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Typedefs | |
typedef int(*) | ast_heap_cmp_fn (void *elm1, void *elm2) |
Function type for comparing nodes in a heap. | |
Functions | |
ast_heap * | ast_heap_create (unsigned int init_height, ast_heap_cmp_fn cmp_fn, ssize_t index_offset) |
Create a max heap. | |
ast_heap * | ast_heap_destroy (struct ast_heap *h) |
Destroy a max heap. | |
void * | ast_heap_peek (struct ast_heap *h, unsigned int index) |
Peek at an element on a heap. | |
void * | ast_heap_pop (struct ast_heap *h) |
Pop the max element off of the heap. | |
int | ast_heap_push (struct ast_heap *h, void *elm) |
Push an element on to a heap. | |
int | ast_heap_rdlock (struct ast_heap *h) |
Read-Lock a heap. | |
void * | ast_heap_remove (struct ast_heap *h, void *elm) |
Remove a specific element from a heap. | |
size_t | ast_heap_size (struct ast_heap *h) |
Get the current size of a heap. | |
int | ast_heap_unlock (struct ast_heap *h) |
Unlock a heap. | |
int | ast_heap_verify (struct ast_heap *h) |
Verify that a heap has been properly constructed. | |
int | ast_heap_wrlock (struct ast_heap *h) |
Write-Lock a heap. |
Definition in file heap.h.
typedef int(*) ast_heap_cmp_fn(void *elm1, void *elm2) |
Function type for comparing nodes in a heap.
elm1 | the first element | |
elm2 | the second element |
negative | if elm1 < elm2 | |
0 | if elm1 == elm2 | |
positive | if elm1 > elm2 |
struct ast_heap* ast_heap_create | ( | unsigned int | init_height, | |
ast_heap_cmp_fn | cmp_fn, | |||
ssize_t | index_offset | |||
) |
Create a max heap.
init_height | The initial height of the heap to allocate space for. To start out, there will be room for (2 ^ init_height) - 1 entries. However, the heap will grow as needed. | |
cmp_fn | The function that should be used to compare elements in the heap. | |
index_offset | This parameter is optional, but must be provided to be able to use ast_heap_remove(). This is the number of bytes into the element where an ssize_t has been made available for the heap's internal use. The heap will use this field to keep track of the element's current position in the heap. The offsetof() macro is useful for providing a proper value for this argument. If ast_heap_remove() will not be used, then a negative value can be provided to indicate that no field for an offset has been allocated. |
struct myobj { int foo; int bar; char stuff[8]; char things[8]; ssize_t __heap_index; }; ... static int myobj_cmp(void *obj1, void *obj2); ... struct ast_heap *h; h = ast_heap_create(8, myobj_cmp, offsetof(struct myobj, __heap_index));
Definition at line 110 of file heap.c.
References ast_calloc, ast_free, ast_log(), ast_rwlock_init(), and LOG_ERROR.
Referenced by ast_timing_init(), and load_resource_list().
00112 { 00113 struct ast_heap *h; 00114 00115 if (!cmp_fn) { 00116 ast_log(LOG_ERROR, "A comparison function must be provided\n"); 00117 return NULL; 00118 } 00119 00120 if (!init_height) { 00121 init_height = 8; 00122 } 00123 00124 if (!(h = ast_calloc(1, sizeof(*h)))) { 00125 return NULL; 00126 } 00127 00128 h->cmp_fn = cmp_fn; 00129 h->index_offset = index_offset; 00130 h->avail_len = (1 << init_height) - 1; 00131 00132 if (!(h->heap = ast_calloc(1, h->avail_len * sizeof(void *)))) { 00133 ast_free(h); 00134 return NULL; 00135 } 00136 00137 ast_rwlock_init(&h->lock); 00138 00139 return h; 00140 }
Destroy a max heap.
h | the heap to destroy |
Definition at line 142 of file heap.c.
References ast_free, ast_rwlock_destroy(), ast_heap::heap, and ast_heap::lock.
Referenced by load_resource_list().
00143 { 00144 ast_free(h->heap); 00145 h->heap = NULL; 00146 00147 ast_rwlock_destroy(&h->lock); 00148 00149 ast_free(h); 00150 00151 return NULL; 00152 }
void* ast_heap_peek | ( | struct ast_heap * | h, | |
unsigned int | index | |||
) |
Peek at an element on a heap.
h | the heap | |
index | index of the element to return. The first element is at index 1, and the last element is at the index == the size of the heap. |
struct ast_heap *h; ... size_t size, i; void *cur_obj; ast_heap_rdlock(h); size = ast_heap_size(h); for (i = 1; i <= size && (cur_obj = ast_heap_peek(h, i)); i++) { ... Do stuff with cur_obj ... } ast_heap_unlock(h);
Definition at line 260 of file heap.c.
