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_ctf_event_class;
  41 struct bt_ctf_event;
  42 struct bt_ctf_field;
  43 struct bt_ctf_field_type;
  44 struct bt_ctf_stream_class;
  45
  46 /*
  47  * bt_ctf_event_class_create: create an event class.
  48  *
  49  * Allocate a new event class of the given name. The creation of an event class
  50  * sets its reference count to 1. A unique event id is automatically assigned
  51  * to the event class.
  52  *
  53  * @param name Event class name (will be copied).
  54  *
  55  * Returns an allocated event class on success, NULL on error.
  56  */
  57 extern struct bt_ctf_event_class *bt_ctf_event_class_create(const char *name);
  58
  59 /*
  60  * bt_ctf_event_class_get_name: Get an event class' name.
  61  *
  62  * @param event_class Event class.
  63  *
  64  * Returns the event class' name, NULL on error.
  65  */
  66 extern const char *bt_ctf_event_class_get_name(
  67                 struct bt_ctf_event_class *event_class);
  68
  69 /*
  70  * bt_ctf_event_class_get_id: Get an event class' id.
  71  *
  72  * @param event_class Event class.
  73  *
  74  * Returns the event class' id, a negative value on error.
  75  */
  76 extern int64_t bt_ctf_event_class_get_id(
  77                 struct bt_ctf_event_class *event_class);
  78
  79 /*
  80  * bt_ctf_event_class_set_id: Set an event class' id.
  81  *
  82  * Set an event class' id. Must be unique stream-wise.
  83  * Note that event classes are already assigned a unique id when added to a
  84  * stream class if none was set explicitly.
  85  *
  86  * @param event_class Event class.
  87  * @param id Event class id.
  88  *
  89  * Returns 0 on success, a negative value on error.
  90  */
  91 extern int bt_ctf_event_class_set_id(
  92                 struct bt_ctf_event_class *event_class, uint32_t id);
  93
  94 /*
  95  * bt_ctf_event_class_get_stream_class: Get an event class' stream class.
  96  *
  97  * @param event_class Event class.
  98  *
  99  * Returns the event class' stream class, NULL on error or if the event class
 100  * is not associated with a stream class.
 101  */
 102 extern struct bt_ctf_stream_class *bt_ctf_event_class_get_stream_class(
 103                 struct bt_ctf_event_class *event_class);
 104
 105 /*
 106  * bt_ctf_event_class_get_payload_type: get an event class' payload.
 107  *
 108  * Get an event class' payload type.
 109  *
 110  * @param event_class Event class.
 111  *
 112  * Returns the event class' payload, NULL on error.
 113  */
 114 extern struct bt_ctf_field_type *bt_ctf_event_class_get_payload_type(
 115                 struct bt_ctf_event_class *event_class);
 116
 117 /*
 118  * bt_ctf_event_class_set_payload_type: set an event class' payload.
 119  *
 120  * Set an event class' payload type.
 121  *
 122  * @param event_class Event class.
 123  * @param payload The payload's type (must be a structure).
 124  *
 125  * Returns 0 on success, a negative value on error.
 126  */
 127 extern int bt_ctf_event_class_set_payload_type(
 128                 struct bt_ctf_event_class *event_class,
 129                 struct bt_ctf_field_type *payload);
 130
 131 /*
 132  * bt_ctf_event_class_add_field: add a field to an event class.
 133  *
 134  * Add a field of type "type" to the event class. The event class will share
 135  * type's ownership by increasing its reference count. The "name" will be
 136  * copied.
 137  *
 138  * @param event_class Event class.
 139  * @param type Field type to add to the event class.
 140  * @param name Name of the new field.
 141  *
 142  * Returns 0 on success, a negative value on error.
 143  *
 144  * Note: Returns an error if the payload is not a structure.
 145  */
 146 extern int bt_ctf_event_class_add_field(struct bt_ctf_event_class *event_class,
 147                 struct bt_ctf_field_type *type,
 148                 const char *name);
 149
 150 /*
 151  * bt_ctf_event_class_get_field_count: Get an event class' field count.
 152  *
 153  * @param event_class Event class.
 154  *
 155  * Returns the event class' field count, a negative value on error.
 156  *
 157  * Note: Returns an error if the payload is not a structure.
 158  */
 159 extern int bt_ctf_event_class_get_field_count(
 160                 struct bt_ctf_event_class *event_class);
 161
 162 /*
 163  * bt_ctf_event_class_get_field: Get event class' field type and name by index.
