include/babeltrace/ctf-ir/stream-class.h

   1 #ifndef BABELTRACE_CTF_IR_STREAM_CLASS_H
   2 #define BABELTRACE_CTF_IR_STREAM_CLASS_H
   3
   4 /*
   5  * BabelTrace - CTF IR: Stream Class
   6  *
   7  * Copyright 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 <babeltrace/ctf-ir/visitor.h>
  35
  36 #ifdef __cplusplus
  37 extern "C" {
  38 #endif
  39
  40 /**
  41 @defgroup ctfirstreamclass CTF IR stream class
  42 @ingroup ctfir
  43 @brief CTF IR stream class.
  44
  45 @code
  46 #include <babeltrace/ctf-ir/stream-class.h>
  47 @endcode
  48
  49 @note
  50 See \ref ctfirwriterstreamclass which documents additional CTF IR stream
  51 class functions exclusive to the CTF IR writer mode.
  52
  53 A CTF IR <strong><em>stream class</em></strong> is a template that you
  54 can use to create concrete \link ctfirstream CTF IR streams\endlink.
  55
  56 A stream class has the following properties, both of which \em must
  57 be unique amongst all the stream classes contained in the same
  58 \link ctfirtraceclass CTF IR trace class\endlink:
  59
  60 - A \b name.
  61 - A numeric \b ID.
  62
  63 In the Babeltrace CTF IR system, a \link ctfirtraceclass trace class\endlink
  64 contains zero or more stream classes,
  65 and a stream class contains zero or more
  66 \link ctfireventclass event classes\endlink.
  67 You can add an event class
  68 to a stream class with bt_ctf_stream_class_add_event_class().
  69 You can add a stream class to a trace class with
  70 bt_ctf_trace_add_stream_class().
  71
  72 A stream class owns three \link ctfirfieldtypes field types\endlink:
  73
  74 - An optional <strong>stream packet context</strong> field type, which
  75   represents the \c stream.packet.context CTF scope.
  76 - An optional <strong>stream event header</strong> field type, which
  77   represents the \c stream.event.header CTF scope.
  78 - An optional <strong>stream event context</strong> field type, which
  79   represents the \c stream.event.context CTF scope.
  80
  81 Those three field types \em must be structure field types as of
  82 Babeltrace \btversion.
  83
  84 As per the CTF specification, the event header field type \em must
  85 contain a field named \c id if the stream class contains more than one
  86 event class.
  87
  88 As a reminder, here's the structure of a CTF packet:
  89
  90 @imgpacketstructure
  91
  92 Before you can create a stream from a stream class with
  93 bt_ctf_stream_create(), you \em must add the prepared stream class to a
  94 trace class by calling bt_ctf_trace_add_stream_class().
  95
  96 As with any Babeltrace object, CTF IR stream class objects have
  97 <a href="https://en.wikipedia.org/wiki/Reference_counting">reference
  98 counts</a>. See \ref refs to learn more about the reference counting
  99 management of Babeltrace objects.
 100
 101 The following functions \em freeze their stream class parameter on
 102 success:
 103
 104 - bt_ctf_trace_add_stream_class()
 105 - bt_ctf_event_create()
 106 - bt_ctf_writer_create_stream()
 107   (\link ctfirwriter CTF IR writer\endlink mode only)
 108
 109 You cannot modify a frozen stream class: it is considered immutable,
 110 except for:
 111
 112 - Adding an event class to it with
 113   bt_ctf_stream_class_add_event_class().
 114 - \link refs Reference counting\endlink.
 115
 116 @sa ctfirstream
 117 @sa ctfireventclass
 118 @sa ctfirtraceclass
 119 @sa ctfirwriterstreamclass
 120
 121 @file
 122 @brief CTF IR stream class type and functions.
 123 @sa ctfirstreamclass
 124
 125 @addtogroup ctfirstreamclass
 126 @{
 127 */
 128
 129 /**
 130 @struct bt_ctf_stream_class
 131 @brief A CTF IR stream class.
 132 @sa ctfirstreamclass
 133 */
 134 struct bt_ctf_stream_class;
 135 struct bt_ctf_event_class;
 136 struct bt_ctf_clock;
 137
 138 /**
 139 @name Creation and parent access functions
 140 @{
 141 */
 142
 143 /**
 144 @brief  Creates a default CTF IR stream class named \p name, or a
 145         default unnamed stream class if \p name is \c NULL.
