include/babeltrace/ctf-writer/writer.h

   1 #ifndef BABELTRACE_CTF_WRITER_WRITER_H
   2 #define BABELTRACE_CTF_WRITER_WRITER_H
   3
   4 /*
   5  * BabelTrace - CTF Writer: Writer
   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_writer;
  38 struct bt_ctf_stream;
  39 struct bt_ctf_stream_class;
  40 struct bt_ctf_clock;
  41
  42 enum bt_ctf_byte_order {
  43         BT_CTF_BYTE_ORDER_NATIVE = 0,
  44         BT_CTF_BYTE_ORDER_LITTLE_ENDIAN,
  45         BT_CTF_BYTE_ORDER_BIG_ENDIAN,
  46         BT_CTF_BYTE_ORDER_NETWORK,
  47 };
  48
  49 /*
  50  * bt_ctf_writer_create: create a writer instance.
  51  *
  52  * Allocate a new writer that will produce a trace in the given path.
  53  * The creation of a writer sets its reference count to 1.
  54  *
  55  * @param path Path to the trace's containing folder (string is copied).
  56  *
  57  * Returns an allocated writer on success, NULL on error.
  58  */
  59 extern struct bt_ctf_writer *bt_ctf_writer_create(const char *path);
  60
  61 /*
  62  * bt_ctf_writer_create_stream: create a stream instance.
  63  *
  64  * Allocate a new stream instance and register it to the writer. The creation of
  65  * a stream sets its reference count to 1.
  66  *
  67  * @param writer Writer instance.
  68  * @param stream_class Stream class to instantiate.
  69  *
  70  * Returns an allocated writer on success, NULL on error.
  71  */
  72 extern struct bt_ctf_stream *bt_ctf_writer_create_stream(
  73                 struct bt_ctf_writer *writer,
  74                 struct bt_ctf_stream_class *stream_class);
  75
  76 /*
  77  * bt_ctf_writer_add_environment_field: add an environment field to the trace.
  78  *
  79  * Add an environment field to the trace. The name and value parameters are
  80  * copied.
  81  *
  82  * @param writer Writer instance.
  83  * @param name Name of the environment field (will be copied).
  84  * @param value Value of the environment field (will be copied).
  85  *
  86  * Returns 0 on success, a negative value on error.
  87  */
  88 extern int bt_ctf_writer_add_environment_field(struct bt_ctf_writer *writer,
  89                 const char *name,
  90                 const char *value);
  91
  92 /*
  93  * bt_ctf_writer_add_clock: add a clock to the trace.
  94  *
  95  * Add a clock to the trace. Clocks assigned to stream classes must be
  96  * registered to the writer.
  97  *
  98  * @param writer Writer instance.
  99  * @param clock Clock to add to the trace.
 100  *
 101  * Returns 0 on success, a negative value on error.
 102  */
 103 extern int bt_ctf_writer_add_clock(struct bt_ctf_writer *writer,
 104                 struct bt_ctf_clock *clock);
 105
 106 /*
 107  * bt_ctf_writer_get_metadata_string: get meta-data string.
 108  *
 109  * Get the trace's TSDL meta-data. The caller assumes the ownership of the
 110  * returned string.
 111  *
 112  * @param writer Writer instance.
 113  *
 114  * Returns the metadata string on success, NULL on error.
 115  */
 116 extern char *bt_ctf_writer_get_metadata_string(struct bt_ctf_writer *writer);
 117
 118 /*
 119  * bt_ctf_writer_flush_metadata: flush the trace's metadata to disk.
 120  *
 121  * Flush the trace's metadata to the metadata file. Note that the metadata will
 122  * be flushed automatically when the Writer instance is released (last call to
 123  * bt_ctf_writer_put).
 124  *
 125  * @param writer Writer instance.
 126  */
 127 extern void bt_ctf_writer_flush_metadata(struct bt_ctf_writer *writer);
 128
 129 /*
 130  * bt_ctf_writer_set_byte_order: set a field type's byte order.
 131  *
 132  * Set the trace's byte order. Defaults to BT_CTF_BYTE_ORDER_NATIVE,
 133  * the host machine's endianness.
 134  *
 135  * @param writer Writer instance.
 136  * @param byte_order Trace's byte order.
 137  *
 138  * Returns 0 on success, a negative value on error.
 139  */
 140 extern int bt_ctf_writer_set_byte_order(struct bt_ctf_writer *writer,
 141                 enum bt_ctf_byte_order byte_order);
 142
 143 /*
 144  * bt_ctf_writer_get and bt_ctf_writer_put: increment and decrement the
 145  * writer's reference count.
 146  *
 147  * These functions ensure that the writer won't be destroyed while it
 148  * is in use. The same number of get and put (plus one extra put to
 149  * release the initial reference done at creation) have to be done to
 150  * destroy a writer.
 151  *
 152  * When the writer's reference count is decremented to 0 by a
 153  * bt_ctf_writer_put, the writer is freed.
 154  *
 155  * @param writer Writer instance.
 156  */
 157 extern void bt_ctf_writer_get(struct bt_ctf_writer *writer);
 158 extern void bt_ctf_writer_put(struct bt_ctf_writer *writer);
 159
 160 #ifdef __cplusplus
 161 }
 162 #endif
 163
 164 #endif /* BABELTRACE_CTF_WRITER_WRITER_H */