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 bt_msg_iter_medium_status
{
54 * The medium function called by the message iterator
55 * function reached the end of the file.
57 BT_MSG_ITER_MEDIUM_STATUS_EOF
= 1,
60 * There is no data available right now, try again later.
62 BT_MSG_ITER_MEDIUM_STATUS_AGAIN
= 11,
64 /** Unsupported operation. */
65 BT_MSG_ITER_MEDIUM_STATUS_UNSUPPORTED
= -3,
67 /** Invalid argument. */
68 BT_MSG_ITER_MEDIUM_STATUS_INVAL
= -2,
71 BT_MSG_ITER_MEDIUM_STATUS_ERROR
= -1,
73 /** Everything okay. */
74 BT_MSG_ITER_MEDIUM_STATUS_OK
= 0,
78 * CTF message iterator API status code.
80 enum bt_msg_iter_status
{
84 * The medium function called by the message iterator
85 * function reached the end of the file.
87 BT_MSG_ITER_STATUS_EOF
= BT_MSG_ITER_MEDIUM_STATUS_EOF
,
90 * There is no data available right now, try again later.
92 * Some condition resulted in the
93 * bt_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 BT_MSG_ITER_STATUS_AGAIN
= BT_MSG_ITER_MEDIUM_STATUS_AGAIN
,
100 /** Invalid argument. */
101 BT_MSG_ITER_STATUS_INVAL
= BT_MSG_ITER_MEDIUM_STATUS_INVAL
,
103 /** Unsupported operation. */
104 BT_MSG_ITER_STATUS_UNSUPPORTED
= BT_MSG_ITER_MEDIUM_STATUS_UNSUPPORTED
,
106 /** General error. */
107 BT_MSG_ITER_STATUS_ERROR
= BT_MSG_ITER_MEDIUM_STATUS_ERROR
,
109 /** Everything okay. */
110 BT_MSG_ITER_STATUS_OK
= 0,
114 * CTF message iterator seek operation directives.
116 enum bt_msg_iter_seek_whence
{
118 * Set the iterator's position to an absolute offset in the underlying
121 BT_MSG_ITER_SEEK_WHENCE_SET
,
127 * Those user functions are called by the message iterator
128 * functions to request medium actions.
130 struct bt_msg_iter_medium_ops
{
132 * Returns the next byte buffer to be used by the binary file
133 * reader to deserialize binary data.
135 * This function \em must be defined.
137 * The purpose of this function is to return a buffer of bytes
138 * to the message 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
144 * The returned buffer's ownership remains the medium, in that
145 * it won't be freed by the message iterator functions. The
146 * returned buffer won't be modified by the message
147 * iterator functions either.
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
156 * This function must return one of the following statuses:
158 * - <b>#BT_MSG_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_MSG_ITER_MEDIUM_STATUS_AGAIN</b>: No data is
163 * available right now. In this case, the message
164 * iterator function called by the user returns
165 * #BT_MSG_ITER_STATUS_AGAIN, and it is the user's
166 * responsibility to make sure enough data becomes available
167 * before calling the \em same message iterator
168 * function again to continue the decoding process.
169 * - <b>#BT_MSG_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 message
172 * iterator function called by the user returns
173 * #BT_MSG_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_MSG_ITER_MEDIUM_STATUS_EOF on the \em following
182 * - <b>#BT_MSG_ITER_MEDIUM_STATUS_ERROR</b>: A fatal
183 * error occured during this operation. In this case, the
184 * message iterator function called by the user returns
185 * #BT_MSG_ITER_STATUS_ERROR.
187 * If #BT_MSG_ITER_MEDIUM_STATUS_OK is not returned, the
188 * values of \p buffer_sz and \p buffer_addr are \em ignored by
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)
197 enum bt_msg_iter_medium_status (* request_bytes
)(size_t request_sz
,
198 uint8_t **buffer_addr
, size_t *buffer_sz
, void *data
);
201 * Repositions the underlying stream's position.
203 * This *optional* method repositions the underlying stream
204 * to a given absolute or relative position, as indicated by
205 * the whence directive.
207 * @param whence One of #bt_msg_iter_seek_whence values
208 * @param offset Offset to use for the given directive
209 * @param data User data
210 * @returns One of #bt_msg_iter_medium_status values
212 enum bt_msg_iter_medium_status (* seek
)(
213 enum bt_msg_iter_seek_whence whence
,
214 off_t offset
, void *data
);
217 * Returns a stream instance (weak reference) for the given
220 * This is called after a packet header is read, and the
221 * corresponding stream class is found by the message
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)
227 * @param data User data
228 * @returns Stream instance (weak reference) or
231 bt_stream
* (* borrow_stream
)(bt_stream_class
*stream_class
,
232 int64_t stream_id
, void *data
);
235 /** CTF message iterator. */
239 * Creates a CTF message iterator.
