include/babeltrace/ctf-ir/packet.h

   1 #ifndef BABELTRACE_CTF_IR_PACKET_H
   2 #define BABELTRACE_CTF_IR_PACKET_H
   3
   4 /*
   5  * BabelTrace - CTF IR: Stream packet
   6  *
   7  * Copyright 2016 Philippe Proulx <pproulx@efficios.com>
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a copy
  10  * of this software and associated documentation files (the "Software"), to deal
  11  * in the Software without restriction, including without limitation the rights
  12  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  13  * copies of the Software, and to permit persons to whom the Software is
  14  * furnished to do so, subject to the following conditions:
  15  *
  16  * The above copyright notice and this permission notice shall be included in
  17  * all copies or substantial portions of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  22  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  23  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  24  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  25  * SOFTWARE.
  26  *
  27  * The Common Trace Format (CTF) Specification is available at
  28  * http://www.efficios.com/ctf
  29  */
  30
  31 #include <stdint.h>
  32
  33 #ifdef __cplusplus
  34 extern "C" {
  35 #endif
  36
  37 /**
  38 @defgroup ctfirpacket CTF IR packet
  39 @ingroup ctfir
  40 @brief CTF IR packet.
  41
  42 A CTF IR <strong><em>packet</em></strong> is a container of packet
  43 fields, that is, of the <strong>trace packet header</strong> and
  44 <strong>stream packet context</strong> fields.
  45
  46 As a reminder, here's the structure of a CTF packet:
  47
  48 @imgpacketstructure
  49
  50 You can create a CTF IR packet \em from a
  51 \link ctfirstream CTF IR stream\endlink with bt_ctf_packet_create(). The
  52 stream you use to create a packet object becomes its parent.
  53
  54 When you set the trace packet header and stream packet context fields of
  55 a packet with resp. bt_ctf_packet_set_header() and
  56 bt_ctf_packet_set_context(), their field type \em must be equivalent to
  57 the field types returned by resp. bt_ctf_trace_get_packet_header_type()
  58 and bt_ctf_stream_class_get_packet_context_type() for its parent trace
  59 class and stream class.
  60
  61 You can attach a packet object to a \link ctfirevent CTF IR
  62 event\endlink object with bt_ctf_event_set_packet().
  63
  64 As with any Babeltrace object, CTF IR packet objects have
  65 <a href="https://en.wikipedia.org/wiki/Reference_counting">reference
  66 counts</a>. See \ref refs to learn more about the reference counting
  67 management of Babeltrace objects.
  68
  69 bt_notification_event_create() \em freezes its event parameter on
  70 success, which in turns freezes the event's associated packet object.
  71 This is the only way that a CTF IR packet object can be frozen.
  72 You cannot modify a frozen packet: it is considered immutable,
  73 except for \link refs reference counting\endlink.
  74
  75 @sa ctfirstream
  76 @sa ctfirstreamclass
  77 @sa ctfirtraceclass
  78
  79 @file
  80 @brief CTF IR packet type and functions.
  81 @sa ctfirpacket
  82
  83 @addtogroup ctfirpacket
  84 @{
  85 */
  86
  87 /**
  88 @struct bt_ctf_packet
  89 @brief A CTF IR packet.
  90 @sa ctfirpacket
  91 */
  92 struct bt_ctf_packet;
  93 struct bt_ctf_stream;
  94
  95 /**
  96 @name Creation and parent access functions
  97 @{
  98 */
  99
 100 /**
 101 @brief  Creates a default CTF IR packet with \p stream as its parent
 102         CTF IR stream.
 103
 104 On success, the packet object's trace packet header and stream packet
 105 context fields are not set. You can set them with resp.
 106 bt_ctf_packet_set_header() and bt_ctf_packet_set_context().
 107
 108 @param[in] stream       Parent CTF IR stream of the packet to create.
 109 @returns                Created packet, or \c NULL on error.
 110
 111 @prenotnull{stream}
 112 @postsuccessrefcountret1
 113 */
 114 extern struct bt_ctf_packet *bt_ctf_packet_create(
 115                 struct bt_ctf_stream *stream);
 116
 117 /**
 118 @brief  Returns the parent CTF IR stream of the CTF IR packet \p packet.
 119
 120 This function returns a reference to the stream which was used to create
 121 the packet object in the first place with bt_ctf_packet_create().
