include/babeltrace2-ctf-writer/writer.h

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * Copyright (C) 2010-2019 EfficiOS Inc. and Linux Foundation
   5  */
   6
   7 #ifndef BABELTRACE2_CTF_WRITER_WRITER_H
   8 #define BABELTRACE2_CTF_WRITER_WRITER_H
   9
  10 #include <babeltrace2-ctf-writer/field-types.h>
  11 #include <babeltrace2-ctf-writer/stream-class.h>
  12 #include <babeltrace2-ctf-writer/stream.h>
  13 #include <babeltrace2-ctf-writer/trace.h>
  14
  15 #ifdef __cplusplus
  16 extern "C" {
  17 #endif
  18
  19 struct bt_ctf_writer;
  20 struct bt_ctf_stream;
  21 struct bt_ctf_stream_class;
  22 struct bt_ctf_clock;
  23
  24 /*
  25  * bt_ctf_writer_create: create a writer instance.
  26  *
  27  * Allocate a new writer that will produce a trace in the given path.
  28  * The creation of a writer sets its reference count to 1.
  29  *
  30  * @param path Path to the trace's containing folder (string is copied).
  31  *
  32  * Returns an allocated writer on success, NULL on error.
  33  */
  34 extern struct bt_ctf_writer *bt_ctf_writer_create(const char *path);
  35
  36 /*
  37  * bt_ctf_writer_get_trace: Get a writer's associated trace.
  38  *
  39  * @param writer Writer instance.
  40  *
  41  * Return the writer's associated instance, NULL on error.
  42  */
  43 extern struct bt_ctf_trace *bt_ctf_writer_get_trace(
  44                 struct bt_ctf_writer *writer);
  45
  46 /*
  47  * bt_ctf_writer_create_stream: create a stream instance.
  48  *
  49  * Allocate a new stream instance and register it to the writer. The creation of
  50  * a stream sets its reference count to 1.
  51  *
  52  * @param writer Writer instance.
  53  * @param stream_class Stream class to instantiate.
  54  *
  55  * Returns an allocated stream on success, NULL on error.
  56  */
  57 extern struct bt_ctf_stream *bt_ctf_writer_create_stream(
  58                 struct bt_ctf_writer *writer,
  59                 struct bt_ctf_stream_class *stream_class);
  60
  61 /*
  62  * bt_ctf_writer_add_environment_field: add an environment field to the trace.
  63  *
  64  * Add an environment field to the trace. The name and value parameters are
  65  * copied.
  66  *
  67  * @param writer Writer instance.
  68  * @param name Name of the environment field (will be copied).
  69  * @param value Value of the environment field (will be copied).
  70  *
  71  * Returns 0 on success, a negative value on error.
  72  */
  73 extern int bt_ctf_writer_add_environment_field(struct bt_ctf_writer *writer,
  74                 const char *name,
  75                 const char *value);
  76
  77 /*
  78  * bt_ctf_writer_add_environment_field_int64: add an environment field to the trace.
  79  *
  80  * Add an environment field to the trace. The name and value parameters are
  81  * copied.
  82  *
  83  * @param writer Writer instance.
  84  * @param name Name of the environment field (will be copied).
  85  * @param value Value of the environment field.
  86  *
  87  * Returns 0 on success, a negative value on error.
  88  */
  89 extern int bt_ctf_writer_add_environment_field_int64(
  90                 struct bt_ctf_writer *writer,
  91                 const char *name,
  92                 int64_t value);
  93
  94 /*
  95  * bt_ctf_writer_add_clock: add a clock to the trace.
  96  *
  97  * Add a clock to the trace. Clocks assigned to stream classes must be
  98  * registered to the writer.
  99  *
 100  * @param writer Writer instance.
 101  * @param clock Clock to add to the trace.
 102  *
 103  * Returns 0 on success, a negative value on error.
 104  */
 105 extern int bt_ctf_writer_add_clock(struct bt_ctf_writer *writer,
 106                 struct bt_ctf_clock *clock);
 107
 108 /*
 109  * bt_ctf_writer_get_metadata_string: get meta-data string.
 110  *
 111  * Get the trace's TSDL meta-data. The caller assumes the ownership of the
 112  * returned string.
 113  *
 114  * @param writer Writer instance.
 115  *
 116  * Returns the metadata string on success, NULL on error.
 117  */
 118 extern char *bt_ctf_writer_get_metadata_string(struct bt_ctf_writer *writer);
 119
 120 /*
 121  * bt_ctf_writer_flush_metadata: flush the trace's metadata to disk.
 122  *
 123  * Flush the trace's metadata to the metadata file. Note that the metadata will
 124  * be flushed automatically when the Writer instance is released (last call to
 125  * bt_ctf_writer_put).
 126  *
 127  * @param writer Writer instance.
 128  */
 129 extern void bt_ctf_writer_flush_metadata(struct bt_ctf_writer *writer);
 130
 131 /*
 132  * bt_ctf_writer_set_byte_order: set a field type's byte order.
 133  *
 134  * Set the trace's byte order. Defaults to the host machine's endianness.
 135  *
 136  * @param writer Writer instance.
 137  * @param byte_order Trace's byte order.
 138  *
 139  * Returns 0 on success, a negative value on error.
 140  *
 141  * Note: byte_order must not be BT_CTF_BYTE_ORDER_NATIVE since, according
 142  * to the CTF specification, is defined as "the byte order described in the
 143  * trace description".
 144  */
 145 extern int bt_ctf_writer_set_byte_order(struct bt_ctf_writer *writer,
 146                 enum bt_ctf_byte_order byte_order);
 147
 148 /*
 149  * bt_ctf_writer_get and bt_ctf_writer_put: increment and decrement the
 150  * writer's reference count.
 151  *
 152  * You may also use bt_ctf_get() and bt_ctf_put() with writer objects.
 153  *
 154  * These functions ensure that the writer won't be destroyed while it
 155  * is in use. The same number of get and put (plus one extra put to
 156  * release the initial reference done at creation) have to be done to
 157  * destroy a writer.
 158  *
 159  * When the writer's reference count is decremented to 0 by a
 160  * bt_ctf_writer_put, the writer is freed.
 161  *
 162  * @param writer Writer instance.
 163  */
 164
 165 /* Pre-2.0 CTF writer compatibility */
 166 static inline
 167 void bt_ctf_writer_get(struct bt_ctf_writer *writer)
 168 {
 169         bt_ctf_object_get_ref(writer);
 170 }
 171
 172 /* Pre-2.0 CTF writer compatibility */
 173 static inline
 174 void bt_ctf_writer_put(struct bt_ctf_writer *writer)
 175 {
 176         bt_ctf_object_put_ref(writer);
 177 }
 178
 179 #ifdef __cplusplus
 180 }
 181 #endif
 182
 183 #endif /* BABELTRACE2_CTF_WRITER_WRITER_H */