db/recno/rec_utils.c

   1 /*
   2  * Copyright (c) 2003 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*-
  26  * Copyright (c) 1990, 1993, 1994
  27  *      The Regents of the University of California.  All rights reserved.
  28  *
  29  * Redistribution and use in source and binary forms, with or without
  30  * modification, are permitted provided that the following conditions
  31  * are met:
  32  * 1. Redistributions of source code must retain the above copyright
  33  *    notice, this list of conditions and the following disclaimer.
  34  * 2. Redistributions in binary form must reproduce the above copyright
  35  *    notice, this list of conditions and the following disclaimer in the
  36  *    documentation and/or other materials provided with the distribution.
  37  * 3. All advertising materials mentioning features or use of this software
  38  *    must display the following acknowledgement:
  39  *      This product includes software developed by the University of
  40  *      California, Berkeley and its contributors.
  41  * 4. Neither the name of the University nor the names of its contributors
  42  *    may be used to endorse or promote products derived from this software
  43  *    without specific prior written permission.
  44  *
  45  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  46  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  47  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  48  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  49  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  50  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  51  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  52  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  53  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  54  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  55  * SUCH DAMAGE.
  56  */
  57
  58 #if defined(LIBC_SCCS) && !defined(lint)
  59 static char sccsid[] = "@(#)rec_utils.c 8.6 (Berkeley) 7/16/94";
  60 #endif /* LIBC_SCCS and not lint */
  61 #include <sys/cdefs.h>
  62
  63 #include <sys/param.h>
  64
  65 #include <stdio.h>
  66 #include <stdlib.h>
  67 #include <string.h>
  68
  69 #include <db.h>
  70 #include "recno.h"
  71
  72 /*
  73  * __rec_ret --
  74  *      Build return data.
  75  *
  76  * Parameters:
  77  *      t:      tree
  78  *      e:      key/data pair to be returned
  79  *   nrec:      record number
  80  *    key:      user's key structure
  81  *      data:   user's data structure
  82  *
  83  * Returns:
  84  *      RET_SUCCESS, RET_ERROR.
  85  */
  86 int
  87 __rec_ret(t, e, nrec, key, data)
  88         BTREE *t;
  89         EPG *e;
  90         recno_t nrec;
  91         DBT *key, *data;
  92 {
  93         RLEAF *rl;
  94         void *p;
  95
  96         if (key == NULL)
  97                 goto dataonly;
  98
  99         /* We have to copy the key, it's not on the page. */
 100         if (sizeof(recno_t) > t->bt_rkey.size) {
 101                 p = (void *)(t->bt_rkey.data == NULL ?
 102                     malloc(sizeof(recno_t)) :
 103                     realloc(t->bt_rkey.data, sizeof(recno_t)));
 104                 if (p == NULL)
 105                         return (RET_ERROR);
 106                 t->bt_rkey.data = p;
 107                 t->bt_rkey.size = sizeof(recno_t);
 108         }
 109         memmove(t->bt_rkey.data, &nrec, sizeof(recno_t));
 110         key->size = sizeof(recno_t);
 111         key->data = t->bt_rkey.data;
 112
 113 dataonly:
 114         if (data == NULL)
 115                 return (RET_SUCCESS);
 116
 117         /*
 118          * We must copy big keys/data to make them contigous.  Otherwise,
 119          * leave the page pinned and don't copy unless the user specified
 120          * concurrent access.
 121          */
 122         rl = GETRLEAF(e->page, e->index);
 123         if (rl->flags & P_BIGDATA) {
 124                 if (__ovfl_get(t, rl->bytes,
 125                     &data->size, &t->bt_rdata.data, &t->bt_rdata.size))
 126                         return (RET_ERROR);
 127                 data->data = t->bt_rdata.data;
 128         } else if (F_ISSET(t, B_DB_LOCK)) {
 129                 /* Use +1 in case the first record retrieved is 0 length. */
 130                 if (rl->dsize + 1 > t->bt_rdata.size) {
 131                         p = (void *)(t->bt_rdata.data == NULL ?
 132                             malloc(rl->dsize + 1) :
 133                             realloc(t->bt_rdata.data, rl->dsize + 1));
 134                         if (p == NULL)
 135                                 return (RET_ERROR);
 136                         t->bt_rdata.data = p;
 137                         t->bt_rdata.size = rl->dsize + 1;
 138                 }
 139                 memmove(t->bt_rdata.data, rl->bytes, rl->dsize);
 140                 data->size = rl->dsize;
 141                 data->data = t->bt_rdata.data;
 142         } else {
 143                 data->size = rl->dsize;
 144                 data->data = rl->bytes;
 145         }
 146         return (RET_SUCCESS);
 147 }