 146
 147 On success, the packet context field type of the created stream class
 148 has the following fields:
 149
 150 - <code>timestamp_begin</code>: a 64-bit unsigned integer field type.
 151 - <code>timestamp_end</code>: a 64-bit unsigned integer field type.
 152 - <code>content_size</code>: a 64-bit unsigned integer field type.
 153 - <code>packet_size</code>: a 64-bit unsigned integer field type.
 154 - <code>events_discarded</code>: a 64-bit unsigned integer field type.
 155
 156 On success, the event header field type of the created stream class
 157 has the following fields:
 158
 159 - <code>code</code>: a 32-bit unsigned integer field type.
 160 - <code>timestamp</code>: a 64-bit unsigned integer field type.
 161
 162 You can modify those default field types after the stream class is
 163 created with bt_ctf_stream_class_set_packet_context_type() and
 164 bt_ctf_stream_class_set_event_header_type().
 165
 166 @param[in] name Name of the stream class to create (can be \c NULL to
 167                 create an unnamed stream class).
 168 @returns        Created stream class, or \c NULL on error.
 169
 170 @postsuccessrefcountret1
 171 */
 172 extern struct bt_ctf_stream_class *bt_ctf_stream_class_create(const char *name);
 173
 174 /**
 175 @brief  Returns the parent CTF IR trace class of the CTF IR stream
 176         class \p stream_class.
 177
 178 It is possible that the stream class was not added to a trace class
 179 yet, in which case this function returns \c NULL. You can add a
 180 stream class to a trace class with
 181 bt_ctf_trace_add_stream_class().
 182
 183 @param[in] stream_class Stream class of which to get the parent
 184                         trace class.
 185 @returns                Parent trace class of \p stream_class,
 186                         or \c NULL if \p stream_class was not
 187                         added to a trace class yet or on error.
 188
 189 @prenotnull{stream_class}
 190 @postrefcountsame{stream_class}
 191 @postsuccessrefcountretinc
 192
 193 @sa bt_ctf_trace_add_stream_class(): Add a stream class to
 194         a trace class.
 195 */
 196 extern struct bt_ctf_trace *bt_ctf_stream_class_get_trace(
 197                 struct bt_ctf_stream_class *stream_class);
 198
 199 /** @} */
 200
 201 /**
 202 @name Properties functions
 203 @{
 204 */
 205
 206 /**
 207 @brief  Returns the name of the CTF IR stream class \p stream_class.
 208
 209 On success, \p stream_class remains the sole owner of the returned
 210 string.
 211
 212 @param[in] stream_class Stream class of which to get the name.
 213 @returns                Name of stream class \p stream_class, or
 214                         \c NULL if \p stream_class is unnamed or
 215                         on error.
 216
 217 @prenotnull{stream_class}
 218 @postrefcountsame{stream_class}
 219
 220 @sa bt_ctf_stream_class_set_name(): Sets the name of a given
 221         stream class.
 222 */
 223 extern const char *bt_ctf_stream_class_get_name(
 224                 struct bt_ctf_stream_class *stream_class);
 225
 226 /**
 227 @brief  Sets the name of the CTF IR stream class
 228         \p stream_class to \p name.
 229
 230 \p name must be unique amongst the names of all the stream classes
 231 of the trace class to which you eventually add \p stream_class.
 232
 233 @param[in] stream_class Stream class of which to set the name.
 234 @param[in] name         Name of the stream class (copied on success).
 235 @returns                0 on success, or a negative value on error.
 236
 237 @prenotnull{stream_class}
 238 @prenotnull{name}
 239 @prehot{stream_class}
 240 @postrefcountsame{stream_class}
 241
 242 @sa bt_ctf_stream_class_get_name(): Returns the name of a given
 243         stream class.
 244 */
 245 extern int bt_ctf_stream_class_set_name(
 246                 struct bt_ctf_stream_class *stream_class, const char *name);
 247
 248 /**
 249 @brief  Returns the numeric ID of the CTF IR stream class \p stream_class.