 164  *
 165  * @param event_class Event class.
 166  * @param field_name Pointer to a const char* where the field's name will
 167  *      be returned.
 168  * @param field_type Pointer to a bt_ctf_field_type* where the field's type will
 169  *      be returned.
 170  * @param index Index of field.
 171  *
 172  * Returns 0 on success, a negative error on value.
 173  *
 174  * Note: Returns an error if the payload is not a structure.
 175  */
 176 extern int bt_ctf_event_class_get_field(struct bt_ctf_event_class *event_class,
 177                 const char **field_name, struct bt_ctf_field_type **field_type,
 178                 int index);
 179
 180 /*
 181  * bt_ctf_event_class_get_field_type_by_name: Get an event class's field by name
 182  *
 183  * @param event_class Event class.
 184  * @param name Name of the field.
 185  *
 186  * Returns a field type on success, NULL on error.
 187  *
 188  * Note: Returns an error if the payload is not a structure.
 189  */
 190 extern struct bt_ctf_field_type *bt_ctf_event_class_get_field_by_name(
 191                 struct bt_ctf_event_class *event_class, const char *name);
 192
 193 /*
 194  * bt_ctf_event_class_get_context_type: Get an event class's context type
 195  *
 196  * @param event_class Event class.
 197  *
 198  * Returns a field type (a structure) on success, NULL on error.
 199  */
 200 extern struct bt_ctf_field_type *bt_ctf_event_class_get_context_type(
 201                 struct bt_ctf_event_class *event_class);
 202
 203 /*
 204  * bt_ctf_event_class_set_context_type: Set an event class's context type
 205  *
 206  * @param event_class Event class.
 207  * @param context Event context field type (must be a structure).
 208  *
 209  * Returns 0 on success, a negative value on error.
 210  */
 211 extern int bt_ctf_event_class_set_context_type(
 212                 struct bt_ctf_event_class *event_class,
 213                 struct bt_ctf_field_type *context);
 214
 215 /*
 216  * bt_ctf_event_class_get and bt_ctf_event_class_put: increment and decrement
 217  * the event class' reference count.
 218  *
 219  * These functions ensure that the event class won't be destroyed while it
 220  * is in use. The same number of get and put (plus one extra put to
 221  * release the initial reference done at creation) have to be done to
 222  * destroy an event class.
 223  *
 224  * When the event class' reference count is decremented to 0 by a
 225  * bt_ctf_event_class_put, the event class is freed.
 226  *
 227  * @param event_class Event class.
 228  */
 229 extern void bt_ctf_event_class_get(struct bt_ctf_event_class *event_class);
 230 extern void bt_ctf_event_class_put(struct bt_ctf_event_class *event_class);
 231
 232 /*
 233  * bt_ctf_event_create: instanciate an event.
 234  *
 235  * Allocate a new event of the given event class. The creation of an event
 236  * sets its reference count to 1. Each instance shares the ownership of the
 237  * event class using its reference count.
 238  *
 239  * An event class must be associated with a stream class before events
 240  * may be instanciated.
 241  *
 242  * @param event_class Event class.
 243  *
 244  * Returns an allocated field type on success, NULL on error.
 245  */
 246 extern struct bt_ctf_event *bt_ctf_event_create(
 247                 struct bt_ctf_event_class *event_class);
 248
 249 /*
 250  * bt_ctf_event_get_class: get an event's class.
 251  *
 252  * @param event Event.
 253  *
 254  * Returns the event's class, NULL on error.
 255  */
 256 extern struct bt_ctf_event_class *bt_ctf_event_get_class(
 257                 struct bt_ctf_event *event);
 258
 259 /*
 260  * bt_ctf_event_get_clock: get an event's associated clock.
 261  *
 262  * @param event Event.
 263  *
 264  * Returns the event's clock, NULL on error.
 265  */
 266 extern struct bt_ctf_clock *bt_ctf_event_get_clock(
 267                 struct bt_ctf_event *event);
 268
 269 /*
 270  * bt_ctf_event_get_payload: get an event's field.
 271  *
 272  * Returns the field matching "name". bt_ctf_field_put() must be called on the
 273  * returned value.
 274  *
 275  * @param event Event instance.
 276  * @param name Event field name, see notes.
 277  *
 278  * Returns a field instance on success, NULL on error.
