[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/babeltrace.h>
#include <babeltrace/babeltrace-internal.h>

#include "../metadata/ctf-meta.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_notif_iter_medium_status {
	/**
	 * End of file.
	 *
	 * The medium function called by the notification iterator
	 * function reached the end of the file.
	 */
	BT_NOTIF_ITER_MEDIUM_STATUS_EOF = 1,

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

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

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

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

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

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

	/**
	 * There is no data available right now, try again later.
	 *
	 * Some condition resulted in the
	 * bt_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_NOTIF_ITER_STATUS_AGAIN = BT_NOTIF_ITER_MEDIUM_STATUS_AGAIN,

	/** Invalid argument. */
	BT_NOTIF_ITER_STATUS_INVAL = BT_NOTIF_ITER_MEDIUM_STATUS_INVAL,

	/** Unsupported operation. */
	BT_NOTIF_ITER_STATUS_UNSUPPORTED = BT_NOTIF_ITER_MEDIUM_STATUS_UNSUPPORTED,

	/** General error. */
	BT_NOTIF_ITER_STATUS_ERROR = BT_NOTIF_ITER_MEDIUM_STATUS_ERROR,

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

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

/**
 * Medium operations.
 *
 * Those user functions are called by the notification iterator
 * functions to request medium actions.
 */
struct bt_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_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_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_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_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_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_NOTIF_ITER_MEDIUM_STATUS_EOF on the \em following
	 *     call.
	 *   - <b>#BT_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_NOTIF_ITER_STATUS_ERROR.
	 *
	 * If #BT_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_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_notif_iter_seek_whence values
	 * @param offset	Offset to use for the given directive
	 * @param data		User data
	 * @returns		One of #bt_notif_iter_medium_status values
	 */
	enum bt_notif_iter_medium_status (* seek)(
			enum bt_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_stream * (* borrow_stream)(
			struct bt_stream_class *stream_class,
			int64_t stream_id, void *data);
};

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

/**
 * 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_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_notif_iter *bt_notif_iter_create(struct ctf_trace_class *tc,
	size_t max_request_sz, struct bt_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_notif_iter_destroy(struct bt_notif_iter *notif_iter);

/**
 * Returns the next notification from a CTF notification iterator.
 *
 * Upon successful completion, #BT_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_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 notification		Returned notification if the function's
 *				return value is #BT_NOTIF_ITER_STATUS_OK
 * @returns			One of #bt_notif_iter_status values
 */
BT_HIDDEN
enum bt_notif_iter_status bt_notif_iter_get_next_notification(
		struct bt_notif_iter *notit,
		struct bt_self_notification_iterator *notif_iter,
		struct bt_notification **notification);

/**
 * Returns the first packet header and context fields. This function
 * never needs to call the `borrow_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_notif_iter_status values
 */
BT_HIDDEN
enum bt_notif_iter_status bt_notif_iter_borrow_packet_header_context_fields(
		struct bt_notif_iter *notit,
		struct bt_field **packet_header_field,
		struct bt_field **packet_context_field);

struct bt_notif_iter_packet_properties {
	uint64_t exp_packet_total_size;
	uint64_t exp_packet_content_size;
	uint64_t stream_class_id;
	int64_t data_stream_id;

	struct {
		uint64_t discarded_events;
		uint64_t packets;
		uint64_t beginning_clock;
		uint64_t end_clock;
	} snapshots;
};

BT_HIDDEN
enum bt_notif_iter_status bt_notif_iter_get_packet_properties(
		struct bt_notif_iter *notit,
		struct bt_notif_iter_packet_properties *props);

BT_HIDDEN
void bt_notif_iter_set_medops_data(struct bt_notif_iter *notit,
		void *medops_data);

BT_HIDDEN
enum bt_notif_iter_status bt_notif_iter_seek(
		struct bt_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_notif_iter_get_current_packet_offset(
		struct bt_notif_iter *notit);

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

/*
 * Resets the iterator so that the next requested medium bytes are
 * assumed to be the first bytes of a new stream. The first notification
 * which this iterator emits after calling bt_notif_iter_reset() is a
 * BT_NOTIFICATION_TYPE_STREAM_BEGINNING one.
 */
BT_HIDDEN
void bt_notif_iter_reset(struct bt_notif_iter *notit);

