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/context.h>
  28 #include <babeltrace/clock-types.h>
  29
  30 #ifdef __cplusplus
  31 extern "C" {
  32 #endif
  33
  34 struct definition;
  35 struct bt_ctf_event;
  36 struct bt_ctf_event_decl;
  37 struct bt_ctf_field_decl;
  38
  39 /*
  40  * the top-level scopes in CTF
  41  */
  42 enum bt_ctf_scope {
  43         BT_TRACE_PACKET_HEADER          = 0,
  44         BT_STREAM_PACKET_CONTEXT        = 1,
  45         BT_STREAM_EVENT_HEADER          = 2,
  46         BT_STREAM_EVENT_CONTEXT         = 3,
  47         BT_EVENT_CONTEXT                = 4,
  48         BT_EVENT_FIELDS                 = 5,
  49 };
  50
  51 /*
  52  * the supported CTF types
  53  */
  54 enum ctf_type_id {
  55         CTF_TYPE_UNKNOWN = 0,
  56         CTF_TYPE_INTEGER,
  57         CTF_TYPE_FLOAT,
  58         CTF_TYPE_ENUM,
  59         CTF_TYPE_STRING,
  60         CTF_TYPE_STRUCT,
  61         CTF_TYPE_UNTAGGED_VARIANT,
  62         CTF_TYPE_VARIANT,
  63         CTF_TYPE_ARRAY,
  64         CTF_TYPE_SEQUENCE,
  65         NR_CTF_TYPES,
  66 };
  67
  68 /*
  69  * the supported CTF string encodings
  70  */
  71 enum ctf_string_encoding {
  72         CTF_STRING_NONE = 0,
  73         CTF_STRING_UTF8,
  74         CTF_STRING_ASCII,
  75         CTF_STRING_UNKNOWN,
  76 };
  77
  78 /*
  79  * bt_ctf_get_top_level_scope: return a definition of the top-level scope
  80  *
  81  * Top-level scopes are defined in the bt_ctf_scope enum.
  82  * In order to get a field or a field list, the user needs to pass a
  83  * scope as argument, this scope can be a top-level scope or a scope
  84  * relative to an arbitrary field. This function provides the mapping
  85  * between the enum and the actual definition of top-level scopes.
  86  * On error return NULL.
  87  */
  88 const struct definition *bt_ctf_get_top_level_scope(const struct bt_ctf_event *event,
  89                 enum bt_ctf_scope scope);
  90
  91 /*
  92  * bt_ctf_event_get_name: returns the name of the event or NULL on error
  93  */
  94 const char *bt_ctf_event_name(const struct bt_ctf_event *event);
  95
  96 /*
  97  * bt_ctf_get_cycles: returns the timestamp of the event as written
  98  * in the packet (in cycles) or -1ULL on error.
  99  */
 100 uint64_t bt_ctf_get_cycles(const struct bt_ctf_event *event);
 101
 102 /*
 103  * bt_ctf_get_timestamp: returns the timestamp of the event offsetted
 104  * with the system clock source (in ns) or -1ULL on error
 105  */
 106 uint64_t bt_ctf_get_timestamp(const struct bt_ctf_event *event);
 107
 108 /*
 109  * bt_ctf_get_field_list: obtain the list of fields for compound type
 110  *
 111  * This function can be used to obtain the list of fields
 112  * contained within a compound type: array, sequence,
 113  * structure, or variant.
 114
 115  * This function sets the "list" pointer to an array of definition
 116  * pointers and set count to the number of elements in the array.
 117  * Return 0 on success and a negative value on error.
 118  *
 119  * The content pointed to by "list" should *not* be freed. It stays
 120  * valid as long as the event is unchanged (as long as the iterator
 121  * from which the event is extracted is unchanged).
