GNUnet  0.17.5
Data Structures | Macros | Functions
container_heap.c File Reference

Implementation of a heap. More...

#include "platform.h"
#include "gnunet_container_lib.h"
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Data Structures

struct  GNUNET_CONTAINER_HeapNode
 Node in the heap. More...
 
struct  GNUNET_CONTAINER_Heap
 Handle to a node in a heap. More...
 

Macros

#define LOG(kind, ...)
 
#define EXTRA_CHECKS   0
 
#define CHECK(n)   do {} while (0)
 

Functions

struct GNUNET_CONTAINER_HeapGNUNET_CONTAINER_heap_create (enum GNUNET_CONTAINER_HeapOrder order)
 Create a new heap. More...
 
void GNUNET_CONTAINER_heap_destroy (struct GNUNET_CONTAINER_Heap *heap)
 Destroys the heap. More...
 
void * GNUNET_CONTAINER_heap_peek (const struct GNUNET_CONTAINER_Heap *heap)
 Get element stored at the root of heap. More...
 
int GNUNET_CONTAINER_heap_peek2 (const struct GNUNET_CONTAINER_Heap *heap, void **element, GNUNET_CONTAINER_HeapCostType *cost)
 Get element and cost stored at the root of heap. More...
 
unsigned int GNUNET_CONTAINER_heap_get_size (const struct GNUNET_CONTAINER_Heap *heap)
 Get the current size of the heap. More...
 
GNUNET_CONTAINER_HeapCostType GNUNET_CONTAINER_heap_node_get_cost (const struct GNUNET_CONTAINER_HeapNode *node)
 Get the current cost of the node. More...
 
static int node_iterator (const struct GNUNET_CONTAINER_Heap *heap, struct GNUNET_CONTAINER_HeapNode *node, GNUNET_CONTAINER_HeapIterator iterator, void *iterator_cls)
 Iterate over the children of the given node. More...
 
void GNUNET_CONTAINER_heap_iterate (const struct GNUNET_CONTAINER_Heap *heap, GNUNET_CONTAINER_HeapIterator iterator, void *iterator_cls)
 Iterate over all entries in the heap. More...
 
void * GNUNET_CONTAINER_heap_walk_get_next (struct GNUNET_CONTAINER_Heap *heap)
 Perform a random walk of the tree. More...
 
static void insert_node (struct GNUNET_CONTAINER_Heap *heap, struct GNUNET_CONTAINER_HeapNode *pos, struct GNUNET_CONTAINER_HeapNode *node)
 Insert the given node 'node' into the subtree starting at 'pos' (while keeping the tree somewhat balanced). More...
 
struct GNUNET_CONTAINER_HeapNodeGNUNET_CONTAINER_heap_insert (struct GNUNET_CONTAINER_Heap *heap, void *element, GNUNET_CONTAINER_HeapCostType cost)
 Inserts a new element into the heap. More...
 
void * GNUNET_CONTAINER_heap_remove_root (struct GNUNET_CONTAINER_Heap *heap)
 Remove root of the heap. More...
 
static void remove_node (struct GNUNET_CONTAINER_HeapNode *node)
 Remove the given node 'node' from the tree and update the 'tree_size' fields accordingly. More...
 
void * GNUNET_CONTAINER_heap_remove_node (struct GNUNET_CONTAINER_HeapNode *node)
 Removes a node from the heap. More...
 
void GNUNET_CONTAINER_heap_update_cost (struct GNUNET_CONTAINER_HeapNode *node, GNUNET_CONTAINER_HeapCostType new_cost)
 Updates the cost of any node in the tree. More...
 

Detailed Description

Implementation of a heap.

Author
Nathan Evans
Christian Grothoff

Definition in file container_heap.c.

Macro Definition Documentation

◆ LOG

#define LOG (   kind,
  ... 
)
Value:
GNUNET_log_from (kind, "util-container-heap", \
__VA_ARGS__)
#define GNUNET_log_from(kind, comp,...)

Definition at line 31 of file container_heap.c.

◆ EXTRA_CHECKS

#define EXTRA_CHECKS   0

Definition at line 34 of file container_heap.c.

