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Diffstat (limited to 'source4/lib/ldb/common/util.c')
-rw-r--r-- | source4/lib/ldb/common/util.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/source4/lib/ldb/common/util.c b/source4/lib/ldb/common/util.c new file mode 100644 index 0000000000..d198a1ad92 --- /dev/null +++ b/source4/lib/ldb/common/util.c @@ -0,0 +1,102 @@ +/* + 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) { + size_t test_t; + int r; + + test_i = (min_i + max_i) / 2; + r = comp_fn(needle, *(void **)(base_p + (size * test_i))); + if (r == 0) { + /* scan back for first element */ + while (test_t > 0 && + comp_fn(needle, *(void **)(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 **)(base_p + (size * min_i))) == 0) { + return min_i; + } + + return -1; +} |