Add support for structure fields in the Python bindings
[babeltrace.git] / 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 * bt_ctf_get_struct_field_count: return the number of fields in a structure.
216 * Returns a negative value on error.
217 */
218 uint64_t bt_ctf_get_struct_field_count(const struct bt_definition *field);
219
220 /*
221 * Field access functions
222 *
223 * These functions return the value associated with the field passed in
224 * parameter.
225 *
226 * If the field does not exist or is not of the type requested, the value
227 * returned is undefined. To check if an error occured, use the
228 * bt_ctf_field_get_error() function after accessing a field.
229 *
230 * bt_ctf_get_enum_int gets the integer field of an enumeration.
231 * bt_ctf_get_enum_str gets the string matching the current enumeration
232 * value, or NULL if the current value does not match any string.
233 */
234 uint64_t bt_ctf_get_uint64(const struct bt_definition *field);
235 int64_t bt_ctf_get_int64(const struct bt_definition *field);
236 const struct bt_definition *bt_ctf_get_enum_int(const struct bt_definition *field);
237 const char *bt_ctf_get_enum_str(const struct bt_definition *field);
238 char *bt_ctf_get_char_array(const struct bt_definition *field);
239 char *bt_ctf_get_string(const struct bt_definition *field);
240 double bt_ctf_get_float(const struct bt_definition *field);
241 const struct bt_definition *bt_ctf_get_variant(const struct bt_definition *field);
242 const struct bt_definition *bt_ctf_get_struct_field_index(
243 const struct bt_definition *field, uint64_t i);
244
245 /*
246 * bt_ctf_field_get_error: returns the last error code encountered while
247 * accessing a field and reset the error flag.
248 * Return 0 if no error, a negative value otherwise.
249 */
250 int bt_ctf_field_get_error(void);
251
252 /*
253 * bt_ctf_get_event_decl_list: get a list of all the event declarations in
254 * a trace.
255 *
256 * The list array is pointed to the array of event declarations.
257 * The number of events in the array is written in count.
258 *
259 * Return 0 on success and a negative value on error.
260 *
261 * The content pointed to by "list" should *not* be freed. It stays
262 * valid as long as the trace is opened.
263 */
264 int bt_ctf_get_event_decl_list(int handle_id, struct bt_context *ctx,
265 struct bt_ctf_event_decl * const **list,
266 unsigned int *count);
267
268 /*
269 * bt_ctf_get_decl_event_name: return the name of the event or NULL on error
270 */
271 const char *bt_ctf_get_decl_event_name(const struct bt_ctf_event_decl *event);
272
273 /*
274 * bt_ctf_get_decl_fields: get all field declarations in a scope of an event
275 *
276 * The list array is pointed to the array of field declaration.
277 * The number of field declaration in the array is written in count.
278 *
279 * Returns 0 on success and a negative value on error
280 *
281 * The content pointed to by "list" should *not* be freed. It stays
282 * valid as long as the trace is opened.
283 */
284 int bt_ctf_get_decl_fields(struct bt_ctf_event_decl *event_decl,
285 enum bt_ctf_scope scope,
286 struct bt_ctf_field_decl const * const **list,
287 unsigned int *count);
288
289 /*
290 * bt_ctf_get_decl_field_name: return the name of a field decl or NULL on error
291 */
292 const char *bt_ctf_get_decl_field_name(const struct bt_ctf_field_decl *field);
293
294 #ifdef __cplusplus
295 }
296 #endif
297
298 #endif /* _BABELTRACE_CTF_EVENTS_H */
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