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 #ifdef __cplusplus
  34 extern "C" {
  35 #endif
  36
  37 struct bt_ctf_event_class;
  38 struct bt_ctf_stream_class;
  39 struct bt_ctf_clock;
  40
  41 /*
  42  * bt_ctf_stream_class_create: create a stream class.
  43  *
  44  * Allocate a new stream class of the given name. The creation of an event class
  45  * sets its reference count to 1.
  46  *
  47  * @param name Stream name.
  48  *
  49  * Returns an allocated stream class on success, NULL on error.
  50  */
  51 extern struct bt_ctf_stream_class *bt_ctf_stream_class_create(const char *name);
  52
  53 /*
  54  * bt_ctf_stream_class_get_clock: get the clock associated with a stream class.
  55  *
  56  * @param stream_class Stream class.
  57  *
  58  * Returns a clock instance, NULL on error.
  59  */
  60 extern struct bt_ctf_clock *bt_ctf_stream_class_get_clock(
  61                 struct bt_ctf_stream_class *stream_class);
  62
  63 /*
  64  * bt_ctf_stream_class_set_clock: assign a clock to a stream class.
  65  *
  66  * Assign a clock to a stream class. This clock will be sampled each time an
  67  * event is appended to an instance of this stream class.
  68  *
  69  * @param stream_class Stream class.
  70  * @param clock Clock to assign to the provided stream class.
  71  *
  72  * Returns 0 on success, a negative value on error.
  73  */
  74 extern int bt_ctf_stream_class_set_clock(
  75                 struct bt_ctf_stream_class *stream_class,
  76                 struct bt_ctf_clock *clock);
  77
  78 /*
  79  * bt_ctf_stream_class_get_id: Get a stream class' id.
  80  *
  81  * @param stream_class Stream class.
  82  *
  83  * Returns the stream class' id, a negative value on error.
  84  */
  85 extern int64_t bt_ctf_stream_class_get_id(
  86                 struct bt_ctf_stream_class *stream_class);
  87
  88 /*
  89  * bt_ctf_stream_class_set_id: Set a stream class' id.
  90  *
  91  * Set a stream class' id. Must be unique trace-wise.
  92  * Note that stream classes are assigned a unique id when a stream instance
  93  * is created for the first time from a trace or writer.
  94  *
  95  * @param stream_class Stream class.
  96  * @param id Stream class id.
  97  *
  98  * Returns 0 on success, a negative value on error.
  99  */
 100 extern int bt_ctf_stream_class_set_id(
 101                 struct bt_ctf_stream_class *stream_class, uint32_t id);
 102
 103 /*
 104  * bt_ctf_stream_class_set_clock: assign a clock to a stream class.
 105  *
 106  * Add an event class to a stream class. New events can be added even after a
 107  * stream has beem instanciated and events have been appended. However, a stream
 108  * will not accept events of a class that has not been registered beforehand.
 109  * The stream class will share the ownership of "event_class" by incrementing
 110  * its reference count.
 111  *
 112  * @param stream_class Stream class.
 113  * @param event_class Event class to add to the provided stream class.
 114  *
 115  * Returns 0 on success, a negative value on error.
 116  */
 117 extern int bt_ctf_stream_class_add_event_class(
 118                 struct bt_ctf_stream_class *stream_class,
 119                 struct bt_ctf_event_class *event_class);
 120
 121 /*
 122  * bt_ctf_stream_class_get and bt_ctf_stream_class_put: increment and
 123  * decrement the stream class' reference count.
 124  *
 125  * These functions ensure that the stream class won't be destroyed while it
 126  * is in use. The same number of get and put (plus one extra put to
 127  * release the initial reference done at creation) have to be done to
 128  * destroy a stream class.
 129  *
 130  * When the stream class' reference count is decremented to 0 by a
 131  * bt_ctf_stream_class_put, the stream class is freed.
 132  *
 133  * @param stream_class Stream class.
 134  */
 135 extern void bt_ctf_stream_class_get(struct bt_ctf_stream_class *stream_class);
 136 extern void bt_ctf_stream_class_put(struct bt_ctf_stream_class *stream_class);
 137
 138 #ifdef __cplusplus
 139 }
 140 #endif
 141
 142 #endif /* BABELTRACE_CTF_IR_STREAM_CLASS_H */