include/babeltrace/logging.h

   1 #ifndef BABELTRACE_LOGGING_H
   2 #define BABELTRACE_LOGGING_H
   3
   4 /*
   5  * Babeltrace - Logging
   6  *
   7  * Copyright (c) 2017 Philippe Proulx <pproulx@efficios.com>
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a copy
  10  * of this software and associated documentation files (the "Software"), to deal
  11  * in the Software without restriction, including without limitation the rights
  12  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  13  * copies of the Software, and to permit persons to whom the Software is
  14  * furnished to do so, subject to the following conditions:
  15  *
  16  * The above copyright notice and this permission notice shall be included in
  17  * all copies or substantial portions of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  22  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  23  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  24  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  25  * SOFTWARE.
  26  */
  27
  28 #include <stdint.h>
  29 #include <stdbool.h>
  30 #include <stddef.h>
  31 #include <babeltrace/ref.h>
  32
  33 #ifdef __cplusplus
  34 extern "C" {
  35 #endif
  36
  37 /**
  38 @defgroup logging Logging
  39 @ingroup apiref
  40 @brief Logging.
  41
  42 @code
  43 #include <babeltrace/logging.h>
  44 @endcode
  45
  46 The functions in this module control the Babeltrace library's logging
  47 behaviour.
  48
  49 You can set the current global log level of the library with
  50 bt_logging_set_global_level(). Note that, if the level you set is below
  51 the minimal logging level (configured at build time, which you can get
  52 with bt_logging_get_minimal_level()), the logging statement between the
  53 current global log level and the minimal log level are not executed.
  54
  55 @file
  56 @brief Logging functions.
  57 @sa logging
  58
  59 @addtogroup logging
  60 @{
  61 */
  62
  63 /**
  64 @brief Log levels.
  65 */
  66 enum bt_logging_level {
  67         /// Additional, low-level debugging context information.
  68         BT_LOGGING_LEVEL_VERBOSE        = 1,
  69
  70         /**
  71         Debugging information, only useful when searching for the
  72         cause of a bug.
  73         */
  74         BT_LOGGING_LEVEL_DEBUG          = 2,
  75
  76         /**
  77         Non-debugging information and failure to load optional
  78         subsystems.
  79         */
  80         BT_LOGGING_LEVEL_INFO           = 3,
  81
  82         /**
  83         Errors caused by a bad usage of the library, that is, a
  84         non-observance of the documented function preconditions.
  85
  86         The library's and object's states remain consistent when a
  87         warning is issued.
  88         */
  89         BT_LOGGING_LEVEL_WARN           = 4,
  90
  91         /**
  92         An important error from which the library cannot recover, but
  93         the executed stack of functions can still return cleanly.
  94         */
  95         BT_LOGGING_LEVEL_ERROR          = 5,
  96
  97         /**
  98         The library cannot continue to work in this condition: it must
  99         terminate immediately, without even returning to the user's
 100         execution.
 101         */
 102         BT_LOGGING_LEVEL_FATAL          = 6,
 103
 104         /// Logging is disabled.
 105         BT_LOGGING_LEVEL_NONE           = 0xff,
 106 };
 107
 108 /**
 109 @brief  Returns the minimal log level of the Babeltrace library.
 110
 111 The minimal log level is defined at the library's build time. Any
 112 logging statement with a level below the minimal log level is not
 113 compiled. This means that it is useless, although possible, to set the
 114 global log level with bt_logging_set_global_level() below this level.
 115
 116 @returns        Minimal, build time log level.
 117
 118 @sa bt_logging_get_global_level(): Returns the current global log level.
 119 */
 120 extern enum bt_logging_level bt_logging_get_minimal_level(void);
 121
 122 /**
 123 @brief  Returns the current global log level of the Babeltrace library.
 124
 125 @returns        Current global log level.
 126
 127 @sa bt_logging_set_global_level(): Sets the current global log level.
 128 @sa bt_logging_get_minimal_level(): Returns the minimal log level.
 129 */
 130 extern enum bt_logging_level bt_logging_get_global_level(void);
 131
 132 /**
 133 @brief  Sets the current global log level of the Babeltrace library
 134         to \p log_level.
 135
 136 If \p log_level is below what bt_logging_get_minimal_level() returns,
 137 the logging statements with a level between \p log_level and the minimal
 138 log level cannot be executed.
 139
 140 @param[in] log_level    Library's new global log level.
 141
 142 @sa bt_logging_get_global_level(): Returns the global log level.
 143 */
 144 extern void bt_logging_set_global_level(enum bt_logging_level log_level);
 145
 146 /** @} */
 147
 148 #ifdef __cplusplus
 149 }
 150 #endif
 151
 152 #endif /* BABELTRACE_LOGGING_H */