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 */