◆ CHECK

#define CHECK (   n)    do {} while (0)

Definition at line 128 of file container_heap.c.

Function Documentation

◆ node_iterator()

static int node_iterator ( const struct GNUNET_CONTAINER_Heap heap,
struct GNUNET_CONTAINER_HeapNode node,
GNUNET_CONTAINER_HeapIterator  iterator,
void *  iterator_cls 
)
static

Iterate over the children of the given node.

Parameters
heapargument to give to iterator
nodenode to iterate over
iteratorfunction to call on each node
iterator_clsclosure for iterator
Returns
GNUNET_YES to continue to iterate

Definition at line 209 of file container_heap.c.

212 {
213  if (node == NULL)
214  return GNUNET_YES;
215  if (GNUNET_YES !=
216  node_iterator (heap, node->left_child, iterator, iterator_cls))
217  return GNUNET_NO;
218  if (GNUNET_YES !=
219  node_iterator (heap, node->right_child, iterator, iterator_cls))
220  return GNUNET_NO;
221  return iterator (iterator_cls, node, node->element, node->cost);
222 }
static int node_iterator(const struct GNUNET_CONTAINER_Heap *heap, struct GNUNET_CONTAINER_HeapNode *node, GNUNET_CONTAINER_HeapIterator iterator, void *iterator_cls)
Iterate over the children of the given node.
static int iterator(void *cls, const struct GNUNET_PeerIdentity *key, void *value)
Iterator over hash map entries.
@ GNUNET_YES
@ GNUNET_NO
Definition: gnunet_common.h:98
void * element
Our element.
struct GNUNET_CONTAINER_HeapNode * left_child
Left child.
GNUNET_CONTAINER_HeapCostType cost
Cost for this element.
struct GNUNET_CONTAINER_HeapNode * right_child
Right child.

References GNUNET_CONTAINER_HeapNode::cost, GNUNET_CONTAINER_HeapNode::element, GNUNET_NO, GNUNET_YES, iterator(), GNUNET_CONTAINER_HeapNode::left_child, and GNUNET_CONTAINER_HeapNode::right_child.

Referenced by GNUNET_CONTAINER_heap_iterate().

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◆ insert_node()

static void insert_node ( struct GNUNET_CONTAINER_Heap heap,
struct GNUNET_CONTAINER_HeapNode pos,
struct GNUNET_CONTAINER_HeapNode node 
)
static

Insert the given node 'node' into the subtree starting at 'pos' (while keeping the tree somewhat balanced).

Parameters
heapheap to modify
posexisting tree
nodenode to insert (which may be a subtree itself)

Definition at line 263 of file container_heap.c.

266 {
268 
269  GNUNET_assert (node->parent == NULL);
270  while ((heap->order == GNUNET_CONTAINER_HEAP_ORDER_MAX) ? (pos->cost >=
271  node->cost)
272  : (pos->cost <= node->cost))
273  {
274  /* node is descendent of pos */
275  pos->tree_size += (1 + node->tree_size);
276  if (pos->left_child == NULL)
277  {
278  pos->left_child = node;
279  node->parent = pos;
280  return;
281  }
282  if (pos->right_child == NULL)
283  {
284  pos->right_child = node;
285  node->parent = pos;
286  return;
287  }
288  /* keep it balanced by descending into smaller subtree */
289  if (pos->left_child->tree_size < pos->right_child->tree_size)
290  pos = pos->left_child;
291  else
292  pos = pos->right_child;
293  }
294  /* make 'node' parent of 'pos' */
295  parent = pos->parent;
296  pos->parent = NULL;
297  node->parent = parent;
298  if (NULL == parent)
299  {
300  heap->root = node;
301  }
302  else
303  {
304  if (parent->left_child == pos)
305  parent->left_child = node;
306  else
307  parent->right_child = node;
308  }
309  /* insert 'pos' below 'node' */
310  insert_node (heap, node, pos);
311  CHECK (pos);
312 }
static void insert_node(struct GNUNET_CONTAINER_Heap *heap, struct GNUNET_CONTAINER_HeapNode *pos, struct GNUNET_CONTAINER_HeapNode *node)
Insert the given node 'node' into the subtree starting at 'pos' (while keeping the tree somewhat bala...
#define CHECK(n)
@ GNUNET_CONTAINER_HEAP_ORDER_MAX
Heap with the maximum cost at the root.
#define GNUNET_assert(cond)
Use this for fatal errors that cannot be handled.
struct GNUNET_CONTAINER_HeapNode * parent
Parent node.
struct GNUNET_CONTAINER_Heap * heap
Heap this node belongs to.
unsigned int tree_size
Number of elements below this node in the heap (excluding this node itself).
struct GNUNET_CONTAINER_HeapNode * root
Root of the heap.
enum GNUNET_CONTAINER_HeapOrder order
How is the heap sorted?

