1 #ifndef CTF_NOTIF_ITER_H
2 #define CTF_NOTIF_ITER_H
5 * Babeltrace - CTF notification 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
32 #include <babeltrace/babeltrace.h>
33 #include <babeltrace/babeltrace-internal.h>
36 * @file ctf-notif-iter.h
38 * CTF notification iterator
40 * This is a common internal API used by CTF source plugins. It allows
41 * one to get notifications from a user-provided medium.
45 * Medium operations status codes.
47 enum bt_notif_iter_medium_status
{
51 * The medium function called by the notification iterator
52 * function reached the end of the file.
54 BT_NOTIF_ITER_MEDIUM_STATUS_EOF
= 1,
57 * There is no data available right now, try again later.
59 BT_NOTIF_ITER_MEDIUM_STATUS_AGAIN
= 11,
61 /** Unsupported operation. */
62 BT_NOTIF_ITER_MEDIUM_STATUS_UNSUPPORTED
= -3,
64 /** Invalid argument. */
65 BT_NOTIF_ITER_MEDIUM_STATUS_INVAL
= -2,
68 BT_NOTIF_ITER_MEDIUM_STATUS_ERROR
= -1,
70 /** Everything okay. */
71 BT_NOTIF_ITER_MEDIUM_STATUS_OK
= 0,
75 * CTF notification iterator API status code.
77 enum bt_notif_iter_status
{
81 * The medium function called by the notification iterator
82 * function reached the end of the file.
84 BT_NOTIF_ITER_STATUS_EOF
= BT_NOTIF_ITER_MEDIUM_STATUS_EOF
,
87 * There is no data available right now, try again later.
89 * Some condition resulted in the
90 * bt_notif_iter_medium_ops::request_bytes() user function not
91 * having access to any data now. You should retry calling the
92 * last called notification iterator function once the situation
95 BT_NOTIF_ITER_STATUS_AGAIN
= BT_NOTIF_ITER_MEDIUM_STATUS_AGAIN
,
97 /** Invalid argument. */
98 BT_NOTIF_ITER_STATUS_INVAL
= BT_NOTIF_ITER_MEDIUM_STATUS_INVAL
,
100 /** Unsupported operation. */
101 BT_NOTIF_ITER_STATUS_UNSUPPORTED
= BT_NOTIF_ITER_MEDIUM_STATUS_UNSUPPORTED
,
103 /** General error. */
104 BT_NOTIF_ITER_STATUS_ERROR
= BT_NOTIF_ITER_MEDIUM_STATUS_ERROR
,
106 /** Everything okay. */
107 BT_NOTIF_ITER_STATUS_OK
= 0,
111 * CTF notification iterator seek operation directives.
113 enum bt_notif_iter_seek_whence
{
115 * Set the iterator's position to an absolute offset in the underlying
118 BT_NOTIF_ITER_SEEK_WHENCE_SET
,
124 * Those user functions are called by the notification iterator
125 * functions to request medium actions.
127 struct bt_notif_iter_medium_ops
{
129 * Returns the next byte buffer to be used by the binary file
130 * reader to deserialize binary data.
132 * This function \em must be defined.
134 * The purpose of this function is to return a buffer of bytes
135 * to the notification iterator, of a maximum of \p request_sz
136 * bytes. If this function cannot return a buffer of at least
137 * \p request_sz bytes, it may return a smaller buffer. In
138 * either cases, \p buffer_sz must be set to the returned buffer
141 * The returned buffer's ownership remains the medium, in that
142 * it won't be freed by the notification iterator functions. The
143 * returned buffer won't be modified by the notification
144 * iterator functions either.
146 * When this function is called for the first time for a given
147 * file, the offset within the file is considered to be 0. The
148 * next times this function is called, the returned buffer's
149 * byte offset within the complete file must be the previous
150 * offset plus the last returned value of \p buffer_sz by this
153 * This function must return one of the following statuses:
155 * - <b>#BT_NOTIF_ITER_MEDIUM_STATUS_OK</b>: Everything
156 * is okay, i.e. \p buffer_sz is set to a positive value
157 * reflecting the number of available bytes in the buffer
158 * starting at the address written in \p buffer_addr.
