lib/libc/db/recno/rec_utils.c

   1 /*      $NetBSD: rec_utils.c,v 1.12 2008/09/10 17:52:36 joerg Exp $     */
   2
   3 /*-
   4  * Copyright (c) 1990, 1993, 1994
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #if HAVE_NBTOOL_CONFIG_H
  33 #include "nbtool_config.h"
  34 #endif
  35
  36 #include <sys/cdefs.h>
  37 __RCSID("$NetBSD: rec_utils.c,v 1.12 2008/09/10 17:52:36 joerg Exp $");
  38
  39 #include <sys/param.h>
  40
  41 #include <assert.h>
  42 #include <stdio.h>
  43 #include <stdlib.h>
  44 #include <string.h>
  45
  46 #include <db.h>
  47 #include "recno.h"
  48
  49 /*
  50  * __rec_ret --
  51  *      Build return data.
  52  *
  53  * Parameters:
  54  *      t:      tree
  55  *      e:      key/data pair to be returned
  56  *   nrec:      record number
  57  *    key:      user's key structure
  58  *      data:   user's data structure
  59  *
  60  * Returns:
  61  *      RET_SUCCESS, RET_ERROR.
  62  */
  63 int
  64 __rec_ret(BTREE *t, EPG *e, recno_t nrec, DBT *key, DBT *data)
  65 {
  66         RLEAF *rl;
  67         void *p;
  68
  69         if (key == NULL)
  70                 goto dataonly;
  71
  72         /* We have to copy the key, it's not on the page. */
  73         if (sizeof(recno_t) > t->bt_rkey.size) {
  74                 p = (void *)(t->bt_rkey.data == NULL ?
  75                     malloc(sizeof(recno_t)) :
  76                     realloc(t->bt_rkey.data, sizeof(recno_t)));
  77                 if (p == NULL)
  78                         return (RET_ERROR);
  79                 t->bt_rkey.data = p;
  80                 t->bt_rkey.size = sizeof(recno_t);
  81         }
  82         memmove(t->bt_rkey.data, &nrec, sizeof(recno_t));
  83         key->size = sizeof(recno_t);
  84         key->data = t->bt_rkey.data;
  85
  86 dataonly:
  87         if (data == NULL)
  88                 return (RET_SUCCESS);
  89
  90         /*
  91          * We must copy big keys/data to make them contigous.  Otherwise,
  92          * leave the page pinned and don't copy unless the user specified
  93          * concurrent access.
  94          */
  95         rl = GETRLEAF(e->page, e->index);
  96         if (rl->flags & P_BIGDATA) {
  97                 if (__ovfl_get(t, rl->bytes,
  98                     &data->size, &t->bt_rdata.data, &t->bt_rdata.size))
  99                         return (RET_ERROR);
 100                 data->data = t->bt_rdata.data;
 101         } else if (F_ISSET(t, B_DB_LOCK)) {
 102                 /* Use +1 in case the first record retrieved is 0 length. */
 103                 if (rl->dsize + 1 > t->bt_rdata.size) {
 104                         p = (void *)(t->bt_rdata.data == NULL ?
 105                             malloc(rl->dsize + 1) :
 106                             realloc(t->bt_rdata.data, rl->dsize + 1));
 107                         if (p == NULL)
 108                                 return (RET_ERROR);
 109                         t->bt_rdata.data = p;
 110                         t->bt_rdata.size = rl->dsize + 1;
 111                 }
 112                 memmove(t->bt_rdata.data, rl->bytes, rl->dsize);
 113                 data->size = rl->dsize;
 114                 data->data = t->bt_rdata.data;
 115         } else {
 116                 data->size = rl->dsize;
 117                 data->data = rl->bytes;
 118         }
 119         return (RET_SUCCESS);
 120 }