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6204d33c JD |
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 | ||
20 | #include <babeltrace/format.h> | |
21 | #include <babeltrace/context.h> | |
22 | ||
6946751f JD |
23 | #ifdef __cplusplus |
24 | extern "C" { | |
25 | #endif | |
26 | ||
f60efc0e JD |
27 | /* Flags for the iterator read_event */ |
28 | enum { | |
29 | BT_ITER_FLAG_LOST_EVENTS = (1 << 0), | |
30 | }; | |
31 | ||
6204d33c | 32 | /* Forward declarations */ |
e8c92a62 | 33 | struct bt_iter; |
e8c92a62 | 34 | struct bt_saved_pos; |
6204d33c | 35 | |
31265d84 JD |
36 | /* |
37 | * bt_iter is an abstract class, each format has to implement its own | |
38 | * iterator derived from this parent class. | |
39 | */ | |
40 | ||
41 | /* | |
42 | * bt_iter_pos | |
43 | * | |
44 | * This structure represents the position where to set an iterator. | |
45 | * | |
46 | * type represents the type of seek to use. | |
47 | * u is the argument of the seek if necessary : | |
03798a93 | 48 | * - seek_time is the real timestamp to seek to when using BT_SEEK_TIME, it |
836c4dd8 | 49 | * is expressed in nanoseconds |
31265d84 JD |
50 | * - restore is a position saved with bt_iter_get_pos, it is used with |
51 | * BT_SEEK_RESTORE. | |
f7ed6563 MD |
52 | * |
53 | * Note about BT_SEEK_LAST: if many events happen to be at the last | |
54 | * timestamp, it is implementation-defined which event will be the last, | |
55 | * and the order of events with the same timestamp may not be the same | |
56 | * as normal iteration on the trace. Therefore, it is recommended to | |
57 | * only use BT_SEEK_LAST to get the timestamp of the last event(s) in | |
58 | * the trace. | |
31265d84 | 59 | */ |
e8c92a62 | 60 | struct bt_iter_pos { |
6204d33c JD |
61 | enum { |
62 | BT_SEEK_TIME, /* uses u.seek_time */ | |
63 | BT_SEEK_RESTORE, /* uses u.restore */ | |
64 | BT_SEEK_CUR, | |
65 | BT_SEEK_BEGIN, | |
f7ed6563 | 66 | BT_SEEK_LAST, |
6204d33c JD |
67 | } type; |
68 | union { | |
69 | uint64_t seek_time; | |
e8c92a62 | 70 | struct bt_saved_pos *restore; |
6204d33c JD |
71 | } u; |
72 | }; | |
73 | ||
6204d33c | 74 | /* |
e8c92a62 | 75 | * bt_iter_next: Move trace collection position to the next event. |
6204d33c JD |
76 | * |
77 | * Returns 0 on success, a negative value on error | |
78 | */ | |
e8c92a62 | 79 | int bt_iter_next(struct bt_iter *iter); |
6204d33c JD |
80 | |
81 | /* | |
90fcbacc | 82 | * bt_iter_get_pos - Get the current iterator position. |
6204d33c JD |
83 | * |
84 | * The position returned by this function needs to be freed by | |
e8c92a62 | 85 | * bt_iter_free_pos after use. |
6204d33c | 86 | */ |
5a23202c | 87 | struct bt_iter_pos *bt_iter_get_pos(struct bt_iter *iter); |
6204d33c JD |
88 | |
89 | /* | |
e8c92a62 | 90 | * bt_iter_free_pos - Free the position. |
6204d33c | 91 | */ |
e8c92a62 | 92 | void bt_iter_free_pos(struct bt_iter_pos *pos); |
6204d33c JD |
93 | |
94 | /* | |
90fcbacc | 95 | * bt_iter_set_pos: move the iterator to a given position. |
6204d33c | 96 | * |
dc81689e JD |
97 | * On error, the stream_heap is reinitialized and returned empty. |
98 | * | |
6204d33c | 99 | * Return 0 for success. |
dc81689e JD |
100 | * |
101 | * Return EOF if the position requested is after the last event of the | |
102 | * trace collection. | |
103 | * Return -EINVAL when called with invalid parameter. | |
104 | * Return -ENOMEM if the stream_heap could not be properly initialized. | |
105 | */ | |
106 | int bt_iter_set_pos(struct bt_iter *iter, const struct bt_iter_pos *pos); | |
107 | ||
108 | /* | |
109 | * bt_iter_create_time_pos: create a position based on time | |
110 | * | |
111 | * This function allocates and returns a new bt_iter_pos (which must be freed | |
112 | * with bt_iter_free_pos) to be able to restore an iterator position based on a | |
03798a93 | 113 | * real timestamp. |
6204d33c | 114 | */ |
dc81689e JD |
115 | struct bt_iter_pos *bt_iter_create_time_pos(struct bt_iter *iter, |
116 | uint64_t timestamp); | |
6204d33c | 117 | |
6946751f JD |
118 | #ifdef __cplusplus |
119 | } | |
120 | #endif | |
121 | ||
6204d33c | 122 | #endif /* _BABELTRACE_ITERATOR_H */ |