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,
65 CTF_MSG_ITER_MEDIUM_STATUS_ERROR
= -1,
67 /** Everything okay. */
68 CTF_MSG_ITER_MEDIUM_STATUS_OK
= 0,
72 * CTF message iterator API status code.
74 enum ctf_msg_iter_status
{
78 * The medium function called by the message iterator
79 * function reached the end of the file.
81 CTF_MSG_ITER_STATUS_EOF
= CTF_MSG_ITER_MEDIUM_STATUS_EOF
,
84 * There is no data available right now, try again later.
86 * Some condition resulted in the
87 * ctf_msg_iter_medium_ops::request_bytes() user function not
88 * having access to any data now. You should retry calling the
89 * last called message iterator function once the situation
92 CTF_MSG_ITER_STATUS_AGAIN
= CTF_MSG_ITER_MEDIUM_STATUS_AGAIN
,
95 CTF_MSG_ITER_STATUS_ERROR
= CTF_MSG_ITER_MEDIUM_STATUS_ERROR
,
97 /** Everything okay. */
98 CTF_MSG_ITER_STATUS_OK
= CTF_MSG_ITER_MEDIUM_STATUS_OK
,
104 * Those user functions are called by the message iterator
105 * functions to request medium actions.
107 struct ctf_msg_iter_medium_ops
{
109 * Returns the next byte buffer to be used by the binary file
110 * reader to deserialize binary data.
112 * This function \em must be defined.
114 * The purpose of this function is to return a buffer of bytes
115 * to the message iterator, of a maximum of \p request_sz
116 * bytes. If this function cannot return a buffer of at least
117 * \p request_sz bytes, it may return a smaller buffer. In
118 * either cases, \p buffer_sz must be set to the returned buffer
121 * The returned buffer's ownership remains the medium, in that
122 * it won't be freed by the message iterator functions. The
123 * returned buffer won't be modified by the message
124 * iterator functions either.
126 * When this function is called for the first time for a given
127 * file, the offset within the file is considered to be 0. The
128 * next times this function is called, the returned buffer's
129 * byte offset within the complete file must be the previous
130 * offset plus the last returned value of \p buffer_sz by this
133 * This function must return one of the following statuses:
135 * - <b>#CTF_MSG_ITER_MEDIUM_STATUS_OK</b>: Everything
136 * is okay, i.e. \p buffer_sz is set to a positive value
137 * reflecting the number of available bytes in the buffer
138 * starting at the address written in \p buffer_addr.
139 * - <b>#CTF_MSG_ITER_MEDIUM_STATUS_AGAIN</b>: No data is
140 * available right now. In this case, the message
141 * iterator function called by the user returns
142 * #CTF_MSG_ITER_STATUS_AGAIN, and it is the user's
143 * responsibility to make sure enough data becomes available
144 * before calling the \em same message iterator
145 * function again to continue the decoding process.
146 * - <b>#CTF_MSG_ITER_MEDIUM_STATUS_EOF</b>: The end of
147 * the file was reached, and no more data will ever be
148 * available for this file. In this case, the message
149 * iterator function called by the user returns
150 * #CTF_MSG_ITER_STATUS_EOF. This must \em not be
151 * returned when returning at least one byte of data to the
152 * caller, i.e. this must be returned when there's
153 * absolutely nothing left; should the request size be
154 * larger than what's left in the file, this function must
155 * return what's left, setting \p buffer_sz to the number of
156 * remaining bytes, and return
157 * #CTF_MSG_ITER_MEDIUM_STATUS_EOF on the \em following
159 * - <b>#CTF_MSG_ITER_MEDIUM_STATUS_ERROR</b>: A fatal
160 * error occured during this operation. In this case, the
161 * message iterator function called by the user returns
162 * #CTF_MSG_ITER_STATUS_ERROR.
164 * If #CTF_MSG_ITER_MEDIUM_STATUS_OK is not returned, the
165 * values of \p buffer_sz and \p buffer_addr are \em ignored by
168 * @param request_sz Requested buffer size (bytes)
169 * @param buffer_addr Returned buffer address
170 * @param buffer_sz Returned buffer's size (bytes)
171 * @param data User data
172 * @returns Status code (see description above)
174 enum ctf_msg_iter_medium_status (* request_bytes
)(size_t request_sz
,
175 uint8_t **buffer_addr
, size_t *buffer_sz
, void *data
);
178 * Repositions the underlying stream's position.
180 * This *optional* method repositions the underlying stream
181 * to a given absolute position in the medium.
183 * @param offset Offset to use for the given directive
184 * @param data User data
185 * @returns One of #ctf_msg_iter_medium_status values
187 enum ctf_msg_iter_medium_status (* seek
)(off_t offset
, void *data
);
190 * Returns a stream instance (weak reference) for the given
193 * This is called after a packet header is read, and the
194 * corresponding stream class is found by the message
197 * @param stream_class Stream class of the stream to get
198 * @param stream_id Stream (instance) ID of the stream
199 * to get (-1ULL if not available)
200 * @param data User data
201 * @returns Stream instance (weak reference) or
204 bt_stream
* (* borrow_stream
)(bt_stream_class
*stream_class
,
205 int64_t stream_id
, void *data
);
208 /** CTF message iterator. */
212 * Creates a CTF message iterator.
