[babeltrace.git] / plugins / ctf / common / notif-iter / notif-iter.h

#ifndef CTF_NOTIF_ITER_H
#define CTF_NOTIF_ITER_H

/*
 * Babeltrace - CTF notification iterator
 *                  ¯¯¯¯¯        ¯¯¯¯
 * Copyright (c) 2015-2016 EfficiOS Inc. and Linux Foundation
 * Copyright (c) 2015-2016 Philippe Proulx <pproulx@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 <stdint.h>
#include <stdio.h>
#include <stddef.h>
#include <babeltrace/ctf-ir/trace.h>
#include <babeltrace/ctf-ir/fields.h>
#include <babeltrace/ctf-ir/event.h>
#include <babeltrace/graph/clock-class-priority-map.h>
#include <babeltrace/babeltrace-internal.h>

/**
 * @file ctf-notif-iter.h
 *
 * CTF notification iterator
 *     ¯¯¯¯¯        ¯¯¯¯
 * This is a common internal API used by CTF source plugins. It allows
 * one to get notifications from a user-provided medium.
 */

/**
 * Medium operations status codes.
 */
enum bt_ctf_notif_iter_medium_status {
	/**
	 * End of file.
	 *
	 * The medium function called by the notification iterator
	 * function reached the end of the file.
	 */
	BT_CTF_NOTIF_ITER_MEDIUM_STATUS_EOF = 1,

	/**
	 * There is no data available right now, try again later.
	 */
	BT_CTF_NOTIF_ITER_MEDIUM_STATUS_AGAIN = 11,

	/** Unsupported operation. */
	BT_CTF_NOTIF_ITER_MEDIUM_STATUS_UNSUPPORTED = -3,

	/** Invalid argument. */
	BT_CTF_NOTIF_ITER_MEDIUM_STATUS_INVAL = -2,

	/** General error. */
	BT_CTF_NOTIF_ITER_MEDIUM_STATUS_ERROR = -1,

	/** Everything okay. */
	BT_CTF_NOTIF_ITER_MEDIUM_STATUS_OK = 0,
};

/**
 * CTF notification iterator API status code.
 */
enum bt_ctf_notif_iter_status {
	/**
	 * End of file.
	 *
	 * The medium function called by the notification iterator
	 * function reached the end of the file.
	 */
	BT_CTF_NOTIF_ITER_STATUS_EOF = BT_CTF_NOTIF_ITER_MEDIUM_STATUS_EOF,

	/**
	 * There is no data available right now, try again later.
	 *
	 * Some condition resulted in the
	 * bt_ctf_notif_iter_medium_ops::request_bytes() user function not
	 * having access to any data now. You should retry calling the
	 * last called notification iterator function once the situation
	 * is resolved.
	 */
	BT_CTF_NOTIF_ITER_STATUS_AGAIN = BT_CTF_NOTIF_ITER_MEDIUM_STATUS_AGAIN,

	/** Invalid argument. */
	BT_CTF_NOTIF_ITER_STATUS_INVAL = BT_CTF_NOTIF_ITER_MEDIUM_STATUS_INVAL,

	/** Unsupported operation. */
	BT_CTF_NOTIF_ITER_STATUS_UNSUPPORTED = BT_CTF_NOTIF_ITER_MEDIUM_STATUS_UNSUPPORTED,

	/** General error. */
	BT_CTF_NOTIF_ITER_STATUS_ERROR = BT_CTF_NOTIF_ITER_MEDIUM_STATUS_ERROR,

	/** Everything okay. */
	BT_CTF_NOTIF_ITER_STATUS_OK =	0,
};

/**
 * CTF notification iterator seek operation directives.
 */
enum bt_ctf_notif_iter_seek_whence {
	/**
	 * Set the iterator's position to an absolute offset in the underlying
	 * medium.
	 */
	BT_CTF_NOTIF_ITER_SEEK_WHENCE_SET,
};