/*
 * Notify the iterator that the trace class changed somehow (new
 * stream/event classes).
 */
BT_HIDDEN
void bt_notif_trace_class_changed(struct bt_notif_iter *notit);

static inline
const char *bt_notif_iter_medium_status_string(
		enum bt_notif_iter_medium_status status)
{
	switch (status) {
	case BT_NOTIF_ITER_MEDIUM_STATUS_EOF:
		return "BT_NOTIF_ITER_MEDIUM_STATUS_EOF";
	case BT_NOTIF_ITER_MEDIUM_STATUS_AGAIN:
		return "BT_NOTIF_ITER_MEDIUM_STATUS_AGAIN";
	case BT_NOTIF_ITER_MEDIUM_STATUS_INVAL:
		return "BT_NOTIF_ITER_MEDIUM_STATUS_INVAL";
	case BT_NOTIF_ITER_MEDIUM_STATUS_ERROR:
		return "BT_NOTIF_ITER_MEDIUM_STATUS_ERROR";
	case BT_NOTIF_ITER_MEDIUM_STATUS_OK:
		return "BT_NOTIF_ITER_MEDIUM_STATUS_OK";
	default:
		return "(unknown)";
	}
}

static inline
const char *bt_notif_iter_status_string(
		enum bt_notif_iter_status status)
{
	switch (status) {
	case BT_NOTIF_ITER_STATUS_EOF:
		return "BT_NOTIF_ITER_STATUS_EOF";
	case BT_NOTIF_ITER_STATUS_AGAIN:
		return "BT_NOTIF_ITER_STATUS_AGAIN";
	case BT_NOTIF_ITER_STATUS_INVAL:
		return "BT_NOTIF_ITER_STATUS_INVAL";
	case BT_NOTIF_ITER_STATUS_ERROR:
		return "BT_NOTIF_ITER_STATUS_ERROR";
	case BT_NOTIF_ITER_STATUS_OK:
		return "BT_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>
9d408fca	32	#include <babeltrace/babeltrace.h>
e98a2d6e PP	33	#include <babeltrace/babeltrace-internal.h>
e98a2d6e PP	34
44c440bc PP	35	#include "../metadata/ctf-meta.h"
44c440bc PP	36
e98a2d6e PP	37	/**
	38	* @file ctf-notif-iter.h
	39	*
	40	* CTF notification iterator
	41	* ¯¯¯¯¯ ¯¯¯¯
	42	* This is a common internal API used by CTF source plugins. It allows
	43	* one to get notifications from a user-provided medium.
	44	*/
	45
	46	/**
	47	* Medium operations status codes.
	48	*/
50842bdc	49	enum bt_notif_iter_medium_status {
e98a2d6e PP	50	/**
	51	* End of file.
	52	*
	53	* The medium function called by the notification iterator
	54	* function reached the end of the file.
	55	*/
50842bdc	56	BT_NOTIF_ITER_MEDIUM_STATUS_EOF = 1,
e98a2d6e PP	57
	58	/**
	59	* There is no data available right now, try again later.
	60	*/
50842bdc	61	BT_NOTIF_ITER_MEDIUM_STATUS_AGAIN = 11,
9e0c8dbb JG	62
9e0c8dbb JG	63	/** Unsupported operation. */
50842bdc	64	BT_NOTIF_ITER_MEDIUM_STATUS_UNSUPPORTED = -3,
e98a2d6e PP	65
e98a2d6e PP	66	/** Invalid argument. */
50842bdc	67	BT_NOTIF_ITER_MEDIUM_STATUS_INVAL = -2,
e98a2d6e PP	68
e98a2d6e PP	69	/** General error. */
50842bdc	70	BT_NOTIF_ITER_MEDIUM_STATUS_ERROR = -1,
e98a2d6e PP	71
e98a2d6e PP	72	/** Everything okay. */
50842bdc	73	BT_NOTIF_ITER_MEDIUM_STATUS_OK = 0,
e98a2d6e PP	74	};
	75
	76	/**
	77	* CTF notification iterator API status code.
	78	*/
50842bdc	79	enum bt_notif_iter_status {
e98a2d6e PP	80	/**
	81	* End of file.
	82	*
	83	* The medium function called by the notification iterator
	84	* function reached the end of the file.
	85	*/
50842bdc	86	BT_NOTIF_ITER_STATUS_EOF = BT_NOTIF_ITER_MEDIUM_STATUS_EOF,
e98a2d6e PP	87
	88	/**
	89	* There is no data available right now, try again later.
	90	*
	91	* Some condition resulted in the
50842bdc	92	* bt_notif_iter_medium_ops::request_bytes() user function not
e98a2d6e PP	93	* having access to any data now. You should retry calling the
