-/*-
- * Copyright (c) 1990, 1993, 1994
- * The Regents of the University of California. All rights reserved.
- *
- * This code is derived from software contributed to Berkeley by
- * Mike Olson.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- * must display the following acknowledgement:
- * This product includes software developed by the University of
- * California, Berkeley and its contributors.
- * 4. Neither the name of the University nor the names of its contributors
- * may be used to endorse or promote products derived from this software
- * without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- */
-
-#if defined(LIBC_SCCS) && !defined(lint)
-static char sccsid[] = "@(#)bt_utils.c 8.8 (Berkeley) 7/20/94";
-#endif /* LIBC_SCCS and not lint */
-#include <sys/cdefs.h>
-__FBSDID("$FreeBSD: src/lib/libc/db/btree/bt_utils.c,v 1.3 2003/01/01 18:48:42 schweikh Exp $");
-
-#include <sys/param.h>
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include <db.h>
-#include "btree.h"
-
-/*
- * __bt_ret --
- * Build return key/data pair.
- *
- * Parameters:
- * t: tree
- * e: key/data pair to be returned
- * key: user's key structure (NULL if not to be filled in)
- * rkey: memory area to hold key
- * data: user's data structure (NULL if not to be filled in)
- * rdata: memory area to hold data
- * copy: always copy the key/data item
- *
- * Returns:
- * RET_SUCCESS, RET_ERROR.
- */
-int
-__bt_ret(t, e, key, rkey, data, rdata, copy)
- BTREE *t;
- EPG *e;
- DBT *key, *rkey, *data, *rdata;
- int copy;
-{
- BLEAF *bl;
- void *p;
-
- bl = GETBLEAF(e->page, e->index);
-
- /*
- * We must copy big keys/data to make them contigous. Otherwise,
- * leave the page pinned and don't copy unless the user specified
- * concurrent access.
- */
- if (key == NULL)
- goto dataonly;
-
- if (bl->flags & P_BIGKEY) {
- if (__ovfl_get(t, bl->bytes,
- &key->size, &rkey->data, &rkey->size))
- return (RET_ERROR);
- key->data = rkey->data;
- } else if (copy || F_ISSET(t, B_DB_LOCK)) {
- if (bl->ksize > rkey->size) {
- p = (void *)(rkey->data == NULL ?
- malloc(bl->ksize) : realloc(rkey->data, bl->ksize));
- if (p == NULL)
- return (RET_ERROR);
- rkey->data = p;
- rkey->size = bl->ksize;
- }
- memmove(rkey->data, bl->bytes, bl->ksize);
- key->size = bl->ksize;
- key->data = rkey->data;
- } else {
- key->size = bl->ksize;
- key->data = bl->bytes;
- }
-
-dataonly:
- if (data == NULL)
- return (RET_SUCCESS);
-
- if (bl->flags & P_BIGDATA) {
- if (__ovfl_get(t, bl->bytes + bl->ksize,
- &data->size, &rdata->data, &rdata->size))
- return (RET_ERROR);
- data->data = rdata->data;
- } else if (copy || F_ISSET(t, B_DB_LOCK)) {
- /* Use +1 in case the first record retrieved is 0 length. */
- if (bl->dsize + 1 > rdata->size) {
- p = (void *)(rdata->data == NULL ?
- malloc(bl->dsize + 1) :
- realloc(rdata->data, bl->dsize + 1));
- if (p == NULL)
- return (RET_ERROR);
- rdata->data = p;
- rdata->size = bl->dsize + 1;
- }
- memmove(rdata->data, bl->bytes + bl->ksize, bl->dsize);
- data->size = bl->dsize;
- data->data = rdata->data;
- } else {
- data->size = bl->dsize;
- data->data = bl->bytes + bl->ksize;
- }
-
- return (RET_SUCCESS);
-}
-
-/*
- * __BT_CMP -- Compare a key to a given record.
- *
- * Parameters:
- * t: tree
- * k1: DBT pointer of first arg to comparison
- * e: pointer to EPG for comparison
- *
- * Returns:
- * < 0 if k1 is < record
- * = 0 if k1 is = record
- * > 0 if k1 is > record
- */
-int
-__bt_cmp(t, k1, e)
- BTREE *t;
- const DBT *k1;
- EPG *e;
-{
- BINTERNAL *bi;
- BLEAF *bl;
- DBT k2;
- PAGE *h;
- void *bigkey;
-
- /*
- * The left-most key on internal pages, at any level of the tree, is
- * guaranteed by the following code to be less than any user key.
- * This saves us from having to update the leftmost key on an internal
- * page when the user inserts a new key in the tree smaller than
- * anything we've yet seen.
- */
- h = e->page;
- if (e->index == 0 && h->prevpg == P_INVALID && !(h->flags & P_BLEAF))
- return (1);
-
- bigkey = NULL;
- if (h->flags & P_BLEAF) {
- bl = GETBLEAF(h, e->index);
- if (bl->flags & P_BIGKEY)
- bigkey = bl->bytes;
- else {
- k2.data = bl->bytes;
- k2.size = bl->ksize;
- }
- } else {
- bi = GETBINTERNAL(h, e->index);
- if (bi->flags & P_BIGKEY)
- bigkey = bi->bytes;
- else {
- k2.data = bi->bytes;
- k2.size = bi->ksize;
- }
- }
-
- if (bigkey) {
- if (__ovfl_get(t, bigkey,
- &k2.size, &t->bt_rdata.data, &t->bt_rdata.size))
- return (RET_ERROR);
- k2.data = t->bt_rdata.data;
- }
- return ((*t->bt_cmp)(k1, &k2));
-}
-
-/*
- * __BT_DEFCMP -- Default comparison routine.
- *
- * Parameters:
- * a: DBT #1
- * b: DBT #2
- *
- * Returns:
- * < 0 if a is < b
- * = 0 if a is = b
- * > 0 if a is > b
- */
-int
-__bt_defcmp(a, b)
- const DBT *a, *b;
-{
- size_t len;
- u_char *p1, *p2;
-
- /*
- * XXX
- * If a size_t doesn't fit in an int, this routine can lose.
- * What we need is an integral type which is guaranteed to be
- * larger than a size_t, and there is no such thing.
- */
- len = MIN(a->size, b->size);
- for (p1 = a->data, p2 = b->data; len--; ++p1, ++p2)
- if (*p1 != *p2)
- return ((int)*p1 - (int)*p2);
- return ((int)a->size - (int)b->size);
-}
-
-/*
- * __BT_DEFPFX -- Default prefix routine.
- *
- * Parameters:
- * a: DBT #1
- * b: DBT #2
- *
- * Returns:
- * Number of bytes needed to distinguish b from a.
- */
-size_t
-__bt_defpfx(a, b)
- const DBT *a, *b;
-{
- u_char *p1, *p2;
- size_t cnt, len;
-
- cnt = 1;
- len = MIN(a->size, b->size);
- for (p1 = a->data, p2 = b->data; len--; ++p1, ++p2, ++cnt)
- if (*p1 != *p2)
- return (cnt);
-
- /* a->size must be <= b->size, or they wouldn't be in this order. */
- return (a->size < b->size ? a->size + 1 : a->size);
-}
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