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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/heap.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.  * @param data Pointer to data to be sorted.
  45.  * @param n Number of elements to be sorted.
  46.  * @param e_size Size of one element.
  47.  * @param cmp Comparator function.
  48.  *
  49.  */
  50. void qsort(void * data, count_t n, size_t e_size, int (* cmp) (void * a, void * b))
  51. {
  52.     __u8 buf_tmp[EBUFSIZE];
  53.     __u8 buf_pivot[EBUFSIZE];
  54.     void * tmp = buf_tmp;
  55.     void * pivot = buf_pivot;
  56.  
  57.     if (e_size > EBUFSIZE) {
  58.         pivot = (void *) malloc(e_size);
  59.         tmp = (void *) malloc(e_size);
  60.    
  61.         if (!tmp || !pivot) {
  62.             panic("Cannot allocate memory\n");
  63.         }
  64.     }
  65.  
  66.     _qsort(data, n, e_size, cmp, tmp, pivot);
  67.    
  68.     if (e_size > EBUFSIZE) {
  69.         free(tmp);
  70.         free(pivot);
  71.     }
  72. }
  73.  
  74. /** Quicksort
  75.  *
  76.  * Apply generic quicksort algorithm on supplied data, using pre-allocated buffers.
  77.  *
  78.  * @param data Pointer to data to be sorted.
  79.  * @param n Number of elements to be sorted.
  80.  * @param e_size Size of one element.
  81.  * @param cmp Comparator function.
  82.  * @param tmp Pointer to scratch memory buffer e_size bytes long.
  83.  * @param pivot Pointer to scratch memory buffer e_size bytes long.
  84.  *
  85.  */
  86. void _qsort(void * data, count_t n, size_t e_size, int (* cmp) (void * a, void * b), void *tmp, void *pivot)
  87. {
  88.     if (n > 4) {
  89.         int i = 0, j = n - 1;
  90.  
  91.         memcpy(pivot, data, e_size);
  92.  
  93.         while (1) {
  94.             while ((cmp(data + i * e_size, pivot) < 0) && i < n) i++;
  95.             while ((cmp(data + j * e_size, pivot) >=0) && j > 0) j--;
  96.             if (i<j) {
  97.                 memcpy(tmp, data + i * e_size, e_size);
  98.                 memcpy(data + i * e_size, data + j * e_size, e_size);
  99.                 memcpy(data + j * e_size, tmp, e_size);
  100.             } else {
  101.                 break;
  102.             }
  103.         }
  104.  
  105.         _qsort(data, j + 1, e_size, cmp, tmp, pivot);
  106.         _qsort(data + (j + 1) * e_size, n - j - 1, e_size, cmp, tmp, pivot);
  107.     } else {
  108.         _bubblesort(data, n, e_size, cmp, tmp);
  109.     }
  110. }
  111.  
  112. /** Bubblesort wrapper
  113.  *
  114.  * This is only a wrapper that takes care of memory allocation for storing
  115.  * the slot element for generic bubblesort algorithm.
  116.  *
  117.  * @param data Pointer to data to be sorted.
  118.  * @param n Number of elements to be sorted.
  119.  * @param e_size Size of one element.
  120.  * @param cmp Comparator function.
  121.  *
  122.  */
  123. void bubblesort(void * data, count_t n, size_t e_size, int (* cmp) (void * a, void * b))
  124. {
  125.     __u8 buf_slot[EBUFSIZE];
  126.     void * slot = buf_slot;
  127.    
  128.     if (e_size > EBUFSIZE) {
  129.         slot = (void *) malloc(e_size);
  130.        
  131.         if (!slot) {
  132.             panic("Cannot allocate memory\n");
  133.         }
  134.     }
  135.  
  136.     _bubblesort(data, n, e_size, cmp, slot);
  137.    
  138.     if (e_size > EBUFSIZE) {
  139.         free(slot);
  140.     }
  141. }
  142.  
  143. /** Bubblesort
  144.  *
  145.  * Apply generic bubblesort algorithm on supplied data, using pre-allocated buffer.
  146.  *
  147.  * @param data Pointer to data to be sorted.
  148.  * @param n Number of elements to be sorted.
  149.  * @param e_size Size of one element.
  150.  * @param cmp Comparator function.
  151.  * @param slot Pointer to scratch memory buffer e_size bytes long.
  152.  *
  153.  */
  154. void _bubblesort(void * data, count_t n, size_t e_size, int (* cmp) (void * a, void * b), void *slot)
  155. {
  156.     bool done = false;
  157.     void * p;
  158.  
  159.     while (!done) {
  160.         done = true;
  161.         for (p = data; p < data + e_size * (n - 1); p = p + e_size) {
  162.             if (cmp(p, p + e_size) == 1) {
  163.                 memcpy(slot, p, e_size);
  164.                 memcpy(p, p + e_size, e_size);
  165.                 memcpy(p + e_size, slot, e_size);
  166.                 done = false;
  167.             }
  168.         }
  169.     }
  170.  
  171. }
  172.  
  173. /*
  174.  * Comparator returns 1 if a > b, 0 if a == b, -1 if a < b
  175.  */
  176. int int_cmp(void * a, void * b)
  177. {
  178.     return (* (int *) a > * (int*)b) ? 1 : (*(int *)a < * (int *)b) ? -1 : 0;
  179. }
  180.  
  181. int __u8_cmp(void * a, void * b)
  182. {
  183.     return (* (__u8 *) a > * (__u8 *)b) ? 1 : (*(__u8 *)a < * (__u8 *)b) ? -1 : 0;
  184. }
  185.  
  186. int __u16_cmp(void * a, void * b)
  187. {
  188.     return (* (__u16 *) a > * (__u16 *)b) ? 1 : (*(__u16 *)a < * (__u16 *)b) ? -1 : 0;
  189. }
  190.  
  191. int __u32_cmp(void * a, void * b)
  192. {
  193.     return (* (__u32 *) a > * (__u32 *)b) ? 1 : (*(__u32 *)a < * (__u32 *)b) ? -1 : 0;
  194. }
  195.