	94	* last called notification iterator function once the situation
	95	* is resolved.
	96	*/
50842bdc	97	BT_NOTIF_ITER_STATUS_AGAIN = BT_NOTIF_ITER_MEDIUM_STATUS_AGAIN,
e98a2d6e PP	98
e98a2d6e PP	99	/** Invalid argument. */
50842bdc	100	BT_NOTIF_ITER_STATUS_INVAL = BT_NOTIF_ITER_MEDIUM_STATUS_INVAL,
e98a2d6e	101
9e0c8dbb	102	/** Unsupported operation. */
50842bdc	103	BT_NOTIF_ITER_STATUS_UNSUPPORTED = BT_NOTIF_ITER_MEDIUM_STATUS_UNSUPPORTED,
9e0c8dbb	104
e98a2d6e	105	/** General error. */
50842bdc	106	BT_NOTIF_ITER_STATUS_ERROR = BT_NOTIF_ITER_MEDIUM_STATUS_ERROR,
e98a2d6e PP	107
e98a2d6e PP	108	/** Everything okay. */
50842bdc	109	BT_NOTIF_ITER_STATUS_OK = 0,
e98a2d6e PP	110	};
e98a2d6e PP	111
9e0c8dbb JG	112	/**
	113	* CTF notification iterator seek operation directives.
	114	*/
50842bdc	115	enum bt_notif_iter_seek_whence {
9e0c8dbb JG	116	/**
	117	* Set the iterator's position to an absolute offset in the underlying
	118	* medium.
	119	*/
50842bdc	120	BT_NOTIF_ITER_SEEK_WHENCE_SET,
9e0c8dbb JG	121	};
9e0c8dbb JG	122
e98a2d6e PP	123	/**
	124	* Medium operations.
	125	*
	126	* Those user functions are called by the notification iterator
	127	* functions to request medium actions.
	128	*/
50842bdc	129	struct bt_notif_iter_medium_ops {
e98a2d6e PP	130	/**
	131	* Returns the next byte buffer to be used by the binary file
	132	* reader to deserialize binary data.
	133	*
	134	* This function \em must be defined.
	135	*
	136	* The purpose of this function is to return a buffer of bytes
	137	* to the notification iterator, of a maximum of \p request_sz
	138	* bytes. If this function cannot return a buffer of at least
	139	* \p request_sz bytes, it may return a smaller buffer. In
	140	* either cases, \p buffer_sz must be set to the returned buffer
	141	* size (in bytes).
	142	*
	143	* The returned buffer's ownership remains the medium, in that
	144	* it won't be freed by the notification iterator functions. The
	145	* returned buffer won't be modified by the notification
	146	* iterator functions either.
	147	*
	148	* When this function is called for the first time for a given
	149	* file, the offset within the file is considered to be 0. The
	150	* next times this function is called, the returned buffer's
	151	* byte offset within the complete file must be the previous
	152	* offset plus the last returned value of \p buffer_sz by this
	153	* medium.
	154	*
	155	* This function must return one of the following statuses:
	156	*
50842bdc	157	* - <b>#BT_NOTIF_ITER_MEDIUM_STATUS_OK</b>: Everything
e98a2d6e PP	158	* is okay, i.e. \p buffer_sz is set to a positive value
	159	* reflecting the number of available bytes in the buffer
	160	* starting at the address written in \p buffer_addr.
50842bdc	161	* - <b>#BT_NOTIF_ITER_MEDIUM_STATUS_AGAIN</b>: No data is
e98a2d6e PP	162	* available right now. In this case, the notification
e98a2d6e PP	163	* iterator function called by the user returns
50842bdc	164	* #BT_NOTIF_ITER_STATUS_AGAIN, and it is the user's
e98a2d6e PP	165	* responsibility to make sure enough data becomes available
	166	* before calling the \em same notification iterator
	167	* function again to continue the decoding process.
