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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 | ||
6204d33c | 23 | /* Forward declarations */ |
e8c92a62 | 24 | struct bt_iter; |
e8c92a62 | 25 | struct bt_saved_pos; |
6204d33c | 26 | |
e8c92a62 | 27 | struct bt_iter_pos { |
6204d33c JD |
28 | enum { |
29 | BT_SEEK_TIME, /* uses u.seek_time */ | |
30 | BT_SEEK_RESTORE, /* uses u.restore */ | |
31 | BT_SEEK_CUR, | |
32 | BT_SEEK_BEGIN, | |
33 | BT_SEEK_END, | |
34 | } type; | |
35 | union { | |
36 | uint64_t seek_time; | |
e8c92a62 | 37 | struct bt_saved_pos *restore; |
6204d33c JD |
38 | } u; |
39 | }; | |
40 | ||
41 | /* | |
e8c92a62 | 42 | * bt_iter_create - Allocate a trace collection iterator. |
6204d33c JD |
43 | * |
44 | * begin_pos and end_pos are optional parameters to specify the position | |
45 | * at which the trace collection should be seeked upon iterator | |
46 | * creation, and the position at which iteration will start returning | |
47 | * "EOF". | |
48 | * | |
49 | * By default, if begin_pos is NULL, a BT_SEEK_CUR is performed at | |
50 | * creation. By default, if end_pos is NULL, a BT_SEEK_END (end of | |
51 | * trace) is the EOF criterion. | |
52 | */ | |
e8c92a62 JD |
53 | struct bt_iter *bt_iter_create(struct bt_context *ctx, |
54 | struct bt_iter_pos *begin_pos, | |
55 | struct bt_iter_pos *end_pos); | |
6204d33c JD |
56 | |
57 | /* | |
e8c92a62 | 58 | * bt_iter_destroy - Free a trace collection iterator. |
6204d33c | 59 | */ |
e8c92a62 | 60 | void bt_iter_destroy(struct bt_iter *iter); |
6204d33c JD |
61 | |
62 | /* | |
e8c92a62 | 63 | * bt_iter_next: Move trace collection position to the next event. |
6204d33c JD |
64 | * |
65 | * Returns 0 on success, a negative value on error | |
66 | */ | |
e8c92a62 | 67 | int bt_iter_next(struct bt_iter *iter); |
6204d33c JD |
68 | |
69 | /* | |
90fcbacc | 70 | * bt_iter_get_pos - Get the current iterator position. |
6204d33c JD |
71 | * |
72 | * The position returned by this function needs to be freed by | |
e8c92a62 | 73 | * bt_iter_free_pos after use. |
6204d33c | 74 | */ |
e8c92a62 | 75 | struct bt_iter_pos * |
90fcbacc | 76 | bt_iter_get_pos(struct bt_iter *iter); |
6204d33c JD |
77 | |
78 | /* | |
e8c92a62 | 79 | * bt_iter_free_pos - Free the position. |
6204d33c | 80 | */ |
e8c92a62 | 81 | void bt_iter_free_pos(struct bt_iter_pos *pos); |
6204d33c JD |
82 | |
83 | /* | |
90fcbacc | 84 | * bt_iter_set_pos: move the iterator to a given position. |
6204d33c | 85 | * |
dc81689e JD |
86 | * On error, the stream_heap is reinitialized and returned empty. |
87 | * | |
6204d33c | 88 | * Return 0 for success. |
dc81689e JD |
89 | * |
90 | * Return EOF if the position requested is after the last event of the | |
91 | * trace collection. | |
92 | * Return -EINVAL when called with invalid parameter. | |
93 | * Return -ENOMEM if the stream_heap could not be properly initialized. | |
94 | */ | |
95 | int bt_iter_set_pos(struct bt_iter *iter, const struct bt_iter_pos *pos); | |
96 | ||
97 | /* | |
98 | * bt_iter_create_time_pos: create a position based on time | |
99 | * | |
100 | * This function allocates and returns a new bt_iter_pos (which must be freed | |
101 | * with bt_iter_free_pos) to be able to restore an iterator position based on a | |
102 | * timestamp. | |
6204d33c | 103 | */ |
dc81689e JD |
104 | struct bt_iter_pos *bt_iter_create_time_pos(struct bt_iter *iter, |
105 | uint64_t timestamp); | |
6204d33c | 106 | |
6204d33c | 107 | #endif /* _BABELTRACE_ITERATOR_H */ |