| 1 | #ifndef BABELTRACE_GRAPH_NOTIFICATION_HEAP_H |
| 2 | #define BABELTRACE_GRAPH_NOTIFICATION_HEAP_H |
| 3 | |
| 4 | /* |
| 5 | * Babeltrace - Notification Heap |
| 6 | * |
| 7 | * Copyright (c) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 8 | * Copyright (c) 2016 Jérémie Galarneau <jeremie.galarneau@efficios.com> |
| 9 | * |
| 10 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 11 | * of this software and associated documentation files (the "Software"), to deal |
| 12 | * in the Software without restriction, including without limitation the rights |
| 13 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 14 | * copies of the Software, and to permit persons to whom the Software is |
| 15 | * furnished to do so, subject to the following conditions: |
| 16 | * |
| 17 | * The above copyright notice and this permission notice shall be included in |
| 18 | * all copies or substantial portions of the Software. |
| 19 | * |
| 20 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 21 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 22 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| 23 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 24 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 25 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
| 26 | * SOFTWARE. |
| 27 | */ |
| 28 | |
| 29 | #include <stddef.h> |
| 30 | |
| 31 | /* For bt_bool */ |
| 32 | #include <babeltrace/types.h> |
| 33 | |
| 34 | #ifdef __cplusplus |
| 35 | extern "C" { |
| 36 | #endif |
| 37 | |
| 38 | struct bt_notification; |
| 39 | |
| 40 | /** |
| 41 | * bt_notification_time_compare - Compare two notifications' timestamps |
| 42 | * |
| 43 | * Compare two notifications in the time domain. Return true if 'a' happened |
| 44 | * prior to 'b'. In the case where both notifications are deemed to have |
| 45 | * happened at the same time, an implementation-defined critarion shall be |
| 46 | * used to order the notifications. This criterion shall ensure a consistent |
| 47 | * ordering over multiple runs. |
| 48 | */ |
| 49 | typedef bt_bool (*bt_notification_time_compare_func)( |
| 50 | struct bt_notification *a, struct bt_notification *b, |
| 51 | void *user_data); |
| 52 | |
| 53 | /** |
| 54 | * bt_notification_heap_create - create a new bt_notification heap. |
| 55 | * |
| 56 | * @comparator: Function to use for notification comparisons. |
| 57 | * |
| 58 | * Returns a new notification heap, NULL on error. |
| 59 | */ |
| 60 | extern struct bt_notification_heap *bt_notification_heap_create( |
| 61 | bt_notification_time_compare_func comparator, void *user_data); |
| 62 | |
| 63 | /** |
| 64 | * bt_notification_heap_insert - insert an element into the heap |
| 65 | * |
| 66 | * @heap: the heap to be operated on |
| 67 | * @notification: the notification to add |
| 68 | * |
| 69 | * Insert a notification into the heap. |
| 70 | * |
| 71 | * Returns 0 on success, a negative value on error. |
| 72 | */ |
| 73 | extern int bt_notification_heap_insert(struct bt_notification_heap *heap, |
| 74 | struct bt_notification *notification); |
| 75 | |
| 76 | /** |
| 77 | * bt_notification_heap_peek - return the element on top of the heap. |
| 78 | * |
| 79 | * @heap: the heap to be operated on |
| 80 | * |
| 81 | * Returns the top element of the heap, without performing any modification |
| 82 | * to the heap structure. Returns NULL if the heap is empty. The returned |
| 83 | * notification must be bt_put() by the caller. |
| 84 | */ |
| 85 | extern struct bt_notification *bt_notification_heap_peek( |
| 86 | struct bt_notification_heap *heap); |
| 87 | |
| 88 | /** |
| 89 | * bt_notification_heap_pop - remove the element sitting on top of the heap. |
| 90 | * @heap: the heap to be operated on |
| 91 | * |
| 92 | * Returns the top element of the heap. The element is removed from the |
| 93 | * heap. Returns NULL if the heap is empty. The returned notification must be |
| 94 | * bt_put() by the caller. |
| 95 | */ |
| 96 | extern struct bt_notification *bt_notification_heap_pop( |
| 97 | struct bt_notification_heap *heap); |
| 98 | |
| 99 | #ifdef __cplusplus |
| 100 | } |
| 101 | #endif |
| 102 | |
| 103 | #endif /* BABELTRACE_GRAPH_NOTIFICATION_HEAP_H */ |