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  1. /*
  2.  * Copyright (C) 2005 Sergey Bondari
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  13.  *   documentation and/or other materials provided with the distribution.
  14.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. #include <mm/slab.h>
  30. #include <memstr.h>
  31. #include <sort.h>
  32. #include <panic.h>
  33.  
  34. #define EBUFSIZE    32
  35.  
  36. void _qsort(void * data, count_t n, size_t e_size, int (* cmp) (void * a, void * b), void *tmp, void *pivot);
  37. void _bubblesort(void * data, count_t n, size_t e_size, int (* cmp) (void * a, void * b), void *slot);
  38.  
  39. /** Quicksort wrapper
  40.  *
  41.  * This is only a wrapper that takes care of memory allocations for storing
  42.  * the pivot and temporary elements for generic quicksort algorithm.
  43.  *
  44.  * This function _can_ sleep
  45.  *
  46.  * @param data Pointer to data to be sorted.
  47.  * @param n Number of elements to be sorted.
  48.  * @param e_size Size of one element.
  49.  * @param cmp Comparator function.
  50.  *
  51.  */
  52. void qsort(void * data, count_t n, size_t e_size, int (* cmp) (void * a, void * b))
  53. {
  54.     __u8 buf_tmp[EBUFSIZE];
  55.     __u8 buf_pivot[EBUFSIZE];
  56.     void * tmp = buf_tmp;
  57.     void * pivot = buf_pivot;
  58.  
  59.     if (e_size > EBUFSIZE) {
  60.         pivot = (void *) malloc(e_size, 0);
  61.         tmp = (void *) malloc(e_size, 0);
  62.     }
  63.  
  64.     _qsort(data, n, e_size, cmp, tmp, pivot);
  65.    
  66.     if (e_size > EBUFSIZE) {
  67.         free(tmp);
  68.         free(pivot);
  69.     }
  70. }
  71.  
  72. /** Quicksort
  73.  *
  74.  * Apply generic quicksort algorithm on supplied data, using pre-allocated buffers.
  75.  *
  76.  * @param data Pointer to data to be sorted.
  77.  * @param n Number of elements to be sorted.
  78.  * @param e_size Size of one element.
  79.  * @param cmp Comparator function.
  80.  * @param tmp Pointer to scratch memory buffer e_size bytes long.
  81.  * @param pivot Pointer to scratch memory buffer e_size bytes long.
  82.  *
  83.  */
  84. void _qsort(void * data, count_t n, size_t e_size, int (* cmp) (void * a, void * b), void *tmp, void *pivot)
  85. {
  86.     if (n > 4) {
  87.         int i = 0, j = n - 1;
  88.  
  89.         memcpy(pivot, data, e_size);
  90.  
  91.         while (1) {
  92.             while ((cmp(data + i * e_size, pivot) < 0) && i < n) i++;
  93.             while ((cmp(data + j * e_size, pivot) >=0) && j > 0) j--;
  94.             if (i<j) {
  95.                 memcpy(tmp, data + i * e_size, e_size);
  96.                 memcpy(data + i * e_size, data + j * e_size, e_size);
  97.                 memcpy(data + j * e_size, tmp, e_size);
  98.             } else {
  99.                 break;
  100.             }
  101.         }
  102.  
  103.         _qsort(data, j + 1, e_size, cmp, tmp, pivot);
  104.         _qsort(data + (j + 1) * e_size, n - j - 1, e_size, cmp, tmp, pivot);
  105.     } else {
  106.         _bubblesort(data, n, e_size, cmp, tmp);
  107.     }
  108. }
  109.  
  110. /** Bubblesort wrapper
  111.  *
  112.  * This is only a wrapper that takes care of memory allocation for storing
  113.  * the slot element for generic bubblesort algorithm.
  114.  *
  115.  * @param data Pointer to data to be sorted.
  116.  * @param n Number of elements to be sorted.
  117.  * @param e_size Size of one element.
  118.  * @param cmp Comparator function.
  119.  *
  120.  */
  121. void bubblesort(void * data, count_t n, size_t e_size, int (* cmp) (void * a, void * b))
  122. {
  123.     __u8 buf_slot[EBUFSIZE];
  124.     void * slot = buf_slot;
  125.    
  126.     if (e_size > EBUFSIZE) {
  127.         slot = (void *) malloc(e_size, 0);
  128.     }
  129.  
  130.     _bubblesort(data, n, e_size, cmp, slot);
  131.    
  132.     if (e_size > EBUFSIZE) {
  133.         free(slot);
  134.     }
  135. }
  136.  
  137. /** Bubblesort
  138.  *
  139.  * Apply generic bubblesort algorithm on supplied data, using pre-allocated buffer.
  140.  *
  141.  * @param data Pointer to data to be sorted.
  142.  * @param n Number of elements to be sorted.
  143.  * @param e_size Size of one element.
  144.  * @param cmp Comparator function.
  145.  * @param slot Pointer to scratch memory buffer e_size bytes long.
  146.  *
  147.  */
  148. void _bubblesort(void * data, count_t n, size_t e_size, int (* cmp) (void * a, void * b), void *slot)
  149. {
  150.     bool done = false;
  151.     void * p;
  152.  
  153.     while (!done) {
  154.         done = true;
  155.         for (p = data; p < data + e_size * (n - 1); p = p + e_size) {
  156.             if (cmp(p, p + e_size) == 1) {
  157.                 memcpy(slot, p, e_size);
  158.                 memcpy(p, p + e_size, e_size);
  159.                 memcpy(p + e_size, slot, e_size);
  160.                 done = false;
  161.             }
  162.         }
  163.     }
  164.  
  165. }
  166.  
  167. /*
  168.  * Comparator returns 1 if a > b, 0 if a == b, -1 if a < b
  169.  */
  170. int int_cmp(void * a, void * b)
  171. {
  172.     return (* (int *) a > * (int*)b) ? 1 : (*(int *)a < * (int *)b) ? -1 : 0;
  173. }
  174.  
  175. int __u8_cmp(void * a, void * b)
  176. {
  177.     return (* (__u8 *) a > * (__u8 *)b) ? 1 : (*(__u8 *)a < * (__u8 *)b) ? -1 : 0;
  178. }
  179.  
  180. int __u16_cmp(void * a, void * b)
  181. {
  182.     return (* (__u16 *) a > * (__u16 *)b) ? 1 : (*(__u16 *)a < * (__u16 *)b) ? -1 : 0;
  183. }
  184.  
  185. int __u32_cmp(void * a, void * b)
  186. {
  187.     return (* (__u32 *) a > * (__u32 *)b) ? 1 : (*(__u32 *)a < * (__u32 *)b) ? -1 : 0;
  188. }
  189.