/**
 * Medium operations.
 *
 * Those user functions are called by the notification iterator
 * functions to request medium actions.
 */
struct bt_ctf_notif_iter_medium_ops {
	/**
	 * Returns the next byte buffer to be used by the binary file
	 * reader to deserialize binary data.
	 *
	 * This function \em must be defined.
	 *
	 * The purpose of this function is to return a buffer of bytes
	 * to the notification iterator, of a maximum of \p request_sz
	 * bytes. If this function cannot return a buffer of at least
	 * \p request_sz bytes, it may return a smaller buffer. In
	 * either cases, \p buffer_sz must be set to the returned buffer
	 * size (in bytes).
	 *
	 * The returned buffer's ownership remains the medium, in that
	 * it won't be freed by the notification iterator functions. The
	 * returned buffer won't be modified by the notification
	 * iterator functions either.
	 *
	 * When this function is called for the first time for a given
	 * file, the offset within the file is considered to be 0. The
	 * next times this function is called, the returned buffer's
	 * byte offset within the complete file must be the previous
	 * offset plus the last returned value of \p buffer_sz by this
	 * medium.
	 *
	 * This function must return one of the following statuses:
	 *
	 *   - <b>#BT_CTF_NOTIF_ITER_MEDIUM_STATUS_OK</b>: Everything
	 *     is okay, i.e. \p buffer_sz is set to a positive value
	 *     reflecting the number of available bytes in the buffer
	 *     starting at the address written in \p buffer_addr.
	 *   - <b>#BT_CTF_NOTIF_ITER_MEDIUM_STATUS_AGAIN</b>: No data is
	 *     available right now. In this case, the notification
	 *     iterator function called by the user returns
	 *     #BT_CTF_NOTIF_ITER_STATUS_AGAIN, and it is the user's
	 *     responsibility to make sure enough data becomes available
	 *     before calling the \em same notification iterator
	 *     function again to continue the decoding process.
	 *   - <b>#BT_CTF_NOTIF_ITER_MEDIUM_STATUS_EOF</b>: The end of
	 *     the file was reached, and no more data will ever be
	 *     available for this file. In this case, the notification
	 *     iterator function called by the user returns
	 *     #BT_CTF_NOTIF_ITER_STATUS_EOF. This must \em not be
	 *     returned when returning at least one byte of data to the
	 *     caller, i.e. this must be returned when there's
	 *     absolutely nothing left; should the request size be
	 *     larger than what's left in the file, this function must
	 *     return what's left, setting \p buffer_sz to the number of
	 *     remaining bytes, and return
	 *     #BT_CTF_NOTIF_ITER_MEDIUM_STATUS_EOF on the \em following
	 *     call.
	 *   - <b>#BT_CTF_NOTIF_ITER_MEDIUM_STATUS_ERROR</b>: A fatal
	 *     error occured during this operation. In this case, the
	 *     notification iterator function called by the user returns
	 *     #BT_CTF_NOTIF_ITER_STATUS_ERROR.
	 *
	 * If #BT_CTF_NOTIF_ITER_MEDIUM_STATUS_OK is not returned, the
	 * values of \p buffer_sz and \p buffer_addr are \em ignored by
	 * the caller.
	 *
	 * @param request_sz	Requested buffer size (bytes)
	 * @param buffer_addr	Returned buffer address
	 * @param buffer_sz	Returned buffer's size (bytes)
	 * @param data		User data
	 * @returns		Status code (see description above)
	 */
	enum bt_ctf_notif_iter_medium_status (* request_bytes)(
			size_t request_sz, uint8_t **buffer_addr,
			size_t *buffer_sz, void *data);

	/**
	 * Repositions the underlying stream's position.
	 *
	 * This *optional* method repositions the underlying stream
	 * to a given absolute or relative position, as indicated by
	 * the whence directive.
	 *
	 * @param whence	One of #bt_ctf_notif_iter_seek_whence values
	 * @param offset	Offset to use for the given directive
	 * @param data		User data
	 * @returns		One of #bt_ctf_notif_iter_medium_status values
	 */
	enum bt_ctf_notif_iter_medium_status (* seek)(
			enum bt_ctf_notif_iter_seek_whence whence,
			off_t offset, void *data);

	/**
	 * Returns a stream instance (weak reference) for the given
	 * stream class.
	 *
	 * This is called after a packet header is read, and the
	 * corresponding stream class is found by the notification
	 * iterator.
	 *
	 * @param stream_class	Stream class of the stream to get
	 * @param stream_id	Stream (instance) ID of the stream
	 *			to get (-1ULL if not available)
	 * @param data		User data
	 * @returns		Stream instance (weak reference) or
	 *			\c NULL on error
	 */
	struct bt_ctf_stream * (* get_stream)(
			struct bt_ctf_stream_class *stream_class,
			uint64_t stream_id, void *data);
};

