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