boost/log/sources/basic_logger.hpp
/* * Copyright Andrey Semashev 2007 - 2015. * Distributed under the Boost Software License, Version 1.0. * (See accompanying file LICENSE_1_0.txt or copy at * http://www.boost.org/LICENSE_1_0.txt) */ /*! * \file basic_logger.hpp * \author Andrey Semashev * \date 08.03.2007 * * The header contains implementation of a base class for loggers. Convenience macros * for defining custom loggers are also provided. */ #ifndef BOOST_LOG_SOURCES_BASIC_LOGGER_HPP_INCLUDED_ #define BOOST_LOG_SOURCES_BASIC_LOGGER_HPP_INCLUDED_ #include <exception> #include <utility> #include <ostream> #include <boost/assert.hpp> #include <boost/move/core.hpp> #include <boost/move/utility_core.hpp> #include <boost/core/addressof.hpp> #include <boost/type_traits/is_nothrow_swappable.hpp> #include <boost/type_traits/is_nothrow_move_constructible.hpp> #include <boost/preprocessor/facilities/empty.hpp> #include <boost/preprocessor/facilities/identity.hpp> #include <boost/preprocessor/seq/enum.hpp> #include <boost/log/detail/config.hpp> #include <boost/log/detail/parameter_tools.hpp> #include <boost/log/attributes/attribute_set.hpp> #include <boost/log/attributes/attribute_name.hpp> #include <boost/log/attributes/attribute.hpp> #include <boost/log/core/core.hpp> #include <boost/log/core/record.hpp> #include <boost/log/sources/features.hpp> #include <boost/log/sources/threading_models.hpp> #include <boost/log/detail/header.hpp> #ifdef BOOST_HAS_PRAGMA_ONCE #pragma once #endif namespace boost { BOOST_LOG_OPEN_NAMESPACE namespace sources { /*! * \brief Basic logger class * * The \c basic_logger class template serves as a base class for all loggers * provided by the library. It can also be used as a base for user-defined * loggers. The template parameters are: * * \li \c CharT - logging character type * \li \c FinalT - final type of the logger that eventually derives from * the \c basic_logger. There may be other classes in the hierarchy * between the final class and \c basic_logger. * \li \c ThreadingModelT - threading model policy. Must provide methods * of the Boost.Thread locking concept used in \c basic_logger class * and all its derivatives in the hierarchy up to the \c FinalT class. * The \c basic_logger class itself requires methods of the * SharedLockable concept. The threading model policy must also be * default and copy-constructible and support member function \c swap. * There are currently two policies provided: \c single_thread_model * and \c multi_thread_model. * * The logger implements fundamental facilities of loggers, such as storing * source-specific attribute set and formatting log record messages. The basic * logger interacts with the logging core in order to apply filtering and * pass records to sinks. */ template< typename CharT, typename FinalT, typename ThreadingModelT > class basic_logger : public ThreadingModelT { typedef basic_logger this_type; BOOST_COPYABLE_AND_MOVABLE_ALT(this_type) public: //! Character type typedef CharT char_type; //! Final logger type typedef FinalT final_type; //! Threading model type typedef ThreadingModelT threading_model; #if !defined(BOOST_LOG_NO_THREADS) //! Lock requirement for the swap_unlocked method typedef boost::log::aux::multiple_unique_lock2< threading_model, threading_model > swap_lock; //! Lock requirement for the add_attribute_unlocked method typedef boost::log::aux::exclusive_lock_guard< threading_model > add_attribute_lock; //! Lock requirement for the remove_attribute_unlocked method typedef boost::log::aux::exclusive_lock_guard< threading_model > remove_attribute_lock; //! Lock requirement for the remove_all_attributes_unlocked method typedef boost::log::aux::exclusive_lock_guard< threading_model > remove_all_attributes_lock; //! Lock requirement for the get_attributes method typedef boost::log::aux::shared_lock_guard< const threading_model > get_attributes_lock; //! Lock requirement for the open_record_unlocked method typedef boost::log::aux::shared_lock_guard< threading_model > open_record_lock; //! Lock requirement for the set_attributes method typedef boost::log::aux::exclusive_lock_guard< threading_model > set_attributes_lock; #else typedef no_lock< threading_model > swap_lock; typedef no_lock< threading_model > add_attribute_lock; typedef no_lock< threading_model > remove_attribute_lock; typedef no_lock< threading_model > remove_all_attributes_lock; typedef no_lock< const threading_model > get_attributes_lock; typedef no_lock< threading_model > open_record_lock; typedef no_lock< threading_model > set_attributes_lock; #endif //! Lock requirement for the push_record_unlocked method typedef no_lock< threading_model > push_record_lock; private: //! A pointer to the logging system core_ptr m_pCore; //! Logger-specific attribute set attribute_set m_Attributes; public: /*! * Constructor. Initializes internal data structures of the basic logger class, * acquires reference to the logging core. */ basic_logger() : threading_model(), m_pCore(core::get()) { } /*! * Copy constructor. Copies all attributes from the source logger. * * \note Not thread-safe. The source logger must be locked in the final class before copying. * * \param that Source logger */ basic_logger(basic_logger const& that) : threading_model(static_cast< threading_model const& >(that)), m_pCore(that.m_pCore), m_Attributes(that.m_Attributes) { } /*! * Move constructor. Moves all attributes from the source logger. * * \note Not thread-safe. The source logger must be locked in the final class before copying. * * \param that Source logger */ basic_logger(BOOST_RV_REF(basic_logger) that) BOOST_NOEXCEPT_IF(boost::is_nothrow_move_constructible< threading_model >::value && boost::is_nothrow_move_constructible< core_ptr >::value && boost::is_nothrow_move_constructible< attribute_set >::value) : threading_model(boost::move(static_cast< threading_model& >(that))), m_pCore(boost::move(that.m_pCore)), m_Attributes(boost::move(that.m_Attributes)) { } /*! * Constructor with named arguments. The constructor ignores all arguments. The result of * construction is equivalent to default construction. */ template< typename ArgsT > explicit basic_logger(ArgsT const&) : threading_model(), m_pCore(core::get()) { } protected: /*! * An accessor to the logging system pointer */ core_ptr const& core() const { return m_pCore; } /*! * An accessor to the logger attributes */ attribute_set& attributes() { return m_Attributes; } /*! * An accessor to the logger attributes */ attribute_set const& attributes() const { return m_Attributes; } /*! * An accessor to the threading model base */ threading_model& get_threading_model() BOOST_NOEXCEPT { return *this; } /*! * An accessor to the threading model base */ threading_model const& get_threading_model() const BOOST_NOEXCEPT { return *this; } /*! * An accessor to the final logger */ final_type* final_this() BOOST_NOEXCEPT { BOOST_LOG_ASSUME(this != NULL); return static_cast< final_type* >(this); } /*! * An accessor to the final logger */ final_type const* final_this() const BOOST_NOEXCEPT { BOOST_LOG_ASSUME(this != NULL); return static_cast< final_type const* >(this); } /*! * Unlocked \c swap */ void swap_unlocked(basic_logger& that) { get_threading_model().swap(that.get_threading_model()); m_Attributes.swap(that.m_Attributes); } /*! * Unlocked \c add_attribute */ std::pair< attribute_set::iterator, bool > add_attribute_unlocked(attribute_name const& name, attribute const& attr) { return m_Attributes.insert(name, attr); } /*! * Unlocked \c remove_attribute */ void remove_attribute_unlocked(attribute_set::iterator it) { m_Attributes.erase(it); } /*! * Unlocked \c remove_all_attributes */ void remove_all_attributes_unlocked() { m_Attributes.clear(); } /*! * Unlocked \c open_record */ record open_record_unlocked() { return m_pCore->open_record(m_Attributes); } /*! * Unlocked \c open_record */ template< typename ArgsT > record open_record_unlocked(ArgsT const&) { return m_pCore->open_record(m_Attributes); } /*! * Unlocked \c push_record */ void push_record_unlocked(BOOST_RV_REF(record) rec) { m_pCore->push_record(boost::move(rec)); } /*! * Unlocked \c get_attributes */ attribute_set get_attributes_unlocked() const { return m_Attributes; } /*! * Unlocked \c set_attributes */ void set_attributes_unlocked(attribute_set const& attrs) { m_Attributes = attrs; } //! Assignment is closed (should be implemented through copy and swap in the final class) BOOST_DELETED_FUNCTION(basic_logger& operator= (basic_logger const&)) }; /*! * Free-standing swap for all loggers */ template< typename CharT, typename FinalT, typename ThreadingModelT > inline void swap( basic_logger< CharT, FinalT, ThreadingModelT >& left, basic_logger< CharT, FinalT, ThreadingModelT >& right) BOOST_NOEXCEPT_IF(boost::is_nothrow_swappable< FinalT >::value) { static_cast< FinalT& >(left).swap(static_cast< FinalT& >(right)); } /*! * \brief A composite logger that inherits a number of features * * The composite logger is a helper class that simplifies feature composition into the final logger. * The user's logger class is expected to derive from the composite logger class, instantiated with * the character type, the user's logger class, the threading model and the list of the required features. * The former three parameters are passed to the \c basic_logger class template. The feature list * must be an MPL type sequence, where each element is a unary MPL metafunction class, that upon * applying on its argument results in a logging feature class that derives from the argument. * Every logger feature provided by the library can participate in the feature list. */ template< typename CharT, typename FinalT, typename ThreadingModelT, typename FeaturesT > class basic_composite_logger : public boost::log::sources::aux::inherit_features< basic_logger< CharT, FinalT, ThreadingModelT >, FeaturesT >::type { private: //! Base type (the hierarchy of features) typedef typename boost::log::sources::aux::inherit_features< basic_logger< CharT, FinalT, ThreadingModelT >, FeaturesT >::type base_type; protected: //! The composite logger type (for use in the user's logger class) typedef basic_composite_logger logger_base; BOOST_COPYABLE_AND_MOVABLE_ALT(logger_base) public: //! Threading model being used typedef typename base_type::threading_model threading_model; //! Lock requirement for the swap_unlocked method typedef typename base_type::swap_lock