948 lines
23 KiB
C
948 lines
23 KiB
C
/*-
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* See the file LICENSE for redistribution information.
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*
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* Copyright (c) 1996, 1997, 1998
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* Sleepycat Software. All rights reserved.
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*/
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#include "config.h"
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#ifndef lint
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static const char sccsid[] = "@(#)db_dup.c 10.35 (Sleepycat) 12/2/98";
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#endif /* not lint */
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#ifndef NO_SYSTEM_INCLUDES
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#include <sys/types.h>
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#include <errno.h>
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#include <string.h>
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#endif
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#include "db_int.h"
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#include "db_page.h"
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#include "btree.h"
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#include "db_am.h"
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static int __db_addpage __P((DBC *,
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PAGE **, db_indx_t *, int (*)(DBC *, u_int32_t, PAGE **)));
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static int __db_dsplit __P((DBC *,
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PAGE **, db_indx_t *, u_int32_t, int (*)(DBC *, u_int32_t, PAGE **)));
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/*
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* __db_dput --
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* Put a duplicate item onto a duplicate page at the given index.
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*
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* PUBLIC: int __db_dput __P((DBC *, DBT *,
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* PUBLIC: PAGE **, db_indx_t *, int (*)(DBC *, u_int32_t, PAGE **)));
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*/
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int
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__db_dput(dbc, dbt, pp, indxp, newfunc)
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DBC *dbc;
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DBT *dbt;
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PAGE **pp;
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db_indx_t *indxp;
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int (*newfunc) __P((DBC *, u_int32_t, PAGE **));
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{
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BOVERFLOW bo;
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DBT *data_dbtp, hdr_dbt, *hdr_dbtp;
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PAGE *pagep;
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db_indx_t size, isize;
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db_pgno_t pgno;
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int ret;
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/*
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* We need some access method independent threshold for when we put
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* a duplicate item onto an overflow page.
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*/
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if (dbt->size > 0.25 * dbc->dbp->pgsize) {
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if ((ret = __db_poff(dbc, dbt, &pgno, newfunc)) != 0)
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return (ret);
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UMRW(bo.unused1);
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B_TSET(bo.type, B_OVERFLOW, 0);
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UMRW(bo.unused2);
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bo.tlen = dbt->size;
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bo.pgno = pgno;
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hdr_dbt.data = &bo;
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hdr_dbt.size = isize = BOVERFLOW_SIZE;
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hdr_dbtp = &hdr_dbt;
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size = BOVERFLOW_PSIZE;
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data_dbtp = NULL;
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} else {
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size = BKEYDATA_PSIZE(dbt->size);
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isize = BKEYDATA_SIZE(dbt->size);
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hdr_dbtp = NULL;
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data_dbtp = dbt;
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}
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pagep = *pp;
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if (size > P_FREESPACE(pagep)) {
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if (*indxp == NUM_ENT(*pp) && NEXT_PGNO(*pp) == PGNO_INVALID)
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ret = __db_addpage(dbc, pp, indxp, newfunc);
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else
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ret = __db_dsplit(dbc, pp, indxp, isize, newfunc);
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if (ret != 0)
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/*
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* XXX
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* Pages not returned to free list.
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*/
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return (ret);
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pagep = *pp;
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}
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/*
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* Now, pagep references the page on which to insert and indx is the
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* the location to insert.
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*/
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if ((ret = __db_pitem(dbc,
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pagep, (u_int32_t)*indxp, isize, hdr_dbtp, data_dbtp)) != 0)
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return (ret);
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(void)memp_fset(dbc->dbp->mpf, pagep, DB_MPOOL_DIRTY);
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return (0);
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}
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/*
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* __db_drem --
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* Remove a duplicate at the given index on the given page.
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*
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* PUBLIC: int __db_drem __P((DBC *,
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* PUBLIC: PAGE **, u_int32_t, int (*)(DBC *, PAGE *)));
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*/
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int
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__db_drem(dbc, pp, indx, freefunc)
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DBC *dbc;
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PAGE **pp;
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u_int32_t indx;
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int (*freefunc) __P((DBC *, PAGE *));
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{
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PAGE *pagep;
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int ret;
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pagep = *pp;
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/* Check if we are freeing a big item. */
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if (B_TYPE(GET_BKEYDATA(pagep, indx)->type) == B_OVERFLOW) {
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if ((ret = __db_doff(dbc,
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GET_BOVERFLOW(pagep, indx)->pgno, freefunc)) != 0)
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return (ret);
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ret = __db_ditem(dbc, pagep, indx, BOVERFLOW_SIZE);
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} else
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ret = __db_ditem(dbc, pagep, indx,
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BKEYDATA_SIZE(GET_BKEYDATA(pagep, indx)->len));
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if (ret != 0)
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return (ret);
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if (NUM_ENT(pagep) == 0) {
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/*
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* If the page is emptied, then the page is freed and the pp
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* parameter is set to reference the next, locked page in the
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* duplicate chain, if one exists. If there was no such page,
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* then it is set to NULL.
