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b469d2dd JD |
1 | #ifndef _BABELTRACE_CONTEXT_H |
2 | #define _BABELTRACE_CONTEXT_H | |
3 | ||
4 | /* | |
5 | * BabelTrace | |
6 | * | |
7 | * context header | |
8 | * | |
9 | * Copyright 2012 EfficiOS Inc. and Linux Foundation | |
10 | * | |
11 | * Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
12 | * Julien Desfossez <julien.desfossez@efficios.com> | |
13 | * | |
6cba487f MD |
14 | * Permission is hereby granted, free of charge, to any person obtaining |
15 | * a copy of this software and associated documentation files (the | |
16 | * "Software"), to deal in the Software without restriction, including | |
17 | * without limitation the rights to use, copy, modify, merge, publish, | |
18 | * distribute, sublicense, and/or sell copies of the Software, and to | |
19 | * permit persons to whom the Software is furnished to do so, subject to | |
20 | * the following conditions: | |
b469d2dd | 21 | * |
6cba487f MD |
22 | * The above copyright notice and this permission notice shall be |
23 | * included in all copies or substantial portions of the Software. | |
b469d2dd JD |
24 | */ |
25 | ||
613f532b | 26 | #include <unistd.h> |
0d4c669f | 27 | #include <babeltrace/format.h> |
613f532b | 28 | |
08c22d05 MD |
29 | /* struct bt_context is opaque to the user */ |
30 | struct bt_context; | |
613f532b | 31 | struct stream_pos; |
b469d2dd JD |
32 | |
33 | /* | |
34 | * bt_context_create : create a Babeltrace context | |
35 | * | |
6cba487f MD |
36 | * Allocate a new context. The creation of the context sets the refcount |
37 | * to 1. | |
b469d2dd JD |
38 | * |
39 | * Returns an allocated context on success and NULL on error | |
40 | */ | |
6cba487f | 41 | struct bt_context *bt_context_create(void); |
b469d2dd JD |
42 | |
43 | /* | |
6cba487f | 44 | * bt_context_add_trace : Add a trace by path to the context |
b469d2dd | 45 | * |
2f5d314f MD |
46 | * Open a trace. |
47 | * | |
48 | * packet_seek can be NULL to use the default packet_seek handler | |
49 | * provided by the trace format. If non-NULL, it is used as an override | |
50 | * of the handler for seeks across packets. It takes as parameter a | |
51 | * stream position, the packet index it needs to seek to (for SEEK_SET), | |
52 | * and a "whence" parameter (either SEEK_CUR: seek to next packet, or | |
53 | * SEEK_SET: seek to packet at packet index). | |
6cba487f | 54 | * |
0d4c669f MD |
55 | * If "path" is NULL, stream_list is used instread as a list of streams |
56 | * to open for the trace. | |
57 | ||
58 | * The metadata parameter acts as a metadata override when not NULL. | |
59 | * | |
1059a2bf JD |
60 | * Return: the trace handle id (>= 0) on success, a negative |
61 | * value on error. | |
6cba487f MD |
62 | */ |
63 | int bt_context_add_trace(struct bt_context *ctx, const char *path, | |
613f532b MD |
64 | const char *format, |
65 | void (*packet_seek)(struct stream_pos *pos, | |
0d4c669f MD |
66 | size_t index, int whence), |
67 | struct mmap_stream_list *stream_list, | |
68 | FILE *metadata); | |
6cba487f | 69 | |
6cba487f MD |
70 | /* |
71 | * bt_context_remove_trace: Remove a trace from the context. | |
72 | * | |
73 | * Effectively closing the trace. | |
b469d2dd | 74 | */ |
6cba487f | 75 | void bt_context_remove_trace(struct bt_context *ctx, int trace_id); |
b469d2dd JD |
76 | |
77 | /* | |
6cba487f MD |
78 | * bt_context_get and bt_context_put : increments and decrement the |
79 | * refcount of the context | |
b469d2dd | 80 | * |
6cba487f MD |
81 | * These functions ensures that the context won't be destroyed when it |
82 | * is in use. The same number of get and put (plus one extra put to | |
83 | * release the initial reference done at creation) has to be done to | |
84 | * destroy a context. | |
b469d2dd | 85 | * |
6cba487f MD |
86 | * When the context refcount is decremented to 0 by a bt_context_put, |
87 | * the context is freed. | |
b469d2dd | 88 | */ |
6cba487f MD |
89 | void bt_context_get(struct bt_context *ctx); |
90 | void bt_context_put(struct bt_context *ctx); | |
b469d2dd JD |
91 | |
92 | #endif /* _BABELTRACE_CONTEXT_H */ |