include/babeltrace/ctf-ir/event.h

   1 #ifndef BABELTRACE_CTF_IR_EVENT_H
   2 #define BABELTRACE_CTF_IR_EVENT_H
   3
   4 /*
   5  * BabelTrace - CTF IR: Event
   6  *
   7  * Copyright 2013, 2014 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   8  *
   9  * Author: Jérémie Galarneau <jeremie.galarneau@efficios.com>
  10  *
  11  * Permission is hereby granted, free of charge, to any person obtaining a copy
  12  * of this software and associated documentation files (the "Software"), to deal
  13  * in the Software without restriction, including without limitation the rights
  14  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  15  * copies of the Software, and to permit persons to whom the Software is
  16  * furnished to do so, subject to the following conditions:
  17  *
  18  * The above copyright notice and this permission notice shall be included in
  19  * all copies or substantial portions of the Software.
  20  *
  21  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  22  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  23  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  24  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  25  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  26  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  27  * SOFTWARE.
  28  *
  29  * The Common Trace Format (CTF) Specification is available at
  30  * http://www.efficios.com/ctf
  31  */
  32
  33 #include <stdint.h>
  34 #include <stddef.h>
  35
  36 #ifdef __cplusplus
  37 extern "C" {
  38 #endif
  39
  40 struct bt_value;
  41 struct bt_clock_class;
  42
  43 /**
  44 @defgroup ctfirevent CTF IR event
  45 @ingroup ctfir
  46 @brief CTF IR event.
  47
  48 @code
  49 #include <babeltrace/ctf-ir/event.h>
  50 @endcode
  51
  52 A CTF IR <strong><em>event</em></strong> is a container of event
  53 fields:
  54
  55 - <strong>Stream event header</strong> field, described by the
  56   <em>stream event header field type</em> of a
  57   \link ctfirstreamclass CTF IR stream class\endlink.
  58 - <strong>Stream event context</strong> field, described by the
  59   <em>stream event context field type</em> of a stream class.
  60 - <strong>Event context</strong> field, described by the
  61   <em>event context field type</em> of a
  62   \link ctfireventclass CTF IR event class\endlink.
  63 - <strong>Event payload</strong>, described by the
  64   <em>event payload field type</em> of an event class.
  65
  66 As a reminder, here's the structure of a CTF packet:
  67
  68 @imgpacketstructure
  69
  70 You can create a CTF IR event \em from a
  71 \link ctfireventclass CTF IR event class\endlink with
  72 bt_event_create(). The event class you use to create an event
  73 object becomes its parent.
  74
  75 If the \link ctfirtraceclass CTF IR trace class\endlink of an event
  76 object (parent of its \link ctfirstreamclass CTF IR stream class\endlink,
  77 which is the parent of its event class) was created by a
  78 \link ctfwriter CTF writer\endlink object, then the only possible
  79 action you can do with this event object is to append it to a
  80 \link ctfirstream CTF IR stream\endlink with
  81 bt_stream_append_event(). Otherwise, you can create an event
  82 notification with bt_notification_event_create(). The event you pass
  83 to this function \em must have an attached packet object first.
  84
  85 You can attach a \link ctfirpacket CTF IR packet object\endlink to an
  86 event object with bt_event_set_packet().
  87
  88 A CTF IR event has a mapping of
  89 \link ctfirclockvalue CTF IR clock values\endlink. A clock value is
  90 an instance of a specific
  91 \link ctfirclockclass CTF IR clock class\endlink when the event is
  92 emitted. You can set an event object's clock value with
  93 bt_event_set_clock_value().
  94
  95 As with any Babeltrace object, CTF IR event objects have
  96 <a href="https://en.wikipedia.org/wiki/Reference_counting">reference
  97 counts</a>. See \ref refs to learn more about the reference counting
  98 management of Babeltrace objects.
  99
 100 bt_notification_event_create() \em freezes its event parameter on
 101 success. You cannot modify a frozen event object: it is considered
 102 immutable, except for \link refs reference counting\endlink.
 103
 104 @sa ctfireventclass
 105 @sa ctfirpacket
 106
 107 @file
 108 @brief CTF IR event type and functions.
 109 @sa ctfirevent
 110
 111 @addtogroup ctfirevent
 112 @{
 113 */
 114
 115 /**
 116 @struct bt_event
 117 @brief A CTF IR event.
 118 @sa ctfirevent
 119 */
 120 struct bt_event;
 121 struct bt_clock;
 122 struct bt_clock_value;
 123 struct bt_event_class;
 124 struct bt_field;
 125 struct bt_field_type;
 126 struct bt_stream_class;
 127 struct bt_packet;
 128
 129 /**
 130 @name Creation and parent access functions
 131 @{
 132 */
 133
 134 /**
 135 @brief  Creates a default CTF IR event from the CTF IR event class
 136         \p event_class.