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*
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* !!!
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* __db_relink will set the dirty bit for us.
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*/
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if ((ret = __db_relink(dbc, DB_REM_PAGE, pagep, pp, 0)) != 0)
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return (ret);
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if ((ret = freefunc(dbc, pagep)) != 0)
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return (ret);
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} else
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(void)memp_fset(dbc->dbp->mpf, pagep, DB_MPOOL_DIRTY);
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return (0);
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}
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/*
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* __db_dend --
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* Find the last page in a set of offpage duplicates.
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*
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* PUBLIC: int __db_dend __P((DBC *, db_pgno_t, PAGE **));
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*/
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int
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__db_dend(dbc, pgno, pp)
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DBC *dbc;
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db_pgno_t pgno;
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PAGE **pp;
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{
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DB *dbp;
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PAGE *h;
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int ret;
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dbp = dbc->dbp;
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/*
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* This implements DB_KEYLAST. The last page is returned in pp; pgno
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* should be the page number of the first page of the duplicate chain.
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*
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* *pp may be non-NULL -- if given a valid page use it.
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*/
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if (*pp != NULL)
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goto started;
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for (;;) {
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if ((ret = memp_fget(dbp->mpf, &pgno, 0, pp)) != 0) {
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(void)__db_pgerr(dbp, pgno);
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return (ret);
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}
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started: h = *pp;
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if ((pgno = NEXT_PGNO(h)) == PGNO_INVALID)
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break;
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if ((ret = memp_fput(dbp->mpf, h, 0)) != 0)
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return (ret);
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}
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return (0);
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}
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/*
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* __db_dsplit --
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* Split a page of duplicates, calculating the split point based
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* on an element of size "size" being added at "*indxp".
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* On entry hp contains a pointer to the page-pointer of the original
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* page. On exit, it returns a pointer to the page containing "*indxp"
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* and "indxp" has been modified to reflect the index on the new page
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* where the element should be added. The function returns with
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* the page on which the insert should happen, not yet put.
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*/
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static int
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__db_dsplit(dbc, hp, indxp, size, newfunc)
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DBC *dbc;
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PAGE **hp;
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db_indx_t *indxp;
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u_int32_t size;
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int (*newfunc) __P((DBC *, u_int32_t, PAGE **));
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{
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PAGE *h, *np, *tp;
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BKEYDATA *bk;
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DBT page_dbt;
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DB *dbp;
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size_t pgsize;
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db_indx_t halfbytes, i, indx, lastsum, nindex, oindex, s, sum;
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int did_indx, ret, t_ret;
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h = *hp;
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indx = *indxp;
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ret = 0;
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dbp = dbc->dbp;
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pgsize = dbp->pgsize;
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/* Create a temporary page to do compaction onto. */
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if ((ret = __os_malloc(pgsize, NULL, &tp)) != 0)
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return (ret);
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/* Create new page for the split. */
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if ((ret = newfunc(dbc, P_DUPLICATE, &np)) != 0) {
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__os_free(tp, pgsize);
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return (ret);
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}
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P_INIT(np, pgsize, PGNO(np), PGNO(h), NEXT_PGNO(h), 0,
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P_DUPLICATE);
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P_INIT(tp, pgsize, PGNO(h), PREV_PGNO(h), PGNO(np), 0,
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P_DUPLICATE);
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/* Figure out the split point */
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halfbytes = (pgsize - HOFFSET(h)) / 2;
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did_indx = 0;
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for (sum = 0, lastsum = 0, i = 0; i < NUM_ENT(h); i++) {
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if (i == indx) {
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sum += size;
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did_indx = 1;
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if (lastsum < halfbytes && sum >= halfbytes) {
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/* We've crossed the halfway point. */
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if ((db_indx_t)(halfbytes - lastsum) <
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(db_indx_t)(sum - halfbytes)) {
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*hp = np;
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*indxp = 0;
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} else
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*indxp = i;
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break;
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}
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*indxp = i;
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lastsum = sum;
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}
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if (B_TYPE(GET_BKEYDATA(h, i)->type) == B_KEYDATA)
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sum += BKEYDATA_SIZE(GET_BKEYDATA(h, i)->len);
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else
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sum += BOVERFLOW_SIZE;
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if (lastsum < halfbytes && sum >= halfbytes) {
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/* We've crossed the halfway point. */
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if ((db_indx_t)(sum - halfbytes) <
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(db_indx_t)(halfbytes - lastsum))
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i++;
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break;
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}
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}
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/*
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* Check if we have set the return values of the index pointer and
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* page pointer.