159 * - <b>#BT_NOTIF_ITER_MEDIUM_STATUS_AGAIN</b>: No data is
160 * available right now. In this case, the notification
161 * iterator function called by the user returns
162 * #BT_NOTIF_ITER_STATUS_AGAIN, and it is the user's
163 * responsibility to make sure enough data becomes available
164 * before calling the \em same notification iterator
165 * function again to continue the decoding process.
166 * - <b>#BT_NOTIF_ITER_MEDIUM_STATUS_EOF</b>: The end of
167 * the file was reached, and no more data will ever be
168 * available for this file. In this case, the notification
169 * iterator function called by the user returns
170 * #BT_NOTIF_ITER_STATUS_EOF. This must \em not be
171 * returned when returning at least one byte of data to the
172 * caller, i.e. this must be returned when there's
173 * absolutely nothing left; should the request size be
174 * larger than what's left in the file, this function must
175 * return what's left, setting \p buffer_sz to the number of
176 * remaining bytes, and return
177 * #BT_NOTIF_ITER_MEDIUM_STATUS_EOF on the \em following
179 * - <b>#BT_NOTIF_ITER_MEDIUM_STATUS_ERROR</b>: A fatal
180 * error occured during this operation. In this case, the
181 * notification iterator function called by the user returns
182 * #BT_NOTIF_ITER_STATUS_ERROR.
184 * If #BT_NOTIF_ITER_MEDIUM_STATUS_OK is not returned, the
185 * values of \p buffer_sz and \p buffer_addr are \em ignored by
188 * @param request_sz Requested buffer size (bytes)
189 * @param buffer_addr Returned buffer address
190 * @param buffer_sz Returned buffer's size (bytes)
191 * @param data User data
192 * @returns Status code (see description above)
194 enum bt_notif_iter_medium_status (* request_bytes
)(
195 size_t request_sz
, uint8_t **buffer_addr
,
196 size_t *buffer_sz
, void *data
);
199 * Repositions the underlying stream's position.
201 * This *optional* method repositions the underlying stream
202 * to a given absolute or relative position, as indicated by
203 * the whence directive.
205 * @param whence One of #bt_notif_iter_seek_whence values
206 * @param offset Offset to use for the given directive
207 * @param data User data
208 * @returns One of #bt_notif_iter_medium_status values
210 enum bt_notif_iter_medium_status (* seek
)(
211 enum bt_notif_iter_seek_whence whence
,
212 off_t offset
, void *data
);
215 * Returns a stream instance (weak reference) for the given
218 * This is called after a packet header is read, and the
219 * corresponding stream class is found by the notification
222 * @param stream_class Stream class of the stream to get
223 * @param stream_id Stream (instance) ID of the stream
224 * to get (-1ULL if not available)
225 * @param data User data
226 * @returns Stream instance (weak reference) or
229 struct bt_stream
* (* get_stream
)(
230 struct bt_stream_class
*stream_class
,
231 uint64_t stream_id
, void *data
);
234 /** CTF notification iterator. */
235 struct bt_notif_iter
;
237 // TODO: Replace by the real thing
238 enum bt_notif_iter_notif_type
{
239 BT_NOTIF_ITER_NOTIF_NEW_PACKET
,
240 BT_NOTIF_ITER_NOTIF_END_OF_PACKET
,
241 BT_NOTIF_ITER_NOTIF_EVENT
,
244 struct bt_notif_iter_notif
{
245 enum bt_notif_iter_notif_type type
;
248 struct bt_notif_iter_notif_new_packet
{
249 struct bt_notif_iter_notif base
;
250 struct bt_packet
*packet
;
253 struct bt_notif_iter_notif_end_of_packet
{
254 struct bt_notif_iter_notif base
;
255 struct bt_packet
*packet
;
258 struct bt_notif_iter_notif_event
{
259 struct bt_notif_iter_notif base
;
260 struct bt_event
*event
;
264 * Creates a CTF notification iterator.
266 * Upon successful completion, the reference count of \p trace is
269 * @param trace Trace to read
270 * @param max_request_sz Maximum buffer size, in bytes, to
272 * bt_notif_iter_medium_ops::request_bytes()
274 * @param medops Medium operations
275 * @param medops_data User data (passed to medium operations)
276 * @returns New CTF notification iterator on
277 * success, or \c NULL on error
280 struct bt_notif_iter
*bt_notif_iter_create(struct bt_trace
*trace
,
281 size_t max_request_sz
, struct bt_notif_iter_medium_ops medops
,
285 * Destroys a CTF notification iterator, freeing all internal resources.
