lib/babeltrace/ctf-ir/stream.h

   1 #ifndef BABELTRACE_CTF_IR_STREAM_H
   2 #define BABELTRACE_CTF_IR_STREAM_H
   3
   4 /*
   5  * BabelTrace - CTF IR: Stream
   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 <babeltrace/ctf-ir/stream-class.h>
  34
  35 #ifdef __cplusplus
  36 extern "C" {
  37 #endif
  38
  39 struct bt_ctf_event;
  40 struct bt_ctf_stream;
  41
  42 /*
  43  * bt_ctf_stream_get_discarded_events_count: get the number of discarded
  44  * events associated with this stream.
  45  *
  46  * Note that discarded events are not stored if the stream's packet
  47  * context has no "events_discarded" field. An error will be returned
  48  * in that case.
  49  *
  50  * @param stream Stream instance.
  51  *
  52  * Returns the number of discarded events, a negative value on error.
  53  */
  54 extern int bt_ctf_stream_get_discarded_events_count(
  55                 struct bt_ctf_stream *stream, uint64_t *count);
  56
  57 /*
  58  * bt_ctf_stream_append_discarded_events: increment discarded events count.
  59  *
  60  * Increase the current packet's discarded event count. Has no effect if the
  61  * stream class' packet context has no "events_discarded" field.
  62  *
  63  * @param stream Stream instance.
  64  * @param event_count Number of discarded events to add to the stream's current
  65  *      packet.
  66  */
  67 extern void bt_ctf_stream_append_discarded_events(struct bt_ctf_stream *stream,
  68                 uint64_t event_count);
  69
  70 /*
  71  * bt_ctf_stream_append_event: append an event to the stream.
  72  *
  73  * Append "event" to the stream's current packet. The stream's associated clock
  74  * will be sampled during this call. The event shall not be modified after
  75  * being appended to a stream. The stream will share the event's ownership by
  76  * incrementing its reference count. The current packet is not flushed to disk
  77  * until the next call to bt_ctf_stream_flush.
  78  *
  79  * @param stream Stream instance.
  80  * @param event Event instance to append to the stream's current packet.
  81  *
  82  * Returns 0 on success, a negative value on error.
  83  */
  84 extern int bt_ctf_stream_append_event(struct bt_ctf_stream *stream,
  85                 struct bt_ctf_event *event);
  86
  87 /*
  88  * bt_ctf_stream_get_packet_context: get a stream's packet context.
  89  *
  90  * @param stream Stream instance.
  91  *
  92  * Returns a field instance on success, NULL on error.
  93  */
  94 extern struct bt_ctf_field *bt_ctf_stream_get_packet_context(
  95                 struct bt_ctf_stream *stream);
  96
  97 /*
  98  * bt_ctf_stream_set_packet_context: set a stream's packet context.
  99  *
 100  * The packet context's type must match the stream class' packet
 101  * context type.
 102  *
 103  * @param stream Stream instance.
 104  * @param packet_context Packet context field instance.
 105  *
 106  * Returns a field instance on success, NULL on error.
 107  */
 108 extern int bt_ctf_stream_set_packet_context(
 109                 struct bt_ctf_stream *stream,
 110                 struct bt_ctf_field *packet_context);
 111
 112 /*
 113  * bt_ctf_stream_flush: flush a stream.
 114  *
 115  * The stream's current packet's events will be flushed, thus closing the
 116  * current packet. Events subsequently appended to the stream will be
 117  * added to a new packet.
 118  *
 119  * Flushing will also set the packet context's default attributes if
 120  * they remained unset while populating the current packet. These default
 121  * attributes, along with their expected types, are detailed in stream-class.h.
 122  *
 123  * @param stream Stream instance.
 124  *
 125  * Returns 0 on success, a negative value on error.
 126  */
 127 extern int bt_ctf_stream_flush(struct bt_ctf_stream *stream);
 128
 129 /*
 130  * bt_ctf_stream_get and bt_ctf_stream_put: increment and decrement the
 131  * stream's reference count.
 132  *
 133  * These functions ensure that the stream won't be destroyed while it
 134  * is in use. The same number of get and put (plus one extra put to
 135  * release the initial reference done at creation) have to be done to
 136  * destroy a stream.
 137  *
 138  * When the stream's reference count is decremented to 0 by a
 139  * bt_ctf_stream_put, the stream is freed.
 140  *
 141  * @param stream Stream instance.
 142  */
 143 extern void bt_ctf_stream_get(struct bt_ctf_stream *stream);
 144 extern void bt_ctf_stream_put(struct bt_ctf_stream *stream);
 145
 146 #ifdef __cplusplus
 147 }
 148 #endif
 149
 150 #endif /* BABELTRACE_CTF_IR_STREAM_H */