 279  *
 280  * Note: Passing a name will cause the function to perform a look-up by
 281  *      name assuming the event's payload is a structure. This will return
 282  *      the raw payload instance if name is NULL.
 283  */
 284 extern struct bt_ctf_field *bt_ctf_event_get_payload(struct bt_ctf_event *event,
 285                 const char *name);
 286
 287 /*
 288  * bt_ctf_event_set_payload: set an event's field.
 289  *
 290  * Set a manually allocated field as an event's payload. The event will share
 291  * the field's ownership by using its reference count.
 292  * bt_ctf_field_put() must be called on the returned value.
 293  *
 294  * @param event Event instance.
 295  * @param name Event field name, see notes.
 296  * @param value Instance of a field whose type corresponds to the event's field.
 297  *
 298  * Returns 0 on success, a negative value on error.
 299  *
 300  * Note: The function will return an error if a name is provided and the payload
 301  *      type is not a structure. If name is NULL, the payload field will be set
 302  *      directly and must match the event class' payload's type.
 303  */
 304 extern int bt_ctf_event_set_payload(struct bt_ctf_event *event,
 305                 const char *name,
 306                 struct bt_ctf_field *value);
 307
 308 /*
 309  * bt_ctf_event_get_payload_by_index: Get event's field by index.
 310  *
 311  * Returns the field associated with the provided index. bt_ctf_field_put()
 312  * must be called on the returned value. The indexes to be provided are
 313  * the same as can be retrieved from the event class.
 314  *
 315  * @param event Event.
 316  * @param index Index of field.
 317  *
 318  * Returns the event's field, NULL on error.
 319  *
 320  * Note: Will return an error if the payload's type is not a structure.
 321  */
 322 extern struct bt_ctf_field *bt_ctf_event_get_payload_by_index(
 323                 struct bt_ctf_event *event, int index);
 324
 325 /*
 326  * bt_ctf_event_get_header: get an event's header.
 327  *
 328  * @param event Event instance.
 329  *
 330  * Returns a field instance on success, NULL on error.
 331  */
 332 extern struct bt_ctf_field *bt_ctf_event_get_header(
 333                 struct bt_ctf_event *event);
 334
 335 /*
 336  * bt_ctf_event_set_header: set an event's header.
 337  *
 338  * The event header's type must match the stream class' event
 339  * header type.
 340  *
 341  * @param event Event instance.
 342  * @param header Event header field instance.
 343  *
 344  * Returns a field instance on success, NULL on error.
 345  */
 346 extern int bt_ctf_event_set_header(
 347                 struct bt_ctf_event *event,
 348                 struct bt_ctf_field *header);
 349
 350 /*
 351  * bt_ctf_event_get_event_context: Get an event's context
 352  *
 353  * @param event_class Event class.
 354  *
 355  * Returns a field on success (a structure), NULL on error.
 356  *
 357  * Note: This function is named this way instead of the expected
 358  * "bt_ctf_event_get_context" in order to work around a name clash with
 359  * an unrelated function bearing this name in context.h.
 360  */
 361 extern struct bt_ctf_field *bt_ctf_event_get_event_context(
 362                 struct bt_ctf_event *event);
 363
 364 /*
 365  * bt_ctf_event_set_event_context: Set an event's context
 366  *
 367  * @param event Event.
 368  * @param context Event context field (must match the event class'
 369  *      context type).
 370  *
 371  * Returns 0 on success, a negative value on error.
 372  */
 373 extern int bt_ctf_event_set_event_context(struct bt_ctf_event *event,
 374                 struct bt_ctf_field *context);
 375
 376 /*
 377  * bt_ctf_event_get and bt_ctf_event_put: increment and decrement
 378  * the event's reference count.
 379  *
 380  * These functions ensure that the event won't be destroyed while it
 381  * is in use. The same number of get and put (plus one extra put to
 382  * release the initial reference done at creation) have to be done to
 383  * destroy an event.
 384  *
 385  * When the event's reference count is decremented to 0 by a
 386  * bt_ctf_event_put, the event is freed.
 387  *
 388  * @param event Event instance.
 389  */
 390 extern void bt_ctf_event_get(struct bt_ctf_event *event);
 391 extern void bt_ctf_event_put(struct bt_ctf_event *event);
 392
 393 #ifdef __cplusplus
 394 }
 395 #endif
 396
 397 #endif /* BABELTRACE_CTF_IR_EVENT_H */