287 * The registered trace's reference count is decremented.
289 * @param notif_iter CTF notification iterator
292 void bt_notif_iter_destroy(struct bt_notif_iter
*notif_iter
);
295 * Returns the next notification from a CTF notification iterator.
297 * Upon successful completion, #BT_NOTIF_ITER_STATUS_OK is
298 * returned, and the next notification is written to \p notif.
299 * In this case, the caller is responsible for calling
300 * bt_notification_put() on the returned notification.
302 * If this function returns #BT_NOTIF_ITER_STATUS_AGAIN, the caller
303 * should make sure that data becomes available to its medium, and
304 * call this function again, until another status is returned.
306 * @param notif_iter CTF notification iterator
307 * @param cc_prio_map Clock class priority map to use when
308 * creating an event notification
309 * @param notification Returned notification if the function's
310 * return value is #BT_NOTIF_ITER_STATUS_OK
311 * @returns One of #bt_notif_iter_status values
314 enum bt_notif_iter_status
bt_notif_iter_get_next_notification(
315 struct bt_notif_iter
*notit
,
316 struct bt_clock_class_priority_map
*cc_prio_map
,
317 struct bt_notification
**notification
);
320 * Returns the first packet header and context fields. This function
321 * never needs to call the `get_stream()` medium operation because
322 * it does not create packet or event objects.
324 * @param notif_iter CTF notification iterator
325 * @param packet_header_field Packet header field (\c NULL if there's
326 * no packet header field)
327 * @param packet_context_field Packet context field (\c NULL if there's
328 * no packet context field)
329 * @returns One of #bt_notif_iter_status values
332 enum bt_notif_iter_status
bt_notif_iter_get_packet_header_context_fields(
333 struct bt_notif_iter
*notit
,
334 struct bt_field
**packet_header_field
,
335 struct bt_field
**packet_context_field
);
338 void bt_notif_iter_set_medops_data(struct bt_notif_iter
*notit
,
342 enum bt_notif_iter_status
bt_notif_iter_seek(
343 struct bt_notif_iter
*notit
, off_t offset
);
346 * Get the current packet's offset in bytes relative to the media's initial
350 off_t
bt_notif_iter_get_current_packet_offset(
351 struct bt_notif_iter
*notit
);
353 /* Get the current packet's size (in bits). */
355 off_t
bt_notif_iter_get_current_packet_size(
356 struct bt_notif_iter
*notit
);
359 const char *bt_notif_iter_medium_status_string(
360 enum bt_notif_iter_medium_status status
)
363 case BT_NOTIF_ITER_MEDIUM_STATUS_EOF
:
364 return "BT_NOTIF_ITER_MEDIUM_STATUS_EOF";
365 case BT_NOTIF_ITER_MEDIUM_STATUS_AGAIN
:
366 return "BT_NOTIF_ITER_MEDIUM_STATUS_AGAIN";
367 case BT_NOTIF_ITER_MEDIUM_STATUS_INVAL
:
368 return "BT_NOTIF_ITER_MEDIUM_STATUS_INVAL";
369 case BT_NOTIF_ITER_MEDIUM_STATUS_ERROR
:
370 return "BT_NOTIF_ITER_MEDIUM_STATUS_ERROR";
371 case BT_NOTIF_ITER_MEDIUM_STATUS_OK
:
372 return "BT_NOTIF_ITER_MEDIUM_STATUS_OK";
379 const char *bt_notif_iter_status_string(
380 enum bt_notif_iter_status status
)
383 case BT_NOTIF_ITER_STATUS_EOF
:
384 return "BT_NOTIF_ITER_STATUS_EOF";
385 case BT_NOTIF_ITER_STATUS_AGAIN
:
386 return "BT_NOTIF_ITER_STATUS_AGAIN";
387 case BT_NOTIF_ITER_STATUS_INVAL
:
388 return "BT_NOTIF_ITER_STATUS_INVAL";
389 case BT_NOTIF_ITER_STATUS_ERROR
:
390 return "BT_NOTIF_ITER_STATUS_ERROR";
391 case BT_NOTIF_ITER_STATUS_OK
:
392 return "BT_NOTIF_ITER_STATUS_OK";
398 #endif /* CTF_NOTIF_ITER_H */