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rec_utils.c revision 1.1.1.2 
      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 }
    123