 250
 251 @param[in] stream_class Stream class of which to get the numeric ID.
 252 @returns                ID of stream class \p stream_class, or a
 253                         negative value on error.
 254
 255 @prenotnull{stream_class}
 256 @postrefcountsame{stream_class}
 257
 258 @sa bt_ctf_stream_class_set_id(): Sets the numeric ID of a given
 259         stream class.
 260 */
 261 extern int64_t bt_ctf_stream_class_get_id(
 262                 struct bt_ctf_stream_class *stream_class);
 263
 264 /**
 265 @brief  Sets the numeric ID of the CTF IR stream class
 266         \p stream_class to \p id.
 267
 268 \p id must be unique amongst the IDs of all the stream classes
 269 of the trace class to which you eventually add \p stream_class.
 270
 271 @param[in] stream_class Stream class of which to set the numeric ID.
 272 @param[in] id           ID of the stream class.
 273 @returns                0 on success, or a negative value on error.
 274
 275 @prenotnull{stream_class}
 276 @prehot{stream_class}
 277 @postrefcountsame{stream_class}
 278
 279 @sa bt_ctf_stream_class_get_id(): Returns the numeric ID of a given
 280         stream class.
 281 */
 282 extern int bt_ctf_stream_class_set_id(
 283                 struct bt_ctf_stream_class *stream_class, uint32_t id);
 284
 285 /** @} */
 286
 287 /**
 288 @name Contained field types functions
 289 @{
 290 */
 291
 292 /**
 293 @brief  Returns the packet context field type of the CTF IR stream class
 294         \p stream_class.
 295
 296 @param[in] stream_class Stream class of which to get the packet
 297                         context field type.
 298 @returns                Packet context field type of \p stream_class,
 299                         or \c NULL on error.
 300
 301 @prenotnull{stream_class}
 302 @postrefcountsame{stream_class}
 303 @postsuccessrefcountretinc
 304
 305 @sa bt_ctf_stream_class_set_packet_context_type(): Sets the packet
 306         context field type of a given stream class.
 307 */
 308 extern struct bt_ctf_field_type *bt_ctf_stream_class_get_packet_context_type(
 309                 struct bt_ctf_stream_class *stream_class);
 310
 311 /**
 312 @brief  Sets the packet context field type of the CTF IR stream class
 313         \p stream_class to \p packet_context_type.
 314
 315 As of Babeltrace \btversion, \p packet_context_type \em must be a
 316 CTF IR structure field type object.
 317
 318 @param[in] stream_class         Stream class of which to set the packet
 319                                 context field type.
 320 @param[in] packet_context_type  Packet context field type.
 321 @returns                        0 on success, or a negative value on error.
 322
 323 @prenotnull{stream_class}
 324 @prenotnull{packet_context_type}
 325 @prehot{stream_class}
 326 @preisstructft{packet_context_type}
 327 @postrefcountsame{stream_class}
 328 @postsuccessrefcountinc{packet_context_type}
 329
 330 @sa bt_ctf_stream_class_get_packet_context_type(): Returns the packet
 331         context field type of a given stream class.
 332 */
 333 extern int bt_ctf_stream_class_set_packet_context_type(
 334                 struct bt_ctf_stream_class *stream_class,
 335                 struct bt_ctf_field_type *packet_context_type);
 336
 337 /**
 338 @brief  Returns the event header field type of the CTF IR stream class
 339         \p stream_class.
 340
 341 @param[in] stream_class Stream class of which to get the event header
 342                         field type.
 343 @returns                Event header field type of \p stream_class,
 344                         or \c NULL on error.
 345
 346 @prenotnull{stream_class}
 347 @postrefcountsame{stream_class}
 348 @postsuccessrefcountretinc
 349
 350 @sa bt_ctf_stream_class_set_event_header_type(): Sets the event
 351         header field type of a given stream class.
 352 */
 353 extern struct bt_ctf_field_type *
 354 bt_ctf_stream_class_get_event_header_type(
 355                 struct bt_ctf_stream_class *stream_class);
 356
 357 /**
 358 @brief  Sets the event header field type of the CTF IR stream class
 359         \p stream_class to \p event_header_type.
