = dbc->c_close(dbc)) != 0)
goto out;
/* Sync the file so that we know that the meta data goes to disk. */
if (!file_existed && (ret = dbp->sync(dbp, 0)) != 0)
goto out;
return (0);
out: (void)__ham_close(dbp);
return (ret);
}
/*
* PUBLIC: int __ham_close __P((DB *));
*/
int
__ham_close(dbp)
DB *dbp;
{
COMPQUIET(dbp, NULL);
return (0);
}
/************************** LOCAL CREATION ROUTINES **********************/
/*
* Returns 0 on No Error
*/
static void
__ham_init_htab(dbc, nelem, ffactor)
DBC *dbc;
u_int32_t nelem, ffactor;
{
DB *dbp;
HASH_CURSOR *hcp;
int32_t l2, nbuckets;
hcp = (HASH_CURSOR *)dbc->internal;
dbp = dbc->dbp;
memset(hcp->hdr, 0, sizeof(HASHHDR));
hcp->hdr->ffactor = ffactor;
hcp->hdr->pagesize = dbp->pgsize;
ZERO_LSN(hcp->hdr->lsn);
hcp->hdr->magic = DB_HASHMAGIC;
hcp->hdr->version = DB_HASHVERSION;
if (dbp->h_hash == NULL)
dbp->h_hash = hcp->hdr->version < 5 ? __ham_func4 : __ham_func5;
hcp->hdr->h_charkey = dbp->h_hash(CHARKEY, sizeof(CHARKEY));
if (nelem != 0 && hcp->hdr->ffactor != 0) {
nelem = (nelem - 1) / hcp->hdr->ffactor + 1;
l2 = __db_log2(nelem > 2 ? nelem : 2);
} else
l2 = 2;
nbuckets = 1 << l2;
hcp->hdr->ovfl_point = l2;
hcp->hdr->last_freed = PGNO_INVALID;
hcp->hdr->max_bucket = hcp->hdr->high_mask = nbuckets - 1;
hcp->hdr->low_mask = (nbuckets >> 1) - 1;
memcpy(hcp->hdr->uid, dbp->fileid, DB_FILE_ID_LEN);
}
static int
__ham_delete(dbp, txn, key, flags)
DB *dbp;
DB_TXN *txn;
DBT *key;
u_int32_t flags;
{
DBC *dbc;
HASH_CURSOR *hcp;
int ret, tret;
DB_PANIC_CHECK(dbp);
if ((ret =
__db_delchk(dbp, key, flags, F_ISSET(dbp, DB_AM_RDONLY))) != 0)
return (ret);
if ((ret = dbp->cursor(dbp, txn, &dbc, DB_WRITELOCK)) != 0)
return (ret);
DEBUG_LWRITE(dbc, txn, "ham_delete", key, NULL, flags);
hcp = (HASH_CURSOR *)dbc->internal;
GET_META(dbp, hcp, ret);
if (ret != 0)
goto out;
hcp->stats.hash_deleted++;
if ((ret = __ham_lookup(dbc, key, 0, DB_LOCK_WRITE)) == 0) {
if (F_ISSET(hcp, H_OK))
ret = __ham_del_pair(dbc, 1);
else
ret = DB_NOTFOUND;
}
RELEASE_META(dbp, hcp);
out: if ((tret = dbc->c_close(dbc)) != 0 && ret == 0)
ret = tret;
return (ret);
}
/* ****************** CURSORS ********************************** */
/*
* __ham_c_init --
* Initialize the hash-specific portion of a cursor.
*
* PUBLIC: int __ham_c_init __P((DBC *));
*/
int
__ham_c_init(dbc)
DBC *dbc;
{
HASH_CURSOR *new_curs;
int ret;
if ((ret = __os_calloc(1, sizeof(struct cursor_t), &new_curs)) != 0)
return (ret);
if ((ret =
__os_malloc(dbc->dbp->pgsize, NULL, &new_curs->split_buf)) != 0) {
__os_free(new_curs, sizeof(*new_curs));
return (ret);
}
new_curs->dbc = dbc;
dbc->internal = new_curs;
dbc->c_am_close = __ham_c_close;
dbc->c_am_destroy = __ham_c_destroy;
dbc->c_del = __ham_c_del;
dbc->c_get = __ham_c_get;
dbc->c_put = __ham_c_put;
__ham_item_init(new_curs);
return (0);
}
/*
* __ham_c_close --
* Close down the cursor from a single use.
*/
static int
__ham_c_close(dbc)
DBC *dbc;
{
int ret;
if ((ret = __ham_item_done(dbc, 0)) != 0)
return (ret);
__ham_item_init((HASH_CURSOR *)dbc->internal);
return (0);
}
/*
* __ham_c_destroy --
* Cleanup the access method private part of a cursor.
