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 ctfwriterstreamclass which documents additional CTF IR stream
  51 class functions exclusive to the CTF 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 ctfwriter CTF 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(). If the stream class's parent
 114   \link ctfirtraceclass trace class\endlink is static, however,
 115   you cannot call bt_ctf_stream_class_add_event_class()
 116   (see bt_ctf_trace_is_static() and bt_ctf_trace_set_is_static()).
 117 - \link refs Reference counting\endlink.
 118
 119 @sa ctfirstream
 120 @sa ctfireventclass
 121 @sa ctfirtraceclass
 122 @sa ctfwriterstreamclass
 123
 124 @file
 125 @brief CTF IR stream class type and functions.
 126 @sa ctfirstreamclass
 127
 128 @addtogroup ctfirstreamclass
 129 @{
 130 */
 131
 132 /**
 133 @struct bt_ctf_stream_class
 134 @brief A CTF IR stream class.
 135 @sa ctfirstreamclass
 136 */
 137 struct bt_ctf_stream_class;
 138 struct bt_ctf_event_class;
 139 struct bt_ctf_clock;
 140
 141 /**
 142 @name Creation and parent access functions
 143 @{
 144 */
 145
 146 /**
 147 @brief  Creates an empty CTF IR stream class named \p name, or an
 148         unnamed empty stream class if \p name is \c NULL.
 149
 150 On success, the packet context, event header, and event context field
 151 types are empty structure field types. You can modify those default
 152 field types after the stream class is created with
 153 bt_ctf_stream_class_set_packet_context_type(),
 154 bt_ctf_stream_class_set_event_header_type(), and
 155 bt_ctf_stream_class_set_event_context_type().
 156
 157 @param[in] name Name of the stream class to create (copied on success),
 158                 or \c NULL to create an unnamed stream class.
 159 @returns        Created empty stream class, or \c NULL on error.
 160
 161 @postsuccessrefcountret1
 162
 163 @sa bt_ctf_stream_class_create(): Creates a default stream class.
 164 */
 165 extern struct bt_ctf_stream_class *bt_ctf_stream_class_create_empty(
 166                 const char *name);
 167
 168 /**
 169 @brief  Creates a default CTF IR stream class named \p name, or a
 170         default unnamed stream class if \p name is \c NULL.
 171
 172 On success, the packet context field type of the created stream class
 173 has the following fields:
 174
 175 - <code>timestamp_begin</code>: a 64-bit unsigned integer field type.
 176 - <code>timestamp_end</code>: a 64-bit unsigned integer field type.
 177 - <code>content_size</code>: a 64-bit unsigned integer field type.
 178 - <code>packet_size</code>: a 64-bit unsigned integer field type.
 179 - <code>events_discarded</code>: a 64-bit unsigned integer field type.
 180
 181 On success, the event header field type of the created stream class
 182 has the following fields:
 183
 184 - <code>code</code>: a 32-bit unsigned integer field type.
 185 - <code>timestamp</code>: a 64-bit unsigned integer field type.
 186
 187 You can modify those default field types after the stream class is
 188 created with bt_ctf_stream_class_set_packet_context_type() and
 189 bt_ctf_stream_class_set_event_header_type().
 190
 191 @param[in] name Name of the stream class to create (copied on success),
 192                 or \c NULL to create an unnamed stream class.
 193 @returns        Created default stream class, or \c NULL on error.
 194
 195 @postsuccessrefcountret1
 196
 197 @sa bt_ctf_stream_class_create_empty(): Creates an empty stream class.
 198 */
 199 extern struct bt_ctf_stream_class *bt_ctf_stream_class_create(const char *name);
 200
 201 /**
 202 @brief  Returns the parent CTF IR trace class of the CTF IR stream
 203         class \p stream_class.
 204
 205 It is possible that the stream class was not added to a trace class
 206 yet, in which case this function returns \c NULL. You can add a
 207 stream class to a trace class with
 208 bt_ctf_trace_add_stream_class().
 209
 210 @param[in] stream_class Stream class of which to get the parent
 211                         trace class.
