/*
This file is part of GNUnet.
- (C) 2008, 2009 Christian Grothoff (and other contributing authors)
-
+ Copyright (C) 2008, 2009 GNUnet e.V.
+
GNUnet is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published
- by the Free Software Foundation; either version 2, or (at your
+ by the Free Software Foundation; either version 3, or (at your
option) any later version.
-
+
GNUnet is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
-
+
You should have received a copy of the GNU General Public License
along with GNUnet; see the file COPYING. If not, write to the
- Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA.
+ Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ Boston, MA 02110-1301, USA.
*/
/**
*/
#include "platform.h"
-#include "gnunet_util_lib.h"
+#include "gnunet_container_lib.h"
+#define LOG(kind,...) GNUNET_log_from (kind, "util", __VA_ARGS__)
-#define DEBUG 0
+#define EXTRA_CHECKS 0
/**
* Node in the heap.
*/
struct GNUNET_CONTAINER_HeapNode
{
+ /**
+ * Heap this node belongs to.
+ */
+ struct GNUNET_CONTAINER_Heap *heap;
+
/**
* Parent node.
*/
* Number of elements in the heap.
*/
unsigned int size;
-
+
/**
* How is the heap sorted?
*/
};
-#if DEBUG
+#if EXTRA_CHECKS
/**
* Check if internal invariants hold for the given node.
*
* @param node subtree to check
- */
+ */
static void
check (const struct GNUNET_CONTAINER_HeapNode *node)
-{
+{
if (NULL == node)
return;
GNUNET_assert (node->tree_size ==
- ( (node->left_child == NULL) ? 0 : 1 + node->left_child->tree_size) +
- ( (node->right_child == NULL) ? 0 : 1 + node->right_child->tree_size) );
+ ((node->left_child ==
+ NULL) ? 0 : 1 + node->left_child->tree_size) +
+ ((node->right_child ==
+ NULL) ? 0 : 1 + node->right_child->tree_size));
check (node->left_child);
check (node->right_child);
}
{
struct GNUNET_CONTAINER_Heap *heap;
- heap = GNUNET_malloc (sizeof (struct GNUNET_CONTAINER_Heap));
+ heap = GNUNET_new (struct GNUNET_CONTAINER_Heap);
heap->order = order;
return heap;
}
/**
- * Get element stored at root of heap.
+ * Get element stored at the root of @a heap.
*
- * @param heap heap to inspect
- * @return NULL if heap is empty
+ * @param heap Heap to inspect.
+ * @return Element at the root, or NULL if heap is empty.
*/
void *
GNUNET_CONTAINER_heap_peek (const struct GNUNET_CONTAINER_Heap *heap)
}
+/**
+ * Get @a element and @a cost stored at the root of @a heap.
+ *
+ * @param[in] heap Heap to inspect.
+ * @param[out] element Root element is returned here.
+ * @param[out] cost Cost of @a element is returned here.
+ * @return #GNUNET_YES if an element is returned,
+ * #GNUNET_NO if the heap is empty.
+ */
+int
+GNUNET_CONTAINER_heap_peek2 (const struct GNUNET_CONTAINER_Heap *heap,
+ void **element,
+ GNUNET_CONTAINER_HeapCostType *cost)
+{
+ if (NULL == heap->root)
+ return GNUNET_NO;
+ if (NULL != element)
+ *element = heap->root->element;
+ if (NULL != cost)
+ *cost = heap->root->cost;
+ return GNUNET_YES;
+}
+
+
/**
* Get the current size of the heap
*
}
+/**
+ * Get the current cost of the node
+ *
+ * @param node the node to get the cost of
+ * @return cost of the node
+ */
+GNUNET_CONTAINER_HeapCostType
+GNUNET_CONTAINER_heap_node_get_cost (const struct GNUNET_CONTAINER_HeapNode
+ *node)
+{
+ return node->cost;
+}
+
+
/**
* Iterate over the children of the given node.