*/
static int
__ham_c_destroy(dbc)
DBC *dbc;
{
HASH_CURSOR *hcp;
hcp = (HASH_CURSOR *)dbc->internal;
if (hcp->split_buf != NULL)
__os_free(hcp->split_buf, dbc->dbp->pgsize);
__os_free(hcp, sizeof(HASH_CURSOR));
return (0);
}
static int
__ham_c_del(dbc, flags)
DBC *dbc;
u_int32_t flags;
{
DB *dbp;
DBT repldbt;
HASH_CURSOR *hcp;
HASH_CURSOR save_curs;
db_pgno_t ppgno, chg_pgno;
int ret, t_ret;
DEBUG_LWRITE(dbc, dbc->txn, "ham_c_del", NULL, NULL, flags);
dbp = dbc->dbp;
DB_PANIC_CHECK(dbp);
hcp = (HASH_CURSOR *)dbc->internal;
if ((ret = __db_cdelchk(dbc->dbp, flags,
F_ISSET(dbc->dbp, DB_AM_RDONLY), IS_VALID(hcp))) != 0)
return (ret);
if (F_ISSET(hcp, H_DELETED))
return (DB_NOTFOUND);
/*
* If we are in the concurrent DB product and this cursor
* is not a write cursor, then this request is invalid.
* If it is a simple write cursor, then we need to upgrade its
* lock.
*/
if (F_ISSET(dbp, DB_AM_CDB)) {
/* Make sure it's a valid update cursor. */
if (!F_ISSET(dbc, DBC_RMW | DBC_WRITER))
return (EINVAL);
if (F_ISSET(dbc, DBC_RMW) &&
(ret = lock_get(dbp->dbenv->lk_info, dbc->locker,
DB_LOCK_UPGRADE, &dbc->lock_dbt, DB_LOCK_WRITE,
&dbc->mylock)) != 0)
return (EAGAIN);
}
GET_META(dbp, hcp, ret);
if (ret != 0)
return (ret);
SAVE_CURSOR(hcp, &save_curs);
hcp->stats.hash_deleted++;
if ((ret = __ham_get_cpage(dbc, DB_LOCK_WRITE)) != 0)
goto out;
if (F_ISSET(hcp, H_ISDUP) && hcp->dpgno != PGNO_INVALID) {
/*
* We are about to remove a duplicate from offpage.
*
* There are 4 cases.
* 1. We will remove an item on a page, but there are more
* items on that page.
* 2. We will remove the last item on a page, but there is a
* following page of duplicates.
* 3. We will remove the last item on a page, this page was the
* last page in a duplicate set, but there were dups before
* it.
* 4. We will remove the last item on a page, removing the last
* duplicate.
* In case 1 hcp->dpagep is unchanged.
* In case 2 hcp->dpagep comes back pointing to the next dup
* page.
* In case 3 hcp->dpagep comes back NULL.
* In case 4 hcp->dpagep comes back NULL.
*
* Case 4 results in deleting the pair off the master page.
* The normal code for doing this knows how to delete the
* duplicates, so we will handle this case in the normal code.
*/
ppgno = PREV_PGNO(hcp->dpagep);
if (ppgno == PGNO_INVALID &&
NEXT_PGNO(hcp->dpagep) == PGNO_INVALID &&
NUM_ENT(hcp->dpagep) == 1)
goto normal;
/* Remove item from duplicate page. */
chg_pgno = hcp->dpgno;
if ((ret = __db_drem(dbc,
&hcp->dpagep, hcp->dndx, __ham_del_page)) != 0)
goto out;
if (hcp->dpagep == NULL) {
if (ppgno != PGNO_INVALID) { /* Case 3 */
hcp->dpgno = ppgno;
if ((ret = __ham_get_cpage(dbc,
DB_LOCK_READ)) != 0)
goto out;
hcp->dndx = NUM_ENT(hcp->dpagep);
F_SET(hcp, H_DELETED);
} else { /* Case 4 */
ret = __ham_del_pair(dbc, 1);
hcp->dpgno = PGNO_INVALID;
/*
* Delpair updated the cursor queue, so we
* don't have to do that here.
*/
chg_pgno = PGNO_INVALID;
}
} else if (PGNO(hcp->dpagep) != hcp->dpgno) {
hcp->dndx = 0; /* Case 2 */
hcp->dpgno = PGNO(hcp->dpagep);
if (ppgno == PGNO_INVALID)
memcpy(HOFFDUP_PGNO(P_ENTRY(hcp->pagep,
H_DATAINDEX(hcp->bndx))),
&hcp->dpgno, sizeof(db_pgno_t));
/*
* We need to put the master page here, because
* although we have a duplicate page, the master
* page is dirty, and ham_item_done assumes that
* if you have a duplicate page, it's the only one
* that can be dirty.
