Max Heap data structure. More...
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Defines | |
#define | ast_heap_rdlock(h) __ast_heap_rdlock(h, __FILE__, __PRETTY_FUNCTION__, __LINE__) |
#define | ast_heap_unlock(h) __ast_heap_unlock(h, __FILE__, __PRETTY_FUNCTION__, __LINE__) |
#define | ast_heap_wrlock(h) __ast_heap_wrlock(h, __FILE__, __PRETTY_FUNCTION__, __LINE__) |
Typedefs | |
typedef int(* | ast_heap_cmp_fn )(void *elm1, void *elm2) |
Function type for comparing nodes in a heap. | |
Functions | |
int | __ast_heap_rdlock (struct ast_heap *h, const char *file, const char *func, int line) |
Read-Lock a heap. | |
int | __ast_heap_unlock (struct ast_heap *h, const char *file, const char *func, int line) |
Unlock a heap. | |
int | __ast_heap_wrlock (struct ast_heap *h, const char *file, const char *func, int line) |
Write-Lock a heap. | |
struct ast_heap * | ast_heap_create (unsigned int init_height, ast_heap_cmp_fn cmp_fn, ssize_t index_offset) |
Create a max heap. | |
struct 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. | |
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_verify (struct ast_heap *h) |
Verify that a heap has been properly constructed. |
Max Heap data structure.
Definition in file heap.h.
#define ast_heap_rdlock | ( | h | ) | __ast_heap_rdlock(h, __FILE__, __PRETTY_FUNCTION__, __LINE__) |
Definition at line 251 of file heap.h.
Referenced by ast_timer_open().
#define ast_heap_unlock | ( | h | ) | __ast_heap_unlock(h, __FILE__, __PRETTY_FUNCTION__, __LINE__) |
Definition at line 252 of file heap.h.
Referenced by _ast_register_timing_interface(), ast_timer_open(), and ast_unregister_timing_interface().
#define ast_heap_wrlock | ( | h | ) | __ast_heap_wrlock(h, __FILE__, __PRETTY_FUNCTION__, __LINE__) |
Definition at line 250 of file heap.h.
Referenced by _ast_register_timing_interface(), and ast_unregister_timing_interface().
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 |
int __ast_heap_rdlock | ( | struct ast_heap * | h, | |
const char * | file, | |||
const char * | func, | |||
int | line | |||
) |
Read-Lock a heap.
h | the heap |
A lock is provided for convenience. It can be assumed that none of the ast_heap API calls are thread safe. This lock does not have to be used if another one is already available to protect the heap.
Definition at line 319 of file heap.c.
References __ast_rwlock_rdlock(), and ast_heap::lock.
00320 { 00321 return __ast_rwlock_rdlock(file, line, func, &h->lock, "&h->lock"); 00322 }
int __ast_heap_unlock | ( | struct ast_heap * | h, | |
const char * | file, | |||
const char * | func, | |||
int | line | |||
) |
Unlock a heap.
h | the heap |
Definition at line 324 of file heap.c.
References __ast_rwlock_unlock(), and ast_heap::lock.
00325 { 00326 return __ast_rwlock_unlock(file, line, func, &h->lock, "&h->lock"); 00327 }
int __ast_heap_wrlock | ( | struct ast_heap * | h, | |
const char * | file, | |||
const char * | func, | |||
int | line | |||
) |
Write-Lock a heap.
h | the heap |
A lock is provided for convenience. It can be assumed that none of the ast_heap API calls are thread safe. This lock does not have to be used if another one is already available to protect the heap.
Definition at line 314 of file heap.c.
References __ast_rwlock_wrlock(), and ast_heap::lock.
00315 { 00316 return __ast_rwlock_wrlock(file, line, func, &h->lock, "&h->lock"); 00317 }
struct ast_heap* ast_heap_create | ( | unsigned int | init_height, | |
ast_heap_cmp_fn | cmp_fn, | |||
ssize_t | index_offset | |||
) | [read] |
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. |
Example Usage:
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 118 of file heap.c.