 360
 361 As of Babeltrace \btversion, \p event_header_type \em must be a
 362 CTF IR structure field type object.
 363
 364 @param[in] stream_class         Stream class of which to set the event
 365                                 header field type.
 366 @param[in] event_header_type    Event header field type.
 367 @returns                        0 on success, or a negative value on error.
 368
 369 @prenotnull{stream_class}
 370 @prenotnull{event_header_type}
 371 @prehot{stream_class}
 372 @preisstructft{event_header_type}
 373 @postrefcountsame{stream_class}
 374 @postsuccessrefcountinc{event_header_type}
 375
 376 @sa bt_ctf_stream_class_get_event_header_type(): Returns the event
 377         header field type of a given stream class.
 378 */
 379 extern int bt_ctf_stream_class_set_event_header_type(
 380                 struct bt_ctf_stream_class *stream_class,
 381                 struct bt_ctf_field_type *event_header_type);
 382
 383 /**
 384 @brief  Returns the per-stream class event context field type of the
 385         CTF IR stream class \p stream_class.
 386
 387 @param[in] stream_class Stream class of which to get the per-stream
 388                         class event context field type.
 389 @returns                Per-stream class event context field type of
 390                         \p stream_class, or \c NULL on error.
 391
 392 @prenotnull{stream_class}
 393 @postrefcountsame{stream_class}
 394 @postsuccessrefcountretinc
 395
 396 @sa bt_ctf_stream_class_set_event_context_type(): Sets the per-stream
 397         class event context field type of a given stream class.
 398 */
 399 extern struct bt_ctf_field_type *
 400 bt_ctf_stream_class_get_event_context_type(
 401                 struct bt_ctf_stream_class *stream_class);
 402
 403 /**
 404 @brief  Sets the per-stream class event context field type of the CTF
 405         IR stream class \p stream_class to \p event_context_type.
 406
 407 As of Babeltrace \btversion, \p event_context_type \em must be a
 408 CTF IR structure field type object.
 409
 410 @param[in] stream_class         Stream class of which to set the
 411                                 per-stream class event context
 412                                 field type.
 413 @param[in] event_context_type   Per-stream class event context context
 414                                 field type.
 415 @returns                        0 on success, or a negative value on error.
 416
 417 @prenotnull{stream_class}
 418 @prenotnull{event_context_type}
 419 @prehot{stream_class}
 420 @preisstructft{event_context_type}
 421 @postrefcountsame{stream_class}
 422 @postsuccessrefcountinc{event_context_type}
 423
 424 @sa bt_ctf_stream_class_get_event_context_type(): Returns the per-stream
 425         class event context field type of a given stream class.
 426 */
 427 extern int bt_ctf_stream_class_set_event_context_type(
 428                 struct bt_ctf_stream_class *stream_class,
 429                 struct bt_ctf_field_type *event_context_type);
 430
 431 /** @} */
 432
 433 /**
 434 @name Event class children functions
 435 @{
 436 */
 437
 438 /**
 439 @brief  Returns the number of event classes contained in the
 440         CTF IR stream class \p stream_class.
 441
 442 @param[in] stream_class Stream class of which to get the number
 443                         of children event classes.
 444 @returns                Number of children event classes
 445                         contained in \p stream_class, or
 446                         a negative value on error.
 447
 448 @prenotnull{stream_class}
 449 @postrefcountsame{stream_class}
 450 */
 451 extern int bt_ctf_stream_class_get_event_class_count(
 452                 struct bt_ctf_stream_class *stream_class);
 453
 454 /**
 455 @brief  Returns the event class at index \p index in the CTF IR stream
 456         class \p stream_class.
 457
 458 @param[in] stream_class Stream class of which to get the event class.
 459 @param[in] index        Index of the event class to find.
 460 @returns                Event class at index \p index, or \c NULL
 461                         on error.
 462
 463 @prenotnull{stream_class}
 464 @pre \p index is lesser than the number of event classes contained in the
 465         stream class \p stream_class (see
 466         bt_ctf_stream_class_get_event_class_count()).
 467 @postrefcountsame{stream_class}
 468 @postsuccessrefcountretinc
 469
 470 @sa bt_ctf_stream_class_get_event_class_by_id(): Finds an event class
 471         by ID.