 212 @returns                Parent trace class of \p stream_class,
 213                         or \c NULL if \p stream_class was not
 214                         added to a trace class yet or on error.
 215
 216 @prenotnull{stream_class}
 217 @postrefcountsame{stream_class}
 218 @postsuccessrefcountretinc
 219
 220 @sa bt_ctf_trace_add_stream_class(): Add a stream class to
 221         a trace class.
 222 */
 223 extern struct bt_ctf_trace *bt_ctf_stream_class_get_trace(
 224                 struct bt_ctf_stream_class *stream_class);
 225
 226 /** @} */
 227
 228 /**
 229 @name Properties functions
 230 @{
 231 */
 232
 233 /**
 234 @brief  Returns the name of the CTF IR stream class \p stream_class.
 235
 236 On success, \p stream_class remains the sole owner of the returned
 237 string.
 238
 239 @param[in] stream_class Stream class of which to get the name.
 240 @returns                Name of stream class \p stream_class, or
 241                         \c NULL if \p stream_class is unnamed or
 242                         on error.
 243
 244 @prenotnull{stream_class}
 245 @postrefcountsame{stream_class}
 246
 247 @sa bt_ctf_stream_class_set_name(): Sets the name of a given
 248         stream class.
 249 */
 250 extern const char *bt_ctf_stream_class_get_name(
 251                 struct bt_ctf_stream_class *stream_class);
 252
 253 /**
 254 @brief  Sets the name of the CTF IR stream class
 255         \p stream_class to \p name.
 256
 257 \p name must be unique amongst the names of all the stream classes
 258 of the trace class to which you eventually add \p stream_class.
 259
 260 @param[in] stream_class Stream class of which to set the name.
 261 @param[in] name         Name of the stream class (copied on success).
 262 @returns                0 on success, or a negative value on error.
 263
 264 @prenotnull{stream_class}
 265 @prenotnull{name}
 266 @prehot{stream_class}
 267 @postrefcountsame{stream_class}
 268
 269 @sa bt_ctf_stream_class_get_name(): Returns the name of a given
 270         stream class.
 271 */
 272 extern int bt_ctf_stream_class_set_name(
 273                 struct bt_ctf_stream_class *stream_class, const char *name);
 274
 275 /**
 276 @brief  Returns the numeric ID of the CTF IR stream class \p stream_class.
 277
 278 @param[in] stream_class Stream class of which to get the numeric ID.
 279 @returns                ID of stream class \p stream_class, or a
 280                         negative value on error.
 281
 282 @prenotnull{stream_class}
 283 @postrefcountsame{stream_class}
 284
 285 @sa bt_ctf_stream_class_set_id(): Sets the numeric ID of a given
 286         stream class.
 287 */
 288 extern int64_t bt_ctf_stream_class_get_id(
 289                 struct bt_ctf_stream_class *stream_class);
 290
 291 /**
 292 @brief  Sets the numeric ID of the CTF IR stream class
 293         \p stream_class to \p id.
 294
 295 \p id must be unique amongst the IDs of all the stream classes
 296 of the trace class to which you eventually add \p stream_class.
 297
 298 @param[in] stream_class Stream class of which to set the numeric ID.
 299 @param[in] id           ID of the stream class.
 300 @returns                0 on success, or a negative value on error.
 301
 302 @prenotnull{stream_class}
 303 @prehot{stream_class}
 304 @pre \p id is lesser than or equal to 9223372036854775807 (\c INT64_MAX).
 305 @postrefcountsame{stream_class}
 306
 307 @sa bt_ctf_stream_class_get_id(): Returns the numeric ID of a given
 308         stream class.
 309 */
 310 extern int bt_ctf_stream_class_set_id(
 311                 struct bt_ctf_stream_class *stream_class, uint64_t id);
 312
 313 /** @} */
 314
 315 /**
 316 @name Contained field types functions
 317 @{
 318 */
 319
 320 /**
 321 @brief  Returns the packet context field type of the CTF IR stream class
 322         \p stream_class.