/** CTF notification iterator. */
struct bt_ctf_notif_iter;

// TODO: Replace by the real thing
enum bt_ctf_notif_iter_notif_type {
	BT_CTF_NOTIF_ITER_NOTIF_NEW_PACKET,
	BT_CTF_NOTIF_ITER_NOTIF_END_OF_PACKET,
	BT_CTF_NOTIF_ITER_NOTIF_EVENT,
};

struct bt_ctf_notif_iter_notif {
	enum bt_ctf_notif_iter_notif_type type;
};

struct bt_ctf_notif_iter_notif_new_packet {
	struct bt_ctf_notif_iter_notif base;
	struct bt_ctf_packet *packet;
};

struct bt_ctf_notif_iter_notif_end_of_packet {
	struct bt_ctf_notif_iter_notif base;
	struct bt_ctf_packet *packet;
};

struct bt_ctf_notif_iter_notif_event {
	struct bt_ctf_notif_iter_notif base;
	struct bt_ctf_event *event;
};

/**
 * Creates a CTF notification iterator.
 *
 * Upon successful completion, the reference count of \p trace is
 * incremented.
 *
 * @param trace			Trace to read
 * @param max_request_sz	Maximum buffer size, in bytes, to
 *				request to
 *				bt_ctf_notif_iter_medium_ops::request_bytes()
 * 				at a time
 * @param medops		Medium operations
 * @param medops_data		User data (passed to medium operations)
 * @returns			New CTF notification iterator on
 *				success, or \c NULL on error
 */
BT_HIDDEN
struct bt_ctf_notif_iter *bt_ctf_notif_iter_create(struct bt_ctf_trace *trace,
	size_t max_request_sz, struct bt_ctf_notif_iter_medium_ops medops,
	void *medops_data);

/**
 * Destroys a CTF notification iterator, freeing all internal resources.
 *
 * The registered trace's reference count is decremented.
 *
 * @param notif_iter		CTF notification iterator
 */
BT_HIDDEN
void bt_ctf_notif_iter_destroy(struct bt_ctf_notif_iter *notif_iter);

/**
 * Returns the next notification from a CTF notification iterator.
 *
 * Upon successful completion, #BT_CTF_NOTIF_ITER_STATUS_OK is
 * returned, and the next notification is written to \p notif.
 * In this case, the caller is responsible for calling
 * bt_notification_put() on the returned notification.
 *
 * If this function returns #BT_CTF_NOTIF_ITER_STATUS_AGAIN, the caller
 * should make sure that data becomes available to its medium, and
 * call this function again, until another status is returned.
 *
 * @param notif_iter		CTF notification iterator
 * @param cc_prio_map		Clock class priority map to use when
 *				creating an event notification
 * @param notification		Returned notification if the function's
 *				return value is #BT_CTF_NOTIF_ITER_STATUS_OK
 * @returns			One of #bt_ctf_notif_iter_status values
 */
BT_HIDDEN
enum bt_ctf_notif_iter_status bt_ctf_notif_iter_get_next_notification(
		struct bt_ctf_notif_iter *notit,
		struct bt_clock_class_priority_map *cc_prio_map,
		struct bt_notification **notification);

/**
 * Returns the first packet header and context fields. This function
 * never needs to call the `get_stream()` medium operation because
 * it does not create packet or event objects.
 *
 * @param notif_iter		CTF notification iterator
 * @param packet_header_field	Packet header field (\c NULL if there's
 *				no packet header field)
 * @param packet_context_field	Packet context field (\c NULL if there's
 *				no packet context field)
 * @returns			One of #bt_ctf_notif_iter_status values
 */
BT_HIDDEN
enum bt_ctf_notif_iter_status bt_ctf_notif_iter_get_packet_header_context_fields(
		struct bt_ctf_notif_iter *notit,
		struct bt_ctf_field **packet_header_field,
		struct bt_ctf_field **packet_context_field);

BT_HIDDEN
void bt_ctf_notif_iter_set_medops_data(struct bt_ctf_notif_iter *notit,
		void *medops_data);

BT_HIDDEN
enum bt_ctf_notif_iter_status bt_ctf_notif_iter_seek(
		struct bt_ctf_notif_iter *notit, off_t offset);

