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      1 /*	$NetBSD: rec_utils.c,v 1.15 2024/05/14 19:00:43 andvar 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 1.15 2024/05/14 19:00:43 andvar 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 contiguous.  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 }
    117