50842bdc	168	* - <b>#BT_NOTIF_ITER_MEDIUM_STATUS_EOF</b>: The end of
e98a2d6e PP	169	* the file was reached, and no more data will ever be
	170	* available for this file. In this case, the notification
	171	* iterator function called by the user returns
50842bdc	172	* #BT_NOTIF_ITER_STATUS_EOF. This must \em not be
e98a2d6e PP	173	* returned when returning at least one byte of data to the
	174	* caller, i.e. this must be returned when there's
	175	* absolutely nothing left; should the request size be
	176	* larger than what's left in the file, this function must
	177	* return what's left, setting \p buffer_sz to the number of
	178	* remaining bytes, and return
50842bdc	179	* #BT_NOTIF_ITER_MEDIUM_STATUS_EOF on the \em following
e98a2d6e	180	* call.
50842bdc	181	* - <b>#BT_NOTIF_ITER_MEDIUM_STATUS_ERROR</b>: A fatal
e98a2d6e PP	182	* error occured during this operation. In this case, the
e98a2d6e PP	183	* notification iterator function called by the user returns
50842bdc	184	* #BT_NOTIF_ITER_STATUS_ERROR.
e98a2d6e	185	*
50842bdc	186	* If #BT_NOTIF_ITER_MEDIUM_STATUS_OK is not returned, the
e98a2d6e PP	187	* values of \p buffer_sz and \p buffer_addr are \em ignored by
	188	* the caller.
	189	*
	190	* @param request_sz Requested buffer size (bytes)
	191	* @param buffer_addr Returned buffer address
	192	* @param buffer_sz Returned buffer's size (bytes)
	193	* @param data User data
	194	* @returns Status code (see description above)
	195	*/
50842bdc	196	enum bt_notif_iter_medium_status (* request_bytes)(
e98a2d6e PP	197	size_t request_sz, uint8_t **buffer_addr,
	198	size_t buffer_sz, void data);
	199
9e0c8dbb JG	200	/**
	201	* Repositions the underlying stream's position.
	202	*
	203	* This optional method repositions the underlying stream
	204	* to a given absolute or relative position, as indicated by
	205	* the whence directive.
	206	*
50842bdc	207	* @param whence One of #bt_notif_iter_seek_whence values
9e0c8dbb JG	208	* @param offset Offset to use for the given directive
9e0c8dbb JG	209	* @param data User data
50842bdc	210	* @returns One of #bt_notif_iter_medium_status values
9e0c8dbb	211	*/
50842bdc PP	212	enum bt_notif_iter_medium_status (* seek)(
50842bdc PP	213	enum bt_notif_iter_seek_whence whence,
9e0c8dbb JG	214	off_t offset, void *data);
9e0c8dbb JG	215
e98a2d6e PP	216	/**
	217	* Returns a stream instance (weak reference) for the given
	218	* stream class.
	219	*
	220	* This is called after a packet header is read, and the
	221	* corresponding stream class is found by the notification
	222	* iterator.
	223	*
b92735af PP	224	* @param stream_class Stream class of the stream to get
	225	* @param stream_id Stream (instance) ID of the stream
	226	* to get (-1ULL if not available)
e98a2d6e PP	227	* @param data User data
	228	* @returns Stream instance (weak reference) or
	229	* \c NULL on error
	230	*/
40f4ba76 PP	231	struct bt_stream * (* borrow_stream)(
40f4ba76 PP	232	struct bt_stream_class *stream_class,
44c440bc	233	int64_t stream_id, void *data);
e98a2d6e PP	234	};
	235
	236	/** CTF notification iterator. */
50842bdc	237	struct bt_notif_iter;
e98a2d6e	238
e98a2d6e PP	239	/**
	240	* Creates a CTF notification iterator.
	241	*
