git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@578 65c4cc65-6c06-0410-ace0-fbb531ad65f3
198 lines
5.4 KiB
C
Executable file
198 lines
5.4 KiB
C
Executable file
/*-
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* Copyright (c) 1990, 1993, 1994
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Mike Olson.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#if defined(LIBC_SCCS) && !defined(lint)
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static char sccsid[] = "@(#)rec_delete.c 8.7 (Berkeley) 7/14/94";
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#endif /* LIBC_SCCS and not lint */
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#include <sys/types.h>
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#include <errno.h>
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#include <stdio.h>
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#include <string.h>
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#include <db.h>
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#include "recno.h"
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static int rec_rdelete __P((BTREE *, recno_t));
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/*
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* __REC_DELETE -- Delete the item(s) referenced by a key.
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*
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* Parameters:
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* dbp: pointer to access method
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* key: key to delete
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* flags: R_CURSOR if deleting what the cursor references
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*
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* Returns:
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* RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
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*/
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int
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__rec_delete(dbp, key, flags)
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const DB *dbp;
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const DBT *key;
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u_int flags;
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{
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BTREE *t;
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recno_t nrec;
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int status;
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t = dbp->internal;
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/* Toss any page pinned across calls. */
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if (t->bt_pinned != NULL) {
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mpool_put(t->bt_mp, t->bt_pinned, 0);
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t->bt_pinned = NULL;
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}
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switch(flags) {
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case 0:
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if ((nrec = *(recno_t *)key->data) == 0)
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goto einval;
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if (nrec > t->bt_nrecs)
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return (RET_SPECIAL);
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--nrec;
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status = rec_rdelete(t, nrec);
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break;
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case R_CURSOR:
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if (!F_ISSET(&t->bt_cursor, CURS_INIT))
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goto einval;
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if (t->bt_nrecs == 0)
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return (RET_SPECIAL);
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status = rec_rdelete(t, t->bt_cursor.rcursor - 1);
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if (status == RET_SUCCESS)
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--t->bt_cursor.rcursor;
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break;
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default:
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einval: errno = EINVAL;
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return (RET_ERROR);
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}
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if (status == RET_SUCCESS)
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F_SET(t, B_MODIFIED | R_MODIFIED);
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return (status);
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}
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/*
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* REC_RDELETE -- Delete the data matching the specified key.
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*
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* Parameters:
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* tree: tree
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* nrec: record to delete
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*
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* Returns:
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* RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found.
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*/
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static int
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rec_rdelete(t, nrec)
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BTREE *t;
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recno_t nrec;
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{
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EPG *e;
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PAGE *h;
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int status;
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/* Find the record; __rec_search pins the page. */
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if ((e = __rec_search(t, nrec, SDELETE)) == NULL)
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return (RET_ERROR);
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/* Delete the record. */
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h = e->page;
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status = __rec_dleaf(t, h, e->index);
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if (status != RET_SUCCESS) {
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mpool_put(t->bt_mp, h, 0);
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return (status);
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}
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mpool_put(t->bt_mp, h, MPOOL_DIRTY);
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return (RET_SUCCESS);
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}
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/*
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* __REC_DLEAF -- Delete a single record from a recno leaf page.
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*
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* Parameters:
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* t: tree
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* index: index on current page to delete
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*
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* Returns:
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* RET_SUCCESS, RET_ERROR.
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*/
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int
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__rec_dleaf(t, h, index)
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BTREE *t;
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PAGE *h;
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u_int32_t index;
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{
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RLEAF *rl;
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indx_t *ip, cnt, offset;
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u_int32_t nbytes;
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char *from;
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void *to;
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/*
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* Delete a record from a recno leaf page. Internal records are never
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* deleted from internal pages, regardless of the records that caused
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* them to be added being deleted. Pages made empty by deletion are
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* not reclaimed. They are, however, made available for reuse.
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*
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* Pack the remaining entries at the end of the page, shift the indices
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* down, overwriting the deleted record and its index. If the record
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* uses overflow pages, make them available for reuse.
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*/
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to = rl = GETRLEAF(h, index);
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if (rl->flags & P_BIGDATA && __ovfl_delete(t, rl->bytes) == RET_ERROR)
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return (RET_ERROR);
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nbytes = NRLEAF(rl);
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/*
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* Compress the key/data pairs. Compress and adjust the [BR]LEAF
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* offsets. Reset the headers.
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*/
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from = (char *)h + h->upper;
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memmove(from + nbytes, from, (char *)to - from);
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h->upper += nbytes;
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offset = h->linp[index];
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for (cnt = &h->linp[index] - (ip = &h->linp[0]); cnt--; ++ip)
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if (ip[0] < offset)
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ip[0] += nbytes;
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for (cnt = &h->linp[NEXTINDEX(h)] - ip; --cnt; ++ip)
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ip[0] = ip[1] < offset ? ip[1] + nbytes : ip[1];
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h->lower -= sizeof(indx_t);
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--t->bt_nrecs;
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return (RET_SUCCESS);
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}
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