| /* |

| * 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/module.h> |

| #include <linux/bsearch.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)) |

| { |

| size_t start = 0, end = num; |

| int result; |

| |

| while (start < end) { |

| size_t mid = start + (end - start) / 2; |

| |

| result = cmp(key, base + mid * size); |

| if (result < 0) |

| end = mid; |

| else if (result > 0) |

| start = mid + 1; |

| else |

| return (void *)base + mid * size; |

| } |

| |

| return NULL; |

| } |

| EXPORT_SYMBOL(bsearch); |