*
*/
static int
node_iterator (const struct GNUNET_CONTAINER_Heap *heap,
- struct GNUNET_CONTAINER_HeapNode *node,
- GNUNET_CONTAINER_HeapIterator iterator,
- void *iterator_cls)
+ struct GNUNET_CONTAINER_HeapNode *node,
+ GNUNET_CONTAINER_HeapIterator iterator, void *iterator_cls)
{
if (node == NULL)
return GNUNET_YES;
- if (GNUNET_YES != node_iterator (heap,
- node->left_child,
- iterator,
- iterator_cls))
+ if (GNUNET_YES !=
+ node_iterator (heap, node->left_child, iterator, iterator_cls))
return GNUNET_NO;
- if (GNUNET_YES != node_iterator (heap,
- node->right_child,
- iterator,
- iterator_cls))
+ if (GNUNET_YES !=
+ node_iterator (heap, node->right_child, iterator, iterator_cls))
return GNUNET_NO;
- return iterator (iterator_cls,
- node,
- node->element,
- node->cost);
+ return iterator (iterator_cls, node, node->element, node->cost);
}
if (heap->root == NULL)
return NULL;
pos = heap->walk_pos;
- if (pos == NULL)
- pos = heap->root;
+ if (pos == NULL)
+ pos = heap->root;
element = pos->element;
- heap->walk_pos
- = (0 == GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, 2))
- ? pos->right_child
- : pos->left_child;
+ heap->walk_pos =
+ (0 ==
+ GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
+ 2)) ? pos->right_child : pos->left_child;
return element;
}
* Insert the given node 'node' into the subtree starting
* at 'pos' (while keeping the tree somewhat balanced).
*
+ * @param heap heap to modify
* @param pos existing tree
* @param node node to insert (which may be a subtree itself)
*/
static void
insert_node (struct GNUNET_CONTAINER_Heap *heap,
- struct GNUNET_CONTAINER_HeapNode *pos,
- struct GNUNET_CONTAINER_HeapNode *node)
+ struct GNUNET_CONTAINER_HeapNode *pos,
+ struct GNUNET_CONTAINER_HeapNode *node)
{
struct GNUNET_CONTAINER_HeapNode *parent;
GNUNET_assert (node->parent == NULL);
- while ( (pos->cost < node->cost) ^ (heap->order == GNUNET_CONTAINER_HEAP_ORDER_MAX) )
+ while ((heap->order == GNUNET_CONTAINER_HEAP_ORDER_MAX) ? (pos->cost >=
+ node->cost)
+ : (pos->cost <= node->cost))
+ {
+ /* node is descendent of pos */
+ pos->tree_size += (1 + node->tree_size);
+ if (pos->left_child == NULL)
+ {
+ pos->left_child = node;
+ node->parent = pos;
+ return;
+ }
+ if (pos->right_child == NULL)
{
- /* node is descendent of pos */
- pos->tree_size += (1 + node->tree_size);
- if (pos->left_child == NULL)
- {
- pos->left_child = node;
- node->parent = pos;
- return;
- }
- if (pos->right_child == NULL)
- {
- pos->right_child = node;
- node->parent = pos;
- return;
- }
- /* keep it balanced by descending into smaller subtree */
- if (pos->left_child->tree_size < pos->right_child->tree_size)
- pos = pos->left_child;
- else
- pos = pos->right_child;
+ pos->right_child = node;
+ node->parent = pos;
+ return;
}
+ /* keep it balanced by descending into smaller subtree */
+ if (pos->left_child->tree_size < pos->right_child->tree_size)
+ pos = pos->left_child;
+ else
+ pos = pos->right_child;
+ }
/* make 'node' parent of 'pos' */
parent = pos->parent;
pos->parent = NULL;
node->parent = parent;
if (NULL == parent)
- {
- heap->root = node;
- }
+ {
+ heap->root = node;
+ }
else
- {
- if (parent->left_child == pos)
- parent->left_child = node;
- else
- parent->right_child = node;
- }
+ {
+ if (parent->left_child == pos)
+ parent->left_child = node;
+ else
+ parent->right_child = node;
+ }
/* insert 'pos' below 'node' */
insert_node (heap, node, pos);
CHECK (pos);
* @return node for the new element
*/
struct GNUNET_CONTAINER_HeapNode *
-GNUNET_CONTAINER_heap_insert (struct GNUNET_CONTAINER_Heap *heap,
- void *element,
- GNUNET_CONTAINER_HeapCostType cost)
+GNUNET_CONTAINER_heap_insert (struct GNUNET_CONTAINER_Heap *heap, void *element,
+ GNUNET_CONTAINER_HeapCostType cost)
{
struct GNUNET_CONTAINER_HeapNode *node;