 137
 138 \p event_class \em must have a parent
 139 \link ctfirstreamclass CTF IR stream class\endlink.
 140
 141 On success, the four fields of the created event object are not set. You
 142 can set them with bt_event_set_header(),
 143 bt_event_set_stream_event_context(),
 144 bt_event_set_context(), and bt_event_set_payload().
 145
 146 This function tries to resolve the needed
 147 \link ctfirfieldtypes CTF IR field type\endlink of the dynamic field
 148 types that are found anywhere in the context or payload field
 149 types of \p event_class and in the root field types of the
 150 parent stream class of \p event_class. If any automatic resolving fails,
 151 this function fails. This means that, if any dynamic field type need
 152 a field type which should be found in the trace packet header root
 153 field type, and if the parent stream class of \p event_class was not
 154 added to a \link ctfirtraceclass CTF IR trace class\endlink yet
 155 with bt_trace_add_stream_class(), then this function fails.
 156
 157 @param[in] event_class  CTF IR event class to use to create the
 158                         CTF IR event.
 159 @returns                Created event object, or \c NULL on error.
 160
 161 @prenotnull{event_class}
 162 @pre \p event_class has a parent stream class.
 163 @postsuccessrefcountret1
 164 */
 165 extern struct bt_event *bt_event_create(struct bt_event_class *event_class);
 166
 167 /**
 168 @brief  Returns the parent CTF IR event class of the CTF IR event
 169         \p event.
 170
 171 This function returns a reference to the event class which was used to
 172 create the event object in the first place with bt_event_create().
 173
 174 @param[in] event        Event of which to get the parent event class.
 175 @returns                Parent event class of \p event,
 176                         or \c NULL on error.
 177
 178 @prenotnull{event}
 179 @postrefcountsame{event}
 180 @postsuccessrefcountretinc
 181 */
 182 extern struct bt_event_class *bt_event_get_class(struct bt_event *event);
 183
 184 /**
 185 @brief  Returns the CTF IR packet associated to the CTF IR event
 186         \p event.
 187
 188 This function returns a reference to the event class which was set to
 189 \p event in the first place with bt_event_set_packet().
 190
 191 @param[in] event        Event of which to get the associated packet.
 192 @returns                Packet associated to \p event,
 193                         or \c NULL if no packet is associated to
 194                         \p event or on error.
 195
 196 @prenotnull{event}
 197 @postrefcountsame{event}
 198 @postsuccessrefcountretinc
 199
 200 @sa bt_event_set_packet(): Associates a given event to a given
 201         packet.
 202 */
 203 extern struct bt_packet *bt_event_get_packet(struct bt_event *event);
 204
 205 /**
 206 @brief  Associates the CTF IR event \p event to the CTF IR packet
 207         \p packet.
 208
 209 The \link ctfirstreamclass CTF IR stream class\endlink of the
 210 parent \link ctfirstream CTF IR stream\endlink of \p packet \em must
 211 be the same as the parent stream class of the
 212 \link ctfireventclass CTF IR event class\endlink returned
 213 by bt_event_get_class() for \p event.
 214
 215 You \em must call this function to create an event-packet association
 216 before you call bt_notification_event_create() with \p event.
 217
 218 On success, this function also sets the parent stream object of
 219 \p event to the parent stream of \p packet.
 220
 221 @param[in] event        Event to which to associate \p packet.
 222 @param[in] packet       Packet to associate to \p event.
 223 @returns                0 on success, or a negative value on error.
 224
 225 @prenotnull{event}
 226 @prenotnull{packet}
 227 @prehot{event}
 228 @pre The parent stream class of \p packet is the same as the parent
 229         stream class of \p event.
 230 @postsuccessrefcountretinc
 231
 232 @sa bt_event_get_packet(): Returns the associated packet of a
 233         given event object.
 234 */
 235 extern int bt_event_set_packet(struct bt_event *event,
 236                 struct bt_packet *packet);
 237
 238 /**
 239 @brief  Returns the parent CTF IR stream associated to the CTF IR event
 240         \p event.
 241
 242 @param[in] event        Event of which to get the parent stream.
 243 @returns                Parent stream of \p event, or \c NULL on error.
 244
 245 @prenotnull{event}
 246 @postrefcountsame{event}
 247 @postsuccessrefcountretinc
 248 */
 249 extern struct bt_stream *bt_event_get_stream(struct bt_event *event);
 250
 251 /** @} */
 252
 253 /**
 254 @name Contained fields functions
 255 @{
 256 */
 257
 258 /**
 259 @brief  Returns the stream event header field of the CTF IR event
 260         \p event.