 122
 123 @param[in] packet       Packet of which to get the parent stream.
 124 @returns                Parent stream of \p packet, or \c NULL on error.
 125
 126 @prenotnull{packet}
 127 @postsuccessrefcountretinc
 128 */
 129 extern struct bt_ctf_stream *bt_ctf_packet_get_stream(
 130                 struct bt_ctf_packet *packet);
 131
 132 /** @} */
 133
 134 /**
 135 @name Contained fields functions
 136 @{
 137 */
 138
 139 /**
 140 @brief  Returns the trace packet header field of the CTF IR packet
 141         \p packet.
 142
 143 @param[in] packet       Packet of which to get the trace packet header
 144                         field.
 145 @returns                Trace packet header field of \p packet,
 146                         or \c NULL if the trace packet header
 147                         field is not set or on error.
 148
 149 @prenotnull{packet}
 150 @postsuccessrefcountretinc
 151
 152 @sa bt_ctf_packet_set_header(): Sets the trace packet header
 153         field of a given packet.
 154 */
 155 extern struct bt_ctf_field *bt_ctf_packet_get_header(
 156                 struct bt_ctf_packet *packet);
 157
 158 /**
 159 @brief  Sets the trace packet header field of the CTF IR packet
 160         \p packet to \p header.
 161
 162 The field type of \p header, as returned by bt_ctf_field_get_type(),
 163 \em must be equivalent to the field type returned by
 164 bt_ctf_trace_get_packet_header_type() for the parent trace class
 165 of \p packet.
 166
 167 @param[in] packet       Packet of which to set the trace packet header
 168                         field.
 169 @param[in] header       Trace packet header field.
 170 @returns                0 on success, or a negative value on error.
 171
 172 @prenotnull{packet}
 173 @prenotnull{header}
 174 @prehot{packet}
 175 @pre \p header has a field type equivalent to the field type returned by
 176         bt_ctf_trace_get_packet_header_type() for the parent trace class
 177         of \p packet.
 178 @postrefcountsame{packet}
 179 @postsuccessrefcountinc{header}
 180
 181 @sa bt_ctf_packet_get_header(): Returns the trace packet header field
 182         of a given packet.
 183 */
 184 extern int bt_ctf_packet_set_header(
 185                 struct bt_ctf_packet *packet, struct bt_ctf_field *header);
 186
 187 /**
 188 @brief  Returns the stream packet context field of the CTF IR packet
 189         \p packet.
 190
 191 @param[in] packet       Packet of which to get the stream packet context
 192                         field.
 193 @returns                Stream packet context field of \p packet,
 194                         or \c NULL if the stream packet context
 195                         field is not set or on error.
 196
 197 @prenotnull{packet}
 198 @postsuccessrefcountretinc
 199
 200 @sa bt_ctf_packet_set_context(): Sets the stream packet context
 201         field of a given packet.
 202 */
 203 extern struct bt_ctf_field *bt_ctf_packet_get_context(
 204                 struct bt_ctf_packet *packet);
 205
 206 /**
 207 @brief  Sets the stream packet context field of the CTF IR packet
 208         \p packet to \p context.
 209
 210 The field type of \p context, as returned by bt_ctf_field_get_type(),
 211 \em must be equivalent to the field type returned by
 212 bt_ctf_stream_class_get_packet_context_type() for the parent stream
 213 class of \p packet.
 214
 215 @param[in] packet       Packet of which to set the stream packet context
 216                         field.
 217 @param[in] context      Stream packet context field.
 218 @returns                0 on success, or a negative value on error.
 219
 220 @prenotnull{packet}
 221 @prenotnull{context}
 222 @prehot{packet}
 223 @pre \p context has a field type equivalent to the field type returned
 224         by bt_ctf_stream_class_get_packet_context_type() for the parent
 225         stream class of \p packet.
 226 @postrefcountsame{packet}
 227 @postsuccessrefcountinc{context}
 228
 229 @sa bt_ctf_packet_get_context(): Returns the stream packet context field
 230         of a given packet.
 231 */
 232 extern int bt_ctf_packet_set_context(
 233                 struct bt_ctf_packet *packet, struct bt_ctf_field *context);
 234
 235 /** @} */
 236
 237 #ifdef __cplusplus
 238 }
 239 #endif
 240
 241 #endif /* BABELTRACE_CTF_IR_PACKET_H */