GNUnet  0.11.x
Data Structures | Macros | Functions
container_heap.c File Reference

Implementation of a heap. More...

#include "platform.h"
#include "gnunet_container_lib.h"
Include dependency graph for container_heap.c:

Go to the source code of this file.

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)

Function Documentation

◆ GNUNET_CONTAINER_heap_peek2()

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.

Parameters
[in]heapHeap to inspect.
[out]elementRoot element is returned here.
[out]costCost of element is returned here.
Returns
GNUNET_YES if an element is returned, GNUNET_NO if the heap is empty.

Definition at line 188 of file container_heap.c.

References GNUNET_CONTAINER_HeapNode::cost, GNUNET_CONTAINER_HeapNode::element, GNUNET_NO, GNUNET_YES, and GNUNET_CONTAINER_Heap::root.

Referenced by GCP_attach_path().

191 {
192  if (NULL == heap->root)
193  return GNUNET_NO;
194  if (NULL != element)
195  *element = heap->root->element;
196  if (NULL != cost)
197  *cost = heap->root->cost;
198  return GNUNET_YES;
199 }
GNUNET_CONTAINER_HeapCostType cost
Cost for this element.
#define GNUNET_NO
Definition: gnunet_common.h:78
void * element
Our element.
#define GNUNET_YES
Definition: gnunet_common.h:77
struct GNUNET_CONTAINER_HeapNode * root
Root of the heap.
Here is the caller graph for this function:

◆ 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 239 of file container_heap.c.

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().

242 {
243  if (node == NULL)
244  return GNUNET_YES;
245  if (GNUNET_YES !=
246  node_iterator (heap, node->left_child, iterator, iterator_cls))
247  return GNUNET_NO;
248  if (GNUNET_YES !=
249  node_iterator (heap, node->right_child, iterator, iterator_cls))
250  return GNUNET_NO;
251  return iterator (iterator_cls, node, node->element, node->cost);
252 }
static int iterator(void *cls, const struct GNUNET_PeerIdentity *key, void *value)
Iterator over hash map entries.
struct GNUNET_CONTAINER_HeapNode * left_child
Left child.
GNUNET_CONTAINER_HeapCostType cost
Cost for this element.
#define GNUNET_NO
Definition: gnunet_common.h:78
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.
void * element
Our element.
#define GNUNET_YES
Definition: gnunet_common.h:77
struct GNUNET_CONTAINER_HeapNode * right_child
Right child.
Here is the call graph for this function:
Here is the caller graph for this function:

◆ 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 311 of file container_heap.c.

References CHECK, GNUNET_CONTAINER_HeapNode::cost, GNUNET_assert, GNUNET_CONTAINER_HEAP_ORDER_MAX, 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().

314 {
316 
317  GNUNET_assert (node->parent == NULL);
318  while ((heap->order == GNUNET_CONTAINER_HEAP_ORDER_MAX) ? (pos->cost >=
319  node->cost)
320  : (pos->cost <= node->cost))
321  {
322  /* node is descendent of pos */
323  pos->tree_size += (1 + node->tree_size);
324  if (pos->left_child == NULL)
325  {
326  pos->left_child = node;
327  node->parent = pos;
328  return;
329  }
330  if (pos->right_child == NULL)
331  {
332  pos->right_child = node;
333  node->parent = pos;
334  return;
335  }
336  /* keep it balanced by descending into smaller subtree */
337  if (pos->left_child->tree_size < pos->right_child->tree_size)
338  pos = pos->left_child;
339  else
340  pos = pos->right_child;
341  }
342  /* make 'node' parent of 'pos' */
343  parent = pos->parent;
344  pos->parent = NULL;
345  node->parent = parent;
346  if (NULL == parent)
347  {
348  heap->root = node;
349  }
350  else
351  {
352  if (parent->left_child == pos)
353  parent->left_child = node;
354  else
355  parent->right_child = node;
356  }
357  /* insert 'pos' below 'node' */
358  insert_node (heap, node, pos);
359  CHECK (pos);
360 }
struct GNUNET_CONTAINER_HeapNode * left_child
Left child.
#define CHECK(n)
static void insert_node(struct GNUNET_CONTAINER_Heap *heap, struct GNUNET_CONTAINER_HeapNode *pos, struct GNUNET_CONTAINER_HeapNode *node)
Insert the given node &#39;node&#39; into the subtree starting at &#39;pos&#39; (while keeping the tree somewhat bala...
#define GNUNET_assert(cond)
Use this for fatal errors that cannot be handled.
GNUNET_CONTAINER_HeapCostType cost
Cost for this element.
unsigned int tree_size
Number of elements below this node in the heap (excluding this node itself).
Node in the heap.
enum GNUNET_CONTAINER_HeapOrder order
How is the heap sorted?
struct GNUNET_CONTAINER_HeapNode * parent
Parent node.
Heap with the maximum cost at the root.
struct GNUNET_CONTAINER_HeapNode * root
Root of the heap.
struct GNUNET_CONTAINER_HeapNode * right_child
Right child.
Here is the caller graph for this function:

