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. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #if defined(LIBC_SCCS) && !defined(lint)
  35 static char sccsid[] = "@(#)rec_utils.c 8.6 (Berkeley) 7/16/94";
  36 #endif /* LIBC_SCCS and not lint */
  37
  38 #include <sys/param.h>
  39
  40 #include <stdio.h>
  41 #include <stdlib.h>
  42 #include <string.h>
  43
  44 #include <db.h>
  45 #include "recno.h"
  46
  47 /*
  48  * __rec_ret --
  49  *      Build return data.
  50  *
  51  * Parameters:
  52  *      t:      tree
  53  *      e:      key/data pair to be returned
  54  *   nrec:      record number
  55  *    key:      user's key structure
  56  *      data:   user's data structure
  57  *
  58  * Returns:
  59  *      RET_SUCCESS, RET_ERROR.
  60  */
  61 int
  62 __rec_ret(t, e, nrec, key, data)
  63         BTREE *t;
  64         EPG *e;
  65         recno_t nrec;
  66         DBT *key, *data;
  67 {
  68         RLEAF *rl;
  69         void *p;
  70
  71         if (key == NULL)
  72                 goto dataonly;
  73
  74         /* We have to copy the key, it's not on the page. */
  75         if (sizeof(recno_t) > t->bt_rkey.size) {
  76                 p = (void *)(t->bt_rkey.data == NULL ?
  77                     malloc(sizeof(recno_t)) :
  78                     realloc(t->bt_rkey.data, sizeof(recno_t)));
  79                 if (p == NULL)
  80                         return (RET_ERROR);
  81                 t->bt_rkey.data = p;
  82                 t->bt_rkey.size = sizeof(recno_t);
  83         }
  84         memmove(t->bt_rkey.data, &nrec, sizeof(recno_t));
  85         key->size = sizeof(recno_t);
  86         key->data = t->bt_rkey.data;
  87
  88 dataonly:
  89         if (data == NULL)
  90                 return (RET_SUCCESS);
  91
  92         /*
  93          * We must copy big keys/data to make them contigous.  Otherwise,
  94          * leave the page pinned and don't copy unless the user specified
  95          * concurrent access.
  96          */
  97         rl = GETRLEAF(e->page, e->index);
  98         if (rl->flags & P_BIGDATA) {
  99                 if (__ovfl_get(t, rl->bytes,
 100                     &data->size, &t->bt_rdata.data, &t->bt_rdata.size))
 101                         return (RET_ERROR);
 102                 data->data = t->bt_rdata.data;
 103         } else if (F_ISSET(t, B_DB_LOCK)) {
 104                 /* Use +1 in case the first record retrieved is 0 length. */
 105                 if (rl->dsize + 1 > t->bt_rdata.size) {
 106                         p = (void *)(t->bt_rdata.data == NULL ?
 107                             malloc(rl->dsize + 1) :
 108                             realloc(t->bt_rdata.data, rl->dsize + 1));
 109                         if (p == NULL)
 110                                 return (RET_ERROR);
 111                         t->bt_rdata.data = p;
 112                         t->bt_rdata.size = rl->dsize + 1;
 113                 }
 114                 memmove(t->bt_rdata.data, rl->bytes, rl->dsize);
 115                 data->size = rl->dsize;
 116                 data->data = t->bt_rdata.data;
 117         } else {
 118                 data->size = rl->dsize;
 119                 data->data = rl->bytes;
 120         }
 121         return (RET_SUCCESS);
 122 }