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
  28 struct ctf_stream;
  29 struct ctf_stream_event;
  30 struct definition;
  31
  32 /*
  33  * the top-level scopes in CTF
  34  */
  35 enum bt_ctf_scope {
  36         BT_TRACE_PACKET_HEADER          = 0,
  37         BT_STREAM_PACKET_CONTEXT        = 1,
  38         BT_STREAM_EVENT_HEADER          = 2,
  39         BT_STREAM_EVENT_CONTEXT         = 3,
  40         BT_EVENT_CONTEXT                = 4,
  41         BT_EVENT_FIELDS                 = 5,
  42 };
  43
  44 /*
  45  * the supported CTF types
  46  */
  47 enum ctf_type_id {
  48         CTF_TYPE_UNKNOWN = 0,
  49         CTF_TYPE_INTEGER,
  50         CTF_TYPE_FLOAT,
  51         CTF_TYPE_ENUM,
  52         CTF_TYPE_STRING,
  53         CTF_TYPE_STRUCT,
  54         CTF_TYPE_UNTAGGED_VARIANT,
  55         CTF_TYPE_VARIANT,
  56         CTF_TYPE_ARRAY,
  57         CTF_TYPE_SEQUENCE,
  58         NR_CTF_TYPES,
  59 };
  60
  61 /*
  62  * the supported CTF string encodings
  63  */
  64 enum ctf_string_encoding {
  65         CTF_STRING_NONE = 0,
  66         CTF_STRING_UTF8,
  67         CTF_STRING_ASCII,
  68         CTF_STRING_UNKNOWN,
  69 };
  70
  71 /*
  72  * the structure to manipulate events
  73  */
  74 struct bt_ctf_event {
  75         struct ctf_stream *stream;
  76         struct ctf_stream_event *event;
  77 };
  78
  79 /*
  80  * bt_ctf_get_top_level_scope: return a definition of the top-level scope
  81  *
  82  * Top-level scopes are defined in the bt_ctf_scope enum.
  83  * In order to get a field or a field list, the user needs to pass a
  84  * scope as argument, this scope can be a top-level scope or a scope
  85  * relative to an arbitrary field. This function provides the mapping
  86  * between the enum and the actual definition of top-level scopes.
  87  * On error return NULL.
  88  */
  89 struct definition *bt_ctf_get_top_level_scope(struct bt_ctf_event *event,
  90                 enum bt_ctf_scope scope);
  91
  92 /*
  93  * bt_ctf_event_get_name: returns the name of the event or NULL on error
  94  */
  95 const char *bt_ctf_event_name(struct bt_ctf_event *event);
  96
  97 /*
  98  * bt_ctf_get_timestamp_raw: returns the timestamp of the event as written in
  99  * the packet or -1ULL on error
 100  */
 101 uint64_t bt_ctf_get_timestamp_raw(struct bt_ctf_event *event);
 102
 103 /*
 104  * bt_ctf_get_timestamp: returns the timestamp of the event offsetted with the
 105  * system clock source or -1ULL on error
 106  */
 107 uint64_t bt_ctf_get_timestamp(struct bt_ctf_event *event);
 108
 109 /*
 110  * bt_ctf_get_field_list: set list pointer to an array of definition
 111  * pointers and set count to the number of elements in the array.
 112  * Return 0 on success and a negative value on error.
 113  */
 114 int bt_ctf_get_field_list(struct bt_ctf_event *event,
 115                 struct definition *scope,
 116                 struct definition const * const **list,
 117                 unsigned int *count);
 118
 119 /*
 120  * bt_ctf_get_field: returns the definition of a specific field
 121  */
 122 struct definition *bt_ctf_get_field(struct bt_ctf_event *event,
 123                 struct definition *scope,
 124                 const char *field);
 125
 126 /*
 127  * bt_ctf_get_index: if the field is an array or a sequence, return the element
 128  * at position index, otherwise return NULL;
 129  */
 130 struct definition *bt_ctf_get_index(struct bt_ctf_event *event,
 131                 struct definition *field,
 132                 unsigned int index);
 133
 134 /*
 135  * bt_ctf_field_name: returns the name of a field or NULL on error
 136  */
 137 const char *bt_ctf_field_name(const struct definition *def);
 138
 139 /*
 140  * bt_ctf_field_type: returns the type of a field or -1 if unknown
 141  */
 142 enum ctf_type_id bt_ctf_field_type(const struct definition *def);
 143
 144 /*
 145  * bt_ctf_get_int_signedness: return the signedness of an integer
 146  *
 147  * return 0 if unsigned
 148  * return 1 if signed
 149  * return -1 on error
 150  */
 151 int bt_ctf_get_int_signedness(const struct definition *field);
 152
 153 /*
 154  * bt_ctf_get_int_base: return the base of an int or a negative value on error
 155  */
 156 int bt_ctf_get_int_base(const struct definition *field);
 157
 158 /*
 159  * bt_ctf_get_int_byte_order: return the byte order of an int or a negative
 160  * value on error
 161  */
 162 int bt_ctf_get_int_byte_order(const struct definition *field);
 163
 164 /*
 165  * bt_ctf_get_encoding: return the encoding of an int or a string.
 166  * return a negative value on error
 167  */
 168 enum ctf_string_encoding bt_ctf_get_encoding(const struct definition *field);
 169
 170 /*
 171  * bt_ctf_get_array_len: return the len of an array or a negative
 172  * value on error
 173  */
 174 int bt_ctf_get_array_len(const struct definition *field);
 175
 176 /*
 177  * Field access functions
 178  *
 179  * These functions return the value associated with the field passed in
 180  * parameter.
 181  *
 182  * If the field does not exist or is not of the type requested, the value
 183  * returned is undefined. To check if an error occured, use the
 184  * bt_ctf_field_error() function after accessing a field.
 185  */
 186 uint64_t bt_ctf_get_uint64(const struct definition *field);
 187 int64_t bt_ctf_get_int64(const struct definition *field);
 188 char *bt_ctf_get_char_array(const struct definition *field);
 189 char *bt_ctf_get_string(const struct definition *field);
 190
 191 /*
 192  * bt_ctf_field_error: returns the last error code encountered while
 193  * accessing a field and reset the error flag.
 194  * Return 0 if no error, a negative value otherwise.
 195  */
 196 int bt_ctf_field_get_error(void);
 197
 198 #endif /* _BABELTRACE_CTF_EVENTS_H */