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*/
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if (!did_indx) {
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*hp = np;
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*indxp = indx - i;
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}
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if (DB_LOGGING(dbc)) {
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page_dbt.size = dbp->pgsize;
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page_dbt.data = h;
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if ((ret = __db_split_log(dbp->dbenv->lg_info,
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dbc->txn, &LSN(h), 0, DB_SPLITOLD, dbp->log_fileid,
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PGNO(h), &page_dbt, &LSN(h))) != 0) {
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__os_free(tp, pgsize);
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return (ret);
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}
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LSN(tp) = LSN(h);
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}
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/*
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* If it's a btree, adjust the cursors.
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*
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* i is the index of the first element to move onto the new page.
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*/
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if (dbp->type == DB_BTREE)
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__bam_ca_split(dbp, PGNO(h), PGNO(h), PGNO(np), i, 0);
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for (nindex = 0, oindex = i; oindex < NUM_ENT(h); oindex++) {
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bk = GET_BKEYDATA(h, oindex);
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if (B_TYPE(bk->type) == B_KEYDATA)
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s = BKEYDATA_SIZE(bk->len);
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else
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s = BOVERFLOW_SIZE;
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np->inp[nindex++] = HOFFSET(np) -= s;
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memcpy((u_int8_t *)np + HOFFSET(np), bk, s);
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NUM_ENT(np)++;
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}
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/*
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* Now do data compaction by copying the remaining stuff onto the
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* temporary page and then copying it back to the real page.
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*/
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for (nindex = 0, oindex = 0; oindex < i; oindex++) {
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bk = GET_BKEYDATA(h, oindex);
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if (B_TYPE(bk->type) == B_KEYDATA)
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s = BKEYDATA_SIZE(bk->len);
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else
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s = BOVERFLOW_SIZE;
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tp->inp[nindex++] = HOFFSET(tp) -= s;
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memcpy((u_int8_t *)tp + HOFFSET(tp), bk, s);
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NUM_ENT(tp)++;
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}
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/*
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* This page (the temporary) should be only half full, so we do two
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* memcpy's, one for the top of the page and one for the bottom of
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* the page. This way we avoid copying the middle which should be
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* about half a page.
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*/
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memcpy(h, tp, LOFFSET(tp));
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memcpy((u_int8_t *)h + HOFFSET(tp),
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(u_int8_t *)tp + HOFFSET(tp), pgsize - HOFFSET(tp));
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__os_free(tp, pgsize);
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if (DB_LOGGING(dbc)) {
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/*
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* XXX
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* If either of these fails, are we leaving pages pinned?
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* Yes, but it seems like this happens in error case.
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*/
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page_dbt.size = pgsize;
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page_dbt.data = h;
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if ((ret = __db_split_log(dbp->dbenv->lg_info,
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dbc->txn, &LSN(h), 0, DB_SPLITNEW, dbp->log_fileid,
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PGNO(h), &page_dbt, &LSN(h))) != 0)
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return (ret);
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page_dbt.size = pgsize;
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page_dbt.data = np;
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if ((ret = __db_split_log(dbp->dbenv->lg_info,
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dbc->txn, &LSN(np), 0, DB_SPLITNEW, dbp->log_fileid,
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PGNO(np), &page_dbt, &LSN(np))) != 0)
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return (ret);
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}
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/*
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* Finally, if there was a next page after the page being
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* split, fix its prev pointer.
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*/
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if (np->next_pgno != PGNO_INVALID)
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ret = __db_relink(dbc, DB_ADD_PAGE, np, NULL, 1);
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/*
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* Figure out if the location we're interested in is on the new
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* page, and if so, reset the callers' pointer. Push the other
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* page back to the store.
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*/
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if (*hp == h)
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t_ret = memp_fput(dbp->mpf, np, DB_MPOOL_DIRTY);
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else
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t_ret = memp_fput(dbp->mpf, h, DB_MPOOL_DIRTY);
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return (ret != 0 ? ret : t_ret);
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}
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/*
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* __db_ditem --
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* Remove an item from a page.
