lib/libc/db/recno/rec_utils.c

   1 /*      $NetBSD: rec_utils.c,v 1.14 2013/12/14 18:04:56 christos 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 1.14 2013/12/14 18:04:56 christos 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(nrec) > t->bt_rkey.size) {
  74                 p = realloc(t->bt_rkey.data, sizeof(nrec));
  75                 if (p == NULL)
  76                         return (RET_ERROR);
  77                 t->bt_rkey.data = p;
  78                 t->bt_rkey.size = sizeof(nrec);
  79         }
  80         memmove(t->bt_rkey.data, &nrec, sizeof(nrec));
  81         key->size = sizeof(nrec);
  82         key->data = t->bt_rkey.data;
  83
  84 dataonly:
  85         if (data == NULL)
  86                 return (RET_SUCCESS);
  87
  88         /*
  89          * We must copy big keys/data to make them contigous.  Otherwise,
  90          * leave the page pinned and don't copy unless the user specified
  91          * concurrent access.
  92          */
  93         rl = GETRLEAF(e->page, e->index);
  94         if (rl->flags & P_BIGDATA) {
  95                 if (__ovfl_get(t, rl->bytes,
  96                     &data->size, &t->bt_rdata.data, &t->bt_rdata.size))
  97                         return (RET_ERROR);
  98                 data->data = t->bt_rdata.data;
  99         } else if (F_ISSET(t, B_DB_LOCK)) {
 100                 /* Use +1 in case the first record retrieved is 0 length. */
 101                 if (rl->dsize + 1 > t->bt_rdata.size) {
 102                         p = realloc(t->bt_rdata.data, rl->dsize + 1);
 103                         if (p == NULL)
 104                                 return (RET_ERROR);
 105                         t->bt_rdata.data = p;
 106                         t->bt_rdata.size = rl->dsize + 1;
 107                 }
 108                 memmove(t->bt_rdata.data, rl->bytes, rl->dsize);
 109                 data->size = rl->dsize;
 110                 data->data = t->bt_rdata.data;
 111         } else {
 112                 data->size = rl->dsize;
 113                 data->data = rl->bytes;
 114         }
 115         return (RET_SUCCESS);
 116 }