Fix : coherency in const parameters
[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
26 #include <stdint.h>
27 #include <babeltrace/iterator.h>
28
29 struct ctf_stream;
30 struct ctf_stream_event;
31 struct definition;
32 struct bt_ctf_iter;
33
34 /*
35 * the top-level scopes in CTF
36 */
37 enum bt_ctf_scope {
38 BT_TRACE_PACKET_HEADER = 0,
39 BT_STREAM_PACKET_CONTEXT = 1,
40 BT_STREAM_EVENT_HEADER = 2,
41 BT_STREAM_EVENT_CONTEXT = 3,
42 BT_EVENT_CONTEXT = 4,
43 BT_EVENT_FIELDS = 5,
44 };
45
46 /*
47 * the supported CTF types
48 */
49 enum ctf_type_id {
50 CTF_TYPE_UNKNOWN = 0,
51 CTF_TYPE_INTEGER,
52 CTF_TYPE_FLOAT,
53 CTF_TYPE_ENUM,
54 CTF_TYPE_STRING,
55 CTF_TYPE_STRUCT,
56 CTF_TYPE_UNTAGGED_VARIANT,
57 CTF_TYPE_VARIANT,
58 CTF_TYPE_ARRAY,
59 CTF_TYPE_SEQUENCE,
60 NR_CTF_TYPES,
61 };
62
63 /*
64 * the structure to manipulate events
65 */
66 struct bt_ctf_event {
67 struct ctf_stream *stream;
68 struct ctf_stream_event *event;
69 };
70
71 /*
72 * bt_ctf_iter_read_event: Read the iterator's current event data.
73 *
74 * @iter: trace collection iterator (input)
75 * @stream: stream containing event at current position (output)
76 * @event: current event (output)
77 * Return 0 on success, negative error value on error.
78 */
79 struct bt_ctf_event *bt_ctf_iter_read_event(struct bt_ctf_iter *iter);
80
81 /*
82 * bt_ctf_iter_create - Allocate a CTF trace collection iterator.
83 *
84 * begin_pos and end_pos are optional parameters to specify the position
85 * at which the trace collection should be seeked upon iterator
86 * creation, and the position at which iteration will start returning
87 * "EOF".
88 *
89 * By default, if begin_pos is NULL, a BT_SEEK_CUR is performed at
90 * creation. By default, if end_pos is NULL, a BT_SEEK_END (end of
91 * trace) is the EOF criterion.
92 */
93 struct bt_ctf_iter *bt_ctf_iter_create(struct bt_context *ctx,
94 struct bt_iter_pos *begin_pos,
95 struct bt_iter_pos *end_pos);
96
97 /*
98 * bt_ctf_get_iter - get iterator from ctf iterator.
99 */
100 struct bt_iter *bt_ctf_get_iter(struct bt_ctf_iter *iter);
101
102 /*
103 * bt_ctf_iter_destroy - Free a CTF trace collection iterator.
104 */
105 void bt_ctf_iter_destroy(struct bt_ctf_iter *iter);
106
107 /*
108 * bt_ctf_get_top_level_scope: return a definition of the top-level scope
109 *
110 * Top-level scopes are defined in the bt_ctf_scope enum.
111 * In order to get a field or a field list, the user needs to pass a
112 * scope as argument, this scope can be a top-level scope or a scope
113 * relative to an arbitrary field. This function provides the mapping
114 * between the enum and the actual definition of top-level scopes.
115 * On error return NULL.
116 */
117 struct definition *bt_ctf_get_top_level_scope(struct bt_ctf_event *event,
118 enum bt_ctf_scope scope);
119
120 /*
121 * bt_ctf_event_get_name: returns the name of the event or NULL on error
122 */
123 const char *bt_ctf_event_name(struct bt_ctf_event *event);
124
125 /*
126 * bt_ctf_get_timestamp: returns the timestamp of the event or -1ULL on error
127 */
128 uint64_t bt_ctf_get_timestamp(struct bt_ctf_event *event);
129
130 /*
131 * bt_ctf_get_field_list: set list pointer to an array of definition
132 * pointers and set count to the number of elements in the array.
133 * Return 0 on success and a negative value on error.
134 */
135 int bt_ctf_get_field_list(struct bt_ctf_event *event,
136 struct definition *scope,
137 struct definition const * const **list,
138 unsigned int *count);
139
140 /*
141 * bt_ctf_get_field: returns the definition of a specific field
142 */
143 struct definition *bt_ctf_get_field(struct bt_ctf_event *event,
144 struct definition *scope,
145 const char *field);
146
147 /*
148 * bt_ctf_get_index: if the field is an array or a sequence, return the element
149 * at position index, otherwise return NULL;
150 */
151 struct definition *bt_ctf_get_index(struct bt_ctf_event *event,
152 struct definition *field,
153 unsigned int index);
154
155 /*
156 * bt_ctf_field_name: returns the name of a field or NULL on error
157 */
158 const char *bt_ctf_field_name(const struct definition *def);
159
160 /*
161 * bt_ctf_field_type: returns the type of a field or -1 if unknown
162 */
163 enum ctf_type_id bt_ctf_field_type(const struct definition *def);
164
165 /*
166 * Field access functions
167 *
168 * These functions return the value associated with the field passed in
169 * parameter.
170 *
171 * If the field does not exist or is not of the type requested, the value
172 * returned is undefined. To check if an error occured, use the
173 * bt_ctf_field_error() function after accessing a field.
174 */
175 uint64_t bt_ctf_get_uint64(const struct definition *field);
176 int64_t bt_ctf_get_int64(const struct definition *field);
177 char *bt_ctf_get_char_array(const struct definition *field);
178 char *bt_ctf_get_string(const struct definition *field);
179
180 /*
181 * bt_ctf_field_error: returns the last error code encountered while
182 * accessing a field and reset the error flag.
183 * Return 0 if no error, a negative value otherwise.
184 */
185 int bt_ctf_field_get_error(void);
186
187 #endif /* _BABELTRACE_CTF_EVENTS_H */
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