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 structure to manipulate events
  63  */
  64 struct bt_ctf_event {
  65         struct ctf_stream *stream;
  66         struct ctf_stream_event *event;
  67 };
  68
  69 /*
  70  * bt_ctf_get_top_level_scope: return a definition of the top-level scope
  71  *
  72  * Top-level scopes are defined in the bt_ctf_scope enum.
  73  * In order to get a field or a field list, the user needs to pass a
  74  * scope as argument, this scope can be a top-level scope or a scope
  75  * relative to an arbitrary field. This function provides the mapping
  76  * between the enum and the actual definition of top-level scopes.
  77  * On error return NULL.
  78  */
  79 struct definition *bt_ctf_get_top_level_scope(struct bt_ctf_event *event,
  80                 enum bt_ctf_scope scope);
  81
  82 /*
  83  * bt_ctf_event_get_name: returns the name of the event or NULL on error
  84  */
  85 const char *bt_ctf_event_name(struct bt_ctf_event *event);
  86
  87 /*
  88  * bt_ctf_get_timestamp: returns the timestamp of the event or -1ULL on error
  89  */
  90 uint64_t bt_ctf_get_timestamp(struct bt_ctf_event *event);
  91
  92 /*
  93  * bt_ctf_get_field_list: set list pointer to an array of definition
  94  * pointers and set count to the number of elements in the array.
  95  * Return 0 on success and a negative value on error.
  96  */
  97 int bt_ctf_get_field_list(struct bt_ctf_event *event,
  98                 struct definition *scope,
  99                 struct definition const * const **list,
 100                 unsigned int *count);
 101
 102 /*
 103  * bt_ctf_get_field: returns the definition of a specific field
 104  */
 105 struct definition *bt_ctf_get_field(struct bt_ctf_event *event,
 106                 struct definition *scope,
 107                 const char *field);
 108
 109 /*
 110  * bt_ctf_get_index: if the field is an array or a sequence, return the element
 111  * at position index, otherwise return NULL;
 112  */
 113 struct definition *bt_ctf_get_index(struct bt_ctf_event *event,
 114                 struct definition *field,
 115                 unsigned int index);
 116
 117 /*
 118  * bt_ctf_field_name: returns the name of a field or NULL on error
 119  */
 120 const char *bt_ctf_field_name(const struct definition *def);
 121
 122 /*
 123  * bt_ctf_field_type: returns the type of a field or -1 if unknown
 124  */
 125 enum ctf_type_id bt_ctf_field_type(struct definition *def);
 126
 127 /*
 128  * Field access functions
 129  *
 130  * These functions return the value associated with the field passed in
 131  * parameter.
 132  *
 133  * If the field does not exist or is not of the type requested, the value
 134  * returned is undefined. To check if an error occured, use the
 135  * bt_ctf_field_error() function after accessing a field.
 136  */
 137 uint64_t bt_ctf_get_uint64(struct definition *field);
 138 int64_t bt_ctf_get_int64(struct definition *field);
 139 char *bt_ctf_get_char_array(struct definition *field);
 140 char *bt_ctf_get_string(struct definition *field);
 141
 142 /*
 143  * bt_ctf_field_error: returns the last error code encountered while
 144  * accessing a field and reset the error flag.
 145  * Return 0 if no error, a negative value otherwise.
 146  */
 147 int bt_ctf_field_get_error(void);
 148
 149 #endif /* _BABELTRACE_CTF_EVENTS_H */