*/
ret = __ham_put_page(dbp, hcp->pagep, 1);
hcp->pagep = NULL;
F_SET(hcp, H_DELETED);
} else /* Case 1 */
F_SET(hcp, H_DELETED);
if (chg_pgno != PGNO_INVALID)
__ham_c_update(hcp, chg_pgno, 0, 0, 1);
} else if (F_ISSET(hcp, H_ISDUP)) { /* on page */
if (hcp->dup_off == 0 && DUP_SIZE(hcp->dup_len) ==
LEN_HDATA(hcp->pagep, hcp->hdr->pagesize, hcp->bndx))
ret = __ham_del_pair(dbc, 1);
else {
repldbt.flags = 0;
F_SET(&repldbt, DB_DBT_PARTIAL);
repldbt.doff = hcp->dup_off;
repldbt.dlen = DUP_SIZE(hcp->dup_len);
repldbt.size = 0;
repldbt.data =
HKEYDATA_DATA(H_PAIRDATA(hcp->pagep, hcp->bndx));
ret = __ham_replpair(dbc, &repldbt, 0);
hcp->dup_tlen -= DUP_SIZE(hcp->dup_len);
F_SET(hcp, H_DELETED);
__ham_c_update(hcp, hcp->pgno,
DUP_SIZE(hcp->dup_len), 0, 1);
}
} else
/* Not a duplicate */
normal: ret = __ham_del_pair(dbc, 1);
out: if ((t_ret = __ham_item_done(dbc, ret == 0)) != 0 && ret == 0)
ret = t_ret;
RELEASE_META(dbp, hcp);
RESTORE_CURSOR(dbp, hcp, &save_curs, ret);
if (F_ISSET(dbp, DB_AM_CDB) && F_ISSET(dbc, DBC_RMW))
(void)__lock_downgrade(dbp->dbenv->lk_info, dbc->mylock,
DB_LOCK_IWRITE, 0);
return (ret);
}
static int
__ham_c_get(dbc, key, data, flags)
DBC *dbc;
DBT *key;
DBT *data;
u_int32_t flags;
{
DB *dbp;
HASH_CURSOR *hcp, save_curs;
db_lockmode_t lock_type;
int get_key, ret, t_ret;
DEBUG_LREAD(dbc, dbc->txn, "ham_c_get",
flags == DB_SET || flags == DB_SET_RANGE ? key : NULL,
NULL, flags);
hcp = (HASH_CURSOR *)dbc->internal;
dbp = dbc->dbp;
DB_PANIC_CHECK(dbp);
SAVE_CURSOR(hcp, &save_curs);
if ((ret =
__db_cgetchk(dbp, key, data, flags, IS_VALID(hcp))) != 0)
return (ret);
/* Clear OR'd in additional bits so we can check for flag equality. */
if (LF_ISSET(DB_RMW)) {
lock_type = DB_LOCK_WRITE;
LF_CLR(DB_RMW);
} else
lock_type = DB_LOCK_READ;
GET_META(dbp, hcp, ret);
if (ret != 0)
return (ret);
hcp->stats.hash_get++;
hcp->seek_size = 0;
ret = 0;
get_key = 1;
switch (flags) {
case DB_PREV:
if (hcp->bucket != BUCKET_INVALID) {
ret = __ham_item_prev(dbc, lock_type);
break;
}
/* FALLTHROUGH */
case DB_LAST:
ret = __ham_item_last(dbc, lock_type);
break;
case DB_FIRST:
ret = __ham_item_first(dbc, lock_type);
break;
case DB_NEXT_DUP:
if (hcp->bucket == BUCKET_INVALID)
ret = EINVAL;
else {
F_SET(hcp, H_DUPONLY);
ret = __ham_item_next(dbc, lock_type);
}
break;
case DB_NEXT:
if (hcp->bucket == BUCKET_INVALID)
hcp->bucket = 0;
ret = __ham_item_next(dbc, lock_type);
break;
case DB_SET:
case DB_SET_RANGE:
case DB_GET_BOTH:
if (F_ISSET(dbc, DBC_CONTINUE)) {
F_SET(hcp, H_DUPONLY);
ret = __ham_item_next(dbc, lock_type);
} else if (F_ISSET(dbc, DBC_KEYSET))
ret = __ham_item(dbc, lock_type);
else
ret = __ham_lookup(dbc, key, 0, lock_type);
get_key = 0;
break;
case DB_CURRENT:
if (F_ISSET(hcp, H_DELETED)) {
ret = DB_KEYEMPTY;
goto out;
}
ret = __ham_item(dbc, lock_type);
break;
}
/*
* Must always enter this loop to do error handling and
* check for big key/data pair.
*/
while (1) {
if (ret != 0 && ret != DB_NOTFOUND)
goto out1;
else if (F_ISSET(hcp, H_OK)) {
/* Get the key. */
if (get_key && (ret = __db_ret(dbp, hcp->pagep,
H_KEYINDEX(hcp->bndx), key, &dbc->rkey.data,
&dbc->rkey.size)) != 0)
goto out1;
ret = __ham_dup_return(dbc, data, flags);
break;
} else if (!F_ISSET(hcp, H_NOMORE)) {
abort();
break;
}
/*
* Ran out of entries in a bucket; change buckets.