References ast_heap::cur_len, and heap_get().
Referenced by ast_timer_open().
00261 { 00262 if (!h->cur_len || !index || index > h->cur_len) { 00263 return NULL; 00264 } 00265 00266 return heap_get(h, index); 00267 }
void* ast_heap_pop | ( | struct ast_heap * | h | ) |
Pop the max element off of the heap.
h | the heap |
Definition at line 255 of file heap.c.
References _ast_heap_remove().
Referenced by load_resource_list().
00256 { 00257 return _ast_heap_remove(h, 1); 00258 }
int ast_heap_push | ( | struct ast_heap * | h, | |
void * | elm | |||
) |
Push an element on to a heap.
h | the heap being added to | |
elm | the element being put on the heap |
0 | success | |
non-zero | failure |
Definition at line 215 of file heap.c.
References ast_heap::avail_len, bubble_up(), ast_heap::cur_len, grow_heap(), and heap_set().
Referenced by _ast_register_timing_interface(), and load_resource().
00216 { 00217 if (h->cur_len == h->avail_len && grow_heap(h)) { 00218 return -1; 00219 } 00220 00221 heap_set(h, ++(h->cur_len), elm); 00222 00223 bubble_up(h, h->cur_len); 00224 00225 return 0; 00226 }
int ast_heap_rdlock | ( | struct ast_heap * | h | ) |
Read-Lock a heap.
h | the heap |
Definition at line 281 of file heap.c.
References ast_rwlock_rdlock(), and ast_heap::lock.
Referenced by ast_timer_open().
00282 { 00283 return ast_rwlock_rdlock(&h->lock); 00284 }
void* ast_heap_remove | ( | struct ast_heap * | h, | |
void * | elm | |||
) |
Remove a specific element from a heap.
h | the heap to remove from | |
elm | the element to remove |
Definition at line 244 of file heap.c.
References _ast_heap_remove(), and get_index().
Referenced by ast_unregister_timing_interface().
00245 { 00246 ssize_t i = get_index(h, elm); 00247 00248 if (i == -1) { 00249 return NULL; 00250 } 00251 00252 return _ast_heap_remove(h, i); 00253 }
size_t ast_heap_size | ( | struct ast_heap * | h | ) |
Get the current size of a heap.
h | the heap |
Definition at line 269 of file heap.c.
References ast_heap::cur_len.
00270 { 00271 return h->cur_len; 00272 }
int ast_heap_unlock | ( | struct ast_heap * | h | ) |
Unlock a heap.
h | the heap |
Definition at line 286 of file heap.c.
References ast_rwlock_unlock(), and ast_heap::lock.
Referenced by _ast_register_timing_interface(), ast_timer_open(), and ast_unregister_timing_interface().
00287 { 00288 return ast_rwlock_unlock(&h->lock); 00289 }
int ast_heap_verify | ( | struct ast_heap * | h | ) |
Verify that a heap has been properly constructed.
h | a heap |
0 | success | |
non-zero | failure |
Definition at line 86 of file heap.c.
References ast_heap::cmp_fn, ast_heap::cur_len, heap_get(), left_node(), and right_node().
00087 { 00088 unsigned int i; 00089 00090 for (i = 1; i <= (h->cur_len / 2); i++) { 00091 int l = left_node(i); 00092 int r = right_node(i); 00093 00094 if (l <= h->cur_len) { 00095 if (h->cmp_fn(heap_get(h, i), heap_get(h, l)) < 0) { 00096 return -1; 00097 } 00098 } 00099 00100 if (r <= h->cur_len) { 00101 if (h->cmp_fn(heap_get(h, i), heap_get(h, r)) < 0) { 00102 return -1; 00103 } 00104 } 00105 } 00106 00107 return 0; 00108 }
int ast_heap_wrlock | ( | struct ast_heap * | h | ) |
Write-Lock a heap.
h | the heap |
Definition at line 276 of file heap.c.
References ast_rwlock_wrlock(), and ast_heap::lock.
Referenced by _ast_register_timing_interface(), and ast_unregister_timing_interface().
00277 { 00278 return ast_rwlock_wrlock(&h->lock); 00279 }