5 * Babeltrace - CTF message iterator
7 * Copyright (c) 2015-2016 EfficiOS Inc. and Linux Foundation
8 * Copyright (c) 2015-2016 Philippe Proulx <pproulx@efficios.com>
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:
17 * The above copyright notice and this permission notice shall be included in
18 * all copies or substantial portions of the Software.
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
33 #include <babeltrace2/babeltrace.h>
34 #include "common/macros.h"
36 #include "../metadata/ctf-meta.h"
39 * @file ctf-msg-iter.h
41 * CTF message iterator
43 * This is a common internal API used by CTF source plugins. It allows
44 * one to get messages from a user-provided medium.
48 * Medium operations status codes.
50 enum ctf_msg_iter_medium_status
{
54 * The medium function called by the message iterator
55 * function reached the end of the file.
57 CTF_MSG_ITER_MEDIUM_STATUS_EOF
= 1,
60 * There is no data available right now, try again later.
62 CTF_MSG_ITER_MEDIUM_STATUS_AGAIN
= 11,
64 /** Unsupported operation. */
65 CTF_MSG_ITER_MEDIUM_STATUS_UNSUPPORTED
= -3,
67 /** Invalid argument. */
68 CTF_MSG_ITER_MEDIUM_STATUS_INVAL
= -2,
71 CTF_MSG_ITER_MEDIUM_STATUS_ERROR
= -1,
73 /** Everything okay. */
74 CTF_MSG_ITER_MEDIUM_STATUS_OK
= 0,
78 * CTF message iterator API status code.
80 enum ctf_msg_iter_status
{
84 * The medium function called by the message iterator
85 * function reached the end of the file.
87 CTF_MSG_ITER_STATUS_EOF
= CTF_MSG_ITER_MEDIUM_STATUS_EOF
,
90 * There is no data available right now, try again later.
92 * Some condition resulted in the
93 * ctf_msg_iter_medium_ops::request_bytes() user function not
94 * having access to any data now. You should retry calling the
95 * last called message iterator function once the situation
98 CTF_MSG_ITER_STATUS_AGAIN
= CTF_MSG_ITER_MEDIUM_STATUS_AGAIN
,
100 /** Invalid argument. */
101 CTF_MSG_ITER_STATUS_INVAL
= CTF_MSG_ITER_MEDIUM_STATUS_INVAL
,
103 /** Unsupported operation. */
104 CTF_MSG_ITER_STATUS_UNSUPPORTED
= CTF_MSG_ITER_MEDIUM_STATUS_UNSUPPORTED
,
106 /** General error. */
107 CTF_MSG_ITER_STATUS_ERROR
= CTF_MSG_ITER_MEDIUM_STATUS_ERROR
,
109 /** Everything okay. */
110 CTF_MSG_ITER_STATUS_OK
= CTF_MSG_ITER_MEDIUM_STATUS_OK
,
116 * Those user functions are called by the message iterator
117 * functions to request medium actions.
119 struct ctf_msg_iter_medium_ops
{
121 * Returns the next byte buffer to be used by the binary file
122 * reader to deserialize binary data.
124 * This function \em must be defined.
126 * The purpose of this function is to return a buffer of bytes
127 * to the message iterator, of a maximum of \p request_sz
128 * bytes. If this function cannot return a buffer of at least
129 * \p request_sz bytes, it may return a smaller buffer. In
130 * either cases, \p buffer_sz must be set to the returned buffer
133 * The returned buffer's ownership remains the medium, in that
134 * it won't be freed by the message iterator functions. The
135 * returned buffer won't be modified by the message
136 * iterator functions either.
138 * When this function is called for the first time for a given
139 * file, the offset within the file is considered to be 0. The
140 * next times this function is called, the returned buffer's
141 * byte offset within the complete file must be the previous
142 * offset plus the last returned value of \p buffer_sz by this
145 * This function must return one of the following statuses:
147 * - <b>#CTF_MSG_ITER_MEDIUM_STATUS_OK</b>: Everything
148 * is okay, i.e. \p buffer_sz is set to a positive value
149 * reflecting the number of available bytes in the buffer
150 * starting at the address written in \p buffer_addr.
