db/recno/FreeBSD/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 #include <sys/cdefs.h>
  38 __FBSDID("$FreeBSD: src/lib/libc/db/recno/rec_utils.c,v 1.2 2002/03/22 21:52:02 obrien Exp $");
  39
  40 #include <sys/param.h>
  41
  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(t, e, nrec, key, data)
  65         BTREE *t;
  66         EPG *e;
  67         recno_t nrec;
  68         DBT *key, *data;
  69 {
  70         RLEAF *rl;
  71         void *p;
  72
  73         if (key == NULL)
  74                 goto dataonly;
  75
  76         /* We have to copy the key, it's not on the page. */
  77         if (sizeof(recno_t) > t->bt_rkey.size) {
  78                 p = (void *)(t->bt_rkey.data == NULL ?
  79                     malloc(sizeof(recno_t)) :
  80                     realloc(t->bt_rkey.data, sizeof(recno_t)));
  81                 if (p == NULL)
  82                         return (RET_ERROR);
  83                 t->bt_rkey.data = p;
  84                 t->bt_rkey.size = sizeof(recno_t);
  85         }
  86         memmove(t->bt_rkey.data, &nrec, sizeof(recno_t));
  87         key->size = sizeof(recno_t);
  88         key->data = t->bt_rkey.data;
  89
  90 dataonly:
  91         if (data == NULL)
  92                 return (RET_SUCCESS);
  93
  94         /*
  95          * We must copy big keys/data to make them contigous.  Otherwise,
  96          * leave the page pinned and don't copy unless the user specified
  97          * concurrent access.
  98          */
  99         rl = GETRLEAF(e->page, e->index);
 100         if (rl->flags & P_BIGDATA) {
 101                 if (__ovfl_get(t, rl->bytes,
 102                     &data->size, &t->bt_rdata.data, &t->bt_rdata.size))
 103                         return (RET_ERROR);
 104                 data->data = t->bt_rdata.data;
 105         } else if (F_ISSET(t, B_DB_LOCK)) {
 106                 /* Use +1 in case the first record retrieved is 0 length. */
 107                 if (rl->dsize + 1 > t->bt_rdata.size) {
 108                         p = (void *)(t->bt_rdata.data == NULL ?
 109                             malloc(rl->dsize + 1) :
 110                             realloc(t->bt_rdata.data, rl->dsize + 1));
 111                         if (p == NULL)
 112                                 return (RET_ERROR);
 113                         t->bt_rdata.data = p;
 114                         t->bt_rdata.size = rl->dsize + 1;
 115                 }
 116                 memmove(t->bt_rdata.data, rl->bytes, rl->dsize);
 117                 data->size = rl->dsize;
 118                 data->data = t->bt_rdata.data;
 119         } else {
 120                 data->size = rl->dsize;
 121                 data->data = rl->bytes;
 122         }
 123         return (RET_SUCCESS);
 124 }