Subversion Repositories HelenOS

Rev

Rev 2071 | Rev 3386 | Go to most recent revision | Blame | Compare with Previous | Last modification | View Log | Download | RSS feed

  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. /** @addtogroup generic
  30.  * @{
  31.  */
  32.  
  33. /**
  34.  * @file
  35.  * @brief   Sorting functions.
  36.  *
  37.  * This files contains functions implementing several sorting
  38.  * algorithms (e.g. quick sort and bubble sort).
  39.  */
  40.  
  41. #include <mm/slab.h>
  42. #include <memstr.h>
  43. #include <sort.h>
  44. #include <panic.h>
  45.  
  46. #define EBUFSIZE    32
  47.  
  48. void _qsort(void * data, count_t n, size_t e_size, int (* cmp) (void * a, void * b), void *tmp, void *pivot);
  49. void _bubblesort(void * data, count_t n, size_t e_size, int (* cmp) (void * a, void * b), void *slot);
  50.  
  51. /** Quicksort wrapper
  52.  *
  53.  * This is only a wrapper that takes care of memory allocations for storing
  54.  * the pivot and temporary elements for generic quicksort algorithm.
  55.  *
  56.  * This function _can_ sleep
  57.  *
  58.  * @param data Pointer to data to be sorted.
  59.  * @param n Number of elements to be sorted.
  60.  * @param e_size Size of one element.
  61.  * @param cmp Comparator function.
  62.  *
  63.  */
  64. void qsort(void * data, count_t n, size_t e_size, int (* cmp) (void * a, void * b))
  65. {
  66.     uint8_t buf_tmp[EBUFSIZE];
  67.     uint8_t buf_pivot[EBUFSIZE];
  68.     void * tmp = buf_tmp;
  69.     void * pivot = buf_pivot;
  70.  
  71.     if (e_size > EBUFSIZE) {
  72.         pivot = (void *) malloc(e_size, 0);
  73.         tmp = (void *) malloc(e_size, 0);
  74.     }
  75.  
  76.     _qsort(data, n, e_size, cmp, tmp, pivot);
  77.    
  78.     if (e_size > EBUFSIZE) {
  79.         free(tmp);
  80.         free(pivot);
  81.     }
  82. }
  83.  
  84. /** Quicksort
  85.  *
  86.  * Apply generic quicksort algorithm on supplied data, using pre-allocated buffers.
  87.  *
  88.  * @param data Pointer to data to be sorted.
  89.  * @param n Number of elements to be sorted.
  90.  * @param e_size Size of one element.
  91.  * @param cmp Comparator function.
  92.  * @param tmp Pointer to scratch memory buffer e_size bytes long.
  93.  * @param pivot Pointer to scratch memory buffer e_size bytes long.
  94.  *
  95.  */
  96. void _qsort(void * data, count_t n, size_t e_size, int (* cmp) (void * a, void * b), void *tmp, void *pivot)
  97. {
  98.     if (n > 4) {
  99.         unsigned int i = 0, j = n - 1;
  100.  
  101.         memcpy(pivot, data, e_size);
  102.  
  103.         while (1) {
  104.             while ((cmp(data + i * e_size, pivot) < 0) && (i < n))
  105.                 i++;
  106.             while ((cmp(data + j * e_size, pivot) >= 0) && (j > 0))
  107.                 j--;
  108.            
  109.             if (i < j) {
  110.                 memcpy(tmp, data + i * e_size, e_size);
  111.                 memcpy(data + i * e_size, data + j * e_size, e_size);
  112.                 memcpy(data + j * e_size, tmp, e_size);
  113.             } else {
  114.                 break;
  115.             }
  116.         }
  117.  
  118.         _qsort(data, j + 1, e_size, cmp, tmp, pivot);
  119.         _qsort(data + (j + 1) * e_size, n - j - 1, e_size, cmp, tmp, pivot);
  120.     } else {
  121.         _bubblesort(data, n, e_size, cmp, tmp);
  122.     }
  123. }
  124.  
  125. /** Bubblesort wrapper
  126.  *
  127.  * This is only a wrapper that takes care of memory allocation for storing
  128.  * the slot element for generic bubblesort algorithm.
  129.  *
  130.  * @param data Pointer to data to be sorted.
  131.  * @param n Number of elements to be sorted.
  132.  * @param e_size Size of one element.
  133.  * @param cmp Comparator function.
  134.  *
  135.  */
  136. void bubblesort(void * data, count_t n, size_t e_size, int (* cmp) (void * a, void * b))
  137. {
  138.     uint8_t buf_slot[EBUFSIZE];
  139.     void * slot = buf_slot;
  140.    
  141.     if (e_size > EBUFSIZE) {
  142.         slot = (void *) malloc(e_size, 0);
  143.     }
  144.  
  145.     _bubblesort(data, n, e_size, cmp, slot);
  146.    
  147.     if (e_size > EBUFSIZE) {
  148.         free(slot);
  149.     }
  150. }
  151.  
  152. /** Bubblesort
  153.  *
  154.  * Apply generic bubblesort algorithm on supplied data, using pre-allocated buffer.
  155.  *
  156.  * @param data Pointer to data to be sorted.
  157.  * @param n Number of elements to be sorted.
  158.  * @param e_size Size of one element.
  159.  * @param cmp Comparator function.
  160.  * @param slot Pointer to scratch memory buffer e_size bytes long.
  161.  *
  162.  */
  163. void _bubblesort(void * data, count_t n, size_t e_size, int (* cmp) (void * a, void * b), void *slot)
  164. {
  165.     bool done = false;
  166.     void * p;
  167.  
  168.     while (!done) {
  169.         done = true;
  170.         for (p = data; p < data + e_size * (n - 1); p = p + e_size) {
  171.             if (cmp(p, p + e_size) == 1) {
  172.                 memcpy(slot, p, e_size);
  173.                 memcpy(p, p + e_size, e_size);
  174.                 memcpy(p + e_size, slot, e_size);
  175.                 done = false;
  176.             }
  177.         }
  178.     }
  179.  
  180. }
  181.  
  182. /*
  183.  * Comparator returns 1 if a > b, 0 if a == b, -1 if a < b
  184.  */
  185. int int_cmp(void * a, void * b)
  186. {
  187.     return (* (int *) a > * (int*)b) ? 1 : (*(int *)a < * (int *)b) ? -1 : 0;
  188. }
  189.  
  190. int uint8_t_cmp(void * a, void * b)
  191. {
  192.     return (* (uint8_t *) a > * (uint8_t *)b) ? 1 : (*(uint8_t *)a < * (uint8_t *)b) ? -1 : 0;
  193. }
  194.  
  195. int uint16_t_cmp(void * a, void * b)
  196. {
  197.     return (* (uint16_t *) a > * (uint16_t *)b) ? 1 : (*(uint16_t *)a < * (uint16_t *)b) ? -1 : 0;
  198. }
  199.  
  200. int uint32_t_cmp(void * a, void * b)
  201. {
  202.     return (* (uint32_t *) a > * (uint32_t *)b) ? 1 : (*(uint32_t *)a < * (uint32_t *)b) ? -1 : 0;
  203. }
  204.  
  205. /** @}
  206.  */
  207.