[babeltrace.git] / include / babeltrace / context.h

#ifndef _BABELTRACE_CONTEXT_H
#define _BABELTRACE_CONTEXT_H

/*
 * BabelTrace
 *
 * context header
 *
 * Copyright 2012 EfficiOS Inc. and Linux Foundation
 *
 * Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *         Julien Desfossez <julien.desfossez@efficios.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <unistd.h>
#include <babeltrace/format.h>

#ifdef __cplusplus
extern "C" {
#endif

/* struct bt_context is opaque to the user */
struct bt_context;
struct stream_pos;
struct bt_ctf_event;

/*
 * bt_context_create : create a Babeltrace context
 *
 * Allocate a new context. The creation of the context sets the refcount
 * to 1.
 *
 * Returns an allocated context on success and NULL on error
 */
struct bt_context *bt_context_create(void);

/*
 * bt_context_add_trace : Add a trace by path to the context
 *
 * Open a trace.
 *
 * path is the path to the trace, it is not recursive. If "path" is NULL,
 * stream_list is used instead as a list of mmap streams to open for the trace.
 *
 * format is a string containing the format name in which the trace was
 * produced.
 *
 * packet_seek can be NULL to use the default packet_seek handler provided by
 * the trace format. If non-NULL, it is used as an override of the handler for
 * seeks across packets. It takes as parameter a stream position, the packet
 * index it needs to seek to (for SEEK_SET), and a "whence" parameter (either
 * SEEK_CUR: seek to next packet, or SEEK_SET: seek to packet at packet index).
 *
 * stream_list is a linked list of streams, it is used to open a trace where
 * the trace data is located in memory mapped areas instead of trace files,
 * this argument should be set to NULL when path is NULL.
 *
 * The metadata parameter acts as a metadata override when not NULL, otherwise
 * the format handles the metadata opening.
 *
 * Return: the trace handle id (>= 0) on success, a negative
 * value on error.
 */
int bt_context_add_trace(struct bt_context *ctx, const char *path,
		const char *format,
		void (*packet_seek)(struct stream_pos *pos,
			size_t index, int whence),
		struct mmap_stream_list *stream_list,
		FILE *metadata);

/*
 * bt_context_remove_trace: Remove a trace from the context.
 *
 * Effectively closing the trace. Return negative error value if trace
 * is not in context.
 */
int bt_context_remove_trace(struct bt_context *ctx, int trace_id);

/*
 * bt_context_get and bt_context_put : increments and decrement the
 * refcount of the context
 *
 * These functions ensures that the context won't be destroyed when it
 * is in use. The same number of get and put (plus one extra put to
 * release the initial reference done at creation) has to be done to
 * destroy a context.
 *
 * When the context refcount is decremented to 0 by a bt_context_put,
 * the context is freed.
 */
void bt_context_get(struct bt_context *ctx);
void bt_context_put(struct bt_context *ctx);

/*
 * bt_ctf_get_context : get the context associated with an event
 *
 * Returns NULL on error
 */
struct bt_context *bt_ctf_event_get_context(const struct bt_ctf_event *event);

#ifdef __cplusplus
}
#endif

#endif /* _BABELTRACE_CONTEXT_H */
Commit	Line	Data
	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	*
	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:
	21	*
	22	* The above copyright notice and this permission notice shall be
	23	* included in all copies or substantial portions of the Software.
	24	*
	25	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	26	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	27	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	28	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	29	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	30	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	31	* SOFTWARE.
	32	*/
	33
	34	#include <unistd.h>
	35	#include <babeltrace/format.h>
	36
	37	#ifdef __cplusplus
	38	extern "C" {
	39	#endif
	40
	41	/* struct bt_context is opaque to the user */
	42	struct bt_context;
	43	struct stream_pos;
	44	struct bt_ctf_event;
	45
	46	/*
	47	* bt_context_create : create a Babeltrace context
	48	*
	49	* Allocate a new context. The creation of the context sets the refcount
	50	* to 1.
	51	*
	52	* Returns an allocated context on success and NULL on error
	53	*/
	54	struct bt_context *bt_context_create(void);
	55
	56	/*
	57	* bt_context_add_trace : Add a trace by path to the context
	58	*
	59	* Open a trace.
	60	*
	61	* path is the path to the trace, it is not recursive. If "path" is NULL,
	62	* stream_list is used instead as a list of mmap streams to open for the trace.
	63	*
	64	* format is a string containing the format name in which the trace was
	65	* produced.
	66	*
	67	* packet_seek can be NULL to use the default packet_seek handler provided by
	68	* the trace format. If non-NULL, it is used as an override of the handler for
	69	* seeks across packets. It takes as parameter a stream position, the packet
	70	* index it needs to seek to (for SEEK_SET), and a "whence" parameter (either
	71	* SEEK_CUR: seek to next packet, or SEEK_SET: seek to packet at packet index).
	72	*
	73	* stream_list is a linked list of streams, it is used to open a trace where
	74	* the trace data is located in memory mapped areas instead of trace files,
	75	* this argument should be set to NULL when path is NULL.
	76	*
	77	* The metadata parameter acts as a metadata override when not NULL, otherwise
	78	* the format handles the metadata opening.
	79	*
	80	* Return: the trace handle id (>= 0) on success, a negative
	81	* value on error.
	82	*/
	83	int bt_context_add_trace(struct bt_context ctx, const char path,
	84	const char *format,
	85	void (packet_seek)(struct stream_pos pos,
	86	size_t index, int whence),
	87	struct mmap_stream_list *stream_list,
	88	FILE *metadata);
	89
	90	/*
	91	* bt_context_remove_trace: Remove a trace from the context.
	92	*
	93	* Effectively closing the trace. Return negative error value if trace
	94	* is not in context.
	95	*/
	96	int bt_context_remove_trace(struct bt_context *ctx, int trace_id);
	97
	98	/*
	99	* bt_context_get and bt_context_put : increments and decrement the
	100	* refcount of the context
	101	*
	102	* These functions ensures that the context won't be destroyed when it
	103	* is in use. The same number of get and put (plus one extra put to
	104	* release the initial reference done at creation) has to be done to
	105	* destroy a context.
	106	*
	107	* When the context refcount is decremented to 0 by a bt_context_put,
	108	* the context is freed.
	109	*/
	110	void bt_context_get(struct bt_context *ctx);
	111	void bt_context_put(struct bt_context *ctx);
	112
	113	/*
	114	* bt_ctf_get_context : get the context associated with an event
	115	*
	116	* Returns NULL on error
	117	*/
	118	struct bt_context bt_ctf_event_get_context(const struct bt_ctf_event event);
	119
	120	#ifdef __cplusplus
	121	}
	122	#endif
	123
	124	#endif /* _BABELTRACE_CONTEXT_H */