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: get the timestamp of the event offsetted
 113  * with the system clock source (in ns) in *timestamp.
 114  *
 115  * Return 0 on success, or -1ULL on error.
 116  */
 117 int bt_ctf_get_timestamp(const struct bt_ctf_event *event, int64_t *timestamp);
 118
 119 /*
 120  * bt_ctf_get_field_list: obtain the list of fields for compound type
 121  *
 122  * This function can be used to obtain the list of fields contained
 123  * within a top-level scope of an event or a compound type: array,
 124  * sequence, structure, or variant.
 125
 126  * This function sets the "list" pointer to an array of definition
 127  * pointers and set count to the number of elements in the array.
 128  * Return 0 on success and a negative value on error.
 129  *
 130  * The content pointed to by "list" should *not* be freed. It stays
 131  * valid as long as the event is unchanged (as long as the iterator
 132  * from which the event is extracted is unchanged).
 133  */
 134 int bt_ctf_get_field_list(const struct bt_ctf_event *event,
 135                 const struct bt_definition *scope,
 136                 struct bt_definition const * const **list,
 137                 unsigned int *count);
 138
 139 /*
 140  * bt_ctf_get_field: returns the definition of a specific field
 141  */
 142 const struct bt_definition *bt_ctf_get_field(const struct bt_ctf_event *event,
 143                 const struct bt_definition *scope,
 144                 const char *field);
 145
 146 /*
 147  * bt_ctf_get_index: if the field is an array or a sequence, return the element
 148  * at position index, otherwise return NULL;
 149  */
 150 const struct bt_definition *bt_ctf_get_index(const struct bt_ctf_event *event,
 151                 const struct bt_definition *field,
 152                 unsigned int index);
 153
 154 /*
 155  * bt_ctf_field_name: returns the name of a field or NULL on error
 156  */
 157 const char *bt_ctf_field_name(const struct bt_definition *def);
 158
 159 /*
 160  * bt_ctf_get_decl_from_def: return the declaration of a field from
 161  * its definition or NULL on error
 162  */
 163 const struct bt_declaration *bt_ctf_get_decl_from_def(const struct bt_definition *def);
 164
 165 /*
 166  * bt_ctf_get_decl_from_field_decl: return the declaration of a field from
 167  * a field_decl or NULL on error
 168  */
 169 const struct bt_declaration *bt_ctf_get_decl_from_field_decl(
 170                 const struct bt_ctf_field_decl *field);
 171
 172 /*
 173  * bt_ctf_field_type: returns the type of a field or -1 if unknown
 174  */
 175 enum ctf_type_id bt_ctf_field_type(const struct bt_declaration *decl);
 176
 177 /*
 178  * bt_ctf_get_int_signedness: return the signedness of an integer
 179  *
 180  * return 0 if unsigned
 181  * return 1 if signed
 182  * return -1 on error
 183  */
 184 int bt_ctf_get_int_signedness(const struct bt_declaration *decl);
 185
 186 /*
 187  * bt_ctf_get_int_base: return the base of an int or a negative value on error
 188  */
 189 int bt_ctf_get_int_base(const struct bt_declaration *decl);
 190
 191 /*
 192  * bt_ctf_get_int_byte_order: return the byte order of an int or a negative
 193  * value on error
 194  */
 195 int bt_ctf_get_int_byte_order(const struct bt_declaration *decl);
 196
 197 /*
 198  * bt_ctf_get_int_len: return the size, in bits, of an int or a negative
 199  * value on error
 200  */
 201 ssize_t bt_ctf_get_int_len(const struct bt_declaration *decl);
 202
 203 /*
 204  * bt_ctf_get_encoding: return the encoding of an int, a string, or of
 205  * the integer contained in a char array or a sequence.
 206  * return a negative value on error
 207  */
 208 enum ctf_string_encoding bt_ctf_get_encoding(const struct bt_declaration *decl);
 209
 210 /*
 211  * bt_ctf_get_array_len: return the len of an array or a negative
 212  * value on error
 213  */
 214 int bt_ctf_get_array_len(const struct bt_declaration *decl);
 215
 216 /*
 217  * bt_ctf_get_struct_field_count: return the number of fields in a structure.
