| 1 | #ifndef _BABELTRACE_ITERATOR_H |
| 2 | #define _BABELTRACE_ITERATOR_H |
| 3 | |
| 4 | /* |
| 5 | * BabelTrace API Iterators |
| 6 | * |
| 7 | * Copyright 2010-2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 8 | * |
| 9 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 10 | * of this software and associated documentation files (the "Software"), to deal |
| 11 | * in the Software without restriction, including without limitation the rights |
| 12 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 13 | * copies of the Software, and to permit persons to whom the Software is |
| 14 | * furnished to do so, subject to the following conditions: |
| 15 | * |
| 16 | * The above copyright notice and this permission notice shall be included in |
| 17 | * all copies or substantial portions of the Software. |
| 18 | * |
| 19 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 20 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 21 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| 22 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 23 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| 24 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
| 25 | * SOFTWARE. |
| 26 | */ |
| 27 | |
| 28 | #include <babeltrace/format.h> |
| 29 | #include <babeltrace/context.h> |
| 30 | |
| 31 | #ifdef __cplusplus |
| 32 | extern "C" { |
| 33 | #endif |
| 34 | |
| 35 | /* Flags for the iterator read_event */ |
| 36 | enum { |
| 37 | BT_ITER_FLAG_LOST_EVENTS = (1 << 0), |
| 38 | }; |
| 39 | |
| 40 | /* Forward declarations */ |
| 41 | struct bt_iter; |
| 42 | struct bt_saved_pos; |
| 43 | |
| 44 | /* |
| 45 | * bt_iter is an abstract class, each format has to implement its own |
| 46 | * iterator derived from this parent class. |
| 47 | */ |
| 48 | |
| 49 | /* |
| 50 | * bt_iter_pos |
| 51 | * |
| 52 | * This structure represents the position where to set an iterator. |
| 53 | * |
| 54 | * type represents the type of seek to use. |
| 55 | * u is the argument of the seek if necessary : |
| 56 | * - seek_time is the real timestamp to seek to when using BT_SEEK_TIME, it |
| 57 | * is expressed in nanoseconds |
| 58 | * - restore is a position saved with bt_iter_get_pos, it is used with |
| 59 | * BT_SEEK_RESTORE. |
| 60 | * |
| 61 | * Note about BT_SEEK_LAST: if many events happen to be at the last |
| 62 | * timestamp, it is implementation-defined which event will be the last, |
| 63 | * and the order of events with the same timestamp may not be the same |
| 64 | * as normal iteration on the trace. Therefore, it is recommended to |
| 65 | * only use BT_SEEK_LAST to get the timestamp of the last event(s) in |
| 66 | * the trace. |
| 67 | */ |
| 68 | enum bt_iter_pos_type { |
| 69 | BT_SEEK_TIME, /* uses u.seek_time */ |
| 70 | BT_SEEK_RESTORE, /* uses u.restore */ |
| 71 | BT_SEEK_CUR, |
| 72 | BT_SEEK_BEGIN, |
| 73 | BT_SEEK_LAST, |
| 74 | }; |
| 75 | |
| 76 | struct bt_iter_pos { |
| 77 | enum bt_iter_pos_type type; |
| 78 | union { |
| 79 | uint64_t seek_time; |
| 80 | struct bt_saved_pos *restore; |
| 81 | } u; |
| 82 | }; |
| 83 | |
| 84 | /* |
| 85 | * bt_iter_next: Move trace collection position to the next event. |
| 86 | * |
| 87 | * Returns 0 on success, a negative value on error |
| 88 | */ |
| 89 | int bt_iter_next(struct bt_iter *iter); |
| 90 | |
| 91 | /* |
| 92 | * bt_iter_get_pos - Get the current iterator position. |
| 93 | * |
| 94 | * The position returned by this function needs to be freed by |
| 95 | * bt_iter_free_pos after use. |
| 96 | */ |
| 97 | struct bt_iter_pos *bt_iter_get_pos(struct bt_iter *iter); |
| 98 | |
| 99 | /* |
| 100 | * bt_iter_free_pos - Free the position. |
| 101 | */ |
| 102 | void bt_iter_free_pos(struct bt_iter_pos *pos); |
| 103 | |
| 104 | /* |
| 105 | * bt_iter_set_pos: move the iterator to a given position. |
| 106 | * |
| 107 | * On error, the stream_heap is reinitialized and returned empty. |
| 108 | * |
| 109 | * Return 0 for success. |
| 110 | * |
| 111 | * Return EOF if the position requested is after the last event of the |
| 112 | * trace collection. |
| 113 | * Return -EINVAL when called with invalid parameter. |
| 114 | * Return -ENOMEM if the stream_heap could not be properly initialized. |
| 115 | */ |
| 116 | int bt_iter_set_pos(struct bt_iter *iter, const struct bt_iter_pos *pos); |
| 117 | |
| 118 | /* |
| 119 | * bt_iter_create_time_pos: create a position based on time |
| 120 | * |
| 121 | * This function allocates and returns a new bt_iter_pos (which must be freed |
| 122 | * with bt_iter_free_pos) to be able to restore an iterator position based on a |
| 123 | * real timestamp. |
| 124 | */ |
| 125 | struct bt_iter_pos *bt_iter_create_time_pos(struct bt_iter *iter, |
| 126 | uint64_t timestamp); |
| 127 | |
| 128 | #ifdef __cplusplus |
| 129 | } |
| 130 | #endif |
| 131 | |
| 132 | #endif /* _BABELTRACE_ITERATOR_H */ |