heap.c
/* -*- c-basic-offset: 4; indent-tabs-mode: nil -*- */
/* ====================================================================
* Copyright (c) 1999-2004 Carnegie Mellon University. All rights
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* This work was supported in part by funding from the Defense Advanced
* Research Projects Agency and the National Science Foundation of the
* United States of America, and the CMU Sphinx Speech Consortium.
*
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/*
* heap.c -- Generic heap structure for inserting in any and popping in sorted
* order.
*
* **********************************************
* CMU ARPA Speech Project
*
* Copyright (c) 1999 Carnegie Mellon University.
* ALL RIGHTS RESERVED.
* **********************************************
*
* HISTORY
* $Log: heap.c,v $
* Revision 1.4 2005/06/22 03:05:49 arthchan2003
* 1, Fixed doxygen documentation, 2, Add keyword.
*
* Revision 1.3 2005/03/30 01:22:48 archan
* Fixed mistakes in last updates. Add
*
*
* 05-Mar-99 M K Ravishankar (rkm@cs.cmu.edu) at Carnegie Mellon University
* Fixed bug in heap_destroy() (in while loop exit condition).
*
* 23-Dec-96 M K Ravishankar (rkm@cs.cmu.edu) at Carnegie Mellon University
* Started.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "sphinxbase/heap.h"
#include "sphinxbase/err.h"
#include "sphinxbase/ckd_alloc.h"
typedef struct heapnode_s {
void *data;
int32 val;
int32 nl, nr;
struct heapnode_s *l;
struct heapnode_s *r;
} heapnode_t;
struct heap_s {
heapnode_t *top;
};
#if 0
static void
heap_dump(heapnode_t * top, int32 level)
{
int32 i;
if (!top)
return;
for (i = 0; i < level; i++)
printf(" ");
/* print top info */
heap_dump(top->l, level + 1);
heap_dump(top->r, level + 1);
}
#endif
heap_t *
heap_new(void)
{
heap_t *h = ckd_calloc(1, sizeof(*h));
return h;
}
static heapnode_t *
subheap_insert(heapnode_t * root, void *data, int32 val)
{
heapnode_t *h;
void *tmpdata;
int32 tmpval;
if (!root) {
h = (heapnode_t *) ckd_calloc(1, sizeof(heapnode_t));
h->data = data;
h->val = val;
h->l = h->r = NULL;
h->nl = h->nr = 0;
return h;
}
/* Root already exists; if new value is less, replace root node */
if (root->val > val) {
tmpdata = root->data;
tmpval = root->val;
root->data = data;
root->val = val;
data = tmpdata;
val = tmpval;
}
/* Insert new or old (replaced) node in right or left subtree; keep them balanced */
if (root->nl > root->nr) {
root->r = subheap_insert(root->r, data, val);
root->nr++;
}
else {
root->l = subheap_insert(root->l, data, val);
root->nl++;
}
return root;
}
int
heap_insert(heap_t *heap, void *data, int32 val)
{
heap->top = subheap_insert(heap->top, data, val);
return 0;
}
static heapnode_t *
subheap_pop(heapnode_t * root)
{
heapnode_t *l, *r;
/* Propagate best value from below into root, if any */
l = root->l;
r = root->r;
if (!l) {
if (!r) {
ckd_free((char *) root);
return NULL;
}
else {
root->data = r->data;
root->val = r->val;
root->r = subheap_pop(r);
root->nr--;
}
}
else {
if ((!r) || (l->val < r->val)) {
root->data = l->data;
root->val = l->val;
root->l = subheap_pop(l);
root->nl--;
}
else {
root->data = r->data;
root->val = r->val;
root->r = subheap_pop(r);
root->nr--;
}
}
return root;
}
int
heap_pop(heap_t *heap, void **data, int32 * val)
{
if (heap->top == NULL)
return 0;
*data = heap->top->data;
*val = heap->top->val;
heap->top = subheap_pop(heap->top);
return 1;
}
int
heap_top(heap_t *heap, void **data, int32 * val)
{
if (heap->top == NULL)
return 0;
*data = heap->top->data;
*val = heap->top->val;
return 1;
}
static int
heap_remove_one(heap_t *heap, heapnode_t *top, void *data)
{
if (top == NULL)
return -1;
else if (top->data == data) {
assert(top == heap->top);
heap->top = subheap_pop(heap->top);
return 0;
}
if (top->l) {
if (top->l->data == data) {
top->l = subheap_pop(top->l);
--top->nl;
return 0;
}
else if (heap_remove_one(heap, top->l, data) == 0) {
--top->nl;
return 0;
}
}
if (top->r) {
if (top->r->data == data) {
top->r = subheap_pop(top->r);
--top->nr;
return 0;
}
else if (heap_remove_one(heap, top->r, data) == 0) {
--top->nr;
return 0;
}
}
return -1;
}
int
heap_remove(heap_t *heap, void *data)
{
return heap_remove_one(heap, heap->top, data);
}
size_t
heap_size(heap_t *heap)
{
if (heap->top == NULL)
return 0;
return heap->top->nl + heap->top->nr + 1;
}
int
heap_destroy(heap_t *heap)
{
void *data;
int32 val;
/* Empty the heap and free it */
while (heap_pop(heap, &data, &val) > 0)
;
ckd_free(heap);
return 0;
}
heapnode_s::data
void * data
Application data at this node.
Definition: heap.c:78
ckd_calloc
#define ckd_calloc(n, sz)
Macros to simplify the use of above functions.
Definition: ckd_alloc.h:248
heapnode_s::l
struct heapnode_s * l
Root of left descendant heap.
Definition: heap.c:82
heap_destroy
SPHINXBASE_EXPORT int heap_destroy(heap_t *heap)
Destroy the given heap; free the heap nodes.
Definition: heap.c:281
ckd_alloc.h
Sphinx's memory allocation/deallocation routines.
heap_new
SPHINXBASE_EXPORT heap_t * heap_new(void)
Allocate a new heap and return handle to it.
Definition: heap.c:113
heap_remove
SPHINXBASE_EXPORT int heap_remove(heap_t *heap, void *data)
Remove an item from the heap.
Definition: heap.c:266
heapnode_s
One node on the heap.
Definition: heap.c:77
ckd_free
SPHINXBASE_EXPORT void ckd_free(void *ptr)
Test and free a 1-D array.
Definition: ckd_alloc.c:241
heap_insert
SPHINXBASE_EXPORT int heap_insert(heap_t *heap, void *data, int32 val)
Insert a new item into the given heap.
Definition: heap.c:161
heap_pop
SPHINXBASE_EXPORT int heap_pop(heap_t *heap, void **data, int32 *val)
Like heap_top but also pop the top item off the heap.
Definition: heap.c:209
heap.h
Heap Implementation.
heapnode_s::r
struct heapnode_s * r
Root of right descendant heap.
Definition: heap.c:83
heap_size
SPHINXBASE_EXPORT size_t heap_size(heap_t *heap)
Return the number of items in the heap.
Definition: heap.c:273
err.h
Implementation of logging routines.
heapnode_s::nr
int32 nr
#left/right descendants of this node (for balancing heap)
Definition: heap.c:81
heap_top
SPHINXBASE_EXPORT int heap_top(heap_t *heap, void **data, int32 *val)
Return the topmost item in the heap.
Definition: heap.c:221
heapnode_s::val
int32 val
Associated with above application data; according to which heap is sorted (in ascending order) ...
Definition: heap.c:79
heap_s
Internal heap data structure.
Definition: heap.c:89