 261
 262 @param[in] event        Event of which to get the stream event header
 263                         field.
 264 @returns                Stream event header field of \p event,
 265                         or \c NULL if the stream event header
 266                         field is not set or on error.
 267
 268 @prenotnull{event}
 269 @postrefcountsame{event}
 270 @postsuccessrefcountretinc
 271
 272 @sa bt_event_get_header(): Sets the stream event header
 273         field of a given event.
 274 */
 275 extern struct bt_field *bt_event_get_header(struct bt_event *event);
 276
 277 /**
 278 @brief  Sets the stream event header field of the CTF IR event
 279         \p event to \p header, or unsets the current stream event header field
 280         from \p event.
 281
 282 If \p header is not \c NULL, the field type of \p header, as returned by
 283 bt_field_get_type(), \em must be equivalent to the field type returned by
 284 bt_stream_class_get_event_header_type() for the parent stream class
 285 of \p event.
 286
 287 @param[in] event        Event of which to set the stream event header
 288                         field.
 289 @param[in] header       Stream event header field.
 290 @returns                0 on success, or a negative value on error.
 291
 292 @prenotnull{event}
 293 @prehot{event}
 294 @pre <strong>\p header, if not \c NULL</strong>, has a field type equivalent to
 295         the field type returned by bt_stream_class_get_event_header_type()
 296         for the parent stream class of \p event.
 297 @postrefcountsame{event}
 298 @post <strong>On success, if \p header is not \c NULL</strong>,
 299         the reference count of \p header is incremented.
 300
 301 @sa bt_event_get_header(): Returns the stream event header field
 302         of a given event.
 303 */
 304 extern int bt_event_set_header(struct bt_event *event,
 305                 struct bt_field *header);
 306
 307 /**
 308 @brief  Returns the stream event context field of the CTF IR event
 309         \p event.
 310
 311 @param[in] event        Event of which to get the stream event context
 312                         field.
 313 @returns                Stream event context field of \p event,
 314                         or \c NULL if the stream event context
 315                         field is not set or on error.
 316
 317 @prenotnull{event}
 318 @postrefcountsame{event}
 319 @postsuccessrefcountretinc
 320
 321 @sa bt_event_set_stream_event_context(): Sets the stream event context
 322         field of a given event.
 323 */
 324 extern struct bt_field *bt_event_get_stream_event_context(
 325                 struct bt_event *event);
 326
 327 /**
 328 @brief  Sets the stream event context field of the CTF IR event
 329         \p event to \p context, or unsets the current stream event context field
 330         from \p event.
 331
 332 If \p context is not \c NULL, the field type of \p context, as returned by
 333 bt_field_get_type(), \em must be equivalent to the field type returned by
 334 bt_stream_class_get_event_context_type() for the parent stream class
 335 of \p event.
 336
 337 @param[in] event        Event of which to set the stream event context field.
 338 @param[in] context      Stream event context field.
 339 @returns                0 on success, or a negative value on error.
 340
 341 @prenotnull{event}
 342 @prehot{event}
 343 @pre <strong>\p context, if not \c NULL</strong>, has a field type equivalent to
 344         the field type returned by bt_stream_class_get_event_context_type()
 345         for the parent stream class of \p event.
 346 @postrefcountsame{event}
 347 @post <strong>On success, if \p context is not \c NULL</strong>, the reference
 348         count of \p context is incremented.
 349
 350 @sa bt_event_get_stream_event_context(): Returns the stream event context
 351         field of a given event.
 352 */
 353 extern int bt_event_set_stream_event_context(struct bt_event *event,
 354                 struct bt_field *context);
 355
 356 /**
 357 @brief  Returns the event context field of the CTF IR event \p event.
 358
 359 @param[in] event        Event of which to get the context field.
 360 @returns                Event context field of \p event, or \c NULL if the
 361                         event context field is not set or on error.
 362
 363 @prenotnull{event}
 364 @postrefcountsame{event}
 365 @postsuccessrefcountretinc
 366
 367 @sa bt_event_set_context(): Sets the event context field of a given
 368         event.
 369 */
 370 extern struct bt_field *bt_event_get_context(struct bt_event *event);
 371
 372 /**
 373 @brief  Sets the event context field of the CTF IR event \p event to \p context,
 374         or unsets the current event context field from \p event.
 375
 376 If \p context is not \c NULL, the field type of \p context, as returned by
 377 bt_field_get_type(), \em must be equivalent to the field type returned by
 378 bt_event_class_get_context_type() for the parent class of \p event.