*/
switch (flags) {
case DB_LAST:
case DB_PREV:
ret = __ham_item_done(dbc, 0);
if (hcp->bucket == 0) {
ret = DB_NOTFOUND;
goto out1;
}
hcp->bucket--;
hcp->bndx = NDX_INVALID;
if (ret == 0)
ret = __ham_item_prev(dbc, lock_type);
break;
case DB_FIRST:
case DB_NEXT:
ret = __ham_item_done(dbc, 0);
hcp->bndx = NDX_INVALID;
hcp->bucket++;
hcp->pgno = PGNO_INVALID;
hcp->pagep = NULL;
if (hcp->bucket > hcp->hdr->max_bucket) {
ret = DB_NOTFOUND;
goto out1;
}
if (ret == 0)
ret = __ham_item_next(dbc, lock_type);
break;
case DB_GET_BOTH:
case DB_NEXT_DUP:
case DB_SET:
case DB_SET_RANGE:
/* Key not found. */
ret = DB_NOTFOUND;
goto out1;
}
}
out1: if ((t_ret = __ham_item_done(dbc, 0)) != 0 && ret == 0)
ret = t_ret;
out: RELEASE_META(dbp, hcp);
RESTORE_CURSOR(dbp, hcp, &save_curs, ret);
return (ret);
}
static int
__ham_c_put(dbc, key, data, flags)
DBC *dbc;
DBT *key;
DBT *data;
u_int32_t flags;
{
DB *dbp;
DBT tmp_val, *myval;
HASH_CURSOR *hcp, save_curs;
u_int32_t nbytes;
int ret, t_ret;
dbp = dbc->dbp;
DB_PANIC_CHECK(dbp);
DEBUG_LWRITE(dbc, dbc->txn, "ham_c_put",
flags == DB_KEYFIRST || flags == DB_KEYLAST ? key : NULL,
data, flags);
hcp = (HASH_CURSOR *)dbc->internal;
if ((ret = __db_cputchk(dbp, key, data, flags,
F_ISSET(dbp, DB_AM_RDONLY), IS_VALID(hcp))) != 0)
return (ret);
if (F_ISSET(hcp, H_DELETED) &&
flags != DB_KEYFIRST && flags != DB_KEYLAST)
return (DB_NOTFOUND);
/*
* If we are in the concurrent DB product and this cursor
* is not a write cursor, then this request is invalid.
* If it is a simple write cursor, then we need to upgrade its
* lock.
*/
if (F_ISSET(dbp, DB_AM_CDB)) {
/* Make sure it's a valid update cursor. */
if (!F_ISSET(dbc, DBC_RMW | DBC_WRITER))
return (EINVAL);
if (F_ISSET(dbc, DBC_RMW) &&
(ret = lock_get(dbp->dbenv->lk_info, dbc->locker,
DB_LOCK_UPGRADE, &dbc->lock_dbt, DB_LOCK_WRITE,
&dbc->mylock)) != 0)
return (EAGAIN);
}
GET_META(dbp, hcp, ret);
if (ret != 0)
return (ret);
SAVE_CURSOR(hcp, &save_curs);
hcp->stats.hash_put++;
switch (flags) {
case DB_KEYLAST:
case DB_KEYFIRST:
nbytes = (ISBIG(hcp, key->size) ? HOFFPAGE_PSIZE :
HKEYDATA_PSIZE(key->size)) +
(ISBIG(hcp, data->size) ? HOFFPAGE_PSIZE :
HKEYDATA_PSIZE(data->size));
if ((ret = __ham_lookup(dbc,
key, nbytes, DB_LOCK_WRITE)) == DB_NOTFOUND) {
ret = 0;
if (hcp->seek_found_page != PGNO_INVALID &&
hcp->seek_found_page != hcp->pgno) {
if ((ret = __ham_item_done(dbc, 0)) != 0)
goto out;
hcp->pgno = hcp->seek_found_page;
hcp->bndx = NDX_INVALID;
}
if (F_ISSET(data, DB_DBT_PARTIAL) && data->doff != 0) {
/*
* A partial put, but the key does not exist
* and we are not beginning the write at 0.
* We must create a data item padded up to doff
* and then write the new bytes represented by
* val.