References __ast_calloc(), ast_calloc, ast_free, ast_log(), ast_rwlock_init, ast_heap::avail_len, ast_heap::cmp_fn, ast_heap::heap, ast_heap::index_offset, ast_heap::lock, and LOG_ERROR.
Referenced by ast_timing_init(), load_resource_list(), and sched_context_create().
00121 { 00122 struct ast_heap *h; 00123 00124 if (!cmp_fn) { 00125 ast_log(LOG_ERROR, "A comparison function must be provided\n"); 00126 return NULL; 00127 } 00128 00129 if (!init_height) { 00130 init_height = 8; 00131 } 00132 00133 if (!(h = 00134 #ifdef MALLOC_DEBUG 00135 __ast_calloc(1, sizeof(*h), file, lineno, func) 00136 #else 00137 ast_calloc(1, sizeof(*h)) 00138 #endif 00139 )) { 00140 return NULL; 00141 } 00142 00143 h->cmp_fn = cmp_fn; 00144 h->index_offset = index_offset; 00145 h->avail_len = (1 << init_height) - 1; 00146 00147 if (!(h->heap = 00148 #ifdef MALLOC_DEBUG 00149 __ast_calloc(1, h->avail_len * sizeof(void *), file, lineno, func) 00150 #else 00151 ast_calloc(1, h->avail_len * sizeof(void *)) 00152 #endif 00153 )) { 00154 ast_free(h); 00155 return NULL; 00156 } 00157 00158 ast_rwlock_init(&h->lock); 00159 00160 return h; 00161 }
Destroy a max heap.
h | the heap to destroy |
Definition at line 163 of file heap.c.
References ast_free, ast_rwlock_destroy, ast_heap::heap, and ast_heap::lock.
Referenced by load_resource_list(), sched_context_destroy(), and timing_shutdown().
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. |
Example code for a traversal:
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 300 of file heap.c.
References ast_heap::cur_len, and heap_get().
Referenced by ast_sched_dump(), ast_sched_report(), ast_sched_runq(), ast_sched_wait(), and ast_timer_open().
void* ast_heap_pop | ( | struct ast_heap * | h | ) |
Pop the max element off of the heap.
h | the heap |
Definition at line 295 of file heap.c.
References _ast_heap_remove().
Referenced by ast_sched_runq(), load_resource_list(), and sched_context_destroy().
00296 { 00297 return _ast_heap_remove(h, 1); 00298 }
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 250 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(), load_resource(), and schedule().
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 284 of file heap.c.
References _ast_heap_remove(), and get_index().
Referenced by ast_sched_del(), and ast_unregister_timing_interface().
00285 { 00286 ssize_t i = get_index(h, elm); 00287 00288 if (i == -1) { 00289 return NULL; 00290 } 00291 00292 return _ast_heap_remove(h, i); 00293 }
size_t ast_heap_size | ( | struct ast_heap * | h | ) |
Get the current size of a heap.
h | the heap |
Definition at line 309 of file heap.c.
References ast_heap::cur_len.
Referenced by ast_sched_dump(), and ast_sched_report().
00310 { 00311 return h->cur_len; 00312 }
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 90 of file heap.c.
References ast_heap::cmp_fn, ast_heap::cur_len, heap_get(), left_node(), and right_node().
00091 { 00092 unsigned int i; 00093 00094 for (i = 1; i <= (h->cur_len / 2); i++) { 00095 int l = left_node(i); 00096 int r = right_node(i); 00097 00098 if (l <= h->cur_len) { 00099 if (h->cmp_fn(heap_get(h, i), heap_get(h, l)) < 0) { 00100 return -1; 00101 } 00102 } 00103 00104 if (r <= h->cur_len) { 00105 if (h->cmp_fn(heap_get(h, i), heap_get(h, r)) < 0) { 00106 return -1; 00107 } 00108 } 00109 } 00110 00111 return 0; 00112 }