/*
 * Get the current packet's offset in bytes relative to the media's initial
 * position.
 */
BT_HIDDEN
off_t bt_ctf_notif_iter_get_current_packet_offset(
		struct bt_ctf_notif_iter *notit);

/* Get the current packet's size (in bits). */
BT_HIDDEN
off_t bt_ctf_notif_iter_get_current_packet_size(
		struct bt_ctf_notif_iter *notit);

static inline
const char *bt_ctf_notif_iter_medium_status_string(
		enum bt_ctf_notif_iter_medium_status status)
{
	switch (status) {
	case BT_CTF_NOTIF_ITER_MEDIUM_STATUS_EOF:
		return "BT_CTF_NOTIF_ITER_MEDIUM_STATUS_EOF";
	case BT_CTF_NOTIF_ITER_MEDIUM_STATUS_AGAIN:
		return "BT_CTF_NOTIF_ITER_MEDIUM_STATUS_AGAIN";
	case BT_CTF_NOTIF_ITER_MEDIUM_STATUS_INVAL:
		return "BT_CTF_NOTIF_ITER_MEDIUM_STATUS_INVAL";
	case BT_CTF_NOTIF_ITER_MEDIUM_STATUS_ERROR:
		return "BT_CTF_NOTIF_ITER_MEDIUM_STATUS_ERROR";
	case BT_CTF_NOTIF_ITER_MEDIUM_STATUS_OK:
		return "BT_CTF_NOTIF_ITER_MEDIUM_STATUS_OK";
	default:
		return "(unknown)";
	}
}

static inline
const char *bt_ctf_notif_iter_status_string(
		enum bt_ctf_notif_iter_status status)
{
	switch (status) {
	case BT_CTF_NOTIF_ITER_STATUS_EOF:
		return "BT_CTF_NOTIF_ITER_STATUS_EOF";
	case BT_CTF_NOTIF_ITER_STATUS_AGAIN:
		return "BT_CTF_NOTIF_ITER_STATUS_AGAIN";
	case BT_CTF_NOTIF_ITER_STATUS_INVAL:
		return "BT_CTF_NOTIF_ITER_STATUS_INVAL";
	case BT_CTF_NOTIF_ITER_STATUS_ERROR:
		return "BT_CTF_NOTIF_ITER_STATUS_ERROR";
	case BT_CTF_NOTIF_ITER_STATUS_OK:
		return "BT_CTF_NOTIF_ITER_STATUS_OK";
	default:
		return "(unknown)";
	}
}