*/
if ((ret = __ham_init_dbt(&tmp_val,
data->size + data->doff,
&dbc->rdata.data, &dbc->rdata.size)) == 0) {
memset(tmp_val.data, 0, data->doff);
memcpy((u_int8_t *)tmp_val.data +
data->doff, data->data, data->size);
myval = &tmp_val;
}
} else
myval = (DBT *)data;
if (ret == 0)
ret = __ham_add_el(dbc, key, myval, H_KEYDATA);
goto done;
}
break;
case DB_BEFORE:
case DB_AFTER:
case DB_CURRENT:
ret = __ham_item(dbc, DB_LOCK_WRITE);
break;
}
if (ret == 0) {
if ((flags == DB_CURRENT && !F_ISSET(hcp, H_ISDUP)) ||
((flags == DB_KEYFIRST || flags == DB_KEYLAST) &&
!F_ISSET(dbp, DB_AM_DUP)))
ret = __ham_overwrite(dbc, data);
else
ret = __ham_add_dup(dbc, data, flags);
}
done: if (ret == 0 && F_ISSET(hcp, H_EXPAND)) {
ret = __ham_expand_table(dbc);
F_CLR(hcp, H_EXPAND);
}
if ((t_ret = __ham_item_done(dbc, ret == 0)) != 0 && ret == 0)
ret = t_ret;
out: RELEASE_META(dbp, hcp);
RESTORE_CURSOR(dbp, hcp, &save_curs, ret);
if (F_ISSET(dbp, DB_AM_CDB) && F_ISSET(dbc, DBC_RMW))
(void)__lock_downgrade(dbp->dbenv->lk_info, dbc->mylock,
DB_LOCK_IWRITE, 0);
return (ret);
}
/********************************* UTILITIES ************************/
/*
* __ham_expand_table --
*/
static int
__ham_expand_table(dbc)
DBC *dbc;
{
DB *dbp;
HASH_CURSOR *hcp;
DB_LSN new_lsn;
u_int32_t old_bucket, new_bucket, spare_ndx;
int ret;
dbp = dbc->dbp;
hcp = (HASH_CURSOR *)dbc->internal;
ret = 0;
DIRTY_META(dbp, hcp, ret);
if (ret)
return (ret);
/*
* If the split point is about to increase, make sure that we
* have enough extra pages. The calculation here is weird.
* We'd like to do this after we've upped max_bucket, but it's
* too late then because we've logged the meta-data split. What
* we'll do between then and now is increment max bucket and then
* see what the log of one greater than that is; here we have to
* look at the log of max + 2. VERY NASTY STUFF.
*/
if (__db_log2(hcp->hdr->max_bucket + 2) > hcp->hdr->ovfl_point) {
/*
* We are about to shift the split point. Make sure that
* if the next doubling is going to be big (more than 8
* pages), we have some extra pages around.
*/
if (hcp->hdr->max_bucket + 1 >= 8 &&
hcp->hdr->spares[hcp->hdr->ovfl_point] <
hcp->hdr->spares[hcp->hdr->ovfl_point - 1] +
hcp->hdr->ovfl_point + 1)
__ham_init_ovflpages(dbc);
}
/* Now we can log the meta-data split. */
if (DB_LOGGING(dbc)) {
if ((ret = __ham_splitmeta_log(dbp->dbenv->lg_info,
dbc->txn, &new_lsn, 0, dbp->log_fileid,
hcp->hdr->max_bucket, hcp->hdr->ovfl_point,
hcp->hdr->spares[hcp->hdr->ovfl_point],
&hcp->hdr->lsn)) != 0)
return (ret);
hcp->hdr->lsn = new_lsn;
}
hcp->stats.hash_expansions++;
new_bucket = ++hcp->hdr->max_bucket;
old_bucket = (hcp->hdr->max_bucket & hcp->hdr->low_mask);
/*
* If the split point is increasing, copy the current contents
* of the spare split bucket to the next bucket.
*/
spare_ndx = __db_log2(hcp->hdr->max_bucket + 1);
if (spare_ndx > hcp->hdr->ovfl_point) {
hcp->hdr->spares[spare_ndx] =
hcp->hdr->spares[hcp->hdr->ovfl_point];
hcp->hdr->ovfl_point = spare_ndx;
}
if (new_bucket > hcp->hdr->high_mask) {
/* Starting a new doubling */
hcp->hdr->low_mask = hcp->hdr->high_mask;
hcp->hdr->high_mask = new_bucket | hcp->hdr->low_mask;
}
if (BUCKET_TO_PAGE(hcp, new_bucket) > MAX_PAGES(hcp)) {
__db_err(dbp->dbenv,
"hash: Cannot allocate new bucket. Pages exhausted.");
return (ENOSPC);
}
/* Relocate records to the new bucket */
return (__ham_split_page(dbc, old_bucket, new_bucket));
}
/*
* PUBLIC: u_int32_t __ham_call_hash __P((HASH_CURSOR *, u_int8_t *, int32_t));
*/
u_int32_t
__ham_call_hash(hcp, k, len)
HASH_CURSOR *hcp;
u_int8_t *k;
int32_t len;
{
u_int32_t n, bucket;
n = (u_int32_t)(hcp->dbc->dbp->h_hash(k, len));
bucket = n & hcp->hdr->high_mask;
if (bucket > hcp->hdr->max_bucket)
bucket = bucket & hcp->hdr->low_mask;
return (bucket);
}
/*
* Check for duplicates, and call __db_ret appropriately. Release
* everything held by the cursor.