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*
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* PUBLIC: int __db_ditem __P((DBC *, PAGE *, u_int32_t, u_int32_t));
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*/
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int
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__db_ditem(dbc, pagep, indx, nbytes)
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DBC *dbc;
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PAGE *pagep;
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u_int32_t indx, nbytes;
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{
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DB *dbp;
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DBT ldbt;
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db_indx_t cnt, offset;
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int ret;
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u_int8_t *from;
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dbp = dbc->dbp;
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if (DB_LOGGING(dbc)) {
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ldbt.data = P_ENTRY(pagep, indx);
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ldbt.size = nbytes;
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if ((ret = __db_addrem_log(dbp->dbenv->lg_info, dbc->txn,
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&LSN(pagep), 0, DB_REM_DUP, dbp->log_fileid, PGNO(pagep),
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(u_int32_t)indx, nbytes, &ldbt, NULL, &LSN(pagep))) != 0)
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return (ret);
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}
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/*
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* If there's only a single item on the page, we don't have to
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* work hard.
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*/
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if (NUM_ENT(pagep) == 1) {
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NUM_ENT(pagep) = 0;
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HOFFSET(pagep) = dbp->pgsize;
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return (0);
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}
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/*
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* Pack the remaining key/data items at the end of the page. Use
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* memmove(3), the regions may overlap.
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*/
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from = (u_int8_t *)pagep + HOFFSET(pagep);
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memmove(from + nbytes, from, pagep->inp[indx] - HOFFSET(pagep));
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HOFFSET(pagep) += nbytes;
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/* Adjust the indices' offsets. */
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offset = pagep->inp[indx];
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for (cnt = 0; cnt < NUM_ENT(pagep); ++cnt)
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if (pagep->inp[cnt] < offset)
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pagep->inp[cnt] += nbytes;
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/* Shift the indices down. */
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--NUM_ENT(pagep);
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if (indx != NUM_ENT(pagep))
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memmove(&pagep->inp[indx], &pagep->inp[indx + 1],
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sizeof(db_indx_t) * (NUM_ENT(pagep) - indx));
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/* If it's a btree, adjust the cursors. */
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if (dbp->type == DB_BTREE)
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__bam_ca_di(dbp, PGNO(pagep), indx, -1);
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return (0);
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}
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|
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/*
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* __db_pitem --
|
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* Put an item on a page.
|
|
*
|
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* PUBLIC: int __db_pitem
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* PUBLIC: __P((DBC *, PAGE *, u_int32_t, u_int32_t, DBT *, DBT *));
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*/
|
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int
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__db_pitem(dbc, pagep, indx, nbytes, hdr, data)
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DBC *dbc;
|
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PAGE *pagep;
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u_int32_t indx;
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u_int32_t nbytes;
|
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DBT *hdr, *data;
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{
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DB *dbp;
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BKEYDATA bk;
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DBT thdr;
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int ret;
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u_int8_t *p;
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|
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/*
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* Put a single item onto a page. The logic figuring out where to
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* insert and whether it fits is handled in the caller. All we do
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* here is manage the page shuffling. We cheat a little bit in that
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* we don't want to copy the dbt on a normal put twice. If hdr is
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* NULL, we create a BKEYDATA structure on the page, otherwise, just
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* copy the caller's information onto the page.
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*
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* This routine is also used to put entries onto the page where the
|
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* entry is pre-built, e.g., during recovery. In this case, the hdr
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* will point to the entry, and the data argument will be NULL.
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*
|
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* !!!
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|
* There's a tremendous potential for off-by-one errors here, since
|
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* the passed in header sizes must be adjusted for the structure's
|
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* placeholder for the trailing variable-length data field.
