lib/babeltrace/ctf-writer/event.h

   1 #ifndef BABELTRACE_CTF_WRITER_EVENT_H
   2 #define BABELTRACE_CTF_WRITER_EVENT_H
   3
   4 /*
   5  * BabelTrace - CTF Writer: Event
   6  *
   7  * Copyright 2013 EfficiOS Inc.
   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 #ifdef __cplusplus
  34 extern "C" {
  35 #endif
  36
  37 struct bt_ctf_event_class;
  38 struct bt_ctf_event;
  39 struct bt_ctf_field;
  40 struct bt_ctf_field_type;
  41
  42 /*
  43  * bt_ctf_event_class_create: create an event class.
  44  *
  45  * Allocate a new event class of the given name. The creation of an event class
  46  * sets its reference count to 1.
  47  *
  48  * @param name Event class name (will be copied).
  49  *
  50  * Returns an allocated event class on success, NULL on error.
  51  */
  52 extern struct bt_ctf_event_class *bt_ctf_event_class_create(const char *name);
  53
  54 /*
  55  * bt_ctf_event_class_add_field: add a field to an event class.
  56  *
  57  * Add a field of type "type" to the event class. The event class will share
  58  * type's ownership by increasing its reference count. The "name" will be
  59  * copied.
  60  *
  61  * @param event_class Event class.
  62  * @param type Field type to add to the event class.
  63  * @param name Name of the new field.
  64  *
  65  * Returns 0 on success, a negative value on error.
  66  */
  67 extern int bt_ctf_event_class_add_field(struct bt_ctf_event_class *event_class,
  68                 struct bt_ctf_field_type *type,
  69                 const char *name);
  70
  71 /*
  72  * bt_ctf_event_class__get and bt_ctf_event_class_put: increment and decrement
  73  * the event class' reference count.
  74  *
  75  * These functions ensure that the event class won't be destroyed while it
  76  * is in use. The same number of get and put (plus one extra put to
  77  * release the initial reference done at creation) have to be done to
  78  * destroy an event class.
  79  *
  80  * When the event class' reference count is decremented to 0 by a
  81  * bt_ctf_event_class_put, the event class is freed.
  82  *
  83  * @param event_class Event class.
  84  */
  85 extern void bt_ctf_event_class_get(struct bt_ctf_event_class *event_class);
  86 extern void bt_ctf_event_class_put(struct bt_ctf_event_class *event_class);
  87
  88 /*
  89  * bt_ctf_event_create: instanciate an event.
  90  *
  91  * Allocate a new event of the given event class. The creation of an event
  92  * sets its reference count to 1. Each instance shares the ownership of the
  93  * event class using its reference count.
  94  *
  95  * @param event_class Event class.
  96  *
  97  * Returns an allocated field type on success, NULL on error.
  98  */
  99 extern struct bt_ctf_event *bt_ctf_event_create(
 100                 struct bt_ctf_event_class *event_class);
 101
 102 /*
 103  * bt_ctf_event_set_payload: set an event's field.
 104  *
 105  * Set a manually allocated field as an event's payload. The event will share
 106  * the field's ownership by using its reference count.
 107  * bt_ctf_field_put() must be called on the returned value.
 108  *
 109  * @param event Event instance.
 110  * @param name Event field name.
 111  * @param value Instance of a field whose type corresponds to the event's field.
 112  *
 113  * Returns 0 on success, a negative value on error.
 114  */
 115 extern int bt_ctf_event_set_payload(struct bt_ctf_event *event,
 116                 const char *name,
 117                 struct bt_ctf_field *value);
 118
 119 /*
 120  * bt_ctf_event_get_payload: get an event's field.
 121  *
 122  * Returns the field matching "name". bt_ctf_field_put() must be called on the
 123  * returned value.
 124  *
 125  * @param event Event instance.
 126  * @param name Event field name.
 127  *
 128  * Returns a field instance on success, NULL on error.
 129  */
 130 extern struct bt_ctf_field *bt_ctf_event_get_payload(struct bt_ctf_event *event,
 131                 const char *name);
 132
 133 /*
 134  * bt_ctf_event_get and bt_ctf_event_put: increment and decrement
 135  * the event's reference count.
 136  *
 137  * These functions ensure that the event won't be destroyed while it
 138  * is in use. The same number of get and put (plus one extra put to
 139  * release the initial reference done at creation) have to be done to
 140  * destroy an event.
 141  *
 142  * When the event's reference count is decremented to 0 by a
 143  * bt_ctf_event_put, the event is freed.
 144  *
 145  * @param event Event instance.
 146  */
 147 extern void bt_ctf_event_get(struct bt_ctf_event *event);
 148 extern void bt_ctf_event_put(struct bt_ctf_event *event);
 149
 150 #ifdef __cplusplus
 151 }
 152 #endif
 153
 154 #endif /* BABELTRACE_CTF_WRITER_EVENT_H */