*/
static int
__ham_dup_return(dbc, val, flags)
DBC *dbc;
DBT *val;
u_int32_t flags;
{
DB *dbp;
HASH_CURSOR *hcp;
PAGE *pp;
DBT *myval, tmp_val;
db_indx_t ndx;
db_pgno_t pgno;
u_int32_t off, tlen;
u_int8_t *hk, type;
int cmp, ret;
db_indx_t len;
/* Check for duplicate and return the first one. */
dbp = dbc->dbp;
hcp = (HASH_CURSOR *)dbc->internal;
ndx = H_DATAINDEX(hcp->bndx);
type = HPAGE_TYPE(hcp->pagep, ndx);
pp = hcp->pagep;
myval = val;
/*
* There are 4 cases:
* 1. We are not in duplicate, simply call db_ret.
* 2. We are looking at keys and stumbled onto a duplicate.
* 3. We are in the middle of a duplicate set. (ISDUP set)
* 4. This is a duplicate and we need to return a specific item.
*/
/*
* Here we check for the case where we just stumbled onto a
* duplicate. In this case, we do initialization and then
* let the normal duplicate code handle it.
*/
if (!F_ISSET(hcp, H_ISDUP)) {
if (type == H_DUPLICATE) {
F_SET(hcp, H_ISDUP);
hcp->dup_tlen = LEN_HDATA(hcp->pagep,
hcp->hdr->pagesize, hcp->bndx);
hk = H_PAIRDATA(hcp->pagep, hcp->bndx);
if (flags == DB_LAST || flags == DB_PREV) {
hcp->dndx = 0;
hcp->dup_off = 0;
do {
memcpy(&len,
HKEYDATA_DATA(hk) + hcp->dup_off,
sizeof(db_indx_t));
hcp->dup_off += DUP_SIZE(len);
hcp->dndx++;
} while (hcp->dup_off < hcp->dup_tlen);
hcp->dup_off -= DUP_SIZE(len);
hcp->dndx--;
} else {
memcpy(&len,
HKEYDATA_DATA(hk), sizeof(db_indx_t));
hcp->dup_off = 0;
hcp->dndx = 0;
}
hcp->dup_len = len;
} else if (type == H_OFFDUP) {
F_SET(hcp, H_ISDUP);
memcpy(&pgno, HOFFDUP_PGNO(P_ENTRY(hcp->pagep, ndx)),
sizeof(db_pgno_t));
if (flags == DB_LAST || flags == DB_PREV) {
if ((ret = __db_dend(dbc,
pgno, &hcp->dpagep)) != 0)
return (ret);
hcp->dpgno = PGNO(hcp->dpagep);
hcp->dndx = NUM_ENT(hcp->dpagep) - 1;
} else if ((ret = __ham_next_cpage(dbc,
pgno, 0, H_ISDUP)) != 0)
return (ret);
}
}
/*
* If we are retrieving a specific key/data pair, then we
* may need to adjust the cursor before returning data.
*/
if (flags == DB_GET_BOTH) {
if (F_ISSET(hcp, H_ISDUP)) {
if (hcp->dpgno != PGNO_INVALID) {
if ((ret = __db_dsearch(dbc, 0, val,
hcp->dpgno, &hcp->dndx, &hcp->dpagep, &cmp))
!= 0)
return (ret);
if (cmp == 0)
hcp->dpgno = PGNO(hcp->dpagep);
} else {
__ham_dsearch(dbc, val, &off, &cmp);
hcp->dup_off = off;
}
} else {
hk = H_PAIRDATA(hcp->pagep, hcp->bndx);
if (((HKEYDATA *)hk)->type == H_OFFPAGE) {
memcpy(&tlen,
HOFFPAGE_TLEN(hk), sizeof(u_int32_t));
memcpy(&pgno,
HOFFPAGE_PGNO(hk), sizeof(db_pgno_t));
if ((ret = __db_moff(dbp, val,
pgno, tlen, dbp->dup_compare, &cmp)) != 0)
return (ret);
} else {
/*
* We do not zero tmp_val since the comparison
* routines may only look at data and size.
*/
tmp_val.data = HKEYDATA_DATA(hk);
tmp_val.size = LEN_HDATA(hcp->pagep,
dbp->pgsize, hcp->bndx);
cmp = dbp->dup_compare == NULL ?
__bam_defcmp(&tmp_val, val) :
dbp->dup_compare(&tmp_val, val);
}
}
if (cmp != 0)
return (DB_NOTFOUND);
}
/*
* Now, everything is initialized, grab a duplicate if
* necessary.
