X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/d001b03dcee41695c0bf66206429c364a89321eb..6532cb48078124e2fcdeda3b8074c4b642a635ac:/src/xbt/heap.c

diff --git a/src/xbt/heap.c b/src/xbt/heap.c
index b6cea7c0e2..2b153804cd 100644
--- a/src/xbt/heap.c
+++ b/src/xbt/heap.c
@@ -1,79 +1,115 @@
 /* a generic and efficient heap                                             */
 
-/* Authors: Arnaud Legrand                                                  */
+/* Copyright (c) 2004, 2005, 2007, 2008, 2009, 2010. The SimGrid Team.
+ * All rights reserved.                                                     */
 
 /* This program is free software; you can redistribute it and/or modify it
-   under the terms of the license (GNU LGPL) which comes with this package. */
+ * under the terms of the license (GNU LGPL) which comes with this package. */
 
 #include "xbt/sysdep.h"
-#include "xbt/error.h"
+#include "xbt/log.h"
 #include "heap_private.h"
 
+#include <stdio.h>
+
+static void xbt_heap_max_heapify(xbt_heap_t H);
+static void xbt_heap_increase_key(xbt_heap_t H, int i);
+
+/** @addtogroup XBT_heap
+ *  \brief This section describes the API to generic heap with O(log(n)) access.
+ */
+
 /**
- * xbt_heap_new:
- * @init_size: initial size of the heap
- * @free_func: function to call on each element when you want to free the whole heap (or NULL if nothing to do).
+ * @brief Creates a new heap.
+ * \param init_size initial size of the heap
+ * \param free_func function to call on each element when you want to free
+ *             the whole heap (or NULL if nothing to do).
  *
  * Creates a new heap.
  */
-xbt_heap_t xbt_heap_new(int init_size, void_f_pvoid_t * const free_func)
+XBT_INLINE xbt_heap_t xbt_heap_new(int init_size,
+                                   void_f_pvoid_t const free_func)
 {
   xbt_heap_t H = xbt_new0(struct xbt_heap, 1);
   H->size = init_size;
   H->count = 0;
-  H->items =
-      (xbt_heapItem_t) xbt_new0(struct xbt_heapItem, init_size);
+  H->items = (xbt_heap_item_t) xbt_new0(struct xbt_heap_item, init_size);
   H->free = free_func;
   return H;
 }
 
 /**
- * xbt_heap_free:
- * @H: poor victim
- *
- * kilkil a heap and its content
+ * @brief Set the update callback function.
+ * @param H the heap we're working on
+ * \param update_callback function to call on each element to update its index when needed.
+ */
+XBT_INLINE void xbt_heap_set_update_callback(xbt_heap_t H,
+                                             void (*update_callback) (void
+                                                                      *,
+                                                                      int))
+{
+  H->update_callback = update_callback;
+}
+
+
+/**
+ * @brief kilkil a heap and its content
+ * @param H poor victim
  */
 void xbt_heap_free(xbt_heap_t H)
 {
   int i;
   if (H->free)
-    for (i = 0; i < H->size; i++)
+    for (i = 0; i < H->count; i++)
       H->free(H->items[i].content);
-  xbt_free(H->items);
-  xbt_free(H);
+  free(H->items);
+  free(H);
   return;
 }
 
 /**
- * xbt_heap_push:
- * @H: the heap we're working on
- * @content: the object you want to add to the heap
- * @key: the key associated to this object
+ * @brief returns the number of elements in the heap
+ * @param H the heap we're working on
+ * @return the number of elements in the heap
+ */
+XBT_INLINE int xbt_heap_size(xbt_heap_t H)
+{
+  return (H->count);
+}
+
+/**
+ * @brief Add an element into the heap.
+ * \param H the heap we're working on
+ * \param content the object you want to add to the heap
+ * \param key the key associated to this object
  *
- * Add an element int the heap. The element with the smallest key is
- * automatically moved at the top of the heap.
+ * The element with the smallest key is automatically moved at the top of the heap.
  */
-void xbt_heap_push(xbt_heap_t H, void *content, xbt_heap_float_t key)
+void xbt_heap_push(xbt_heap_t H, void *content, double key)
 {
   int count = ++(H->count);
+
   int size = H->size;
-  xbt_heapItem_t item;
+  xbt_heap_item_t item;
+
   if (count > size) {
-    H->size = 2 * size + 1;
+    H->size = (size << 1) + 1;
     H->items =
-	(void *) realloc(H->items,
-			 (H->size) * sizeof(struct xbt_heapItem));
+        (void *) realloc(H->items,
+                         (H->size) * sizeof(struct xbt_heap_item));
   }
+
   item = &(H->items[count - 1]);
   item->key = key;
   item->content = content;
-  xbt_heap_increaseKey(H, count - 1);
+  xbt_heap_increase_key(H, count - 1);
   return;
 }
 
