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/*
ldb database library
Copyright (C) Andrew Tridgell 2004
** NOTE! The following LGPL license applies to the ldb
** library. This does NOT imply that all of Samba is released
** under the LGPL
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* Name: ldb
*
* Component: ldb utility functions
*
* Description: miscellanous utility functions for ldb
*
* Author: Andrew Tridgell
*/
#include "includes.h"
#define MAX_MALLOC_SIZE 0x7fffffff
/*
realloc an array, checking for integer overflow in the array size
*/
void *realloc_array(void *ptr, size_t el_size, unsigned count)
{
if (count == 0 ||
count >= MAX_MALLOC_SIZE/el_size) {
return NULL;
}
if (!ptr) {
return malloc(el_size * count);
}
return realloc(ptr, el_size * count);
}
/*
find an element in a list, using the given comparison function and
assuming that the list is already sorted using comp_fn
return -1 if not found, or the index of the first occurance of needle if found
*/
int list_find(const void *needle,
const void *base, size_t nmemb, size_t size, comparison_fn_t comp_fn)
{
const char *base_p = base;
size_t min_i, max_i, test_i;
if (nmemb == 0) {
return -1;
}
min_i = 0;
max_i = nmemb-1;
while (min_i < max_i) {
int r;
test_i = (min_i + max_i) / 2;
r = comp_fn(needle, *(void * const *)(base_p + (size * test_i)));
if (r == 0) {
/* scan back for first element */
while (test_i > 0 &&
comp_fn(needle, *(void * const *)(base_p + (size * (test_i-1)))) == 0) {
test_i--;
}
return test_i;
}
if (r == -1) {
max_i = test_i - 1;
}
if (r == 1) {
min_i = test_i + 1;
}
}
if (comp_fn(needle, *(void * const *)(base_p + (size * min_i))) == 0) {
return min_i;
}
return -1;
}
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