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rec_utils.c revision 1.5 
      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	8.4 (Berkeley) 6/20/94";
     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 -- Build return data as a result of search or scan.
     49  *
     50  * Parameters:
     51  *	t:	tree
     52  *	d:	LEAF to be returned to the user.
     53  *	data:	user's data structure
     54  *
     55  * Returns:
     56  *	RET_SUCCESS, RET_ERROR.
     57  */
     58 int
     59 __rec_ret(t, e, nrec, key, data)
     60 	BTREE *t;
     61 	EPG *e;
     62 	recno_t nrec;
     63 	DBT *key, *data;
     64 {
     65 	register RLEAF *rl;
     66 	register void *p;
     67 
     68 	if (data == NULL)
     69 		goto retkey;
     70 
     71 	rl = GETRLEAF(e->page, e->index);
     72 
     73 	/*
     74 	 * We always copy big data to make it contigous.  Otherwise, we
     75 	 * leave the page pinned and don't copy unless the user specified
     76 	 * concurrent access.
     77 	 */
     78 	if (rl->flags & P_BIGDATA) {
     79 		if (__ovfl_get(t, rl->bytes,
     80 		    &data->size, &t->bt_dbuf, &t->bt_dbufsz))
     81 			return (RET_ERROR);
     82 		data->data = t->bt_dbuf;
     83 	} else if (ISSET(t, B_DB_LOCK)) {
     84 		/* Use +1 in case the first record retrieved is 0 length. */
     85 		if (rl->dsize + 1 > t->bt_dbufsz) {
     86 			p = (void *)(t->bt_dbuf == NULL ?
     87 			    malloc(rl->dsize + 1) :
     88 			    realloc(t->bt_dbuf, rl->dsize + 1));
     89 			if (p == NULL)
     90 				return (RET_ERROR);
     91 			t->bt_dbuf = p;
     92 			t->bt_dbufsz = rl->dsize + 1;
     93 		}
     94 		memmove(t->bt_dbuf, rl->bytes, rl->dsize);
     95 		data->size = rl->dsize;
     96 		data->data = t->bt_dbuf;
     97 	} else {
     98 		data->size = rl->dsize;
     99 		data->data = rl->bytes;
    100 	}
    101 
    102 retkey:	if (key == NULL)
    103 		return (RET_SUCCESS);
    104 
    105 	/* We have to copy the key, it's not on the page. */
    106 	if (sizeof(recno_t) > t->bt_kbufsz) {
    107 		p = (void *)(t->bt_kbuf == NULL ?
    108 		    malloc(sizeof(recno_t)) :
    109 		    realloc(t->bt_kbuf, sizeof(recno_t)));
    110 		if (p == NULL)
    111 			return (RET_ERROR);
    112 		t->bt_kbuf = p;
    113 		t->bt_kbufsz = sizeof(recno_t);
    114 	}
    115 	memmove(t->bt_kbuf, &nrec, sizeof(recno_t));
    116 	key->size = sizeof(recno_t);
    117 	key->data = t->bt_kbuf;
    118 	return (RET_SUCCESS);
    119 }
    120