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_add_field: add a field to an event class.
 107  *
 108  * Add a field of type "type" to the event class. The event class will share
 109  * type's ownership by increasing its reference count. The "name" will be
 110  * copied.
 111  *
 112  * @param event_class Event class.
 113  * @param type Field type to add to the event class.
 114  * @param name Name of the new field.
 115  *
 116  * Returns 0 on success, a negative value on error.
 117  */
 118 extern int bt_ctf_event_class_add_field(struct bt_ctf_event_class *event_class,
 119                 struct bt_ctf_field_type *type,
 120                 const char *name);
 121
 122 /*
 123  * bt_ctf_event_class_get_field_count: Get an event class' field count.
 124  *
 125  * @param event_class Event class.
 126  *
 127  * Returns the event class' field count, a negative value on error.
 128  */
 129 extern int bt_ctf_event_class_get_field_count(
 130                 struct bt_ctf_event_class *event_class);
 131
 132 /*
 133  * bt_ctf_event_class_get_field: Get event class' field type and name by index.
 134  *
 135  * @param event_class Event class.
 136  * @param field_name Pointer to a const char* where the field's name will
 137  *      be returned.
 138  * @param field_type Pointer to a bt_ctf_field_type* where the field's type will
 139  *      be returned.
 140  * @param index Index of field.
 141  *
 142  * Returns 0 on success, a negative error on value.
 143  */
 144 extern int bt_ctf_event_class_get_field(struct bt_ctf_event_class *event_class,
 145                 const char **field_name, struct bt_ctf_field_type **field_type,
 146                 int index);
 147
 148 /*
 149  * bt_ctf_event_class_get_field_type_by_name: Get an event class's field by name
 150  *
 151  * @param event_class Event class.
 152  * @param name Name of the field.
 153  *
 154  * Returns a field type on success, NULL on error.
 155  */
 156 extern struct bt_ctf_field_type *bt_ctf_event_class_get_field_by_name(
 157                 struct bt_ctf_event_class *event_class, const char *name);
 158
 159 /*
 160  * bt_ctf_event_class_get_context_type: Get an event class's context type
 161  *
 162  * @param event_class Event class.
 163  *
 164  * Returns a field type (a structure) on success, NULL on error.
 165  */
 166 extern struct bt_ctf_field_type *bt_ctf_event_class_get_context_type(
 167                 struct bt_ctf_event_class *event_class);
 168
 169 /*
 170  * bt_ctf_event_class_set_context_type: Set an event class's context type
 171  *
 172  * @param event_class Event class.
 173  * @param context Event context field type (must be a structure).
 174  *
 175  * Returns 0 on success, a negative value on error.
 176  */
 177 extern int bt_ctf_event_class_set_context_type(
 178                 struct bt_ctf_event_class *event_class,
 179                 struct bt_ctf_field_type *context);
 180
 181 /*
 182  * bt_ctf_event_class_get and bt_ctf_event_class_put: increment and decrement
 183  * the event class' reference count.
 184  *
 185  * These functions ensure that the event class won't be destroyed while it
 186  * is in use. The same number of get and put (plus one extra put to
 187  * release the initial reference done at creation) have to be done to
 188  * destroy an event class.
 189  *
 190  * When the event class' reference count is decremented to 0 by a
 191  * bt_ctf_event_class_put, the event class is freed.
 192  *
 193  * @param event_class Event class.
 194  */
 195 extern void bt_ctf_event_class_get(struct bt_ctf_event_class *event_class);
 196 extern void bt_ctf_event_class_put(struct bt_ctf_event_class *event_class);
 197
 198 /*
 199  * bt_ctf_event_create: instanciate an event.
 200  *
 201  * Allocate a new event of the given event class. The creation of an event
 202  * sets its reference count to 1. Each instance shares the ownership of the
 203  * event class using its reference count.
 204  *
 205  * An event class must be associated with a stream class before events
 206  * may be instanciated.
 207  *
 208  * @param event_class Event class.
 209  *
 210  * Returns an allocated field type on success, NULL on error.
 211  */
 212 extern struct bt_ctf_event *bt_ctf_event_create(
 213                 struct bt_ctf_event_class *event_class);
 214
 215 /*
 216  * bt_ctf_event_get_class: get an event's class.
 217  *
 218  * @param event Event.
 219  *
 220  * Returns the event's class, NULL on error.
 221  */
 222 extern struct bt_ctf_event_class *bt_ctf_event_get_class(
 223                 struct bt_ctf_event *event);
 224
 225 /*
 226  * bt_ctf_event_get_clock: get an event's associated clock.