 323
 324 @param[in] stream_class Stream class of which to get the packet
 325                         context field type.
 326 @returns                Packet context field type of \p stream_class,
 327                         or \c NULL if \p stream_class has no packet context
 328                         field type or on error.
 329
 330 @prenotnull{stream_class}
 331 @postrefcountsame{stream_class}
 332 @post <strong>On success, if the return value is a field type</strong>, its
 333         reference count is incremented.
 334
 335 @sa bt_ctf_stream_class_set_packet_context_type(): Sets the packet
 336         context field type of a given stream class.
 337 */
 338 extern struct bt_ctf_field_type *bt_ctf_stream_class_get_packet_context_type(
 339                 struct bt_ctf_stream_class *stream_class);
 340
 341 /**
 342 @brief  Sets the packet context field type of the CTF IR stream class
 343         \p stream_class to \p packet_context_type, or unsets the current packet
 344         context field type from \p stream_class.
 345
 346 If \p packet_context_type is \c NULL, then this function unsets the current
 347 packet context field type from \p stream_class, effectively making
 348 \p stream_class a stream class without a packet context field type.
 349
 350 As of Babeltrace \btversion, if \p packet_context_type is not \c NULL,
 351 \p packet_context_type \em must be a CTF IR structure field type object.
 352
 353 @param[in] stream_class         Stream class of which to set the packet
 354                                 context field type.
 355 @param[in] packet_context_type  Packet context field type, or \c NULL to unset
 356                                 the current packet context field type.
 357 @returns                        0 on success, or a negative value on error.
 358
 359 @prenotnull{stream_class}
 360 @prehot{stream_class}
 361 @pre <strong>\p packet_context_type, if not \c NULL</strong>, is a CTF IR
 362         structure field type.
 363 @postrefcountsame{stream_class}
 364 @post <strong>On success, if \p packet_context_type is not \c NULL</strong>,
 365         the reference count of \p packet_context_type is incremented.
 366
 367 @sa bt_ctf_stream_class_get_packet_context_type(): Returns the packet
 368         context field type of a given stream class.
 369 */
 370 extern int bt_ctf_stream_class_set_packet_context_type(
 371                 struct bt_ctf_stream_class *stream_class,
 372                 struct bt_ctf_field_type *packet_context_type);
 373
 374 /**
 375 @brief  Returns the event header field type of the CTF IR stream class
 376         \p stream_class.
 377
 378 @param[in] stream_class Stream class of which to get the event header
 379                         field type.
 380 @returns                Event header field type of \p stream_class,
 381                         or \c NULL if \p stream_class has no event header field
 382                         type or on error.
 383
 384 @prenotnull{stream_class}
 385 @postrefcountsame{stream_class}
 386 @post <strong>On success, if the return value is a field type</strong>, its
 387         reference count is incremented.
 388
 389 @sa bt_ctf_stream_class_set_event_header_type(): Sets the event
 390         header field type of a given stream class.
 391 */
 392 extern struct bt_ctf_field_type *
 393 bt_ctf_stream_class_get_event_header_type(
 394                 struct bt_ctf_stream_class *stream_class);
 395
 396 /**
 397 @brief  Sets the event header field type of the CTF IR stream class
 398         \p stream_class to \p event_header_type, or unsets the current event
 399         header field type from \p stream_class.
 400
 401 If \p event_header_type is \c NULL, then this function unsets the current
 402 event header field type from \p stream_class, effectively making \p stream_class
 403 a stream class without a event header field type.
 404
 405 As of Babeltrace \btversion, if \p event_header_type is not \c NULL,
 406 \p event_header_type \em must be a CTF IR structure field type object.
 407
 408 @param[in] stream_class         Stream class of which to set the event
 409                                 header field type.
 410 @param[in] event_header_type    Event header field type, or \c NULL to unset
 411                                 the current event header field type.
 412 @returns                        0 on success, or a negative value on error.
 413
 414 @prenotnull{stream_class}
 415 @prehot{stream_class}
 416 @pre <strong>\p event_header_type, if not \c NULL</strong>, is a CTF IR
 417         structure field type.