|
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*/
|
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dbp = dbc->dbp;
|
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if (DB_LOGGING(dbc))
|
|
if ((ret = __db_addrem_log(dbp->dbenv->lg_info, dbc->txn,
|
|
&LSN(pagep), 0, DB_ADD_DUP, dbp->log_fileid, PGNO(pagep),
|
|
(u_int32_t)indx, nbytes, hdr, data, &LSN(pagep))) != 0)
|
|
return (ret);
|
|
|
|
if (hdr == NULL) {
|
|
B_TSET(bk.type, B_KEYDATA, 0);
|
|
bk.len = data == NULL ? 0 : data->size;
|
|
|
|
thdr.data = &bk;
|
|
thdr.size = SSZA(BKEYDATA, data);
|
|
hdr = &thdr;
|
|
}
|
|
|
|
/* Adjust the index table, then put the item on the page. */
|
|
if (indx != NUM_ENT(pagep))
|
|
memmove(&pagep->inp[indx + 1], &pagep->inp[indx],
|
|
sizeof(db_indx_t) * (NUM_ENT(pagep) - indx));
|
|
HOFFSET(pagep) -= nbytes;
|
|
pagep->inp[indx] = HOFFSET(pagep);
|
|
++NUM_ENT(pagep);
|
|
|
|
p = P_ENTRY(pagep, indx);
|
|
memcpy(p, hdr->data, hdr->size);
|
|
if (data != NULL)
|
|
memcpy(p + hdr->size, data->data, data->size);
|
|
|
|
/* If it's a btree, adjust the cursors. */
|
|
if (dbp->type == DB_BTREE)
|
|
__bam_ca_di(dbp, PGNO(pagep), indx, 1);
|
|
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* __db_relink --
|
|
* Relink around a deleted page.
|
|
*
|
|
* PUBLIC: int __db_relink __P((DBC *, u_int32_t, PAGE *, PAGE **, int));
|
|
*/
|
|
int
|
|
__db_relink(dbc, add_rem, pagep, new_next, needlock)
|
|
DBC *dbc;
|
|
u_int32_t add_rem;
|
|
PAGE *pagep, **new_next;
|
|
int needlock;
|
|
{
|
|
DB *dbp;
|
|
PAGE *np, *pp;
|
|
DB_LOCK npl, ppl;
|
|
DB_LSN *nlsnp, *plsnp;
|
|
int ret;
|
|
|
|
ret = 0;
|
|
np = pp = NULL;
|
|
npl = ppl = LOCK_INVALID;
|
|
nlsnp = plsnp = NULL;
|
|
dbp = dbc->dbp;
|
|
|
|
/*
|
|
* Retrieve and lock the one/two pages. For a remove, we may need
|
|
* two pages (the before and after). For an add, we only need one
|
|
* because, the split took care of the prev.
|
|
*/
|
|
if (pagep->next_pgno != PGNO_INVALID) {
|
|
if (needlock && (ret = __bam_lget(dbc,
|
|
0, pagep->next_pgno, DB_LOCK_WRITE, &npl)) != 0)
|
|
goto err;
|
|
if ((ret = memp_fget(dbp->mpf,
|
|
&pagep->next_pgno, 0, &np)) != 0) {
|
|
(void)__db_pgerr(dbp, pagep->next_pgno);
|
|
goto err;
|
|
}
|
|
nlsnp = &np->lsn;
|
|
}
|
|
if (add_rem == DB_REM_PAGE && pagep->prev_pgno != PGNO_INVALID) {
|
|
if (needlock && (ret = __bam_lget(dbc,
|
|
0, pagep->prev_pgno, DB_LOCK_WRITE, &ppl)) != 0)
|
|
goto err;
|
|
if ((ret = memp_fget(dbp->mpf,
|
|
&pagep->prev_pgno, 0, &pp)) != 0) {
|
|
(void)__db_pgerr(dbp, pagep->next_pgno);
|
|
goto err;
|
|
}
|
|
plsnp = &pp->lsn;
|
|
}
|
|
|
|
/* Log the change. */
|
|
if (DB_LOGGING(dbc)) {
|
|
if ((ret = __db_relink_log(dbp->dbenv->lg_info, dbc->txn,
|
|
&pagep->lsn, 0, add_rem, dbp->log_fileid,
|
|
pagep->pgno, &pagep->lsn,
|
|
pagep->prev_pgno, plsnp, pagep->next_pgno, nlsnp)) != 0)
|
|
goto err;
|
|
if (np != NULL)
|
|
np->lsn = pagep->lsn;
|
|
if (pp != NULL)
|
|
pp->lsn = pagep->lsn;
|
|
}
|
|
|
|
/*
|
|
* Modify and release the two pages.
|
|
*
|
|
* !!!
|
|
* The parameter new_next gets set to the page following the page we
|
|
* are removing. If there is no following page, then new_next gets
|
|
* set to NULL.