241 * Upon successful completion, the reference count of \p trace is
244 * @param trace Trace to read
245 * @param max_request_sz Maximum buffer size, in bytes, to
247 * bt_msg_iter_medium_ops::request_bytes()
249 * @param medops Medium operations
250 * @param medops_data User data (passed to medium operations)
251 * @returns New CTF message iterator on
252 * success, or \c NULL on error
255 struct bt_msg_iter
*bt_msg_iter_create(struct ctf_trace_class
*tc
,
256 size_t max_request_sz
, struct bt_msg_iter_medium_ops medops
,
257 void *medops_data
, bt_logging_level log_level
,
258 bt_self_component
*self_comp
);
261 * Destroys a CTF message iterator, freeing all internal resources.
263 * The registered trace's reference count is decremented.
265 * @param msg_iter CTF message iterator
268 void bt_msg_iter_destroy(struct bt_msg_iter
*msg_iter
);
271 * Returns the next message from a CTF message iterator.
273 * Upon successful completion, #BT_MSG_ITER_STATUS_OK is
274 * returned, and the next message is written to \p msg.
275 * In this case, the caller is responsible for calling
276 * bt_message_put() on the returned message.
278 * If this function returns #BT_MSG_ITER_STATUS_AGAIN, the caller
279 * should make sure that data becomes available to its medium, and
280 * call this function again, until another status is returned.
282 * @param msg_iter CTF message iterator
283 * @param message Returned message if the function's
284 * return value is #BT_MSG_ITER_STATUS_OK
285 * @returns One of #bt_msg_iter_status values
288 enum bt_msg_iter_status
bt_msg_iter_get_next_message(
289 struct bt_msg_iter
*notit
,
290 bt_self_message_iterator
*msg_iter
,
291 bt_message
**message
);
293 struct bt_msg_iter_packet_properties
{
294 int64_t exp_packet_total_size
;
295 int64_t exp_packet_content_size
;
296 uint64_t stream_class_id
;
297 int64_t data_stream_id
;
300 uint64_t discarded_events
;
302 uint64_t beginning_clock
;
308 enum bt_msg_iter_status
bt_msg_iter_get_packet_properties(
309 struct bt_msg_iter
*notit
,
310 struct bt_msg_iter_packet_properties
*props
);
313 enum bt_msg_iter_status
bt_msg_iter_curr_packet_first_event_clock_snapshot(
314 struct bt_msg_iter
*notit
, uint64_t *first_event_cs
);
317 enum bt_msg_iter_status
bt_msg_iter_curr_packet_last_event_clock_snapshot(
318 struct bt_msg_iter
*notit
, uint64_t *last_event_cs
);
321 void bt_msg_iter_set_medops_data(struct bt_msg_iter
*notit
,
325 enum bt_msg_iter_status
bt_msg_iter_seek(
326 struct bt_msg_iter
*notit
, off_t offset
);
329 * Resets the iterator so that the next requested medium bytes are
330 * assumed to be the first bytes of a new stream. Depending on
331 * bt_msg_iter_set_emit_stream_beginning_message(), the first message
332 * which this iterator emits after calling bt_msg_iter_reset() is of
333 * type `BT_MESSAGE_TYPE_STREAM_BEGINNING`.
336 void bt_msg_iter_reset(struct bt_msg_iter
*notit
);
339 * Like bt_msg_iter_reset(), but preserves stream-dependent state.
342 void bt_msg_iter_reset_for_next_stream_file(struct bt_msg_iter
*notit
);
345 void bt_msg_iter_set_emit_stream_beginning_message(struct bt_msg_iter
*notit
,
349 void bt_msg_iter_set_emit_stream_end_message(struct bt_msg_iter
*notit
,
353 void bt_msg_iter_set_dry_run(struct bt_msg_iter
*notit
,
357 const char *bt_msg_iter_medium_status_string(
358 enum bt_msg_iter_medium_status status
)
361 case BT_MSG_ITER_MEDIUM_STATUS_EOF
:
363 case BT_MSG_ITER_MEDIUM_STATUS_AGAIN
:
365 case BT_MSG_ITER_MEDIUM_STATUS_INVAL
:
367 case BT_MSG_ITER_MEDIUM_STATUS_ERROR
:
369 case BT_MSG_ITER_MEDIUM_STATUS_OK
:
377 const char *bt_msg_iter_status_string(
378 enum bt_msg_iter_status status
)
381 case BT_MSG_ITER_STATUS_EOF
:
383 case BT_MSG_ITER_STATUS_AGAIN
:
385 case BT_MSG_ITER_STATUS_INVAL
:
387 case BT_MSG_ITER_STATUS_ERROR
:
389 case BT_MSG_ITER_STATUS_OK
:
396 #endif /* CTF_MSG_ITER_H */