/* * Copyright (c) 1999 Apple Computer, Inc. All rights reserved. * * @APPLE_LICENSE_HEADER_START@ * * The contents of this file constitute Original Code as defined in and * are subject to the Apple Public Source License Version 1.1 (the * "License"). You may not use this file except in compliance with the * License. Please obtain a copy of the License at * http://www.apple.com/publicsource and read it before using this file. * * This Original Code and all software distributed under the License are * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT. Please see the * License for the specific language governing rights and limitations * under the License. * * @APPLE_LICENSE_HEADER_END@ */ /* * Copyright (c) 1990, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Mike Olson. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include <sys/types.h> #include <errno.h> #include <stdio.h> #include <string.h> #include <db.h> #include "recno.h" static int rec_rdelete __P((BTREE *, recno_t)); /* * __REC_DELETE -- Delete the item(s) referenced by a key. * * Parameters: * dbp: pointer to access method * key: key to delete * flags: R_CURSOR if deleting what the cursor references * * Returns: * RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found. */ int __rec_delete(dbp, key, flags) const DB *dbp; const DBT *key; u_int flags; { BTREE *t; recno_t nrec; int status; t = dbp->internal; /* Toss any page pinned across calls. */ if (t->bt_pinned != NULL) { mpool_put(t->bt_mp, t->bt_pinned, 0); t->bt_pinned = NULL; } switch(flags) { case 0: if ((nrec = *(recno_t *)key->data) == 0) goto einval; if (nrec > t->bt_nrecs) return (RET_SPECIAL); --nrec; status = rec_rdelete(t, nrec); break; case R_CURSOR: if (!ISSET(t, B_SEQINIT)) goto einval; if (t->bt_nrecs == 0) return (RET_SPECIAL); status = rec_rdelete(t, t->bt_rcursor - 1); if (status == RET_SUCCESS) --t->bt_rcursor; break; default: einval: errno = EINVAL; return (RET_ERROR); } if (status == RET_SUCCESS) SET(t, B_MODIFIED | R_MODIFIED); return (status); } /* * REC_RDELETE -- Delete the data matching the specified key. * * Parameters: * tree: tree * nrec: record to delete * * Returns: * RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key not found. */ static int rec_rdelete(t, nrec) BTREE *t; recno_t nrec; { EPG *e; PAGE *h; int status; /* Find the record; __rec_search pins the page. */ if ((e = __rec_search(t, nrec, SDELETE)) == NULL) return (RET_ERROR); /* Delete the record. */ h = e->page; status = __rec_dleaf(t, h, e->index); if (status != RET_SUCCESS) { mpool_put(t->bt_mp, h, 0); return (status); } mpool_put(t->bt_mp, h, MPOOL_DIRTY); return (RET_SUCCESS); } /* * __REC_DLEAF -- Delete a single record from a recno leaf page. * * Parameters: * t: tree * index: index on current page to delete * * Returns: * RET_SUCCESS, RET_ERROR. */ int __rec_dleaf(t, h, index) BTREE *t; PAGE *h; indx_t index; { register RLEAF *rl; register indx_t *ip, cnt, offset; register size_t nbytes; char *from; void *to; /* * Delete a record from a recno leaf page. Internal records are never * deleted from internal pages, regardless of the records that caused * them to be added being deleted. Pages made empty by deletion are * not reclaimed. They are, however, made available for reuse. * * Pack the remaining entries at the end of the page, shift the indices * down, overwriting the deleted record and its index. If the record * uses overflow pages, make them available for reuse. */ to = rl = GETRLEAF(h, index); if (rl->flags & P_BIGDATA && __ovfl_delete(t, rl->bytes) == RET_ERROR) return (RET_ERROR); nbytes = NRLEAF(rl); /* * Compress the key/data pairs. Compress and adjust the [BR]LEAF * offsets. Reset the headers. */ from = (char *)h + h->upper; memmove(from + nbytes, from, (char *)to - from); h->upper += nbytes; offset = h->linp[index]; for (cnt = &h->linp[index] - (ip = &h->linp[0]); cnt--; ++ip) if (ip[0] < offset) ip[0] += nbytes; for (cnt = &h->linp[NEXTINDEX(h)] - ip; --cnt; ++ip) ip[0] = ip[1] < offset ? ip[1] + nbytes : ip[1]; h->lower -= sizeof(indx_t); --t->bt_nrecs; return (RET_SUCCESS); }