 418 @postrefcountsame{stream_class}
 419 @post <strong>On success, if \p event_header_type is not \c NULL</strong>,
 420         the reference count of \p event_header_type is incremented.
 421
 422 @sa bt_ctf_stream_class_get_event_header_type(): Returns the event
 423         header field type of a given stream class.
 424 */
 425 extern int bt_ctf_stream_class_set_event_header_type(
 426                 struct bt_ctf_stream_class *stream_class,
 427                 struct bt_ctf_field_type *event_header_type);
 428
 429 /**
 430 @brief  Returns the event context field type of the CTF IR stream class
 431         \p stream_class.
 432
 433 @param[in] stream_class Stream class of which to get the event context
 434                         field type.
 435 @returns                Event context field type of \p stream_class,
 436                         or \c NULL if \p stream_class has no event context field
 437                         type or on error.
 438
 439 @prenotnull{stream_class}
 440 @postrefcountsame{stream_class}
 441 @post <strong>On success, if the return value is a field type</strong>,
 442         its reference count is incremented.
 443
 444
 445 @sa bt_ctf_stream_class_set_event_context_type(): Sets the event
 446         context field type of a given stream class.
 447 */
 448 extern struct bt_ctf_field_type *
 449 bt_ctf_stream_class_get_event_context_type(
 450                 struct bt_ctf_stream_class *stream_class);
 451
 452 /**
 453 @brief  Sets the event context field type of the CTF IR stream class
 454         \p stream_class to \p event_context_type, or unsets the current event
 455         context field type from \p stream_class.
 456
 457 If \p event_context_type is \c NULL, then this function unsets the current
 458 event context field type from \p stream_class, effectively making \p
 459 stream_class a stream class without a event context field type.
 460
 461 As of Babeltrace \btversion, if \p event_context_type is not \c NULL,
 462 \p event_context_type \em must be a CTF IR structure field type object.
 463
 464 @param[in] stream_class         Stream class of which to set the packet
 465                                 context field type.
 466 @param[in] event_context_type   Event context field type, or \c NULL to unset
 467                                 the current event context field type.
 468 @returns                        0 on success, or a negative value on error.
 469
 470 @prenotnull{stream_class}
 471 @prehot{stream_class}
 472 @pre <strong>\p event_context_type, if not \c NULL</strong>, is a CTF IR
 473         structure field type.
 474 @postrefcountsame{stream_class}
 475 @post <strong>On success, if \p event_context_type is not \c NULL</strong>,
 476         the reference count of \p event_context_type is incremented.
 477
 478 @sa bt_ctf_stream_class_get_event_context_type(): Returns the event context
 479         field type of a given stream class.
 480 */
 481 extern int bt_ctf_stream_class_set_event_context_type(
 482                 struct bt_ctf_stream_class *stream_class,
 483                 struct bt_ctf_field_type *event_context_type);
 484
 485 /** @} */
 486
 487 /**
 488 @name Event class children functions
 489 @{
 490 */
 491
 492 /**
 493 @brief  Returns the number of event classes contained in the
 494         CTF IR stream class \p stream_class.
 495
 496 @param[in] stream_class Stream class of which to get the number
 497                         of children event classes.
 498 @returns                Number of children event classes
 499                         contained in \p stream_class, or
 500                         a negative value on error.
 501
 502 @prenotnull{stream_class}
 503 @postrefcountsame{stream_class}
 504 */
 505 extern int64_t bt_ctf_stream_class_get_event_class_count(
 506                 struct bt_ctf_stream_class *stream_class);
 507
 508 /**
 509 @brief  Returns the event class at index \p index in the CTF IR stream
 510         class \p stream_class.
 511
 512 @param[in] stream_class Stream class of which to get the event class.
 513 @param[in] index        Index of the event class to find.
 514 @returns                Event class at index \p index, or \c NULL
 515                         on error.
 516
 517 @prenotnull{stream_class}
 518 @pre \p index is lesser than the number of event classes contained in the
 519         stream class \p stream_class (see
 520         bt_ctf_stream_class_get_event_class_count()).