|
|
*/
|
|
if (np != NULL) {
|
|
if (add_rem == DB_ADD_PAGE)
|
|
np->prev_pgno = pagep->pgno;
|
|
else
|
|
np->prev_pgno = pagep->prev_pgno;
|
|
if (new_next == NULL)
|
|
ret = memp_fput(dbp->mpf, np, DB_MPOOL_DIRTY);
|
|
else {
|
|
*new_next = np;
|
|
ret = memp_fset(dbp->mpf, np, DB_MPOOL_DIRTY);
|
|
}
|
|
if (ret != 0)
|
|
goto err;
|
|
if (needlock)
|
|
(void)__bam_lput(dbc, npl);
|
|
} else if (new_next != NULL)
|
|
*new_next = NULL;
|
|
|
|
if (pp != NULL) {
|
|
pp->next_pgno = pagep->next_pgno;
|
|
if ((ret = memp_fput(dbp->mpf, pp, DB_MPOOL_DIRTY)) != 0)
|
|
goto err;
|
|
if (needlock)
|
|
(void)__bam_lput(dbc, ppl);
|
|
}
|
|
return (0);
|
|
|
|
err: if (np != NULL)
|
|
(void)memp_fput(dbp->mpf, np, 0);
|
|
if (needlock && npl != LOCK_INVALID)
|
|
(void)__bam_lput(dbc, npl);
|
|
if (pp != NULL)
|
|
(void)memp_fput(dbp->mpf, pp, 0);
|
|
if (needlock && ppl != LOCK_INVALID)
|
|
(void)__bam_lput(dbc, ppl);
|
|
return (ret);
|
|
}
|
|
|
|
/*
|
|
* __db_ddup --
|
|
* Delete an offpage chain of duplicates.
|
|
*
|
|
* PUBLIC: int __db_ddup __P((DBC *, db_pgno_t, int (*)(DBC *, PAGE *)));
|
|
*/
|
|
int
|
|
__db_ddup(dbc, pgno, freefunc)
|
|
DBC *dbc;
|
|
db_pgno_t pgno;
|
|
int (*freefunc) __P((DBC *, PAGE *));
|
|
{
|
|
DB *dbp;
|
|
PAGE *pagep;
|
|
DBT tmp_dbt;
|
|
int ret;
|
|
|
|
dbp = dbc->dbp;
|
|
do {
|
|
if ((ret = memp_fget(dbp->mpf, &pgno, 0, &pagep)) != 0) {
|
|
(void)__db_pgerr(dbp, pgno);
|
|
return (ret);
|
|
}
|
|
|
|
if (DB_LOGGING(dbc)) {
|
|
tmp_dbt.data = pagep;
|
|
tmp_dbt.size = dbp->pgsize;
|
|
if ((ret = __db_split_log(dbp->dbenv->lg_info,
|
|
dbc->txn, &LSN(pagep), 0, DB_SPLITOLD,
|
|
dbp->log_fileid, PGNO(pagep), &tmp_dbt,
|
|
&LSN(pagep))) != 0)
|
|
return (ret);
|
|
}
|
|
pgno = pagep->next_pgno;
|
|
if ((ret = freefunc(dbc, pagep)) != 0)
|
|
return (ret);
|
|
} while (pgno != PGNO_INVALID);
|
|
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* __db_addpage --
|
|
* Create a new page and link it onto the next_pgno field of the
|
|
* current page.
|
|
*/
|
|
static int
|
|
__db_addpage(dbc, hp, indxp, newfunc)
|
|
DBC *dbc;
|
|
PAGE **hp;
|
|
db_indx_t *indxp;
|
|
int (*newfunc) __P((DBC *, u_int32_t, PAGE **));
|
|
{
|
|
DB *dbp;
|
|
PAGE *newpage;
|
|
int ret;
|
|
|
|
dbp = dbc->dbp;
|
|
if ((ret = newfunc(dbc, P_DUPLICATE, &newpage)) != 0)
|
|
return (ret);
|
|
|
|
if (DB_LOGGING(dbc)) {
|
|
if ((ret = __db_addpage_log(dbp->dbenv->lg_info,
|
|
dbc->txn, &LSN(*hp), 0, dbp->log_fileid,
|
|
PGNO(*hp), &LSN(*hp), PGNO(newpage), &LSN(newpage))) != 0) {
|
|
return (ret);
|
|
}
|
|
LSN(newpage) = LSN(*hp);
|
|
}
|
|
|
|
PREV_PGNO(newpage) = PGNO(*hp);
|
|
NEXT_PGNO(*hp) = PGNO(newpage);
|
|
|
|
if ((ret = memp_fput(dbp->mpf, *hp, DB_MPOOL_DIRTY)) != 0)
|
|
return (ret);
|
|
*hp = newpage;
|
|
*indxp = 0;
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* __db_dsearch --
|
|
* Search a set of duplicates for the proper position for a new duplicate.
