WebSVN – HelenOS-historic – Diff – /kernel/trunk/generic/src/lib/sort.c

 /*
  * Copyright (C) 2005 Sergey Bondari
  * All rights reserved.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
+ *
  * - Redistributions of source code must retain the above copyright
  *   notice, this list of conditions and the following disclaimer.
  * - Redistributions in binary form must reproduce the above copyright
  *   notice, this list of conditions and the following disclaimer in the
  *   documentation and/or other materials provided with the distribution.
  * - The name of the author may not be used to endorse or promote products
  *   derived from this software without specific prior written permission.
+ *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 #include <mm/heap.h>
 #include <memstr.h>
 #include <sort.h>
 #include <panic.h>
 #define EBUFSIZE    32
+void _qsort(void * data, count_t n, size_t e_size, int (* cmp) (void * a, void * b), void *tmp, void *pivot);
+void _bubblesort(void * data, count_t n, size_t e_size, int (* cmp) (void * a, void * b), void *slot);
+/** Quicksort wrapper
+ *
+ * This is only a wrapper that takes care of memory allocations for storing
+ * the pivot and temporary elements for generic quicksort algorithm.
+ *
+ * @param data Pointer to data to be sorted.
+ * @param n Number of elements to be sorted.
+ * @param e_size Size of one element.
+ * @param cmp Comparator function.
+ *
+ */
 void qsort(void * data, count_t n, size_t e_size, int (* cmp) (void * a, void * b))
+{
     __u8 buf_tmp[EBUFSIZE];
     __u8 buf_pivot[EBUFSIZE];
     void * tmp = buf_tmp;
     void * pivot = buf_pivot;
     if (e_size > EBUFSIZE) {
         pivot = (void *) malloc(e_size);
         tmp = (void *) malloc(e_size);
         if (!tmp || !pivot) {
             panic("Cannot allocate memory\n");
+        }
+    }
+    _qsort(data, n, e_size, cmp, tmp, pivot);
+    if (e_size > EBUFSIZE) {
+        free(tmp);
+        free(pivot);
+    }
+}
+/** Quicksort
+ *
+ * Apply generic quicksort algorithm on supplied data, using pre-allocated buffers.
+ *
+ * @param data Pointer to data to be sorted.
+ * @param n Number of elements to be sorted.
+ * @param e_size Size of one element.
+ * @param cmp Comparator function.
+ * @param tmp Pointer to scratch memory buffer e_size bytes long.
+ * @param pivot Pointer to scratch memory buffer e_size bytes long.
+ *
+ */
+void _qsort(void * data, count_t n, size_t e_size, int (* cmp) (void * a, void * b), void *tmp, void *pivot)
+{
     if (n > 4) {
         int i = 0, j = n - 1;
         memcpy(pivot, data, e_size);
         while (1) {
             while ((cmp(data + i * e_size, pivot) < 0) && i < n) i++;
             while ((cmp(data + j * e_size, pivot) >=0) && j > 0) j--;
             if (i<j) {
                 memcpy(tmp, data + i * e_size, e_size);
                 memcpy(data + i * e_size, data + j * e_size, e_size);
                 memcpy(data + j * e_size, tmp, e_size);
             } else {
                 break;
+            }
+        }
-        qsort(data, j + 1, e_size, cmp);
+        _qsort(data, j + 1, e_size, cmp, tmp, pivot);
-        qsort(data + (j + 1) * e_size, n - j - 1, e_size, cmp);
+        _qsort(data + (j + 1) * e_size, n - j - 1, e_size, cmp, tmp, pivot);
     } else {
-        bubblesort(data, n, e_size, cmp);
+        _bubblesort(data, n, e_size, cmp, tmp);
-    }
-    if (e_size > EBUFSIZE) {
-        free(tmp);
-        free(pivot);
+    }
+}
+/** Bubblesort wrapper
+ *
+ * This is only a wrapper that takes care of memory allocation for storing
+ * the slot element for generic bubblesort algorithm.
+ *
+ * @param data Pointer to data to be sorted.
+ * @param n Number of elements to be sorted.
+ * @param e_size Size of one element.
+ * @param cmp Comparator function.
+ *
+ */
 void bubblesort(void * data, count_t n, size_t e_size, int (* cmp) (void * a, void * b))
+{
     __u8 buf_slot[EBUFSIZE];
-    bool done = false;
-    void * p;
     void * slot = buf_slot;
     if (e_size > EBUFSIZE) {
         slot = (void *) malloc(e_size);
         if (!slot) {
             panic("Cannot allocate memory\n");
+        }
+    }
+    _bubblesort(data, n, e_size, cmp, slot);
+    if (e_size > EBUFSIZE) {
+        free(slot);
+    }
+}
+/** Bubblesort
+ *
+ * Apply generic bubblesort algorithm on supplied data, using pre-allocated buffer.
+ *
+ * @param data Pointer to data to be sorted.
+ * @param n Number of elements to be sorted.
+ * @param e_size Size of one element.
+ * @param cmp Comparator function.
+ * @param slot Pointer to scratch memory buffer e_size bytes long.
+ *
+ */
+void _bubblesort(void * data, count_t n, size_t e_size, int (* cmp) (void * a, void * b), void *slot)
+{
+    bool done = false;
+    void * p;
     while (!done) {
         done = true;
         for (p = data; p < data + e_size * (n - 1); p = p + e_size) {
             if (cmp(p, p + e_size) == 1) {
                 memcpy(slot, p, e_size);
                 memcpy(p, p + e_size, e_size);
                 memcpy(p + e_size, slot, e_size);
                 done = false;
+            }
+        }
+    }
-    if (e_size > EBUFSIZE) {
-        free(slot);
-    }
+}
 /*
  * Comparator returns 1 if a > b, 0 if a == b, -1 if a < b
  */
 int int_cmp(void * a, void * b)
+{
     return (* (int *) a > * (int*)b) ? 1 : (*(int *)a < * (int *)b) ? -1 : 0;
+}
 int __u8_cmp(void * a, void * b)
+{
     return (* (__u8 *) a > * (__u8 *)b) ? 1 : (*(__u8 *)a < * (__u8 *)b) ? -1 : 0;
+}
 int __u16_cmp(void * a, void * b)
+{
     return (* (__u16 *) a > * (__u16 *)b) ? 1 : (*(__u16 *)a < * (__u16 *)b) ? -1 : 0;
+}
 int __u32_cmp(void * a, void * b)
+{
     return (* (__u32 *) a > * (__u32 *)b) ? 1 : (*(__u32 *)a < * (__u32 *)b) ? -1 : 0;
+}

Subversion Repositories HelenOS-historic

(root)/kernel/trunk/generic/src/lib/sort.c @ 1780 – Rev 350 → 351