214 * Upon successful completion, the reference count of \p trace is
217 * @param trace Trace to read
218 * @param max_request_sz Maximum buffer size, in bytes, to
220 * ctf_msg_iter_medium_ops::request_bytes()
222 * @param medops Medium operations
223 * @param medops_data User data (passed to medium operations)
224 * @returns New CTF message iterator on
225 * success, or \c NULL on error
228 struct ctf_msg_iter
*ctf_msg_iter_create(
229 struct ctf_trace_class
*tc
,
230 size_t max_request_sz
,
231 struct ctf_msg_iter_medium_ops medops
,
233 bt_logging_level log_level
,
234 bt_self_component
*self_comp
,
235 bt_self_message_iterator
*self_msg_iter
);
238 * Destroys a CTF message iterator, freeing all internal resources.
240 * The registered trace's reference count is decremented.
242 * @param msg_iter CTF message iterator
245 void ctf_msg_iter_destroy(struct ctf_msg_iter
*msg_iter
);
248 * Returns the next message from a CTF message iterator.
250 * Upon successful completion, #CTF_MSG_ITER_STATUS_OK is
251 * returned, and the next message is written to \p msg.
252 * In this case, the caller is responsible for calling
253 * bt_message_put() on the returned message.
255 * If this function returns #CTF_MSG_ITER_STATUS_AGAIN, the caller
256 * should make sure that data becomes available to its medium, and
257 * call this function again, until another status is returned.
259 * @param msg_iter CTF message iterator
260 * @param message Returned message if the function's
261 * return value is #CTF_MSG_ITER_STATUS_OK
262 * @returns One of #ctf_msg_iter_status values
265 enum ctf_msg_iter_status
ctf_msg_iter_get_next_message(
266 struct ctf_msg_iter
*msg_it
,
267 const bt_message
**message
);
269 struct ctf_msg_iter_packet_properties
{
270 int64_t exp_packet_total_size
;
271 int64_t exp_packet_content_size
;
272 uint64_t stream_class_id
;
273 int64_t data_stream_id
;
276 uint64_t discarded_events
;
278 uint64_t beginning_clock
;
284 enum ctf_msg_iter_status
ctf_msg_iter_get_packet_properties(
285 struct ctf_msg_iter
*msg_it
,
286 struct ctf_msg_iter_packet_properties
*props
);
289 enum ctf_msg_iter_status
ctf_msg_iter_curr_packet_first_event_clock_snapshot(
290 struct ctf_msg_iter
*msg_it
, uint64_t *first_event_cs
);
293 enum ctf_msg_iter_status
ctf_msg_iter_curr_packet_last_event_clock_snapshot(
294 struct ctf_msg_iter
*msg_it
, uint64_t *last_event_cs
);
297 void ctf_msg_iter_set_medops_data(struct ctf_msg_iter
*msg_it
,
301 enum ctf_msg_iter_status
ctf_msg_iter_seek(
302 struct ctf_msg_iter
*msg_it
, off_t offset
);
305 * Resets the iterator so that the next requested medium bytes are
306 * assumed to be the first bytes of a new stream. Depending on
307 * ctf_msg_iter_set_emit_stream_beginning_message(), the first message
308 * which this iterator emits after calling ctf_msg_iter_reset() is of
309 * type `CTF_MESSAGE_TYPE_STREAM_BEGINNING`.
312 void ctf_msg_iter_reset(struct ctf_msg_iter
*msg_it
);
315 * Like ctf_msg_iter_reset(), but preserves stream-dependent state.
318 void ctf_msg_iter_reset_for_next_stream_file(struct ctf_msg_iter
*msg_it
);
321 void ctf_msg_iter_set_emit_stream_beginning_message(struct ctf_msg_iter
*msg_it
,
325 void ctf_msg_iter_set_emit_stream_end_message(struct ctf_msg_iter
*msg_it
,
329 void ctf_msg_iter_set_dry_run(struct ctf_msg_iter
*msg_it
,
333 const char *ctf_msg_iter_medium_status_string(
334 enum ctf_msg_iter_medium_status status
)
337 case CTF_MSG_ITER_MEDIUM_STATUS_EOF
:
339 case CTF_MSG_ITER_MEDIUM_STATUS_AGAIN
:
341 case CTF_MSG_ITER_MEDIUM_STATUS_ERROR
:
343 case CTF_MSG_ITER_MEDIUM_STATUS_OK
:
351 const char *ctf_msg_iter_status_string(
352 enum ctf_msg_iter_status status
)
355 case CTF_MSG_ITER_STATUS_EOF
:
357 case CTF_MSG_ITER_STATUS_AGAIN
:
359 case CTF_MSG_ITER_STATUS_ERROR
:
361 case CTF_MSG_ITER_STATUS_OK
:
368 #endif /* CTF_MSG_ITER_H */