|
|
*
|
|
* + pgno is the page number of the page on which to begin searching.
|
|
* Since we can continue duplicate searches, it might not be the first
|
|
* page.
|
|
*
|
|
* + If we are continuing a search, then *pp may be non-NULL in which
|
|
* case we do not have to retrieve the page.
|
|
*
|
|
* + If we are continuing a search, then *indxp contains the first
|
|
* on pgno of where we should begin the search.
|
|
*
|
|
* NOTE: if there is no comparison function, then continuing is
|
|
* meaningless, and *pp should always be NULL and *indxp will be
|
|
* ignored.
|
|
*
|
|
* 3 return values::
|
|
*
|
|
* + pp is the returned page pointer of where this element should go.
|
|
* + indxp is the returned index on that page
|
|
* + cmpp is the returned final comparison result.
|
|
*
|
|
* PUBLIC: int __db_dsearch __P((DBC *,
|
|
* PUBLIC: int, DBT *, db_pgno_t, db_indx_t *, PAGE **, int *));
|
|
*/
|
|
int
|
|
__db_dsearch(dbc, is_insert, dbt, pgno, indxp, pp, cmpp)
|
|
DBC *dbc;
|
|
int is_insert, *cmpp;
|
|
DBT *dbt;
|
|
db_pgno_t pgno;
|
|
db_indx_t *indxp;
|
|
PAGE **pp;
|
|
{
|
|
DB *dbp;
|
|
PAGE *h;
|
|
db_indx_t base, indx, lim, save_indx;
|
|
db_pgno_t save_pgno;
|
|
int ret;
|
|
|
|
dbp = dbc->dbp;
|
|
|
|
if (dbp->dup_compare == NULL) {
|
|
/*
|
|
* We may have been given a valid page, but we may not be
|
|
* able to use it. The problem is that the application is
|
|
* doing a join and we're trying to continue the search,
|
|
* but since the items aren't sorted, we can't. Discard
|
|
* the page if it's not the one we're going to start with
|
|
* anyway.
|
|
*/
|
|
if (*pp != NULL && (*pp)->pgno != pgno) {
|
|
if ((ret = memp_fput(dbp->mpf, *pp, 0)) != 0)
|
|
return (ret);
|
|
*pp = NULL;
|
|
}
|
|
|
|
/*
|
|
* If no duplicate function is specified, just go to the end
|
|
* of the duplicate set.
|
|
*/
|
|
if (is_insert) {
|
|
if ((ret = __db_dend(dbc, pgno, pp)) != 0)
|
|
return (ret);
|
|
*indxp = NUM_ENT(*pp);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* We are looking for a specific duplicate, so do a linear
|
|
* search.
|
|
*/
|
|
if (*pp != NULL)
|
|
goto nocmp_started;
|
|
for (;;) {
|
|
if ((ret = memp_fget(dbp->mpf, &pgno, 0, pp)) != 0)
|
|
goto pg_err;
|
|
nocmp_started: h = *pp;
|
|
|
|
for (*indxp = 0; *indxp < NUM_ENT(h); ++*indxp) {
|
|
if ((*cmpp = __bam_cmp(dbp,
|
|
dbt, h, *indxp, __bam_defcmp)) != 0)
|
|
continue;
|
|
/*
|
|
* The duplicate may have already been deleted,
|
|
* if it's a btree page, in which case we skip
|
|
* it.
|
|
*/
|
|
if (dbp->type == DB_BTREE &&
|
|
B_DISSET(GET_BKEYDATA(h, *indxp)->type))
|
|
continue;
|
|
|
|
return (0);
|
|
}
|
|
|
|
if ((pgno = h->next_pgno) == PGNO_INVALID)
|
|
break;
|
|
|
|
if ((ret = memp_fput(dbp->mpf, h, 0)) != 0)
|
|
return (ret);
|
|
}
|
|
*cmpp = 1; /* We didn't succeed... */
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* We have a comparison routine, i.e., the duplicates are sorted.
|
|
* Walk through the chain of duplicates, checking the last entry
|
|
* on each page to decide if it's the page we want to search.
|
|
*
|
|
* *pp may be non-NULL -- if we were given a valid page (e.g., are
|
|
* in mid-search), then use the provided page.
