94df03c868526b1bcdf3fdbe935d8dfbf09406c9
[babeltrace.git] / include / babeltrace / iterator.h
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
23 /* Forward declarations */
24 struct bt_iter;
25 struct bt_saved_pos;
26
27 struct bt_iter_pos {
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;
37 struct bt_saved_pos *restore;
38 } u;
39 };
40
41 /*
42 * bt_iter_next: Move trace collection position to the next event.
43 *
44 * Returns 0 on success, a negative value on error
45 */
46 int bt_iter_next(struct bt_iter *iter);
47
48 /*
49 * bt_iter_get_pos - Get the current iterator position.
50 *
51 * The position returned by this function needs to be freed by
52 * bt_iter_free_pos after use.
53 */
54 struct bt_iter_pos *bt_iter_get_pos(struct bt_iter *iter);
55
56 /*
57 * bt_iter_free_pos - Free the position.
58 */
59 void bt_iter_free_pos(struct bt_iter_pos *pos);
60
61 /*
62 * bt_iter_set_pos: move the iterator to a given position.
63 *
64 * On error, the stream_heap is reinitialized and returned empty.
65 *
66 * Return 0 for success.
67 *
68 * Return EOF if the position requested is after the last event of the
69 * trace collection.
70 * Return -EINVAL when called with invalid parameter.
71 * Return -ENOMEM if the stream_heap could not be properly initialized.
72 */
73 int bt_iter_set_pos(struct bt_iter *iter, const struct bt_iter_pos *pos);
74
75 /*
76 * bt_iter_create_time_pos: create a position based on time
77 *
78 * This function allocates and returns a new bt_iter_pos (which must be freed
79 * with bt_iter_free_pos) to be able to restore an iterator position based on a
80 * timestamp.
81 */
82 struct bt_iter_pos *bt_iter_create_time_pos(struct bt_iter *iter,
83 uint64_t timestamp);
84
85 #endif /* _BABELTRACE_ITERATOR_H */
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