- node = GNUNET_malloc (sizeof (struct GNUNET_CONTAINER_HeapNode));
+ node = GNUNET_new (struct GNUNET_CONTAINER_HeapNode);
+ node->heap = heap;
node->element = element;
node->cost = cost;
heap->size++;
heap->size--;
ret = root->element;
if (root->left_child == NULL)
- {
- heap->root = root->right_child;
- if (root->right_child != NULL)
- root->right_child->parent = NULL;
- }
+ {
+ heap->root = root->right_child;
+ if (root->right_child != NULL)
+ root->right_child->parent = NULL;
+ }
else if (root->right_child == NULL)
- {
- heap->root = root->left_child;
- if (root->left_child != NULL)
- root->left_child->parent = NULL;
- }
+ {
+ heap->root = root->left_child;
+ root->left_child->parent = NULL;
+ }
else
- {
- root->left_child->parent = NULL;
- root->right_child->parent = NULL;
- heap->root = root->left_child;
- insert_node (heap, heap->root, root->right_child);
- }
+ {
+ root->left_child->parent = NULL;
+ root->right_child->parent = NULL;
+ heap->root = root->left_child;
+ insert_node (heap, heap->root, root->right_child);
+ }
+ if (heap->walk_pos == root)
+ heap->walk_pos = heap->root;
GNUNET_free (root);
-#if DEBUG
- GNUNET_assert (( (heap->size == 0) &&
- (heap->root == NULL) ) ||
- (heap->size == heap->root->tree_size + 1) );
+#if EXTRA_CHECKS
+ GNUNET_assert (((heap->size == 0) && (heap->root == NULL)) ||
+ (heap->size == heap->root->tree_size + 1));
CHECK (heap->root);
#endif
return ret;
* 'size' field of the tree.
*/
static void
-remove_node (struct GNUNET_CONTAINER_Heap *heap,
- struct GNUNET_CONTAINER_HeapNode *node)
+remove_node (struct GNUNET_CONTAINER_HeapNode *node)
{
struct GNUNET_CONTAINER_HeapNode *ancestor;
+ struct GNUNET_CONTAINER_Heap *heap = node->heap;
/* update 'size' of the ancestors */
ancestor = node;
- while (NULL != (ancestor = ancestor->parent))
+ while (NULL != (ancestor = ancestor->parent))
ancestor->tree_size--;
/* update 'size' of node itself */
/* unlink 'node' itself and insert children in its place */
if (node->parent == NULL)
+ {
+ if (node->left_child != NULL)
{
- if (node->left_child != NULL)
- {
- heap->root = node->left_child;
- node->left_child->parent = NULL;
- if (node->right_child != NULL)
- {
- node->right_child->parent = NULL;
- insert_node (heap, heap->root, node->right_child);
- }
- }
- else
- {
- heap->root = node->right_child;
- if (node->right_child != NULL)
- node->right_child->parent = NULL;
- }
+ heap->root = node->left_child;
+ node->left_child->parent = NULL;
+ if (node->right_child != NULL)
+ {
+ node->right_child->parent = NULL;
+ insert_node (heap, heap->root, node->right_child);
+ }
}
- else
+ else
{
- if (node->parent->left_child == node)
- node->parent->left_child = NULL;
- else
- node->parent->right_child = NULL;
- if (node->left_child != NULL)
- {
- node->left_child->parent = NULL;
- node->parent->tree_size -= (1 + node->left_child->tree_size);
- insert_node (heap, node->parent, node->left_child);
- }
+ heap->root = node->right_child;
if (node->right_child != NULL)
- {
- node->right_child->parent = NULL;
- node->parent->tree_size -= (1 + node->right_child->tree_size);
- insert_node (heap, node->parent, node->right_child);
- }
+ node->right_child->parent = NULL;
+ }
+ }
+ else
+ {
+ if (node->parent->left_child == node)
+ node->parent->left_child = NULL;
+ else
+ node->parent->right_child = NULL;
+ if (node->left_child != NULL)
+ {
+ node->left_child->parent = NULL;
+ node->parent->tree_size -= (1 + node->left_child->tree_size);
+ insert_node (heap, node->parent, node->left_child);
+ }
+ if (node->right_child != NULL)
+ {
+ node->right_child->parent = NULL;
+ node->parent->tree_size -= (1 + node->right_child->tree_size);
+ insert_node (heap, node->parent, node->right_child);
}
+ }
node->parent = NULL;
node->left_child = NULL;
node->right_child = NULL;
/**
* Removes a node from the heap.