*/
if (F_ISSET(hcp, H_ISDUP)) {
if (hcp->dpgno != PGNO_INVALID) {
pp = hcp->dpagep;
ndx = hcp->dndx;
} else {
/*
* Copy the DBT in case we are retrieving into user
* memory and we need the parameters for it. If the
* user requested a partial, then we need to adjust
* the user's parameters to get the partial of the
* duplicate which is itself a partial.
*/
memcpy(&tmp_val, val, sizeof(*val));
if (F_ISSET(&tmp_val, DB_DBT_PARTIAL)) {
/*
* Take the user's length unless it would go
* beyond the end of the duplicate.
*/
if (tmp_val.doff + hcp->dup_off > hcp->dup_len)
tmp_val.dlen = 0;
else if (tmp_val.dlen + tmp_val.doff >
hcp->dup_len)
tmp_val.dlen =
hcp->dup_len - tmp_val.doff;
/*
* Calculate the new offset.
*/
tmp_val.doff += hcp->dup_off;
} else {
F_SET(&tmp_val, DB_DBT_PARTIAL);
tmp_val.dlen = hcp->dup_len;
tmp_val.doff = hcp->dup_off + sizeof(db_indx_t);
}
myval = &tmp_val;
}
}
/*
* Finally, if we had a duplicate, pp, ndx, and myval should be
* set appropriately.
*/
if ((ret = __db_ret(dbp, pp, ndx, myval, &dbc->rdata.data,
&dbc->rdata.size)) != 0)
return (ret);
/*
* In case we sent a temporary off to db_ret, set the real
* return values.
*/
val->data = myval->data;
val->size = myval->size;
return (0);
}
static int
__ham_overwrite(dbc, nval)
DBC *dbc;
DBT *nval;
{
HASH_CURSOR *hcp;
DBT *myval, tmp_val;
u_int8_t *hk;
hcp = (HASH_CURSOR *)dbc->internal;
if (F_ISSET(dbc->dbp, DB_AM_DUP))
return (__ham_add_dup(dbc, nval, DB_KEYLAST));
else if (!F_ISSET(nval, DB_DBT_PARTIAL)) {
/* Put/overwrite */
memcpy(&tmp_val, nval, sizeof(*nval));
F_SET(&tmp_val, DB_DBT_PARTIAL);
tmp_val.doff = 0;
hk = H_PAIRDATA(hcp->pagep, hcp->bndx);
if (HPAGE_PTYPE(hk) == H_OFFPAGE)
memcpy(&tmp_val.dlen,
HOFFPAGE_TLEN(hk), sizeof(u_int32_t));
else
tmp_val.dlen = LEN_HDATA(hcp->pagep,
hcp->hdr->pagesize,hcp->bndx);
myval = &tmp_val;
} else /* Regular partial put */
myval = nval;
return (__ham_replpair(dbc, myval, 0));
}
/*
* Given a key and a cursor, sets the cursor to the page/ndx on which
* the key resides. If the key is found, the cursor H_OK flag is set
* and the pagep, bndx, pgno (dpagep, dndx, dpgno) fields are set.
* If the key is not found, the H_OK flag is not set. If the sought
* field is non-0, the pagep, bndx, pgno (dpagep, dndx, dpgno) fields
* are set indicating where an add might take place. If it is 0,
* non of the cursor pointer field are valid.
*/
static int
__ham_lookup(dbc, key, sought, mode)
DBC *dbc;
const DBT *key;
u_int32_t sought;
db_lockmode_t mode;
{
DB *dbp;
HASH_CURSOR *hcp;
db_pgno_t pgno;
u_int32_t tlen;
int match, ret, t_ret;
u_int8_t *hk;
dbp = dbc->dbp;
hcp = (HASH_CURSOR *)dbc->internal;
/*
* Set up cursor so that we're looking for space to add an item
* as we cycle through the pages looking for the key.
*/
if ((ret = __ham_item_reset(dbc)) != 0)
return (ret);
hcp->seek_size = sought;
hcp->bucket = __ham_call_hash(hcp, (u_int8_t *)key->data, key->size);
while (1) {
if ((ret = __ham_item_next(dbc, mode)) != 0)
return (ret);
if (F_ISSET(hcp, H_NOMORE))
break;
hk = H_PAIRKEY(hcp->pagep, hcp->bndx);
switch (HPAGE_PTYPE(hk)) {
case H_OFFPAGE:
memcpy(&tlen, HOFFPAGE_TLEN(hk), sizeof(u_int32_t));
if (tlen == key->size) {
memcpy(&pgno,
HOFFPAGE_PGNO(hk), sizeof(db_pgno_t));
if ((ret = __db_moff(dbp,
key, pgno, tlen, NULL, &match)) != 0)
return (ret);
if (match == 0) {
F_SET(hcp, H_OK);
return (0);
}
}
break;
case H_KEYDATA:
if (key->size == LEN_HKEY(hcp->pagep,
hcp->hdr->pagesize, hcp->bndx) &&
memcmp(key->data,
HKEYDATA_DATA(hk), key->size) == 0) {
F_SET(hcp, H_OK);
return (0);
}
break;
case H_DUPLICATE:
case H_OFFDUP:
/*
* These are errors because keys are never
* duplicated, only data items are.
