lib/babeltrace/ctf-writer/event-fields.h

   1 #ifndef BABELTRACE_CTF_WRITER_EVENT_FIELDS_H
   2 #define BABELTRACE_CTF_WRITER_EVENT_FIELDS_H
   3
   4 /*
   5  * BabelTrace - CTF Writer: Event Fields
   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 #include <stdint.h>
  34
  35 #ifdef __cplusplus
  36 extern "C" {
  37 #endif
  38
  39 struct bt_ctf_event_class;
  40 struct bt_ctf_event;
  41 struct bt_ctf_field;
  42 struct bt_ctf_field_type;
  43
  44 /*
  45  * bt_ctf_field_create: create an instance of a field.
  46  *
  47  * Allocate a new field of the type described by the bt_ctf_field_type
  48  * structure.The creation of a field sets its reference count to 1.
  49  *
  50  * @param type Field type to be instanciated.
  51  *
  52  * Returns an allocated field on success, NULL on error.
  53  */
  54 extern struct bt_ctf_field *bt_ctf_field_create(
  55                 struct bt_ctf_field_type *type);
  56
  57 /*
  58  * bt_ctf_field_structure_get_field: get a structure's field.
  59  *
  60  * Get the structure's field corresponding to the provided field name.
  61  * bt_ctf_field_put() must be called on the returned value.
  62  *
  63  * @param structure Structure field instance.
  64  * @param name Name of the field in the provided structure.
  65  *
  66  * Returns a field instance on success, NULL on error.
  67  */
  68 extern struct bt_ctf_field *bt_ctf_field_structure_get_field(
  69                 struct bt_ctf_field *structure, const char *name);
  70
  71 /*
  72  * bt_ctf_field_array_get_field: get an array's field at position "index".
  73  *
  74  * Return the array's field at position "index". bt_ctf_field_put() must be
  75  * called on the returned value.
  76  *
  77  * @param array Array field instance.
  78  * @param index Position of the array's desired element.
  79  *
  80  * Returns a field instance on success, NULL on error.
  81  */
  82 extern struct bt_ctf_field *bt_ctf_field_array_get_field(
  83                 struct bt_ctf_field *array, uint64_t index);
  84
  85 /*
  86  * bt_ctf_field_sequence_set_length: set a sequence's length.
  87  *
  88  * Set the sequence's length field.
  89  *
  90  * @param sequence Sequence field instance.
  91  * @param length_field Integer field instance indicating the sequence's length.
  92  *
  93  * Returns a field instance on success, NULL on error.
  94  */
  95 extern int bt_ctf_field_sequence_set_length(struct bt_ctf_field *sequence,
  96                 struct bt_ctf_field *length_field);
  97
  98 /*
  99  * bt_ctf_field_sequence_get_field: get a sequence's field at position "index".
 100  *
 101  * Return the sequence's field at position "index". The sequence's length must
 102  * have been set prior to calling this function using
 103  * bt_ctf_field_sequence_set_length().
 104  * bt_ctf_field_put() must be called on the returned value.
 105  *
 106  * @param array Sequence field instance.
 107  * @param index Position of the sequence's desired element.
 108  *
 109  * Returns a field instance on success, NULL on error.
 110  */
 111 extern struct bt_ctf_field *bt_ctf_field_sequence_get_field(
 112                 struct bt_ctf_field *sequence, uint64_t index);
 113
 114 /*
 115  * bt_ctf_field_variant_get_field: get a variant's selected field.
 116  *
 117  * Return the variant's selected field. The "tag" field is the selector enum
 118  * field. bt_ctf_field_put() must be called on the returned value.
 119  *
 120  * @param variant Variant field instance.
 121  * @param tag Selector enumeration field.
 122  *
 123  * Returns a field instance on success, NULL on error.
 124  */
 125 extern struct bt_ctf_field *bt_ctf_field_variant_get_field(
 126                 struct bt_ctf_field *variant, struct bt_ctf_field *tag);
 127
 128 /*
 129  * bt_ctf_field_enumeration_get_container: get an enumeration field's container.
 130  *
 131  * Return the enumeration's underlying container field (an integer).
 132  * bt_ctf_field_put() must be called on the returned value.
 133  *
 134  * @param enumeration Enumeration field instance.
 135  *
 136  * Returns a field instance on success, NULL on error.
 137  */
 138 extern struct bt_ctf_field *bt_ctf_field_enumeration_get_container(
 139                 struct bt_ctf_field *enumeration);
 140
 141 /*
 142  * bt_ctf_field_signed_integer_set_value: set a signed integer field's value
 143  *
 144  * Set a signed integer field's value. The value is checked to make sure it
 145  * can be stored in the underlying field.
 146  *
 147  * @param integer Signed integer field instance.
 148  * @param value Signed integer field value.
 149  *
 150  * Returns 0 on success, a negative value on error.
 151  */
 152 extern int bt_ctf_field_signed_integer_set_value(struct bt_ctf_field *integer,
 153                 int64_t value);
 154
 155 /*
 156  * bt_ctf_field_unsigned_integer_set_value: set unsigned integer field's value
 157  *
 158  * Set an unsigned integer field's value. The value is checked to make sure it
 159  * can be stored in the underlying field.
 160  *
 161  * @param integer Unsigned integer field instance.
 162  * @param value Unsigned integer field value.
 163  *
 164  * Returns 0 on success, a negative value on error.
 165  */
 166 extern int bt_ctf_field_unsigned_integer_set_value(struct bt_ctf_field *integer,
 167                 uint64_t value);
 168
 169 /*
 170  * bt_ctf_field_floating_point_set_value: set a floating point field's value
 171  *
 172  * Set a floating point field's value. The underlying type may not support the
 173  * double's full precision.
 174  *
 175  * @param floating_point Floating point field instance.
 176  * @param value Floating point field value.
 177  *
 178  * Returns 0 on success, a negative value on error.
 179  */
 180 extern int bt_ctf_field_floating_point_set_value(
 181                 struct bt_ctf_field *floating_point,
 182                 double value);
 183
 184 /*
 185  * bt_ctf_field_string_set_value: set a string field's value
 186  *
 187  * Set a string field's value.
 188  *
 189  * @param string String field instance.
 190  * @param value String field value (will be copied).
 191  *
 192  * Returns 0 on success, a negative value on error.
 193  */
 194 extern int bt_ctf_field_string_set_value(struct bt_ctf_field *string,
 195                 const char *value);
 196
 197 /*
 198  * bt_ctf_field_get and bt_ctf_field_put: increment and decrement the
 199  * field's reference count.
 200  *
 201  * These functions ensure that the field won't be destroyed when it
 202  * is in use. The same number of get and put (plus one extra put to
 203  * release the initial reference done at creation) have to be done to
 204  * destroy a field.
 205  *
 206  * When the field's reference count is decremented to 0 by a bt_ctf_field_put,
 207  * the field is freed.
 208  *
 209  * @param field Field instance.
 210  */
 211 extern void bt_ctf_field_get(struct bt_ctf_field *field);
 212 extern void bt_ctf_field_put(struct bt_ctf_field *field);
 213
 214 #ifdef __cplusplus
 215 }
 216 #endif
 217
 218 #endif /* BABELTRACE_CTF_WRITER_EVENT_FIELDS_H */