#endif /* CTF_NOTIF_ITER_H */
Commit	Line	Data
e98a2d6e PP	1	#ifndef CTF_NOTIF_ITER_H
	2	#define CTF_NOTIF_ITER_H
	3
	4	/*
	5	* Babeltrace - CTF notification iterator
	6	* ¯¯¯¯¯ ¯¯¯¯
	7	* Copyright (c) 2015-2016 EfficiOS Inc. and Linux Foundation
	8	* Copyright (c) 2015-2016 Philippe Proulx <pproulx@efficios.com>
	9	*
	10	* Permission is hereby granted, free of charge, to any person obtaining a copy
	11	* of this software and associated documentation files (the "Software"), to deal
	12	* in the Software without restriction, including without limitation the rights
	13	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	14	* copies of the Software, and to permit persons to whom the Software is
	15	* furnished to do so, subject to the following conditions:
	16	*
	17	* The above copyright notice and this permission notice shall be included in
	18	* all copies or substantial portions of the Software.
	19	*
	20	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	21	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	22	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	23	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	24	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	25	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	26	* SOFTWARE.
	27	*/
	28
	29	#include <stdint.h>
	30	#include <stdio.h>
	31	#include <stddef.h>
	32	#include <babeltrace/ctf-ir/trace.h>
	33	#include <babeltrace/ctf-ir/fields.h>
	34	#include <babeltrace/ctf-ir/event.h>
599faa1c	35	#include <babeltrace/graph/clock-class-priority-map.h>
e98a2d6e PP	36	#include <babeltrace/babeltrace-internal.h>
	37
	38	/**
	39	* @file ctf-notif-iter.h
	40	*
	41	* CTF notification iterator
	42	* ¯¯¯¯¯ ¯¯¯¯
	43	* This is a common internal API used by CTF source plugins. It allows
	44	* one to get notifications from a user-provided medium.
	45	*/
	46
	47	/**
	48	* Medium operations status codes.
	49	*/
	50	enum bt_ctf_notif_iter_medium_status {
	51	/**
	52	* End of file.
	53	*
	54	* The medium function called by the notification iterator
	55	* function reached the end of the file.
	56	*/
9e0c8dbb	57	BT_CTF_NOTIF_ITER_MEDIUM_STATUS_EOF = 1,
e98a2d6e PP	58
	59	/**
	60	* There is no data available right now, try again later.
	61	*/
9e0c8dbb JG	62	BT_CTF_NOTIF_ITER_MEDIUM_STATUS_AGAIN = 11,
	63
	64	/** Unsupported operation. */
	65	BT_CTF_NOTIF_ITER_MEDIUM_STATUS_UNSUPPORTED = -3,
e98a2d6e PP	66
e98a2d6e PP	67	/** Invalid argument. */
9e0c8dbb	68	BT_CTF_NOTIF_ITER_MEDIUM_STATUS_INVAL = -2,
e98a2d6e PP	69
e98a2d6e PP	70	/** General error. */
9e0c8dbb	71	BT_CTF_NOTIF_ITER_MEDIUM_STATUS_ERROR = -1,
e98a2d6e PP	72
e98a2d6e PP	73	/** Everything okay. */
9e0c8dbb	74	BT_CTF_NOTIF_ITER_MEDIUM_STATUS_OK = 0,
e98a2d6e PP	75	};
	76
	77	/**
	78	* CTF notification iterator API status code.
	79	*/
	80	enum bt_ctf_notif_iter_status {
	81	/**
	82	* End of file.
	83	*
	84	* The medium function called by the notification iterator
	85	* function reached the end of the file.
	86	*/
dc77b521	87	BT_CTF_NOTIF_ITER_STATUS_EOF = BT_CTF_NOTIF_ITER_MEDIUM_STATUS_EOF,
e98a2d6e PP	88
	89	/**
	90	* There is no data available right now, try again later.
	91	*
	92	* Some condition resulted in the
	93	* bt_ctf_notif_iter_medium_ops::request_bytes() user function not
	94	* having access to any data now. You should retry calling the
	95	* last called notification iterator function once the situation
	96	* is resolved.
	97	*/
dc77b521	98	BT_CTF_NOTIF_ITER_STATUS_AGAIN = BT_CTF_NOTIF_ITER_MEDIUM_STATUS_AGAIN,
e98a2d6e PP	99
e98a2d6e PP	100	/** Invalid argument. */
dc77b521	101	BT_CTF_NOTIF_ITER_STATUS_INVAL = BT_CTF_NOTIF_ITER_MEDIUM_STATUS_INVAL,
e98a2d6e	102
9e0c8dbb JG	103	/** Unsupported operation. */
	104	BT_CTF_NOTIF_ITER_STATUS_UNSUPPORTED = BT_CTF_NOTIF_ITER_MEDIUM_STATUS_UNSUPPORTED,
	105
e98a2d6e	106	/** General error. */
