268 lines
6.7 KiB
C
268 lines
6.7 KiB
C
/* $NetBSD: bt_utils.c,v 1.10 2004/06/20 22:20:14 jmc Exp $ */
|
|
|
|
/*-
|
|
* 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. 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 HAVE_NBTOOL_CONFIG_H
|
|
#include "nbtool_config.h"
|
|
#endif
|
|
|
|
#include <sys/cdefs.h>
|
|
#if defined(LIBC_SCCS) && !defined(lint)
|
|
#if 0
|
|
static char sccsid[] = "@(#)bt_utils.c 8.8 (Berkeley) 7/20/94";
|
|
#else
|
|
__RCSID("$NetBSD: bt_utils.c,v 1.10 2004/06/20 22:20:14 jmc Exp $");
|
|
#endif
|
|
#endif /* LIBC_SCCS and not lint */
|
|
|
|
#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;
|
|
{
|
|
register size_t len;
|
|
register u_char *p1, *p2;
|
|
|
|
/*
|
|
* XXX
|
|
* If a size_t doesn't fit in an int, this routine can lose.
|
|
* What we need is a 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;
|
|
{
|
|
register u_char *p1, *p2;
|
|
register 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);
|
|
}
|