lib/libc/db/recno/rec_utils.c

   1 /*-
   2  * Copyright (c) 1990, 1993, 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * @(#)rec_utils.c      8.6 (Berkeley) 7/16/94
  30  * $DragonFly: src/lib/libc/db/recno/rec_utils.c,v 1.4 2005/11/12 23:01:55 swildner Exp $
  31  */
  32
  33 #include <sys/param.h>
  34
  35 #include <stdio.h>
  36 #include <stdlib.h>
  37 #include <string.h>
  38
  39 #include <db.h>
  40 #include "recno.h"
  41
  42 /*
  43  * __rec_ret --
  44  *      Build return data.
  45  *
  46  * Parameters:
  47  *      t:      tree
  48  *      e:      key/data pair to be returned
  49  *   nrec:      record number
  50  *    key:      user's key structure
  51  *      data:   user's data structure
  52  *
  53  * Returns:
  54  *      RET_SUCCESS, RET_ERROR.
  55  */
  56 int
  57 __rec_ret(BTREE *t, EPG *e, recno_t nrec, DBT *key, DBT *data)
  58 {
  59         RLEAF *rl;
  60         void *p;
  61
  62         if (key == NULL)
  63                 goto dataonly;
  64
  65         /* We have to copy the key, it's not on the page. */
  66         if (sizeof(recno_t) > t->bt_rkey.size) {
  67                 p = (void *)(t->bt_rkey.data == NULL ?
  68                     malloc(sizeof(recno_t)) :
  69                     realloc(t->bt_rkey.data, sizeof(recno_t)));
  70                 if (p == NULL)
  71                         return (RET_ERROR);
  72                 t->bt_rkey.data = p;
  73                 t->bt_rkey.size = sizeof(recno_t);
  74         }
  75         memmove(t->bt_rkey.data, &nrec, sizeof(recno_t));
  76         key->size = sizeof(recno_t);
  77         key->data = t->bt_rkey.data;
  78
  79 dataonly:
  80         if (data == NULL)
  81                 return (RET_SUCCESS);
  82
  83         /*
  84          * We must copy big keys/data to make them contigous.  Otherwise,
  85          * leave the page pinned and don't copy unless the user specified
  86          * concurrent access.
  87          */
  88         rl = GETRLEAF(e->page, e->index);
  89         if (rl->flags & P_BIGDATA) {
  90                 if (__ovfl_get(t, rl->bytes,
  91                     &data->size, &t->bt_rdata.data, &t->bt_rdata.size))
  92                         return (RET_ERROR);
  93                 data->data = t->bt_rdata.data;
  94         } else if (F_ISSET(t, B_DB_LOCK)) {
  95                 /* Use +1 in case the first record retrieved is 0 length. */
  96                 if (rl->dsize + 1 > t->bt_rdata.size) {
  97                         p = (void *)(t->bt_rdata.data == NULL ?
  98                             malloc(rl->dsize + 1) :
  99                             realloc(t->bt_rdata.data, rl->dsize + 1));
 100                         if (p == NULL)
 101                                 return (RET_ERROR);
 102                         t->bt_rdata.data = p;
 103                         t->bt_rdata.size = rl->dsize + 1;
 104                 }
 105                 memmove(t->bt_rdata.data, rl->bytes, rl->dsize);
 106                 data->size = rl->dsize;
 107                 data->data = t->bt_rdata.data;
 108         } else {
 109                 data->size = rl->dsize;
 110                 data->data = rl->bytes;
 111         }
 112         return (RET_SUCCESS);
 113 }