- *
- * @param heap heap to modify
+ *
* @param node node to remove
* @return element data stored at the node
*/
void *
-GNUNET_CONTAINER_heap_remove_node (struct GNUNET_CONTAINER_Heap *heap,
- struct GNUNET_CONTAINER_HeapNode *node)
+GNUNET_CONTAINER_heap_remove_node (struct GNUNET_CONTAINER_HeapNode *node)
{
void *ret;
-
+ struct GNUNET_CONTAINER_Heap *heap;
+
+ heap = node->heap;
CHECK (heap->root);
if (heap->walk_pos == node)
(void) GNUNET_CONTAINER_heap_walk_get_next (heap);
- remove_node (heap, node);
+ remove_node (node);
heap->size--;
ret = node->element;
if (heap->walk_pos == node)
heap->walk_pos = NULL;
GNUNET_free (node);
-#if DEBUG
+#if EXTRA_CHECKS
CHECK (heap->root);
- GNUNET_assert (( (heap->size == 0) &&
- (heap->root == NULL) ) ||
- (heap->size == heap->root->tree_size + 1) );
+ GNUNET_assert (((heap->size == 0) && (heap->root == NULL)) ||
+ (heap->size == heap->root->tree_size + 1));
#endif
return ret;
}
/**
* Updates the cost of any node in the tree
*
- * @param heap heap to modify
* @param node node for which the cost is to be changed
* @param new_cost new cost for the node
*/
void
-GNUNET_CONTAINER_heap_update_cost (struct GNUNET_CONTAINER_Heap *heap,
- struct GNUNET_CONTAINER_HeapNode *node,
- GNUNET_CONTAINER_HeapCostType new_cost)
+GNUNET_CONTAINER_heap_update_cost (struct GNUNET_CONTAINER_HeapNode *node,
+ GNUNET_CONTAINER_HeapCostType new_cost)
{
-#if DEBUG
- GNUNET_assert ( ( (heap->size == 0) &&
- (heap->root == NULL) ) ||
- (heap->size == heap->root->tree_size + 1) );
- CHECK (heap->root);
-#endif
- remove_node (heap, node);
-#if DEBUG
- CHECK (heap->root);
- GNUNET_assert ( ( (heap->size == 1) &&
- (heap->root == NULL) ) ||
- (heap->size == heap->root->tree_size + 2) );
-#endif
+ struct GNUNET_CONTAINER_Heap *heap = node->heap;
+
+ remove_node (node);
node->cost = new_cost;
- if (heap->root == NULL)
+ if (NULL == heap->root)
heap->root = node;
else
- insert_node (heap, heap->root, node);
-#if DEBUG
- CHECK (heap->root);
- GNUNET_assert ( ( (heap->size == 0) &&
- (heap->root == NULL) ) ||
- (heap->size == heap->root->tree_size + 1) );
-#endif
+ insert_node (heap,
+ heap->root,
+ node);
}