X-Git-Url: http://info.iut-bm.univ-fcomte.fr/pub/gitweb/simgrid.git/blobdiff_plain/7c5d24856794b213573f5e67bf138db144dac2eb..cc375ad134c19925e1e343bae932be21cf8a8caf:/src/xbt/heap.c

diff --git a/src/xbt/heap.c b/src/xbt/heap.c
index 243e9c3212..e124aab386 100644
--- a/src/xbt/heap.c
+++ b/src/xbt/heap.c
@@ -1,8 +1,7 @@
-/* 	$Id$	 */
-
 /* a generic and efficient heap                                             */
 
-/* Copyright (c) 2004 Arnaud Legrand. All rights reserved.                  */
+/* 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. */
@@ -13,8 +12,10 @@
 
 #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 
+/** @addtogroup XBT_heap
  *  \brief This section describes the API to generic heap with O(log(n)) access.
  */
 
@@ -26,16 +27,31 @@
  *
  * 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;
 }
 
+/**
+ * @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
@@ -45,7 +61,7 @@ void xbt_heap_free(xbt_heap_t H)
   int i;
   if (H->free)
     for (i = 0; i < H->count; i++)
-      (*(H->free))(H->items[i].content);
+      H->free(H->items[i].content);
   free(H->items);
   free(H);
   return;
@@ -56,7 +72,7 @@ void xbt_heap_free(xbt_heap_t H)
  * @param H the heap we're working on
  * @return the number of elements in the heap
  */
-int xbt_heap_size(xbt_heap_t H)
+XBT_INLINE int xbt_heap_size(xbt_heap_t H)
 {
   return (H->count);
 }
@@ -71,21 +87,23 @@ int xbt_heap_size(xbt_heap_t H)
  */
 void xbt_heap_push(xbt_heap_t H, void *content, double key)
 {
-	int count = ++(H->count);
-
-	int size = H->size;
-	xbt_heapItem_t item;
-	
-	if (count > size) {
-		H->size = 2 * size + 1;
-		H->items =(void *) realloc(H->items,(H->size) * sizeof(struct xbt_heapItem));
-	}
-	
-	item = &(H->items[count - 1]);
-	item->key = key;
-	item->content = content;
-	xbt_heap_increaseKey(H, count - 1);
-	return;
+  int count = ++(H->count);
+
+  int size = H->size;
+  xbt_heap_item_t item;
+
+  if (count > size) {
+    H->size = (size << 1) + 1;
+    H->items =
+        (void *) xbt_realloc(H->items,
+                         (H->size) * sizeof(struct xbt_heap_item));
+  }
+
+  item = &(H->items[count - 1]);
+  item->key = key;
+  item->content = content;
+  xbt_heap_increase_key(H, count - 1);
+  return;
 }
 
 /**
@@ -99,6 +117,8 @@ void xbt_heap_push(xbt_heap_t H, void *content, double key)
  */
 void *xbt_heap_pop(xbt_heap_t H)
 {
+  xbt_heap_item_t items = H->items;
+  int size = H->size;
   void *max;
 
   if (H->count == 0)
@@ -106,27 +126,52 @@ void *xbt_heap_pop(xbt_heap_t H)
 
   max = CONTENT(H, 0);
 
-  H->items[0] = H->items[(H->count) - 1];
+  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 *) xbt_realloc(items,
+                         size * sizeof(struct xbt_heap_item));
+    H->size = size;
   }
+
+  if (H->update_callback)
+    H->update_callback(max, -1);
   return max;
 }
 
+/**
+ * @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
  *
  * \return the smallest key in the heap without modifying the heap.
  */
-double xbt_heap_maxkey(xbt_heap_t H)
+XBT_INLINE double xbt_heap_maxkey(xbt_heap_t H)
 {
-  xbt_assert0(H->count != 0,"Empty heap");
+  xbt_assert(H->count != 0, "Empty heap");
   return KEY(H, 0);
 }
 
@@ -139,51 +184,65 @@ double xbt_heap_maxkey(xbt_heap_t H)
  */
 void *xbt_heap_maxcontent(xbt_heap_t H)
 {
-  xbt_assert0(H->count != 0,"Empty heap");
+  xbt_assert(H->count != 0, "Empty heap");
   return CONTENT(H, 0);
 }
 
 /* <<<< 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;
+    }
   }
 }
 
 /* <<<< 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;
 }