151 * - <b>#CTF_MSG_ITER_MEDIUM_STATUS_AGAIN</b>: No data is
152 * available right now. In this case, the message
153 * iterator function called by the user returns
154 * #CTF_MSG_ITER_STATUS_AGAIN, and it is the user's
155 * responsibility to make sure enough data becomes available
156 * before calling the \em same message iterator
157 * function again to continue the decoding process.
158 * - <b>#CTF_MSG_ITER_MEDIUM_STATUS_EOF</b>: The end of
159 * the file was reached, and no more data will ever be
160 * available for this file. In this case, the message
161 * iterator function called by the user returns
162 * #CTF_MSG_ITER_STATUS_EOF. This must \em not be
163 * returned when returning at least one byte of data to the
164 * caller, i.e. this must be returned when there's
165 * absolutely nothing left; should the request size be
166 * larger than what's left in the file, this function must
167 * return what's left, setting \p buffer_sz to the number of
168 * remaining bytes, and return
169 * #CTF_MSG_ITER_MEDIUM_STATUS_EOF on the \em following
171 * - <b>#CTF_MSG_ITER_MEDIUM_STATUS_ERROR</b>: A fatal
172 * error occured during this operation. In this case, the
173 * message iterator function called by the user returns
174 * #CTF_MSG_ITER_STATUS_ERROR.
176 * If #CTF_MSG_ITER_MEDIUM_STATUS_OK is not returned, the
177 * values of \p buffer_sz and \p buffer_addr are \em ignored by
180 * @param request_sz Requested buffer size (bytes)
181 * @param buffer_addr Returned buffer address
182 * @param buffer_sz Returned buffer's size (bytes)
183 * @param data User data
184 * @returns Status code (see description above)
186 enum ctf_msg_iter_medium_status (* request_bytes
)(size_t request_sz
,
187 uint8_t **buffer_addr
, size_t *buffer_sz
, void *data
);
190 * Repositions the underlying stream's position.
192 * This *optional* method repositions the underlying stream
193 * to a given absolute position in the medium.
195 * @param offset Offset to use for the given directive
196 * @param data User data
197 * @returns One of #ctf_msg_iter_medium_status values
199 enum ctf_msg_iter_medium_status (* seek
)(off_t offset
, void *data
);
202 * Returns a stream instance (weak reference) for the given
205 * This is called after a packet header is read, and the
206 * corresponding stream class is found by the message
209 * @param stream_class Stream class of the stream to get
210 * @param stream_id Stream (instance) ID of the stream
211 * to get (-1ULL if not available)
212 * @param data User data
213 * @returns Stream instance (weak reference) or
216 bt_stream
* (* borrow_stream
)(bt_stream_class
*stream_class
,
217 int64_t stream_id
, void *data
);
220 /** CTF message iterator. */
224 * Creates a CTF message iterator.
226 * Upon successful completion, the reference count of \p trace is
229 * @param trace Trace to read
230 * @param max_request_sz Maximum buffer size, in bytes, to
232 * ctf_msg_iter_medium_ops::request_bytes()
234 * @param medops Medium operations
235 * @param medops_data User data (passed to medium operations)
236 * @returns New CTF message iterator on
237 * success, or \c NULL on error
240 struct ctf_msg_iter
*ctf_msg_iter_create(
241 struct ctf_trace_class
*tc
,
242 size_t max_request_sz
,
243 struct ctf_msg_iter_medium_ops medops
,
245 bt_logging_level log_level
,
246 bt_self_component
*self_comp
,
247 bt_self_message_iterator
*self_msg_iter
);
250 * Destroys a CTF message iterator, freeing all internal resources.
252 * The registered trace's reference count is decremented.
254 * @param msg_iter CTF message iterator
257 void ctf_msg_iter_destroy(struct ctf_msg_iter
*msg_iter
);
260 * Returns the next message from a CTF message iterator.
