include/babeltrace/ctf/events.h

   1 #ifndef _BABELTRACE_CTF_EVENTS_H
   2 #define _BABELTRACE_CTF_EVENTS_H
   3
   4 /*
   5  * BabelTrace
   6  *
   7  * CTF events API
   8  *
   9  * Copyright 2011-2012 EfficiOS Inc. and Linux Foundation
  10  *
  11  * Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
  12  *         Julien Desfossez <julien.desfossez@efficios.com>
  13  *
  14  * Permission is hereby granted, free of charge, to any person obtaining
  15  * a copy of this software and associated documentation files (the
  16  * "Software"), to deal in the Software without restriction, including
  17  * without limitation the rights to use, copy, modify, merge, publish,
  18  * distribute, sublicense, and/or sell copies of the Software, and to
  19  * permit persons to whom the Software is furnished to do so, subject to
  20  * the following conditions:
  21  *
  22  * The above copyright notice and this permission notice shall be
  23  * included in all copies or substantial portions of the Software.
  24  *
  25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  26  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  27  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  28  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  29  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  30  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  31  * SOFTWARE.
  32  */
  33
  34 #include <stdint.h>
  35 #include <babeltrace/context.h>
  36 #include <babeltrace/clock-types.h>
  37
  38 #ifdef __cplusplus
  39 extern "C" {
  40 #endif
  41
  42 struct bt_definition;
  43 struct bt_declaration;
  44 struct bt_ctf_event;
  45 struct bt_ctf_event_decl;
  46 struct bt_ctf_field_decl;
  47
  48 /*
  49  * the top-level scopes in CTF
  50  */
  51 enum bt_ctf_scope {
  52         BT_TRACE_PACKET_HEADER          = 0,
  53         BT_STREAM_PACKET_CONTEXT        = 1,
  54         BT_STREAM_EVENT_HEADER          = 2,
  55         BT_STREAM_EVENT_CONTEXT         = 3,
  56         BT_EVENT_CONTEXT                = 4,
  57         BT_EVENT_FIELDS                 = 5,
  58 };
  59
  60 /*
  61  * the supported CTF types
  62  */
  63 enum ctf_type_id {
  64         CTF_TYPE_UNKNOWN = 0,
  65         CTF_TYPE_INTEGER,
  66         CTF_TYPE_FLOAT,
  67         CTF_TYPE_ENUM,
  68         CTF_TYPE_STRING,
  69         CTF_TYPE_STRUCT,
  70         CTF_TYPE_UNTAGGED_VARIANT,
  71         CTF_TYPE_VARIANT,
  72         CTF_TYPE_ARRAY,
  73         CTF_TYPE_SEQUENCE,
  74         NR_CTF_TYPES,
  75 };
  76
  77 /*
  78  * the supported CTF string encodings
  79  */
  80 enum ctf_string_encoding {
  81         CTF_STRING_NONE = 0,
  82         CTF_STRING_UTF8,
  83         CTF_STRING_ASCII,
  84         CTF_STRING_UNKNOWN,
  85 };
  86
  87 /*
  88  * bt_ctf_get_top_level_scope: return a definition of the top-level scope
  89  *
  90  * Top-level scopes are defined in the bt_ctf_scope enum.
  91  * In order to get a field or a field list, the user needs to pass a
  92  * scope as argument, this scope can be a top-level scope or a scope
  93  * relative to an arbitrary field. This function provides the mapping
  94  * between the enum and the actual definition of top-level scopes.
  95  * On error return NULL.
  96  */
  97 const struct bt_definition *bt_ctf_get_top_level_scope(const struct bt_ctf_event *event,
  98                 enum bt_ctf_scope scope);
  99
 100 /*
 101  * bt_ctf_event_get_name: returns the name of the event or NULL on error
 102  */
 103 const char *bt_ctf_event_name(const struct bt_ctf_event *event);
 104
 105 /*
 106  * bt_ctf_get_cycles: returns the timestamp of the event as written
 107  * in the packet (in cycles) or -1ULL on error.
 108  */
 109 uint64_t bt_ctf_get_cycles(const struct bt_ctf_event *event);
 110
 111 /*
 112  * bt_ctf_get_timestamp: returns the timestamp of the event offsetted
 113  * with the system clock source (in ns) or -1ULL on error
 114  */
 115 uint64_t bt_ctf_get_timestamp(const struct bt_ctf_event *event);
 116
 117 /*
 118  * bt_ctf_get_field_list: obtain the list of fields for compound type
 119  *
 120  * This function can be used to obtain the list of fields contained
 121  * within a top-level scope of an event or a compound type: array,
 122  * sequence, structure, or variant.
 123
 124  * This function sets the "list" pointer to an array of definition
 125  * pointers and set count to the number of elements in the array.
 126  * Return 0 on success and a negative value on error.
 127  *
 128  * The content pointed to by "list" should *not* be freed. It stays
 129  * valid as long as the event is unchanged (as long as the iterator
 130  * from which the event is extracted is unchanged).
