include/babeltrace2/logging.h

   1 #ifndef BABELTRACE_LOGGING_H
   2 #define BABELTRACE_LOGGING_H
   3
   4 /*
   5  * Copyright (c) 2017 Philippe Proulx <pproulx@efficios.com>
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a copy
   8  * of this software and associated documentation files (the "Software"), to deal
   9  * in the Software without restriction, including without limitation the rights
  10  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  11  * copies of the Software, and to permit persons to whom the Software is
  12  * furnished to do so, subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included in
  15  * all copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  20  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  21  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  22  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  23  * SOFTWARE.
  24  */
  25
  26 #include <stdint.h>
  27 #include <stdbool.h>
  28 #include <stddef.h>
  29
  30 #ifdef __cplusplus
  31 extern "C" {
  32 #endif
  33
  34 /**
  35 @defgroup logging Logging
  36 @ingroup apiref
  37 @brief Logging.
  38
  39 @code
  40 #include <babeltrace2/logging.h>
  41 @endcode
  42
  43 The functions in this module control the Babeltrace library's logging
  44 behaviour.
  45
  46 You can set the current global log level of the library with
  47 bt_logging_set_global_level(). Note that, if the level you set is below
  48 the minimal logging level (configured at build time, which you can get
  49 with bt_logging_get_minimal_level()), the logging statement between the
  50 current global log level and the minimal log level are not executed.
  51
  52 @file
  53 @brief Logging functions.
  54 @sa logging
  55
  56 @addtogroup logging
  57 @{
  58 */
  59
  60 /**
  61 @brief Log levels.
  62 */
  63 typedef enum bt_logging_level {
  64         /// Additional, low-level debugging context information.
  65         BT_LOGGING_LEVEL_TRACE          = 1,
  66
  67         /**
  68         Debugging information, only useful when searching for the
  69         cause of a bug.
  70         */
  71         BT_LOGGING_LEVEL_DEBUG          = 2,
  72
  73         /**
  74         Non-debugging information and failure to load optional
  75         subsystems.
  76         */
  77         BT_LOGGING_LEVEL_INFO           = 3,
  78
  79         /**
  80         Errors caused by a bad usage of the library, that is, a
  81         non-observance of the documented function preconditions.
  82
  83         The library's and object's states remain consistent when a
  84         warning is issued.
  85         */
  86         BT_LOGGING_LEVEL_WARN           = 4,
  87
  88         /**
  89         An important error from which the library cannot recover, but
  90         the executed stack of functions can still return cleanly.
  91         */
  92         BT_LOGGING_LEVEL_ERROR          = 5,
  93
  94         /**
  95         The library cannot continue to work in this condition: it must
  96         terminate immediately, without even returning to the user's
  97         execution.
  98         */
  99         BT_LOGGING_LEVEL_FATAL          = 6,
 100
 101         /// Logging is disabled.
 102         BT_LOGGING_LEVEL_NONE           = 0xff,
 103 } bt_logging_level;
 104
 105 /**
 106 @brief  Returns the minimal log level of the Babeltrace library.
 107
 108 The minimal log level is defined at the library's build time. Any
 109 logging statement with a level below the minimal log level is not
 110 compiled. This means that it is useless, although possible, to set the
 111 global log level with bt_logging_set_global_level() below this level.
 112
 113 @returns        Minimal, build time log level.
 114
 115 @sa bt_logging_get_global_level(): Returns the current global log level.
 116 */
 117 extern bt_logging_level bt_logging_get_minimal_level(void);
 118
 119 /**
 120 @brief  Returns the current global log level of the Babeltrace library.
 121
 122 @returns        Current global log level.
 123
 124 @sa bt_logging_set_global_level(): Sets the current global log level.
 125 @sa bt_logging_get_minimal_level(): Returns the minimal log level.
 126 */
 127 extern bt_logging_level bt_logging_get_global_level(void);
 128
 129 /**
 130 @brief  Sets the current global log level of the Babeltrace library
 131         to \p log_level.
 132
 133 If \p log_level is below what bt_logging_get_minimal_level() returns,
 134 the logging statements with a level between \p log_level and the minimal
 135 log level cannot be executed.
 136
 137 @param[in] log_level    Library's new global log level.
 138
 139 @sa bt_logging_get_global_level(): Returns the global log level.
 140 */
 141 extern void bt_logging_set_global_level(bt_logging_level log_level);
 142
 143 /** @} */
 144
 145 #ifdef __cplusplus
 146 }
 147 #endif
 148
 149 #endif /* BABELTRACE_LOGGING_H */