 /**
- * xbt_heap_pop:
- * @H: the heap we're working on
+ * @brief Extracts from the heap and returns the element with the smallest key.
+ * \param H the heap we're working on
+ * \return the element with the smallest key
  *
  * Extracts from the heap and returns the element with the smallest
  * key. The element with the next smallest key is automatically moved
@@ -81,85 +117,132 @@ void xbt_heap_push(xbt_heap_t H, void *content, xbt_heap_float_t key)
  */
 void *xbt_heap_pop(xbt_heap_t H)
 {
-  void *max = CONTENT(H, 0);
-  H->items[0] = H->items[(H->count) - 1];
+  xbt_heap_item_t items = H->items;
+  int size = H->size;
+  void *max;
+
+  if (H->count == 0)
+    return NULL;
+
+  max = CONTENT(H, 0);
+
+  items[0] = items[(H->count) - 1];
   (H->count)--;
-  xbt_heap_maxHeapify(H);
-  if (H->count < H->size / 4 && H->size > 16) {
-    H->size = H->size / 2 + 1;
+  xbt_heap_max_heapify(H);
+  if (H->count < size >> 2 && size > 16) {
+    size = (size >> 1) + 1;
     H->items =
-	(void *) realloc(H->items,
-			 (H->size) * sizeof(struct xbt_heapItem));
+        (void *) realloc(items,
+                         size * sizeof(struct xbt_heap_item));
+    H->size = size;
   }
+
+  if (H->update_callback)
+    H->update_callback(max, -1);
   return max;
 }
 
 /**
- * xbt_heap_maxkey:
- * @H: the heap we're working on
+ * @brief Extracts from the heap and returns the element at position i.
+ * \param H the heap we're working on
+ * \param i	element position
+ * \return the element at position i if ok, NULL otherwise
+ *
+ * Extracts from the heap and returns the element at position i. The heap is automatically reorded.
+ */
+void *xbt_heap_remove(xbt_heap_t H, int i)
+{
+  if ((i < 0) || (i > H->count - 1))
+    return NULL;
+  /* put element i at head */
+  if (i > 0) {
+    KEY(H, i) = MIN_KEY_VALUE;
+    xbt_heap_increase_key(H, i);
+  }
+
+  return xbt_heap_pop(H);
+}
+
+/**
+ * @brief returns the smallest key in the heap (heap unchanged)
+ * \param H the heap we're working on
  *
- * Returns the smallest key in the heap without modifying the heap.
+ * \return the smallest key in the heap without modifying the heap.
  */
-xbt_heap_float_t xbt_heap_maxkey(xbt_heap_t H)
+XBT_INLINE double xbt_heap_maxkey(xbt_heap_t H)
 {
+  xbt_assert(H->count != 0, "Empty heap");
   return KEY(H, 0);
 }
 
 /**
- * xbt_heap_maxcontent:
- * @H: the heap we're working on
+ * @brief returns the value associated to the smallest key in the heap (heap unchanged)
+ * \param H the heap we're working on
  *
- * Returns the value associated to the smallest key in the heap
+ * \return the value associated to the smallest key in the heap
  * without modifying the heap.
  */
 void *xbt_heap_maxcontent(xbt_heap_t H)
 {
+  xbt_assert(H->count != 0, "Empty heap");
   return CONTENT(H, 0);
 }
 
-/**
- * xbt_heap_maxcontent:
- * @H: the heap we're working on
- * 
+/* <<<< private >>>>
+ * \param H the heap we're working on
+ *
  * Restores the heap property once an element has been deleted.
  */
-static void xbt_heap_maxHeapify(xbt_heap_t H)
+static void xbt_heap_max_heapify(xbt_heap_t H)
 {
   int i = 0;
+  int count = H->count;
+  xbt_heap_item_t items = H->items;
+
   while (1) {
     int greatest = i;
     int l = LEFT(i);
-    int r = RIGHT(i);
-    int count = H->count;
-    if (l < count && KEY(H, l) < KEY(H, i))
+    int r = l + 1;
+    if (l < count && items[l].key < items[i].key)
       greatest = l;
-    if (r < count && KEY(H, r) < KEY(H, greatest))
+    if (r < count && items[r].key < items[greatest].key)
       greatest = r;
     if (greatest != i) {
-      struct xbt_heapItem tmp = H->items[i];
-      H->items[i] = H->items[greatest];
-      H->items[greatest] = tmp;
+      struct xbt_heap_item tmp = items[i];
+      items[i] = items[greatest];
+      items[greatest] = tmp;
+      if (H->update_callback)
+        H->update_callback(items[i].content, i);
       i = greatest;
-    } else
+    } else {
+      if (H->update_callback)
+        H->update_callback(items[i].content, i);
       return;
+    }
   }
 }
 
-/**
- * xbt_heap_maxcontent:
- * @H: the heap we're working on
- * @i: an item position in the heap
- * 
+/* <<<< private >>>>
+ * \param H the heap we're working on
+ * \param i an item position in the heap
+ *
  * Moves up an item at position i to its correct position. Works only
  * when called from xbt_heap_push. Do not use otherwise.
  */
-static void xbt_heap_increaseKey(xbt_heap_t H, int i)
+static void xbt_heap_increase_key(xbt_heap_t H, int i)
 {
-  while (i > 0 && KEY(H, PARENT(i)) > KEY(H, i)) {
-    struct xbt_heapItem tmp = H->items[i];
-    H->items[i] = H->items[PARENT(i)];
-    H->items[PARENT(i)] = tmp;
-    i = PARENT(i);
+  xbt_heap_item_t items = H->items;
+  int p = PARENT(i);
+  while (i > 0 && items[p].key > items[i].key) {
+    struct xbt_heap_item tmp = items[i];
+    items[i] = items[p];
+    items[p] = tmp;
+    if (H->update_callback)
+      H->update_callback(items[i].content, i);
+    i = p;
+    p = PARENT(i);
   }
+  if (H->update_callback)
+    H->update_callback(items[i].content, i);
   return;
 }