 131  */
 132 int bt_ctf_get_field_list(const struct bt_ctf_event *event,
 133                 const struct bt_definition *scope,
 134                 struct bt_definition const * const **list,
 135                 unsigned int *count);
 136
 137 /*
 138  * bt_ctf_get_field: returns the definition of a specific field
 139  */
 140 const struct bt_definition *bt_ctf_get_field(const struct bt_ctf_event *event,
 141                 const struct bt_definition *scope,
 142                 const char *field);
 143
 144 /*
 145  * bt_ctf_get_index: if the field is an array or a sequence, return the element
 146  * at position index, otherwise return NULL;
 147  */
 148 const struct bt_definition *bt_ctf_get_index(const struct bt_ctf_event *event,
 149                 const struct bt_definition *field,
 150                 unsigned int index);
 151
 152 /*
 153  * bt_ctf_field_name: returns the name of a field or NULL on error
 154  */
 155 const char *bt_ctf_field_name(const struct bt_definition *def);
 156
 157 /*
 158  * bt_ctf_get_decl_from_def: return the declaration of a field from
 159  * its definition or NULL on error
 160  */
 161 const struct bt_declaration *bt_ctf_get_decl_from_def(const struct bt_definition *def);
 162
 163 /*
 164  * bt_ctf_get_decl_from_field_decl: return the declaration of a field from
 165  * a field_decl or NULL on error
 166  */
 167 const struct bt_declaration *bt_ctf_get_decl_from_field_decl(
 168                 const struct bt_ctf_field_decl *field);
 169
 170 /*
 171  * bt_ctf_field_type: returns the type of a field or -1 if unknown
 172  */
 173 enum ctf_type_id bt_ctf_field_type(const struct bt_declaration *decl);
 174
 175 /*
 176  * bt_ctf_get_int_signedness: return the signedness of an integer
 177  *
 178  * return 0 if unsigned
 179  * return 1 if signed
 180  * return -1 on error
 181  */
 182 int bt_ctf_get_int_signedness(const struct bt_declaration *decl);
 183
 184 /*
 185  * bt_ctf_get_int_base: return the base of an int or a negative value on error
 186  */
 187 int bt_ctf_get_int_base(const struct bt_declaration *decl);
 188
 189 /*
 190  * bt_ctf_get_int_byte_order: return the byte order of an int or a negative
 191  * value on error
 192  */
 193 int bt_ctf_get_int_byte_order(const struct bt_declaration *decl);
 194
 195 /*
 196  * bt_ctf_get_int_len: return the size, in bits, of an int or a negative
 197  * value on error
 198  */
 199 ssize_t bt_ctf_get_int_len(const struct bt_declaration *decl);
 200
 201 /*
 202  * bt_ctf_get_encoding: return the encoding of an int, a string, or of
 203  * the integer contained in a char array or a sequence.
 204  * return a negative value on error
 205  */
 206 enum ctf_string_encoding bt_ctf_get_encoding(const struct bt_declaration *decl);
 207
 208 /*
 209  * bt_ctf_get_array_len: return the len of an array or a negative
 210  * value on error
 211  */
 212 int bt_ctf_get_array_len(const struct bt_declaration *decl);
 213
 214 /*
 215  * Field access functions
 216  *
 217  * These functions return the value associated with the field passed in
 218  * parameter.
 219  *
 220  * If the field does not exist or is not of the type requested, the value
 221  * returned is undefined. To check if an error occured, use the
 222  * bt_ctf_field_get_error() function after accessing a field.
 223  *
 224  * bt_ctf_get_enum_int gets the integer field of an enumeration.
 225  * bt_ctf_get_enum_str gets the string matching the current enumeration
 226  * value, or NULL if the current value does not match any string.
 227  */
 228 uint64_t bt_ctf_get_uint64(const struct bt_definition *field);
 229 int64_t bt_ctf_get_int64(const struct bt_definition *field);
 230 const struct bt_definition *bt_ctf_get_enum_int(const struct bt_definition *field);
 231 const char *bt_ctf_get_enum_str(const struct bt_definition *field);
 232 char *bt_ctf_get_char_array(const struct bt_definition *field);
 233 char *bt_ctf_get_string(const struct bt_definition *field);
 234
 235 /*
 236  * bt_ctf_field_get_error: returns the last error code encountered while
 237  * accessing a field and reset the error flag.
 238  * Return 0 if no error, a negative value otherwise.
 239  */
 240 int bt_ctf_field_get_error(void);
 241
 242 /*
 243  * bt_ctf_get_event_decl_list: get a list of all the event declarations in
 244  * a trace.
 245  *
 246  * The list array is pointed to the array of event declarations.
 247  * The number of events in the array is written in count.
 248  *
 249  * Return 0 on success and a negative value on error.
 250  *
 251  * The content pointed to by "list" should *not* be freed. It stays
 252  * valid as long as the trace is opened.
 253  */
 254 int bt_ctf_get_event_decl_list(int handle_id, struct bt_context *ctx,
 255                 struct bt_ctf_event_decl * const **list,
 256                 unsigned int *count);
 257
 258 /*
 259  * bt_ctf_get_decl_event_name: return the name of the event or NULL on error
 260  */
 261 const char *bt_ctf_get_decl_event_name(const struct bt_ctf_event_decl *event);
 262
 263 /*
 264  * bt_ctf_get_decl_fields: get all field declarations in a scope of an event
 265  *
 266  * The list array is pointed to the array of field declaration.
 267  * The number of field declaration in the array is written in count.
 268  *
 269  * Returns 0 on success and a negative value on error
 270  *
 271  * The content pointed to by "list" should *not* be freed. It stays
 272  * valid as long as the trace is opened.
 273  */
 274 int bt_ctf_get_decl_fields(struct bt_ctf_event_decl *event_decl,
 275                 enum bt_ctf_scope scope,
 276                 struct bt_ctf_field_decl const * const **list,
 277                 unsigned int *count);
 278
 279 /*
 280  * bt_ctf_get_decl_field_name: return the name of a field decl or NULL on error
 281  */
 282 const char *bt_ctf_get_decl_field_name(const struct bt_ctf_field_decl *field);
 283
 284 #ifdef __cplusplus
 285 }
 286 #endif
 287
 288 #endif /* _BABELTRACE_CTF_EVENTS_H */