 379
 380 @param[in] event        Event of which to set the context field.
 381 @param[in] context      Event context field.
 382 @returns                0 on success, or a negative value on error.
 383
 384 @prenotnull{event}
 385 @prehot{event}
 386 @pre <strong>\p context, if not \c NULL</strong>, has a field type equivalent to
 387         the field type returned by bt_event_class_get_context_type() for the
 388         parent class of \p event.
 389 @postrefcountsame{event}
 390 @post <strong>On success, if \p context is not \c NULL</strong>, the reference
 391         count of \p context is incremented.
 392
 393 @sa bt_event_get_context(): Returns the context field of a given event.
 394 */
 395 extern int bt_event_set_context(struct bt_event *event,
 396                 struct bt_field *context);
 397
 398 /**
 399 @brief  Returns the payload field of the CTF IR event \p event.
 400
 401 @param[in] event        Event of which to get the payload field.
 402 @returns                Payload field of \p event, or \c NULL if the payload
 403                         field is not set or on error.
 404
 405 @prenotnull{event}
 406 @postrefcountsame{event}
 407 @postsuccessrefcountretinc
 408
 409 @sa bt_event_set_payload(): Sets the payload field of a given
 410         event.
 411 */
 412 extern struct bt_field *bt_event_get_payload(struct bt_event *event);
 413
 414 /**
 415 @brief  Sets the payload field of the CTF IR event \p event to \p payload,
 416         or unsets the current event payload field from \p event.
 417
 418 If \p payload is not \c NULL, the field type of \p payload, as returned by
 419 bt_field_get_type(), \em must be equivalent to the field type returned by
 420 bt_event_class_get_payload_type() for the parent class of \p event.
 421
 422 @param[in] event        Event of which to set the payload field.
 423 @param[in] payload      Event payload field.
 424 @returns                0 on success, or a negative value on error.
 425
 426 @prenotnull{event}
 427 @prehot{event}
 428 @pre <strong>\p payload, if not \c NULL</strong>, has a field type equivalent to
 429         the field typereturned by bt_event_class_get_payload_type() for the
 430         parent class of \p event.
 431 @postrefcountsame{event}
 432 @post <strong>On success, if \p payload is not \c NULL</strong>, the reference
 433         count of \p payload is incremented.
 434
 435 @sa bt_event_get_payload(): Returns the payload field of a given event.
 436 */
 437 extern int bt_event_set_payload(struct bt_event *event,
 438                 struct bt_field *payload);
 439
 440 /** @} */
 441
 442 /**
 443 @name Clock value functions
 444 @{
 445 */
 446
 447 /**
 448 @brief  Returns the value, as of the CTF IR event \p event, of the
 449         clock described by the
 450         \link ctfirclockclass CTF IR clock class\endlink \p clock_class.
 451
 452 @param[in] event        Event of which to get the value of the clock
 453                         described by \p clock_class.
 454 @param[in] clock_class  Class of the clock of which to get the value.
 455 @returns                Value of the clock described by \p clock_class
 456                         as of \p event.
 457
 458 @prenotnull{event}
 459 @prenotnull{clock_class}
 460 @postrefcountsame{event}
 461 @postrefcountsame{clock_class}
 462 @postsuccessrefcountretinc
 463
 464 @sa bt_event_set_clock_value(): Sets the clock value of a given event.
 465 */
 466 extern struct bt_clock_value *bt_event_get_clock_value(
 467                 struct bt_event *event,
 468                 struct bt_clock_class *clock_class);
 469
 470 /**
 471 @brief  Sets the value, as of the CTF IR event \p event, of the
 472         clock described by its \link ctfirclockclass CTF IR
 473         clock class\endlink.
 474
 475 @param[in] event        Event of which to set the value of the clock
 476                         described by the clock class of \p clock_value.
 477 @param[in] clock_value  Value of the clock described by its clock class
 478                         as of \p event.
 479 @returns                0 on success, or a negative value on error.
 480
 481 @prenotnull{event}
 482 @prenotnull{clock_value}
 483 @prehot{event}
 484 @postrefcountsame{event}
 485
 486 @sa bt_event_get_clock_value(): Returns the clock value of
 487         a given event.
 488 */
 489 extern int bt_event_set_clock_value(
 490                 struct bt_event *event,
 491                 struct bt_clock_value *clock_value);
 492
 493 /** @} */
 494
 495 /** @} */
 496
 497 #ifdef __cplusplus
 498 }
 499 #endif
 500
 501 #endif /* BABELTRACE_CTF_IR_EVENT_H */