References CHECK, GNUNET_CONTAINER_HeapNode::cost, GNUNET_assert, GNUNET_CONTAINER_HEAP_ORDER_MAX, GNUNET_CONTAINER_HeapNode::heap, GNUNET_CONTAINER_HeapNode::left_child, GNUNET_CONTAINER_Heap::order, GNUNET_CONTAINER_HeapNode::parent, GNUNET_CONTAINER_HeapNode::right_child, GNUNET_CONTAINER_Heap::root, and GNUNET_CONTAINER_HeapNode::tree_size.

Referenced by GNUNET_CONTAINER_heap_insert(), GNUNET_CONTAINER_heap_remove_root(), GNUNET_CONTAINER_heap_update_cost(), and remove_node().

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◆ remove_node()

static void remove_node ( struct GNUNET_CONTAINER_HeapNode node)
static

Remove the given node 'node' from the tree and update the 'tree_size' fields accordingly.

Preserves the children of 'node' and does NOT change the overall 'size' field of the tree.

Definition at line 389 of file container_heap.c.

390 {
391  struct GNUNET_CONTAINER_HeapNode *ancestor;
392  struct GNUNET_CONTAINER_Heap *heap = node->heap;
393 
394  /* update 'size' of the ancestors */
395  ancestor = node;
396  while (NULL != (ancestor = ancestor->parent))
397  ancestor->tree_size--;
398 
399  /* update 'size' of node itself */
400  if (node->left_child != NULL)
401  node->tree_size -= (1 + node->left_child->tree_size);
402  if (node->right_child != NULL)
403  node->tree_size -= (1 + node->right_child->tree_size);
404 
405  /* unlink 'node' itself and insert children in its place */
406  if (node->parent == NULL)
407  {
408  if (node->left_child != NULL)
409  {
410  heap->root = node->left_child;
411  node->left_child->parent = NULL;
412  if (node->right_child != NULL)
413  {
414  node->right_child->parent = NULL;
415  insert_node (heap, heap->root, node->right_child);
416  }
417  }
418  else
419  {
420  heap->root = node->right_child;
421  if (node->right_child != NULL)
422  node->right_child->parent = NULL;
423  }
424  }
425  else
426  {
427  if (node->parent->left_child == node)
428  node->parent->left_child = NULL;
429  else
430  node->parent->right_child = NULL;
431  if (node->left_child != NULL)
432  {
433  node->left_child->parent = NULL;
434  node->parent->tree_size -= (1 + node->left_child->tree_size);
435  insert_node (heap, node->parent, node->left_child);
436  }
437  if (node->right_child != NULL)
438  {
439  node->right_child->parent = NULL;
440  node->parent->tree_size -= (1 + node->right_child->tree_size);
441  insert_node (heap, node->parent, node->right_child);
442  }
443  }
444  node->parent = NULL;
445  node->left_child = NULL;
446  node->right_child = NULL;
447  GNUNET_assert (node->tree_size == 0);
448  CHECK (heap->root);
449 }
Handle to a node in a heap.

References CHECK, GNUNET_assert, GNUNET_CONTAINER_HeapNode::heap, insert_node(), GNUNET_CONTAINER_HeapNode::left_child, GNUNET_CONTAINER_HeapNode::parent, GNUNET_CONTAINER_HeapNode::right_child, GNUNET_CONTAINER_Heap::root, and GNUNET_CONTAINER_HeapNode::tree_size.

Referenced by GNUNET_CONTAINER_heap_remove_node(), and GNUNET_CONTAINER_heap_update_cost().

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