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 supported CTF string encodings
  65  */
  66 enum ctf_string_encoding {
  67         CTF_STRING_NONE = 0,
  68         CTF_STRING_UTF8,
  69         CTF_STRING_ASCII,
  70         CTF_STRING_UNKNOWN,
  71 };
  72
  73 /*
  74  * the structure to manipulate events
  75  */
  76 struct bt_ctf_event {
  77         struct ctf_stream *stream;
  78         struct ctf_stream_event *event;
  79 };
  80
  81 /*
  82  * bt_ctf_iter_read_event: Read the iterator's current event data.
  83  *
  84  * @iter: trace collection iterator (input)
  85  * @stream: stream containing event at current position (output)
  86  * @event: current event (output)
  87  * Return 0 on success, negative error value on error.
  88  */
  89 struct bt_ctf_event *bt_ctf_iter_read_event(struct bt_ctf_iter *iter);
  90
  91 /*
  92  * bt_ctf_iter_create - Allocate a CTF trace collection iterator.
  93  *
  94  * begin_pos and end_pos are optional parameters to specify the position
  95  * at which the trace collection should be seeked upon iterator
  96  * creation, and the position at which iteration will start returning
  97  * "EOF".
  98  *
  99  * By default, if begin_pos is NULL, a BT_SEEK_CUR is performed at
 100  * creation. By default, if end_pos is NULL, a BT_SEEK_END (end of
 101  * trace) is the EOF criterion.
 102  */
 103 struct bt_ctf_iter *bt_ctf_iter_create(struct bt_context *ctx,
 104                 struct bt_iter_pos *begin_pos,
 105                 struct bt_iter_pos *end_pos);
 106
 107 /*
 108  * bt_ctf_get_iter - get iterator from ctf iterator.
 109  */
 110 struct bt_iter *bt_ctf_get_iter(struct bt_ctf_iter *iter);
 111
 112 /*
 113  * bt_ctf_iter_destroy - Free a CTF trace collection iterator.
 114  */
 115 void bt_ctf_iter_destroy(struct bt_ctf_iter *iter);
 116
 117 /*
 118  * bt_ctf_get_top_level_scope: return a definition of the top-level scope
 119  *
 120  * Top-level scopes are defined in the bt_ctf_scope enum.
 121  * In order to get a field or a field list, the user needs to pass a
 122  * scope as argument, this scope can be a top-level scope or a scope
 123  * relative to an arbitrary field. This function provides the mapping
 124  * between the enum and the actual definition of top-level scopes.
 125  * On error return NULL.
 126  */
 127 struct definition *bt_ctf_get_top_level_scope(struct bt_ctf_event *event,
 128                 enum bt_ctf_scope scope);
 129
 130 /*
 131  * bt_ctf_event_get_name: returns the name of the event or NULL on error
 132  */
 133 const char *bt_ctf_event_name(struct bt_ctf_event *event);
 134
 135 /*
 136  * bt_ctf_get_timestamp_raw: returns the timestamp of the event as written in
 137  * the packet or -1ULL on error
 138  */
 139 uint64_t bt_ctf_get_timestamp_raw(struct bt_ctf_event *event);
 140
 141 /*
 142  * bt_ctf_get_timestamp: returns the timestamp of the event offsetted with the
 143  * system clock source or -1ULL on error
 144  */
 145 uint64_t bt_ctf_get_timestamp(struct bt_ctf_event *event);
 146
 147 /*
 148  * bt_ctf_get_field_list: set list pointer to an array of definition
 149  * pointers and set count to the number of elements in the array.
 150  * Return 0 on success and a negative value on error.
 151  */
 152 int bt_ctf_get_field_list(struct bt_ctf_event *event,
 153                 struct definition *scope,
 154                 struct definition const * const **list,
 155                 unsigned int *count);
 156
 157 /*
 158  * bt_ctf_get_field: returns the definition of a specific field
 159  */
 160 struct definition *bt_ctf_get_field(struct bt_ctf_event *event,
 161                 struct definition *scope,
 162                 const char *field);
 163
 164 /*
 165  * bt_ctf_get_index: if the field is an array or a sequence, return the element
 166  * at position index, otherwise return NULL;
 167  */
 168 struct definition *bt_ctf_get_index(struct bt_ctf_event *event,
 169                 struct definition *field,
 170                 unsigned int index);
 171
 172 /*
 173  * bt_ctf_field_name: returns the name of a field or NULL on error
 174  */
 175 const char *bt_ctf_field_name(const struct definition *def);
 176
 177 /*
 178  * bt_ctf_field_type: returns the type of a field or -1 if unknown
 179  */
 180 enum ctf_type_id bt_ctf_field_type(const struct definition *def);
 181
 182 /*
 183  * bt_ctf_get_int_signedness: return the signedness of an integer
 184  *
 185  * return 0 if unsigned
 186  * return 1 if signed
 187  * return -1 on error
 188  */
 189 int bt_ctf_get_int_signedness(const struct definition *field);
 190
 191 /*
 192  * bt_ctf_get_int_base: return the base of an int or a negative value on error
 193  */
 194 int bt_ctf_get_int_base(const struct definition *field);
 195
 196 /*
 197  * bt_ctf_get_int_byte_order: return the byte order of an int or a negative
 198  * value on error
 199  */
 200 int bt_ctf_get_int_byte_order(const struct definition *field);
 201
 202 /*
 203  * bt_ctf_get_encoding: return the encoding of an int or a string.
 204  * return a negative value on error
 205  */
 206 enum ctf_string_encoding bt_ctf_get_encoding(const struct definition *field);
 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 definition *field);
 213
 214 /*
 215  * Field access functions
 216  *
 217  * These functions return the value associated with the field passed in
 218  * parameter.
 219  *
 220  * If the field does not exist or is not of the type requested, the value
 221  * returned is undefined. To check if an error occured, use the
 222  * bt_ctf_field_error() function after accessing a field.
 223  */
 224 uint64_t bt_ctf_get_uint64(const struct definition *field);
 225 int64_t bt_ctf_get_int64(const struct definition *field);
 226 char *bt_ctf_get_char_array(const struct definition *field);
 227 char *bt_ctf_get_string(const struct definition *field);
 228
 229 /*
 230  * bt_ctf_field_error: returns the last error code encountered while
 231  * accessing a field and reset the error flag.
 232  * Return 0 if no error, a negative value otherwise.
 233  */
 234 int bt_ctf_field_get_error(void);
 235
 236 #endif /* _BABELTRACE_CTF_EVENTS_H */