src/cpp-common/log-cfg.hpp

   1 /*
   2  * SPDX-License-Identifier: MIT
   3  *
   4  * Copyright (c) 2022 Francis Deslauriers <francis.deslauriers@efficios.com>
   5  * Copyright (c) 2022 Philippe Proulx <pproulx@efficios.com>
   6  */
   7
   8 #ifndef BABELTRACE_CPP_COMMON_LOG_CFG_HPP
   9 #define BABELTRACE_CPP_COMMON_LOG_CFG_HPP
  10
  11 #include <babeltrace2/babeltrace.h>
  12 #include "common/assert.h"
  13
  14 namespace bt2_common {
  15
  16 /*
  17  * Logging configuration.
  18  *
  19  * A logging configuration object contains all the execution context
  20  * needed to:
  21  *
  22  * • Log, providing the name of some current component or component
  23  *   class.
  24  *
  25  * • Append a cause to the error of the current thread from the right
  26  *   actor.
  27  *
  28  * For a given logging configuration `L`, the guarantees are as such:
  29  *
  30  * If `L.selfMsgIter()` isn't `nullptr`:
  31  *     • `L.selfComp()` isn't `nullptr`.
  32  *     • `L.compCls()` isn't `nullptr`.
  33  *     • `L.compName()` isn't `nullptr`.
  34  *     • `L.compClsName()` isn't `nullptr`.
  35  *     • `L.moduleName()` is `nullptr`.
  36  *
  37  * If `L.selfComp()` isn't `nullptr`:
  38  *     • `L.compCls()` isn't `nullptr`.
  39  *     • `L.compName()` isn't `nullptr`.
  40  *     • `L.compClsName()` isn't `nullptr`.
  41  *     • `L.moduleName()` is `nullptr`.
  42  *
  43  * If `L.selfCompCls()` isn't `nullptr`:
  44  *     • `L.compCls()` isn't `nullptr`.
  45  *     • `L.compClsName()` isn't `nullptr`.
  46  *     • `L.moduleName()` is `nullptr`.
  47  *
  48  * If `L.compCls()` isn't `nullptr`:
  49  *     • `L.compClsName()` isn't `nullptr`.
  50  *     • `L.moduleName()` is `nullptr`.
  51  *
  52  * If `L.moduleName()` isn't `nullptr`:
  53  *     • `L.selfMsgIter()` is `nullptr`.
  54  *     • `L.selfComp()` is `nullptr`.
  55  *     • `L.compCls()` is `nullptr`.
  56  *     • `L.compName()` is `nullptr`.
  57  *     • `L.compClsName()` is `nullptr`.
  58  */
  59 class LogCfg final
  60 {
  61 public:
  62     explicit LogCfg(const bt_logging_level logLevel, bt_self_message_iterator& selfMsgIter) :
  63         _mLogLevel {logLevel}, _mSelfMsgIter {&selfMsgIter},
  64         _mSelfComp {bt_self_message_iterator_borrow_component(&selfMsgIter)},
  65         _mCompCls {&this->_compClsFromSelfComp(*_mSelfComp)}
  66     {
  67     }
  68
  69     explicit LogCfg(const bt_logging_level logLevel, bt_self_component& selfComp) :
  70         _mLogLevel {logLevel}, _mSelfComp {&selfComp}, _mCompCls {
  71                                                            &this->_compClsFromSelfComp(*_mSelfComp)}
  72     {
  73     }
  74
  75     explicit LogCfg(const bt_logging_level logLevel, bt_self_component_class& selfCompCls) :
  76         _mLogLevel {logLevel}, _mSelfCompCls {&selfCompCls},
  77         _mCompCls {bt_self_component_class_as_component_class(&selfCompCls)}
  78     {
  79     }
  80
  81     explicit LogCfg(const bt_logging_level logLevel, const char * const moduleName) :
  82         _mLogLevel {logLevel}, _mModuleName {moduleName}
  83     {
  84         BT_ASSERT_DBG(_mModuleName);
  85     }
  86
  87     LogCfg(const LogCfg&) = default;
  88     LogCfg& operator=(const LogCfg&) = default;
  89
  90     bt_logging_level logLevel() const noexcept
  91     {
  92         return _mLogLevel;
  93     }
  94
  95     bt_self_component *selfComp() const noexcept
  96     {
  97         return _mSelfComp;
  98     }
  99
 100     const char *compName() const noexcept
 101     {
 102         BT_ASSERT_DBG(_mSelfComp);
 103         return bt_component_get_name(bt_self_component_as_component(_mSelfComp));
 104     }
 105
 106     bt_self_component_class *selfCompCls() const noexcept
 107     {
 108         return _mSelfCompCls;
 109     }
 110
 111     const bt_component_class *compCls() const noexcept
 112     {
 113         return _mCompCls;
 114     }
 115
 116     const char *compClsName() const noexcept
 117     {
 118         BT_ASSERT_DBG(_mCompCls);
 119         return bt_component_class_get_name(_mCompCls);
 120     }
 121
 122     bt_self_message_iterator *selfMsgIter() const noexcept
 123     {
 124         return _mSelfMsgIter;
 125     }
 126
 127     const char *moduleName() const noexcept
 128     {
 129         return _mModuleName;
 130     }
 131
 132 private:
 133     static const bt_component_class& _compClsFromSelfComp(bt_self_component& selfComp) noexcept
 134     {
 135         return *bt_component_borrow_class_const(bt_self_component_as_component(&selfComp));
 136     }
 137
 138     bt_logging_level _mLogLevel;
 139     bt_self_message_iterator *_mSelfMsgIter = nullptr;
 140     bt_self_component *_mSelfComp = nullptr;
 141     bt_self_component_class *_mSelfCompCls = nullptr;
 142     const bt_component_class *_mCompCls = nullptr;
 143     const char *_mModuleName = nullptr;
 144 };
 145
 146 } /* namespace bt2_common */
 147
 148 #endif /* BABELTRACE_CPP_COMMON_LOG_CFG_HPP */