 521 @postrefcountsame{stream_class}
 522 @postsuccessrefcountretinc
 523
 524 @sa bt_ctf_stream_class_get_event_class_by_id(): Finds an event class
 525         by ID.
 526 */
 527 extern struct bt_ctf_event_class *bt_ctf_stream_class_get_event_class_by_index(
 528                 struct bt_ctf_stream_class *stream_class, uint64_t index);
 529
 530 /**
 531 @brief  Returns the event class with ID \c id found in the CTF IR stream
 532         class \p stream_class.
 533
 534 @param[in] stream_class Stream class of which to get the event class.
 535 @param[in] id           ID of the event class to find.
 536 @returns                Event class with ID \p id, or \c NULL
 537                         on error.
 538
 539 @prenotnull{stream_class}
 540 @postrefcountsame{stream_class}
 541 @postsuccessrefcountretinc
 542 */
 543 extern struct bt_ctf_event_class *bt_ctf_stream_class_get_event_class_by_id(
 544                 struct bt_ctf_stream_class *stream_class, uint64_t id);
 545
 546 /**
 547 @brief  Adds the CTF IR event class \p event_class to the
 548         CTF IR stream class \p stream_class.
 549
 550 On success, \p event_class becomes the child of \p stream_class.
 551
 552 You can only add a given event class to one stream class.
 553
 554 You can call this function even if \p stream_class is frozen. Adding
 555 event classes is the only operation that is permitted
 556 on a frozen stream class.
 557
 558 This function tries to resolve the needed
 559 \link ctfirfieldtypes CTF IR field type\endlink of the dynamic field
 560 types that are found anywhere in the context or payload field
 561 types of \p event_class. If any automatic resolving fails:
 562
 563 - If the needed field type should be found in one of the root field
 564   types of \p event_class or \p stream_class, this function fails.
 565 - If \p stream_class is the child of a
 566   \link ctfirtraceclass CTF IR trace class\endlink (it was added
 567   with bt_ctf_trace_add_stream_class()), this function fails.
 568 - If \p stream_class is not the child of a trace class yet, the
 569   automatic resolving is reported to the next call to
 570   bt_ctf_trace_add_stream_class() with \p stream_class.
 571
 572 @param[in] stream_class Stream class to which to add \p event_class.
 573 @param[in] event_class  Event class to add to \p stream_class.
 574 @returns                0 on success, or a negative value on error.
 575
 576 @prenotnull{stream_class}
 577 @prenotnull{event_class}
 578 @prehot{event_class}
 579 @postrefcountsame{stream_class}
 580 @postsuccessrefcountinc{event_class}
 581 @postsuccessfrozen{event_class}
 582 */
 583 extern int bt_ctf_stream_class_add_event_class(
 584                 struct bt_ctf_stream_class *stream_class,
 585                 struct bt_ctf_event_class *event_class);
 586
 587 /** @} */
 588
 589 /**
 590 @name Misc. function
 591 @{
 592 */
 593
 594 /**
 595 @brief  Accepts the visitor \p visitor to visit the hierarchy of the
 596         CTF IR stream class \p stream_class.
 597
 598 This function traverses the hierarchy of \p stream_class in pre-order
 599 and calls \p visitor on each element.
 600
 601 The stream class itself is visited first, and then all its children
 602 event classes.
 603
 604 @param[in] stream_class Stream class to visit.
 605 @param[in] visitor      Visiting function.
 606 @param[in] data         User data.
 607 @returns                0 on success, or a negative value on error.
 608
 609 @prenotnull{stream_class}
 610 @prenotnull{visitor}
 611 */
 612 extern int bt_ctf_stream_class_visit(struct bt_ctf_stream_class *stream_class,
 613                 bt_ctf_visitor visitor, void *data);
 614
 615 /** @} */
 616
 617 /** @} */
 618
 619 #ifdef __cplusplus
 620 }
 621 #endif
 622
 623 #endif /* BABELTRACE_CTF_IR_STREAM_CLASS_H */