dc77b521	107	BT_CTF_NOTIF_ITER_STATUS_ERROR = BT_CTF_NOTIF_ITER_MEDIUM_STATUS_ERROR,
e98a2d6e PP	108
	109	/** Everything okay. */
	110	BT_CTF_NOTIF_ITER_STATUS_OK = 0,
	111	};
	112
9e0c8dbb JG	113	/**
	114	* CTF notification iterator seek operation directives.
	115	*/
	116	enum bt_ctf_notif_iter_seek_whence {
	117	/**
	118	* Set the iterator's position to an absolute offset in the underlying
	119	* medium.
	120	*/
	121	BT_CTF_NOTIF_ITER_SEEK_WHENCE_SET,
	122	};
	123
e98a2d6e PP	124	/**
	125	* Medium operations.
	126	*
	127	* Those user functions are called by the notification iterator
	128	* functions to request medium actions.
	129	*/
	130	struct bt_ctf_notif_iter_medium_ops {
	131	/**
	132	* Returns the next byte buffer to be used by the binary file
	133	* reader to deserialize binary data.
	134	*
	135	* This function \em must be defined.
	136	*
	137	* The purpose of this function is to return a buffer of bytes
	138	* to the notification iterator, of a maximum of \p request_sz
	139	* bytes. If this function cannot return a buffer of at least
	140	* \p request_sz bytes, it may return a smaller buffer. In
	141	* either cases, \p buffer_sz must be set to the returned buffer
	142	* size (in bytes).
	143	*
	144	* The returned buffer's ownership remains the medium, in that
	145	* it won't be freed by the notification iterator functions. The
	146	* returned buffer won't be modified by the notification
	147	* iterator functions either.
	148	*
	149	* When this function is called for the first time for a given
	150	* file, the offset within the file is considered to be 0. The
	151	* next times this function is called, the returned buffer's
	152	* byte offset within the complete file must be the previous
	153	* offset plus the last returned value of \p buffer_sz by this
	154	* medium.
	155	*
	156	* This function must return one of the following statuses:
	157	*
	158	* - <b>#BT_CTF_NOTIF_ITER_MEDIUM_STATUS_OK</b>: Everything
	159	* is okay, i.e. \p buffer_sz is set to a positive value
	160	* reflecting the number of available bytes in the buffer
	161	* starting at the address written in \p buffer_addr.
	162	* - <b>#BT_CTF_NOTIF_ITER_MEDIUM_STATUS_AGAIN</b>: No data is
	163	* available right now. In this case, the notification
	164	* iterator function called by the user returns
	165	* #BT_CTF_NOTIF_ITER_STATUS_AGAIN, and it is the user's
	166	* responsibility to make sure enough data becomes available
	167	* before calling the \em same notification iterator
	168	* function again to continue the decoding process.
	169	* - <b>#BT_CTF_NOTIF_ITER_MEDIUM_STATUS_EOF</b>: The end of
	170	* the file was reached, and no more data will ever be
	171	* available for this file. In this case, the notification
	172	* iterator function called by the user returns
	173	* #BT_CTF_NOTIF_ITER_STATUS_EOF. This must \em not be
	174	* returned when returning at least one byte of data to the
	175	* caller, i.e. this must be returned when there's
	176	* absolutely nothing left; should the request size be
	177	* larger than what's left in the file, this function must
	178	* return what's left, setting \p buffer_sz to the number of
	179	* remaining bytes, and return
	180	* #BT_CTF_NOTIF_ITER_MEDIUM_STATUS_EOF on the \em following
	181	* call.
	182	* - <b>#BT_CTF_NOTIF_ITER_MEDIUM_STATUS_ERROR</b>: A fatal
	183	* error occured during this operation. In this case, the
	184	* notification iterator function called by the user returns
	185	* #BT_CTF_NOTIF_ITER_STATUS_ERROR.
	186	*
	187	* If #BT_CTF_NOTIF_ITER_MEDIUM_STATUS_OK is not returned, the
188	* values of \p buffer_sz and \p buffer_addr are \em ignored by
189	* the caller.
190	*
191	* @param request_sz Requested buffer size (bytes)
192	* @param buffer_addr Returned buffer address
193	* @param buffer_sz Returned buffer's size (bytes)