 122  */
 123 int bt_ctf_get_field_list(const struct bt_ctf_event *event,
 124                 const struct definition *scope,
 125                 struct definition const * const **list,
 126                 unsigned int *count);
 127
 128 /*
 129  * bt_ctf_get_field: returns the definition of a specific field
 130  */
 131 const struct definition *bt_ctf_get_field(const struct bt_ctf_event *event,
 132                 const struct definition *scope,
 133                 const char *field);
 134
 135 /*
 136  * bt_ctf_get_index: if the field is an array or a sequence, return the element
 137  * at position index, otherwise return NULL;
 138  */
 139 const struct definition *bt_ctf_get_index(const struct bt_ctf_event *event,
 140                 const struct definition *field,
 141                 unsigned int index);
 142
 143 /*
 144  * bt_ctf_field_name: returns the name of a field or NULL on error
 145  */
 146 const char *bt_ctf_field_name(const struct definition *def);
 147
 148 /*
 149  * bt_ctf_field_type: returns the type of a field or -1 if unknown
 150  */
 151 enum ctf_type_id bt_ctf_field_type(const struct definition *def);
 152
 153 /*
 154  * bt_ctf_get_int_signedness: return the signedness of an integer
 155  *
 156  * return 0 if unsigned
 157  * return 1 if signed
 158  * return -1 on error
 159  */
 160 int bt_ctf_get_int_signedness(const struct definition *field);
 161
 162 /*
 163  * bt_ctf_get_int_base: return the base of an int or a negative value on error
 164  */
 165 int bt_ctf_get_int_base(const struct definition *field);
 166
 167 /*
 168  * bt_ctf_get_int_byte_order: return the byte order of an int or a negative
 169  * value on error
 170  */
 171 int bt_ctf_get_int_byte_order(const struct definition *field);
 172
 173 /*
 174  * bt_ctf_get_int_len: return the size, in bits, of an int or a negative
 175  * value on error
 176  */
 177 ssize_t bt_ctf_get_int_len(const struct definition *field);
 178
 179 /*
 180  * bt_ctf_get_encoding: return the encoding of an int or a string.
 181  * return a negative value on error
 182  */
 183 enum ctf_string_encoding bt_ctf_get_encoding(const struct definition *field);
 184
 185 /*
 186  * bt_ctf_get_array_len: return the len of an array or a negative
 187  * value on error
 188  */
 189 int bt_ctf_get_array_len(const struct definition *field);
 190
 191 /*
 192  * Field access functions
 193  *
 194  * These functions return the value associated with the field passed in
 195  * parameter.
 196  *
 197  * If the field does not exist or is not of the type requested, the value
 198  * returned is undefined. To check if an error occured, use the
 199  * bt_ctf_field_get_error() function after accessing a field.
 200  *
 201  * bt_ctf_get_enum_int gets the integer field of an enumeration.
 202  * bt_ctf_get_enum_str gets the string matching the current enumeration
 203  * value, or NULL if the current value does not match any string.
 204  */
 205 uint64_t bt_ctf_get_uint64(const struct definition *field);
 206 int64_t bt_ctf_get_int64(const struct definition *field);
 207 const struct definition *bt_ctf_get_enum_int(const struct definition *field);
 208 const char *bt_ctf_get_enum_str(const struct definition *field);
 209 char *bt_ctf_get_char_array(const struct definition *field);
 210 char *bt_ctf_get_string(const struct definition *field);
 211
 212 /*
 213  * bt_ctf_field_get_error: returns the last error code encountered while
 214  * accessing a field and reset the error flag.
 215  * Return 0 if no error, a negative value otherwise.
 216  */
 217 int bt_ctf_field_get_error(void);
 218
 219 /*
 220  * bt_ctf_get_event_decl_list: set list pointer to an array of bt_ctf_event_decl
 221  * pointers and set count to the number of elements in the array.
 222  *
 223  * Return 0 on success and a negative value on error.
 224  */
 225 int bt_ctf_get_event_decl_list(int handle_id, struct bt_context *ctx,
 226                 struct bt_ctf_event_decl * const **list,
 227                 unsigned int *count);
 228
 229 /*
 230  * bt_ctf_get_decl_event_name: return the name of the event or NULL on error
 231  */
 232 const char *bt_ctf_get_decl_event_name(const struct bt_ctf_event_decl *event);
 233
 234 /*
 235  * bt_ctf_get_decl_fields: set list pointer to an array of bt_ctf_field_decl
 236  * pointers and set count to the number of elements in the array.
 237  *
 238  * Returns 0 on success and a negative value on error
 239  */
 240 int bt_ctf_get_decl_fields(struct bt_ctf_event_decl *event_decl,
 241                 enum bt_ctf_scope scope,
 242                 struct bt_ctf_field_decl const * const **list,
 243                 unsigned int *count);
 244
 245 /*
 246  * bt_ctf_get_decl_field_name: return the name of a field decl or NULL on error
 247  */
 248 const char *bt_ctf_get_decl_field_name(const struct bt_ctf_field_decl *field);
 249
 250 #ifdef __cplusplus
 251 }
 252 #endif
 253
 254 #endif /* _BABELTRACE_CTF_EVENTS_H */