262 * Upon successful completion, #CTF_MSG_ITER_STATUS_OK is
263 * returned, and the next message is written to \p msg.
264 * In this case, the caller is responsible for calling
265 * bt_message_put() on the returned message.
267 * If this function returns #CTF_MSG_ITER_STATUS_AGAIN, the caller
268 * should make sure that data becomes available to its medium, and
269 * call this function again, until another status is returned.
271 * @param msg_iter CTF message iterator
272 * @param message Returned message if the function's
273 * return value is #CTF_MSG_ITER_STATUS_OK
274 * @returns One of #ctf_msg_iter_status values
277 enum ctf_msg_iter_status
ctf_msg_iter_get_next_message(
278 struct ctf_msg_iter
*msg_it
,
279 const bt_message
**message
);
281 struct ctf_msg_iter_packet_properties
{
282 int64_t exp_packet_total_size
;
283 int64_t exp_packet_content_size
;
284 uint64_t stream_class_id
;
285 int64_t data_stream_id
;
288 uint64_t discarded_events
;
290 uint64_t beginning_clock
;
296 enum ctf_msg_iter_status
ctf_msg_iter_get_packet_properties(
297 struct ctf_msg_iter
*msg_it
,
298 struct ctf_msg_iter_packet_properties
*props
);
301 enum ctf_msg_iter_status
ctf_msg_iter_curr_packet_first_event_clock_snapshot(
302 struct ctf_msg_iter
*msg_it
, uint64_t *first_event_cs
);
305 enum ctf_msg_iter_status
ctf_msg_iter_curr_packet_last_event_clock_snapshot(
306 struct ctf_msg_iter
*msg_it
, uint64_t *last_event_cs
);
309 void ctf_msg_iter_set_medops_data(struct ctf_msg_iter
*msg_it
,
313 enum ctf_msg_iter_status
ctf_msg_iter_seek(
314 struct ctf_msg_iter
*msg_it
, off_t offset
);
317 * Resets the iterator so that the next requested medium bytes are
318 * assumed to be the first bytes of a new stream. Depending on
319 * ctf_msg_iter_set_emit_stream_beginning_message(), the first message
320 * which this iterator emits after calling ctf_msg_iter_reset() is of
321 * type `CTF_MESSAGE_TYPE_STREAM_BEGINNING`.
324 void ctf_msg_iter_reset(struct ctf_msg_iter
*msg_it
);
327 * Like ctf_msg_iter_reset(), but preserves stream-dependent state.
330 void ctf_msg_iter_reset_for_next_stream_file(struct ctf_msg_iter
*msg_it
);
333 void ctf_msg_iter_set_emit_stream_beginning_message(struct ctf_msg_iter
*msg_it
,
337 void ctf_msg_iter_set_emit_stream_end_message(struct ctf_msg_iter
*msg_it
,
341 void ctf_msg_iter_set_dry_run(struct ctf_msg_iter
*msg_it
,
345 const char *ctf_msg_iter_medium_status_string(
346 enum ctf_msg_iter_medium_status status
)
349 case CTF_MSG_ITER_MEDIUM_STATUS_EOF
:
351 case CTF_MSG_ITER_MEDIUM_STATUS_AGAIN
:
353 case CTF_MSG_ITER_MEDIUM_STATUS_INVAL
:
355 case CTF_MSG_ITER_MEDIUM_STATUS_ERROR
:
357 case CTF_MSG_ITER_MEDIUM_STATUS_OK
:
365 const char *ctf_msg_iter_status_string(
366 enum ctf_msg_iter_status status
)
369 case CTF_MSG_ITER_STATUS_EOF
:
371 case CTF_MSG_ITER_STATUS_AGAIN
:
373 case CTF_MSG_ITER_STATUS_INVAL
:
375 case CTF_MSG_ITER_STATUS_ERROR
:
377 case CTF_MSG_ITER_STATUS_OK
:
384 #endif /* CTF_MSG_ITER_H */