*/
return (__db_pgfmt(dbp, PGNO(hcp->pagep)));
}
hcp->stats.hash_collisions++;
}
/*
* Item was not found, adjust cursor properly.
*/
if (sought != 0)
return (ret);
if ((t_ret = __ham_item_done(dbc, 0)) != 0 && ret == 0)
ret = t_ret;
return (ret);
}
/*
* Initialize a dbt using some possibly already allocated storage
* for items.
* PUBLIC: int __ham_init_dbt __P((DBT *, u_int32_t, void **, u_int32_t *));
*/
int
__ham_init_dbt(dbt, size, bufp, sizep)
DBT *dbt;
u_int32_t size;
void **bufp;
u_int32_t *sizep;
{
int ret;
memset(dbt, 0, sizeof(*dbt));
if (*sizep < size) {
if ((ret = __os_realloc(bufp, size)) != 0) {
*sizep = 0;
return (ret);
}
*sizep = size;
}
dbt->data = *bufp;
dbt->size = size;
return (0);
}
/*
* Adjust the cursor after an insert or delete. The cursor passed is
* the one that was operated upon; we just need to check any of the
* others.
*
* len indicates the length of the item added/deleted
* add indicates if the item indicated by the cursor has just been
* added (add == 1) or deleted (add == 0).
* dup indicates if the addition occurred into a duplicate set.
*
* PUBLIC: void __ham_c_update
* PUBLIC: __P((HASH_CURSOR *, db_pgno_t, u_int32_t, int, int));
*/
void
__ham_c_update(hcp, chg_pgno, len, add, is_dup)
HASH_CURSOR *hcp;
db_pgno_t chg_pgno;
u_int32_t len;
int add, is_dup;
{
DB *dbp;
DBC *cp;
HASH_CURSOR *lcp;
int page_deleted;
/*
* Regular adds are always at the end of a given page, so we never
* have to adjust anyone's cursor after a regular add.
*/
if (!is_dup && add)
return;
/*
* Determine if a page was deleted. If this is a regular update
* (i.e., not is_dup) then the deleted page's number will be that in
* chg_pgno, and the pgno in the cursor will be different. If this
* was an onpage-duplicate, then the same conditions apply. If this
* was an off-page duplicate, then we need to verify if hcp->dpgno
* is the same (no delete) or different (delete) than chg_pgno.
*/
if (!is_dup || hcp->dpgno == PGNO_INVALID)
page_deleted =
chg_pgno != PGNO_INVALID && chg_pgno != hcp->pgno;
else
page_deleted =
chg_pgno != PGNO_INVALID && chg_pgno != hcp->dpgno;
dbp = hcp->dbc->dbp;
DB_THREAD_LOCK(dbp);
for (cp = TAILQ_FIRST(&dbp->active_queue); cp != NULL;
cp = TAILQ_NEXT(cp, links)) {
if (cp->internal == hcp)
continue;
lcp = (HASH_CURSOR *)cp->internal;
if (!is_dup && lcp->pgno != chg_pgno)
continue;
if (is_dup) {
if (F_ISSET(hcp, H_DELETED) && lcp->pgno != chg_pgno)
continue;
if (!F_ISSET(hcp, H_DELETED) && lcp->dpgno != chg_pgno)
continue;
}
if (page_deleted) {
if (is_dup) {
lcp->dpgno = hcp->dpgno;
lcp->dndx = hcp->dndx;
} else {
lcp->pgno = hcp->pgno;
lcp->bndx = hcp->bndx;
lcp->bucket = hcp->bucket;
}
F_CLR(lcp, H_ISDUP);
continue;
}
if (!is_dup && lcp->bndx > hcp->bndx)
lcp->bndx--;
else if (!is_dup && lcp->bndx == hcp->bndx)
F_SET(lcp, H_DELETED);
else if (is_dup && lcp->bndx == hcp->bndx) {
/* Assign dpgno in case there was page conversion. */
lcp->dpgno = hcp->dpgno;
if (add && lcp->dndx >= hcp->dndx )
lcp->dndx++;
else if (!add && lcp->dndx > hcp->dndx)
lcp->dndx--;
else if (!add && lcp->dndx == hcp->dndx)
F_SET(lcp, H_DELETED);
/* Now adjust on-page information. */
if (lcp->dpgno == PGNO_INVALID) {
if (add) {
lcp->dup_tlen += len;
if (lcp->dndx > hcp->dndx)
lcp->dup_off += len;
} else {
lcp->dup_tlen -= len;
if (lcp->dndx > hcp->dndx)
lcp->dup_off -= len;
}
}
}
}
DB_THREAD_UNLOCK(dbp);
}
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