/*
|
* A generic implementation of binary search for the Linux kernel
|
*
|
* Copyright (C) 2008-2009 Ksplice, Inc.
|
* Author: Tim Abbott <tabbott@ksplice.com>
|
*
|
* This program is free software; you can redistribute it and/or
|
* modify it under the terms of the GNU General Public License as
|
* published by the Free Software Foundation; version 2.
|
*/
|
|
#include <linux/export.h>
|
#include <linux/bsearch.h>
|
#include <linux/kprobes.h>
|
|
/*
|
* bsearch - binary search an array of elements
|
* @key: pointer to item being searched for
|
* @base: pointer to first element to search
|
* @num: number of elements
|
* @size: size of each element
|
* @cmp: pointer to comparison function
|
*
|
* This function does a binary search on the given array. The
|
* contents of the array should already be in ascending sorted order
|
* under the provided comparison function.
|
*
|
* Note that the key need not have the same type as the elements in
|
* the array, e.g. key could be a string and the comparison function
|
* could compare the string with the struct's name field. However, if
|
* the key and elements in the array are of the same type, you can use
|
* the same comparison function for both sort() and bsearch().
|
*/
|
void *bsearch(const void *key, const void *base, size_t num, size_t size,
|
int (*cmp)(const void *key, const void *elt))
|
{
|
const char *pivot;
|
int result;
|
|
while (num > 0) {
|
pivot = base + (num >> 1) * size;
|
result = cmp(key, pivot);
|
|
if (result == 0)
|
return (void *)pivot;
|
|
if (result > 0) {
|
base = pivot + size;
|
num--;
|
}
|
num >>= 1;
|
}
|
|
return NULL;
|
}
|
EXPORT_SYMBOL(bsearch);
|
NOKPROBE_SYMBOL(bsearch);
|