194	* @param data User data
195	* @returns Status code (see description above)
196	*/
197	enum bt_ctf_notif_iter_medium_status (* request_bytes)(
198	size_t request_sz, uint8_t **buffer_addr,
199	size_t buffer_sz, void data);
200
9e0c8dbb JG	201	/**
	202	* Repositions the underlying stream's position.
	203	*
	204	* This optional method repositions the underlying stream
	205	* to a given absolute or relative position, as indicated by
	206	* the whence directive.
	207	*
	208	* @param whence One of #bt_ctf_notif_iter_seek_whence values
	209	* @param offset Offset to use for the given directive
	210	* @param data User data
	211	* @returns One of #bt_ctf_notif_iter_medium_status values
	212	*/
	213	enum bt_ctf_notif_iter_medium_status (* seek)(
	214	enum bt_ctf_notif_iter_seek_whence whence,
	215	off_t offset, void *data);
	216
e98a2d6e PP	217	/**
	218	* Returns a stream instance (weak reference) for the given
	219	* stream class.
	220	*
	221	* This is called after a packet header is read, and the
	222	* corresponding stream class is found by the notification
	223	* iterator.
	224	*
b92735af PP	225	* @param stream_class Stream class of the stream to get
	226	* @param stream_id Stream (instance) ID of the stream
	227	* to get (-1ULL if not available)
e98a2d6e PP	228	* @param data User data
	229	* @returns Stream instance (weak reference) or
	230	* \c NULL on error
	231	*/
	232	struct bt_ctf_stream * (* get_stream)(
b92735af PP	233	struct bt_ctf_stream_class *stream_class,
b92735af PP	234	uint64_t stream_id, void *data);
e98a2d6e PP	235	};
	236
	237	/** CTF notification iterator. */
	238	struct bt_ctf_notif_iter;
	239
	240	// TODO: Replace by the real thing
	241	enum bt_ctf_notif_iter_notif_type {
	242	BT_CTF_NOTIF_ITER_NOTIF_NEW_PACKET,
	243	BT_CTF_NOTIF_ITER_NOTIF_END_OF_PACKET,
	244	BT_CTF_NOTIF_ITER_NOTIF_EVENT,
	245	};
	246
	247	struct bt_ctf_notif_iter_notif {
	248	enum bt_ctf_notif_iter_notif_type type;
	249	};
	250
	251	struct bt_ctf_notif_iter_notif_new_packet {
	252	struct bt_ctf_notif_iter_notif base;
	253	struct bt_ctf_packet *packet;
	254	};
	255
	256	struct bt_ctf_notif_iter_notif_end_of_packet {
	257	struct bt_ctf_notif_iter_notif base;
	258	struct bt_ctf_packet *packet;
	259	};
	260
	261	struct bt_ctf_notif_iter_notif_event {
	262	struct bt_ctf_notif_iter_notif base;
	263	struct bt_ctf_event *event;
	264	};
	265
e98a2d6e PP	266	/**
	267	* Creates a CTF notification iterator.
	268	*
	269	* Upon successful completion, the reference count of \p trace is
	270	* incremented.
	271	*
	272	* @param trace Trace to read
	273	* @param max_request_sz Maximum buffer size, in bytes, to
	274	* request to
	275	* bt_ctf_notif_iter_medium_ops::request_bytes()
	276	* at a time
	277	* @param medops Medium operations
	278	* @param medops_data User data (passed to medium operations)
e98a2d6e PP	279	* @returns New CTF notification iterator on
	280	* success, or \c NULL on error
	281	*/
2cf1d51e	282	BT_HIDDEN
e98a2d6e PP	283	struct bt_ctf_notif_iter bt_ctf_notif_iter_create(struct bt_ctf_trace trace,
e98a2d6e PP	284	size_t max_request_sz, struct bt_ctf_notif_iter_medium_ops medops,
55314f2a	285	void *medops_data);
e98a2d6e PP	286
	287	/**
	288	* Destroys a CTF notification iterator, freeing all internal resources.
	289	*
	290	* The registered trace's reference count is decremented.
	291	*
	292	* @param notif_iter CTF notification iterator
	293	*/
2cf1d51e	294	BT_HIDDEN
e98a2d6e PP	295	void bt_ctf_notif_iter_destroy(struct bt_ctf_notif_iter *notif_iter);
e98a2d6e PP	296
e98a2d6e PP	297	/**
	298	* Returns the next notification from a CTF notification iterator.
	299	*
	300	* Upon successful completion, #BT_CTF_NOTIF_ITER_STATUS_OK is
	301	* returned, and the next notification is written to \p notif.
	302	* In this case, the caller is responsible for calling
	303	* bt_notification_put() on the returned notification.
	304	*
	305	* If this function returns #BT_CTF_NOTIF_ITER_STATUS_AGAIN, the caller
	306	* should make sure that data becomes available to its medium, and
	307	* call this function again, until another status is returned.
	308	*
	309	* @param notif_iter CTF notification iterator
0982a26d PP	310	* @param cc_prio_map Clock class priority map to use when
0982a26d PP	311	* creating an event notification
e98a2d6e PP	312	* @param notification Returned notification if the function's
	313	* return value is #BT_CTF_NOTIF_ITER_STATUS_OK
	314	* @returns One of #bt_ctf_notif_iter_status values
	315	*/
2cf1d51e	316	BT_HIDDEN
e98a2d6e	317	enum bt_ctf_notif_iter_status bt_ctf_notif_iter_get_next_notification(
78586d8a	318	struct bt_ctf_notif_iter *notit,
0982a26d	319	struct bt_clock_class_priority_map *cc_prio_map,
78586d8a	320	struct bt_notification **notification);
e98a2d6e	321
87187cbf PP	322	/**
	323	* Returns the first packet header and context fields. This function
	324	* never needs to call the `get_stream()` medium operation because
	325	* it does not create packet or event objects.
	326	*
	327	* @param notif_iter CTF notification iterator
	328	* @param packet_header_field Packet header field (\c NULL if there's
	329	* no packet header field)
	330	* @param packet_context_field Packet context field (\c NULL if there's
	331	* no packet context field)
	332	* @returns One of #bt_ctf_notif_iter_status values
	333	*/
	334	BT_HIDDEN
	335	enum bt_ctf_notif_iter_status bt_ctf_notif_iter_get_packet_header_context_fields(
	336	struct bt_ctf_notif_iter *notit,
	337	struct bt_ctf_field **packet_header_field,
	338	struct bt_ctf_field **packet_context_field);
	339
6de92955 PP	340	BT_HIDDEN
	341	void bt_ctf_notif_iter_set_medops_data(struct bt_ctf_notif_iter *notit,
	342	void *medops_data);
	343
9e0c8dbb JG	344	BT_HIDDEN
	345	enum bt_ctf_notif_iter_status bt_ctf_notif_iter_seek(
	346	struct bt_ctf_notif_iter *notit, off_t offset);
	347
	348	/*
	349	* Get the current packet's offset in bytes relative to the media's initial
	350	* position.
	351	*/
	352	BT_HIDDEN
	353	off_t bt_ctf_notif_iter_get_current_packet_offset(
	354	struct bt_ctf_notif_iter *notit);
	355
	356	/* Get the current packet's size (in bits). */
	357	BT_HIDDEN
	358	off_t bt_ctf_notif_iter_get_current_packet_size(
	359	struct bt_ctf_notif_iter *notit);
	360
fdf0e7a0 PP	361	static inline
	362	const char *bt_ctf_notif_iter_medium_status_string(
	363	enum bt_ctf_notif_iter_medium_status status)
	364	{
	365	switch (status) {
	366	case BT_CTF_NOTIF_ITER_MEDIUM_STATUS_EOF:
	367	return "BT_CTF_NOTIF_ITER_MEDIUM_STATUS_EOF";
	368	case BT_CTF_NOTIF_ITER_MEDIUM_STATUS_AGAIN:
	369	return "BT_CTF_NOTIF_ITER_MEDIUM_STATUS_AGAIN";
	370	case BT_CTF_NOTIF_ITER_MEDIUM_STATUS_INVAL:
	371	return "BT_CTF_NOTIF_ITER_MEDIUM_STATUS_INVAL";
	372	case BT_CTF_NOTIF_ITER_MEDIUM_STATUS_ERROR:
	373	return "BT_CTF_NOTIF_ITER_MEDIUM_STATUS_ERROR";
	374	case BT_CTF_NOTIF_ITER_MEDIUM_STATUS_OK:
	375	return "BT_CTF_NOTIF_ITER_MEDIUM_STATUS_OK";
	376	default:
	377	return "(unknown)";
	378	}
	379	}
	380
	381	static inline
	382	const char *bt_ctf_notif_iter_status_string(
	383	enum bt_ctf_notif_iter_status status)
	384	{
	385	switch (status) {
	386	case BT_CTF_NOTIF_ITER_STATUS_EOF:
	387	return "BT_CTF_NOTIF_ITER_STATUS_EOF";
	388	case BT_CTF_NOTIF_ITER_STATUS_AGAIN:
	389	return "BT_CTF_NOTIF_ITER_STATUS_AGAIN";
	390	case BT_CTF_NOTIF_ITER_STATUS_INVAL:
	391	return "BT_CTF_NOTIF_ITER_STATUS_INVAL";
	392	case BT_CTF_NOTIF_ITER_STATUS_ERROR:
	393	return "BT_CTF_NOTIF_ITER_STATUS_ERROR";
	394	case BT_CTF_NOTIF_ITER_STATUS_OK:
	395	return "BT_CTF_NOTIF_ITER_STATUS_OK";
	396	default:
	397	return "(unknown)";
	398	}
	399	}
	400
e98a2d6e	401	#endif /* CTF_NOTIF_ITER_H */