db/recno/rec_utils.c

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