 227  *
 228  * @param event Event.
 229  *
 230  * Returns the event's clock, NULL on error.
 231  */
 232 extern struct bt_ctf_clock *bt_ctf_event_get_clock(
 233                 struct bt_ctf_event *event);
 234
 235 /*
 236  * bt_ctf_event_get_payload: get an event's field.
 237  *
 238  * Returns the field matching "name". bt_ctf_field_put() must be called on the
 239  * returned value.
 240  *
 241  * @param event Event instance.
 242  * @param name Event field name.
 243  *
 244  * Returns a field instance on success, NULL on error.
 245  */
 246 extern struct bt_ctf_field *bt_ctf_event_get_payload(struct bt_ctf_event *event,
 247                 const char *name);
 248
 249 /*
 250  * bt_ctf_event_set_payload: set an event's field.
 251  *
 252  * Set a manually allocated field as an event's payload. The event will share
 253  * the field's ownership by using its reference count.
 254  * bt_ctf_field_put() must be called on the returned value.
 255  *
 256  * @param event Event instance.
 257  * @param name Event field name.
 258  * @param value Instance of a field whose type corresponds to the event's field.
 259  *
 260  * Returns 0 on success, a negative value on error.
 261  */
 262 extern int bt_ctf_event_set_payload(struct bt_ctf_event *event,
 263                 const char *name,
 264                 struct bt_ctf_field *value);
 265
 266 /*
 267  * bt_ctf_event_get_payload_by_index: Get event's field by index.
 268  *
 269  * Returns the field associated with the provided index. bt_ctf_field_put()
 270  * must be called on the returned value. The indexes to be provided are
 271  * the same as can be retrieved from the event class.
 272  *
 273  * @param event Event.
 274  * @param index Index of field.
 275  *
 276  * Returns the event's field, NULL on error.
 277  */
 278 extern struct bt_ctf_field *bt_ctf_event_get_payload_by_index(
 279                 struct bt_ctf_event *event, int index);
 280
 281 /*
 282  * bt_ctf_event_get_header: get an event's header.
 283  *
 284  * @param event Event instance.
 285  *
 286  * Returns a field instance on success, NULL on error.
 287  */
 288 extern struct bt_ctf_field *bt_ctf_event_get_header(
 289                 struct bt_ctf_event *event);
 290
 291 /*
 292  * bt_ctf_event_set_header: set an event's header.
 293  *
 294  * The event header's type must match the stream class' event
 295  * header type.
 296  *
 297  * @param event Event instance.
 298  * @param header Event header field instance.
 299  *
 300  * Returns a field instance on success, NULL on error.
 301  */
 302 extern int bt_ctf_event_set_header(
 303                 struct bt_ctf_event *event,
 304                 struct bt_ctf_field *header);
 305
 306 /*
 307  * bt_ctf_event_get_event_context: Get an event's context
 308  *
 309  * @param event_class Event class.
 310  *
 311  * Returns a field on success (a structure), NULL on error.
 312  *
 313  * Note: This function is named this way instead of the expected
 314  * "bt_ctf_event_get_context" in order to work around a name clash with
 315  * an unrelated function bearing this name in context.h.
 316  */
 317 extern struct bt_ctf_field *bt_ctf_event_get_event_context(
 318                 struct bt_ctf_event *event);
 319
 320 /*
 321  * bt_ctf_event_set_event_context: Set an event's context
 322  *
 323  * @param event Event.
 324  * @param context Event context field (must match the event class'
 325  *      context type).
 326  *
 327  * Returns 0 on success, a negative value on error.
 328  */
 329 extern int bt_ctf_event_set_event_context(struct bt_ctf_event *event,
 330                 struct bt_ctf_field *context);
 331
 332 /*
 333  * bt_ctf_event_get and bt_ctf_event_put: increment and decrement
 334  * the event's reference count.
 335  *
 336  * These functions ensure that the event won't be destroyed while it
 337  * is in use. The same number of get and put (plus one extra put to
 338  * release the initial reference done at creation) have to be done to
 339  * destroy an event.
 340  *
 341  * When the event's reference count is decremented to 0 by a
 342  * bt_ctf_event_put, the event is freed.
 343  *
 344  * @param event Event instance.
 345  */
 346 extern void bt_ctf_event_get(struct bt_ctf_event *event);
 347 extern void bt_ctf_event_put(struct bt_ctf_event *event);
 348
 349 #ifdef __cplusplus
 350 }
 351 #endif
 352
 353 #endif /* BABELTRACE_CTF_IR_EVENT_H */