 218  * Returns a negative value on error.
 219  */
 220 uint64_t bt_ctf_get_struct_field_count(const struct bt_definition *field);
 221
 222 /*
 223  * Field access functions
 224  *
 225  * These functions return the value associated with the field passed in
 226  * parameter.
 227  *
 228  * If the field does not exist or is not of the type requested, the value
 229  * returned is undefined. To check if an error occured, use the
 230  * bt_ctf_field_get_error() function after accessing a field.
 231  *
 232  * bt_ctf_get_enum_int gets the integer field of an enumeration.
 233  * bt_ctf_get_enum_str gets the string matching the current enumeration
 234  * value, or NULL if the current value does not match any string.
 235  */
 236 uint64_t bt_ctf_get_uint64(const struct bt_definition *field);
 237 int64_t bt_ctf_get_int64(const struct bt_definition *field);
 238 const struct bt_definition *bt_ctf_get_enum_int(const struct bt_definition *field);
 239 const char *bt_ctf_get_enum_str(const struct bt_definition *field);
 240 char *bt_ctf_get_char_array(const struct bt_definition *field);
 241 char *bt_ctf_get_string(const struct bt_definition *field);
 242 double bt_ctf_get_float(const struct bt_definition *field);
 243 const struct bt_definition *bt_ctf_get_variant(const struct bt_definition *field);
 244 const struct bt_definition *bt_ctf_get_struct_field_index(
 245                 const struct bt_definition *field, uint64_t i);
 246
 247 /*
 248  * bt_ctf_field_get_error: returns the last error code encountered while
 249  * accessing a field and reset the error flag.
 250  * Return 0 if no error, a negative value otherwise.
 251  */
 252 int bt_ctf_field_get_error(void);
 253
 254 /*
 255  * bt_ctf_get_event_decl_list: get a list of all the event declarations in
 256  * a trace.
 257  *
 258  * The list array is pointed to the array of event declarations.
 259  * The number of events in the array is written in count.
 260  *
 261  * Return 0 on success and a negative value on error.
 262  *
 263  * The content pointed to by "list" should *not* be freed. It stays
 264  * valid as long as the trace is opened.
 265  */
 266 int bt_ctf_get_event_decl_list(int handle_id, struct bt_context *ctx,
 267                 struct bt_ctf_event_decl * const **list,
 268                 unsigned int *count);
 269
 270 /*
 271  * bt_ctf_get_decl_event_name: return the name of the event or NULL on error
 272  */
 273 const char *bt_ctf_get_decl_event_name(const struct bt_ctf_event_decl *event);
 274
 275 /*
 276  * bt_ctf_get_decl_event_id: return the event-ID of the event or -1ULL on error
 277  */
 278 uint64_t bt_ctf_get_decl_event_id(const struct bt_ctf_event_decl *event);
 279
 280 /*
 281  * bt_ctf_get_decl_fields: get all field declarations in a scope of an event
 282  *
 283  * The list array is pointed to the array of field declaration.
 284  * The number of field declaration in the array is written in count.
 285  *
 286  * Returns 0 on success and a negative value on error
 287  *
 288  * The content pointed to by "list" should *not* be freed. It stays
 289  * valid as long as the trace is opened.
 290  */
 291 int bt_ctf_get_decl_fields(struct bt_ctf_event_decl *event_decl,
 292                 enum bt_ctf_scope scope,
 293                 struct bt_ctf_field_decl const * const **list,
 294                 unsigned int *count);
 295
 296 /*
 297  * bt_ctf_get_decl_field_name: return the name of a field decl or NULL on error
 298  */
 299 const char *bt_ctf_get_decl_field_name(const struct bt_ctf_field_decl *field);
 300
 301 #ifdef __cplusplus
 302 }
 303 #endif
 304
 305 #endif /* _BABELTRACE_CTF_EVENTS_H */