◆ 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 445 of file container_heap.c.

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().

446 {
447  struct GNUNET_CONTAINER_HeapNode *ancestor;
448  struct GNUNET_CONTAINER_Heap *heap = node->heap;
449 
450  /* update 'size' of the ancestors */
451  ancestor = node;
452  while (NULL != (ancestor = ancestor->parent))
453  ancestor->tree_size--;
454 
455  /* update 'size' of node itself */
456  if (node->left_child != NULL)
457  node->tree_size -= (1 + node->left_child->tree_size);
458  if (node->right_child != NULL)
459  node->tree_size -= (1 + node->right_child->tree_size);
460 
461  /* unlink 'node' itself and insert children in its place */
462  if (node->parent == NULL)
463  {
464  if (node->left_child != NULL)
465  {
466  heap->root = node->left_child;
467  node->left_child->parent = NULL;
468  if (node->right_child != NULL)
469  {
470  node->right_child->parent = NULL;
471  insert_node (heap, heap->root, node->right_child);
472  }
473  }
474  else
475  {
476  heap->root = node->right_child;
477  if (node->right_child != NULL)
478  node->right_child->parent = NULL;
479  }
480  }
481  else
482  {
483  if (node->parent->left_child == node)
484  node->parent->left_child = NULL;
485  else
486  node->parent->right_child = NULL;
487  if (node->left_child != NULL)
488  {
489  node->left_child->parent = NULL;
490  node->parent->tree_size -= (1 + node->left_child->tree_size);
491  insert_node (heap, node->parent, node->left_child);
492  }
493  if (node->right_child != NULL)
494  {
495  node->right_child->parent = NULL;
496  node->parent->tree_size -= (1 + node->right_child->tree_size);
497  insert_node (heap, node->parent, node->right_child);
498  }
499  }
500  node->parent = NULL;
501  node->left_child = NULL;
502  node->right_child = NULL;
503  GNUNET_assert (node->tree_size == 0);
504  CHECK (heap->root);
505 }
struct GNUNET_CONTAINER_HeapNode * left_child
Left child.
#define CHECK(n)
static void insert_node(struct GNUNET_CONTAINER_Heap *heap, struct GNUNET_CONTAINER_HeapNode *pos, struct GNUNET_CONTAINER_HeapNode *node)
Insert the given node &#39;node&#39; into the subtree starting at &#39;pos&#39; (while keeping the tree somewhat bala...
#define GNUNET_assert(cond)
Use this for fatal errors that cannot be handled.
Handle to a node in a heap.
unsigned int tree_size
Number of elements below this node in the heap (excluding this node itself).
Node in the heap.
struct GNUNET_CONTAINER_Heap * heap
Heap this node belongs to.
struct GNUNET_CONTAINER_HeapNode * parent
Parent node.
struct GNUNET_CONTAINER_HeapNode * root
Root of the heap.
struct GNUNET_CONTAINER_HeapNode * right_child
Right child.
Here is the call graph for this function:
Here is the caller graph for this function: