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rec_utils.c revision 1.9 
      1 /*	$NetBSD: rec_utils.c,v 1.9 2003/08/07 16:42:44 agc 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 #include <sys/cdefs.h>
     33 #if defined(LIBC_SCCS) && !defined(lint)
     34 #if 0
     35 static char sccsid[] = "@(#)rec_utils.c	8.6 (Berkeley) 7/16/94";
     36 #else
     37 __RCSID("$NetBSD: rec_utils.c,v 1.9 2003/08/07 16:42:44 agc Exp $");
     38 #endif
     39 #endif /* LIBC_SCCS and not lint */
     40 
     41 #include <sys/param.h>
     42 
     43 #include <stdio.h>
     44 #include <stdlib.h>
     45 #include <string.h>
     46 
     47 #include <db.h>
     48 #include "recno.h"
     49 
     50 /*
     51  * __rec_ret --
     52  *	Build return data.
     53  *
     54  * Parameters:
     55  *	t:	tree
     56  *	e:	key/data pair to be returned
     57  *   nrec:	record number
     58  *    key:	user's key structure
     59  *	data:	user's data structure
     60  *
     61  * Returns:
     62  *	RET_SUCCESS, RET_ERROR.
     63  */
     64 int
     65 __rec_ret(t, e, nrec, key, data)
     66 	BTREE *t;
     67 	EPG *e;
     68 	recno_t nrec;
     69 	DBT *key, *data;
     70 {
     71 	RLEAF *rl;
     72 	void *p;
     73 
     74 	if (key == NULL)
     75 		goto dataonly;
     76 
     77 	/* We have to copy the key, it's not on the page. */
     78 	if (sizeof(recno_t) > t->bt_rkey.size) {
     79 		p = (void *)(t->bt_rkey.data == NULL ?
     80 		    malloc(sizeof(recno_t)) :
     81 		    realloc(t->bt_rkey.data, sizeof(recno_t)));
     82 		if (p == NULL)
     83 			return (RET_ERROR);
     84 		t->bt_rkey.data = p;
     85 		t->bt_rkey.size = sizeof(recno_t);
     86 	}
     87 	memmove(t->bt_rkey.data, &nrec, sizeof(recno_t));
     88 	key->size = sizeof(recno_t);
     89 	key->data = t->bt_rkey.data;
     90 
     91 dataonly:
     92 	if (data == NULL)
     93 		return (RET_SUCCESS);
     94 
     95 	/*
     96 	 * We must copy big keys/data to make them contigous.  Otherwise,
     97 	 * leave the page pinned and don't copy unless the user specified
     98 	 * concurrent access.
     99 	 */
    100 	rl = GETRLEAF(e->page, e->index);
    101 	if (rl->flags & P_BIGDATA) {
    102 		if (__ovfl_get(t, rl->bytes,
    103 		    &data->size, &t->bt_rdata.data, &t->bt_rdata.size))
    104 			return (RET_ERROR);
    105 		data->data = t->bt_rdata.data;
    106 	} else if (F_ISSET(t, B_DB_LOCK)) {
    107 		/* Use +1 in case the first record retrieved is 0 length. */
    108 		if (rl->dsize + 1 > t->bt_rdata.size) {
    109 			p = (void *)(t->bt_rdata.data == NULL ?
    110 			    malloc(rl->dsize + 1) :
    111 			    realloc(t->bt_rdata.data, rl->dsize + 1));
    112 			if (p == NULL)
    113 				return (RET_ERROR);
    114 			t->bt_rdata.data = p;
    115 			t->bt_rdata.size = rl->dsize + 1;
    116 		}
    117 		memmove(t->bt_rdata.data, rl->bytes, rl->dsize);
    118 		data->size = rl->dsize;
    119 		data->data = t->bt_rdata.data;
    120 	} else {
    121 		data->size = rl->dsize;
    122 		data->data = rl->bytes;
    123 	}
    124 	return (RET_SUCCESS);
    125 }
    126