	242	* Upon successful completion, the reference count of \p trace is
	243	* incremented.
	244	*
	245	* @param trace Trace to read
	246	* @param max_request_sz Maximum buffer size, in bytes, to
	247	* request to
50842bdc	248	* bt_notif_iter_medium_ops::request_bytes()
e98a2d6e PP	249	* at a time
	250	* @param medops Medium operations
	251	* @param medops_data User data (passed to medium operations)
e98a2d6e PP	252	* @returns New CTF notification iterator on
	253	* success, or \c NULL on error
	254	*/
2cf1d51e	255	BT_HIDDEN
44c440bc	256	struct bt_notif_iter bt_notif_iter_create(struct ctf_trace_class tc,
50842bdc	257	size_t max_request_sz, struct bt_notif_iter_medium_ops medops,
55314f2a	258	void *medops_data);
e98a2d6e PP	259
	260	/**
	261	* Destroys a CTF notification iterator, freeing all internal resources.
	262	*
	263	* The registered trace's reference count is decremented.
	264	*
	265	* @param notif_iter CTF notification iterator
	266	*/
2cf1d51e	267	BT_HIDDEN
50842bdc	268	void bt_notif_iter_destroy(struct bt_notif_iter *notif_iter);
e98a2d6e	269
e98a2d6e PP	270	/**
	271	* Returns the next notification from a CTF notification iterator.
	272	*
50842bdc	273	* Upon successful completion, #BT_NOTIF_ITER_STATUS_OK is
e98a2d6e PP	274	* returned, and the next notification is written to \p notif.
	275	* In this case, the caller is responsible for calling
	276	* bt_notification_put() on the returned notification.
	277	*
50842bdc	278	* If this function returns #BT_NOTIF_ITER_STATUS_AGAIN, the caller
e98a2d6e PP	279	* should make sure that data becomes available to its medium, and
	280	* call this function again, until another status is returned.
	281	*
	282	* @param notif_iter CTF notification iterator
	283	* @param notification Returned notification if the function's
50842bdc PP	284	* return value is #BT_NOTIF_ITER_STATUS_OK
50842bdc PP	285	* @returns One of #bt_notif_iter_status values
e98a2d6e	286	*/
2cf1d51e	287	BT_HIDDEN
50842bdc PP	288	enum bt_notif_iter_status bt_notif_iter_get_next_notification(
50842bdc PP	289	struct bt_notif_iter *notit,
d94d92ac	290	struct bt_self_notification_iterator *notif_iter,
0d72b8c3	291	struct bt_notification **notification);
e98a2d6e	292
87187cbf PP	293	/**
87187cbf PP	294	* Returns the first packet header and context fields. This function
312c056a	295	* never needs to call the `borrow_stream()` medium operation because
87187cbf PP	296	* it does not create packet or event objects.
	297	*
	298	* @param notif_iter CTF notification iterator
	299	* @param packet_header_field Packet header field (\c NULL if there's
	300	* no packet header field)
	301	* @param packet_context_field Packet context field (\c NULL if there's
	302	* no packet context field)
50842bdc	303	* @returns One of #bt_notif_iter_status values
87187cbf PP	304	*/
87187cbf PP	305	BT_HIDDEN
312c056a	306	enum bt_notif_iter_status bt_notif_iter_borrow_packet_header_context_fields(
50842bdc	307	struct bt_notif_iter *notit,
40f4ba76 PP	308	struct bt_field **packet_header_field,
40f4ba76 PP	309	struct bt_field **packet_context_field);
87187cbf	310
44c440bc PP	311	struct bt_notif_iter_packet_properties {
	312	uint64_t exp_packet_total_size;
	313	uint64_t exp_packet_content_size;
	314	uint64_t stream_class_id;
	315	int64_t data_stream_id;
	316
	317	struct {
	318	uint64_t discarded_events;
	319	uint64_t packets;
	320	uint64_t beginning_clock;
	321	uint64_t end_clock;
	322	} snapshots;
	323	};
	324
	325	BT_HIDDEN
	326	enum bt_notif_iter_status bt_notif_iter_get_packet_properties(
	327	struct bt_notif_iter *notit,
	328	struct bt_notif_iter_packet_properties *props);
	329
6de92955	330	BT_HIDDEN
50842bdc	331	void bt_notif_iter_set_medops_data(struct bt_notif_iter *notit,
6de92955 PP	332	void *medops_data);
6de92955 PP	333
9e0c8dbb	334	BT_HIDDEN
50842bdc PP	335	enum bt_notif_iter_status bt_notif_iter_seek(
50842bdc PP	336	struct bt_notif_iter *notit, off_t offset);
9e0c8dbb JG	337
	338	/*
	339	* Get the current packet's offset in bytes relative to the media's initial
	340	* position.
	341	*/
	342	BT_HIDDEN
50842bdc PP	343	off_t bt_notif_iter_get_current_packet_offset(
50842bdc PP	344	struct bt_notif_iter *notit);
9e0c8dbb JG	345
	346	/* Get the current packet's size (in bits). */
	347	BT_HIDDEN
50842bdc PP	348	off_t bt_notif_iter_get_current_packet_size(
50842bdc PP	349	struct bt_notif_iter *notit);
9e0c8dbb	350
f42867e2 PP	351	/*
	352	* Resets the iterator so that the next requested medium bytes are
	353	* assumed to be the first bytes of a new stream. The first notification
	354	* which this iterator emits after calling bt_notif_iter_reset() is a
bb5bb160	355	* BT_NOTIFICATION_TYPE_STREAM_BEGINNING one.
f42867e2 PP	356	*/
	357	BT_HIDDEN
	358	void bt_notif_iter_reset(struct bt_notif_iter *notit);
	359
44c440bc PP	360	/*
	361	* Notify the iterator that the trace class changed somehow (new
	362	* stream/event classes).
	363	*/
	364	BT_HIDDEN
	365	void bt_notif_trace_class_changed(struct bt_notif_iter *notit);
	366
fdf0e7a0	367	static inline
50842bdc PP	368	const char *bt_notif_iter_medium_status_string(
50842bdc PP	369	enum bt_notif_iter_medium_status status)
fdf0e7a0 PP	370	{
fdf0e7a0 PP	371	switch (status) {
50842bdc PP	372	case BT_NOTIF_ITER_MEDIUM_STATUS_EOF:
	373	return "BT_NOTIF_ITER_MEDIUM_STATUS_EOF";
	374	case BT_NOTIF_ITER_MEDIUM_STATUS_AGAIN:
	375	return "BT_NOTIF_ITER_MEDIUM_STATUS_AGAIN";
	376	case BT_NOTIF_ITER_MEDIUM_STATUS_INVAL:
	377	return "BT_NOTIF_ITER_MEDIUM_STATUS_INVAL";
	378	case BT_NOTIF_ITER_MEDIUM_STATUS_ERROR:
	379	return "BT_NOTIF_ITER_MEDIUM_STATUS_ERROR";
	380	case BT_NOTIF_ITER_MEDIUM_STATUS_OK:
	381	return "BT_NOTIF_ITER_MEDIUM_STATUS_OK";
fdf0e7a0 PP	382	default:
	383	return "(unknown)";
	384	}
	385	}
	386
	387	static inline
50842bdc PP	388	const char *bt_notif_iter_status_string(
50842bdc PP	389	enum bt_notif_iter_status status)
fdf0e7a0 PP	390	{
fdf0e7a0 PP	391	switch (status) {
50842bdc PP	392	case BT_NOTIF_ITER_STATUS_EOF:
	393	return "BT_NOTIF_ITER_STATUS_EOF";
	394	case BT_NOTIF_ITER_STATUS_AGAIN:
	395	return "BT_NOTIF_ITER_STATUS_AGAIN";
	396	case BT_NOTIF_ITER_STATUS_INVAL:
	397	return "BT_NOTIF_ITER_STATUS_INVAL";
	398	case BT_NOTIF_ITER_STATUS_ERROR:
	399	return "BT_NOTIF_ITER_STATUS_ERROR";
	400	case BT_NOTIF_ITER_STATUS_OK:
	401	return "BT_NOTIF_ITER_STATUS_OK";
fdf0e7a0 PP	402	default:
	403	return "(unknown)";
	404	}
	405	}
	406
e98a2d6e	407	#endif /* CTF_NOTIF_ITER_H */