|
|
*/
|
|
if (*pp != NULL)
|
|
goto cmp_started;
|
|
for (;;) {
|
|
if ((ret = memp_fget(dbp->mpf, &pgno, 0, pp)) != 0)
|
|
goto pg_err;
|
|
cmp_started: h = *pp;
|
|
|
|
if ((pgno = h->next_pgno) == PGNO_INVALID || __bam_cmp(dbp,
|
|
dbt, h, h->entries - 1, dbp->dup_compare) <= 0)
|
|
break;
|
|
/*
|
|
* Even when continuing a search, make sure we don't skip
|
|
* entries on a new page
|
|
*/
|
|
*indxp = 0;
|
|
|
|
if ((ret = memp_fput(dbp->mpf, h, 0)) != 0)
|
|
return (ret);
|
|
}
|
|
|
|
/* Next, do a binary search on the page. */
|
|
base = F_ISSET(dbc, DBC_CONTINUE) ? *indxp : 0;
|
|
for (lim = NUM_ENT(h) - base; lim != 0; lim >>= 1) {
|
|
indx = base + (lim >> 1);
|
|
if ((*cmpp = __bam_cmp(dbp,
|
|
dbt, h, indx, dbp->dup_compare)) == 0) {
|
|
*indxp = indx;
|
|
|
|
if (dbp->type != DB_BTREE ||
|
|
!B_DISSET(GET_BKEYDATA(h, *indxp)->type))
|
|
return (0);
|
|
goto check_delete;
|
|
}
|
|
if (*cmpp > 0) {
|
|
base = indx + 1;
|
|
lim--;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Base references the smallest index larger than the supplied DBT's
|
|
* data item, potentially both 0 and NUM_ENT.
|
|
*/
|
|
*indxp = base;
|
|
return (0);
|
|
|
|
check_delete:
|
|
/*
|
|
* The duplicate may have already been deleted, if it's a btree page,
|
|
* in which case we wander around, hoping to find an entry that hasn't
|
|
* been deleted. First, wander in a forwardly direction.
|
|
*/
|
|
save_pgno = (*pp)->pgno;
|
|
save_indx = *indxp;
|
|
for (++*indxp;;) {
|
|
for (; *indxp < NUM_ENT(h); ++*indxp) {
|
|
if ((*cmpp = __bam_cmp(dbp,
|
|
dbt, h, *indxp, dbp->dup_compare)) != 0)
|
|
goto check_delete_rev;
|
|
|
|
if (!B_DISSET(GET_BKEYDATA(h, *indxp)->type))
|
|
return (0);
|
|
}
|
|
if ((pgno = h->next_pgno) == PGNO_INVALID)
|
|
break;
|
|
|
|
if ((ret = memp_fput(dbp->mpf, h, 0)) != 0)
|
|
return (ret);
|
|
|
|
if ((ret = memp_fget(dbp->mpf, &pgno, 0, pp)) != 0)
|
|
goto pg_err;
|
|
h = *pp;
|
|
|
|
*indxp = 0;
|
|
}
|
|
|
|
check_delete_rev:
|
|
/* Go back to where we started, and wander in a backwardly direction. */
|
|
if (h->pgno != save_pgno) {
|
|
if ((ret = memp_fput(dbp->mpf, h, 0)) != 0)
|
|
return (ret);
|
|
if ((ret = memp_fget(dbp->mpf, &save_pgno, 0, pp)) != 0)
|
|
goto pg_err;
|
|
h = *pp;
|
|
}
|
|
|
|
for (;;) {
|
|
while (*indxp > 0) {
|
|
--*indxp;
|
|
if ((*cmpp = __bam_cmp(dbp,
|
|
dbt, h, *indxp, dbp->dup_compare)) != 0)
|
|
goto check_delete_fail;
|
|
|
|
if (!B_DISSET(GET_BKEYDATA(h, *indxp)->type))
|
|
return (0);
|
|
}
|
|
if ((pgno = h->prev_pgno) == PGNO_INVALID)
|
|
break;
|
|
|
|
if ((ret = memp_fput(dbp->mpf, h, 0)) != 0)
|
|
return (ret);
|
|
|
|
if ((ret = memp_fget(dbp->mpf, &pgno, 0, pp)) != 0)
|
|
goto pg_err;
|
|
h = *pp;
|
|
|
|
*indxp = NUM_ENT(h);
|
|
}
|
|
|
|
check_delete_fail:
|
|
*cmpp = 1; /* We didn't succeed... */
|
|
return (0);
|
|
|
|
pg_err: __db_pgerr(dbp, pgno);
|
|
return (ret);
|
|
}
|