 472 @sa bt_ctf_stream_class_get_event_class_by_name(): Finds an event class
 473         by name.
 474 */
 475 extern struct bt_ctf_event_class *bt_ctf_stream_class_get_event_class(
 476                 struct bt_ctf_stream_class *stream_class, int index);
 477
 478 /**
 479 @brief  Returns the event class named \c name found in the CTF IR stream
 480         class \p stream_class.
 481
 482 @param[in] stream_class Stream class of which to get the event class.
 483 @param[in] name         Name of the event class to find.
 484 @returns                Event class named \p name, or \c NULL
 485                         on error.
 486
 487 @prenotnull{stream_class}
 488 @prenotnull{name}
 489 @postrefcountsame{stream_class}
 490 @postsuccessrefcountretinc
 491
 492 @sa bt_ctf_stream_class_get_event_class_by_id(): Finds an event class
 493         by ID.
 494 */
 495 extern struct bt_ctf_event_class *bt_ctf_stream_class_get_event_class_by_name(
 496                 struct bt_ctf_stream_class *stream_class, const char *name);
 497
 498 /**
 499 @brief  Returns the event class with ID \c id found in the CTF IR stream
 500         class \p stream_class.
 501
 502 @param[in] stream_class Stream class of which to get the event class.
 503 @param[in] id           ID of the event class to find.
 504 @returns                Event class with ID \p id, or \c NULL
 505                         on error.
 506
 507 @prenotnull{stream_class}
 508 @postrefcountsame{stream_class}
 509 @postsuccessrefcountretinc
 510
 511 @sa bt_ctf_stream_class_get_event_class_by_name(): Finds an event class
 512         by name.
 513 */
 514 extern struct bt_ctf_event_class *bt_ctf_stream_class_get_event_class_by_id(
 515                 struct bt_ctf_stream_class *stream_class, uint32_t id);
 516
 517 /**
 518 @brief  Adds the CTF IR event class \p event_class to the
 519         CTF IR stream class \p stream_class.
 520
 521 On success, \p event_class becomes the child of \p stream_class.
 522
 523 You can only add a given event class to one stream class.
 524
 525 You can call this function even if \p stream_class is frozen. Adding
 526 event classes is the only operation that is permitted
 527 on a frozen stream class.
 528
 529 @param[in] stream_class Stream class to which to add \p event_class.
 530 @param[in] event_class  Event class to add to \p stream_class.
 531 @returns                0 on success, or a negative value on error.
 532
 533 @prenotnull{stream_class}
 534 @prenotnull{event_class}
 535 @prehot{event_class}
 536 @postrefcountsame{stream_class}
 537 @postsuccessrefcountinc{event_class}
 538 @postsuccessfrozen{event_class}
 539 */
 540 extern int bt_ctf_stream_class_add_event_class(
 541                 struct bt_ctf_stream_class *stream_class,
 542                 struct bt_ctf_event_class *event_class);
 543
 544 /** @} */
 545
 546 /**
 547 @name Misc. function
 548 @{
 549 */
 550
 551 /**
 552 @brief  Accepts the visitor \p visitor to visit the hierarchy of the
 553         CTF IR stream class \p stream_class.
 554
 555 This function traverses the hierarchy of \p stream_class in pre-order
 556 and calls \p visitor on each element.
 557
 558 The stream class itself is visited first, and then all its children
 559 event classes.
 560
 561 @param[in] stream_class Stream class to visit.
 562 @param[in] visitor      Visiting function.
 563 @param[in] data         User data.
 564 @returns                0 on success, or a negative value on error.
 565
 566 @prenotnull{stream_class}
 567 @prenotnull{visitor}
 568 */
 569 extern int bt_ctf_stream_class_visit(struct bt_ctf_stream_class *stream_class,
 570                 bt_ctf_visitor visitor, void *data);
 571
 572 /** @} */
 573
 574 /** @} */
 575
 576 // TODO: document for writer
 577 extern struct bt_ctf_clock *bt_ctf_stream_class_get_clock(
 578                 struct bt_ctf_stream_class *stream_class);
 579
 580 #ifdef __cplusplus
 581 }
 582 #endif
 583
 584 #endif /* BABELTRACE_CTF_IR_STREAM_CLASS_H */