swap_lock; #if !defined(BOOST_LOG_NO_THREADS) public: /*! * Default constructor (default-constructs all features) */ basic_composite_logger() {} /*! * Copy constructor */ basic_composite_logger(basic_composite_logger const& that) : base_type (( boost::log::aux::shared_lock_guard< const threading_model >(that.get_threading_model()), static_cast< base_type const& >(that) )) { } /*! * Move constructor */ basic_composite_logger(BOOST_RV_REF(logger_base) that) BOOST_NOEXCEPT_IF(boost::is_nothrow_move_constructible< base_type >::value) : base_type(boost::move(static_cast< base_type& >(that))) { } /*! * Constructor with named parameters */ template< typename ArgsT > explicit basic_composite_logger(ArgsT const& args) : base_type(args) { } /*! * The method adds an attribute to the source-specific attribute set. The attribute will be implicitly added to * every log record made with the current logger. * * \param name The attribute name. * \param attr The attribute factory. * \return A pair of values. If the second member is \c true, then the attribute is added and the first member points to the * attribute. Otherwise the attribute was not added and the first member points to the attribute that prevents * addition. */ std::pair< attribute_set::iterator, bool > add_attribute(attribute_name const& name, attribute const& attr) { typename base_type::add_attribute_lock lock(base_type::get_threading_model()); return base_type::add_attribute_unlocked(name, attr); } /*! * The method removes an attribute from the source-specific attribute set. * * \pre The attribute was added with the add_attribute call for this instance of the logger. * \post The attribute is no longer registered as a source-specific attribute for this logger. The iterator is invalidated after removal. * * \param it Iterator to the previously added attribute. */ void remove_attribute(attribute_set::iterator it) { typename base_type::remove_attribute_lock lock(base_type::get_threading_model()); base_type::remove_attribute_unlocked(it); } /*! * The method removes all attributes from the logger. All iterators and references to the removed attributes are invalidated. */ void remove_all_attributes() { typename base_type::remove_all_attributes_lock lock(base_type::get_threading_model()); base_type::remove_all_attributes_unlocked(); } /*! * The method retrieves a copy of a set with all attributes from the logger. * * \return The copy of the attribute set. Attributes are shallow-copied. */ attribute_set get_attributes() const { typename base_type::get_attributes_lock lock(base_type::get_threading_model()); return base_type::get_attributes_unlocked(); } /*! * The method installs the whole attribute set into the logger. All iterators and references to elements of * the previous set are invalidated. Iterators to the \a attrs set are not valid to be used with the logger (that is, * the logger owns a copy of \a attrs after completion). * * \param attrs The set of attributes to install into the logger. Attributes are shallow-copied. */ void set_attributes(attribute_set const& attrs) { typename base_type::set_attributes_lock lock(base_type::get_threading_model()); base_type::set_attributes_unlocked(attrs); } /*! * The method opens a new log record in the logging core. * * \return A valid record handle if the logging record is opened successfully, an invalid handle otherwise. */ record open_record() { // Perform a quick check first if (this->core()->get_logging_enabled()) { typename base_type::open_record_lock lock(base_type::get_threading_model()); return base_type::open_record_unlocked(boost::log::aux::empty_arg_list()); } else return record(); } /*! * The method opens a new log record in the logging core. * * \param args A set of additional named arguments. The parameter is ignored. * \return A valid record handle if the logging record is opened successfully, an invalid handle otherwise. */ template< typename ArgsT > record open_record(ArgsT const& args) { // Perform a quick check first if (this->core()->get_logging_enabled()) { typename base_type::open_record_lock lock(base_type::get_threading_model()); return base_type::open_record_unlocked(args); } else return record(); } /*! * The method pushes the constructed message to the logging core * * \param rec The log record with the formatted message */ void push_record(BOOST_RV_REF(record) rec) { typename base_type::push_record_lock lock(base_type::get_threading_model()); base_type::push_record_unlocked(boost::move(rec)); } /*! * Thread-safe implementation of swap */ void swap(basic_composite_logger& that) { swap_lock lock(base_type::get_threading_model(), that.get_threading_model()); base_type::swap_unlocked(static_cast< base_type& >(that)); } protected: /*! * Assignment for the final class. Threadsafe, provides strong exception guarantee. */ FinalT& assign(FinalT const& that) { BOOST_LOG_ASSUME(this != NULL); if (static_cast< FinalT* >(this) != boost::addressof(that)) { // We'll have to explicitly create the copy in order to make sure it's unlocked when we attempt to lock *this FinalT tmp(that); boost::log::aux::exclusive_lock_guard< threading_model > lock(base_type::get_threading_model()); base_type::swap_unlocked(tmp); } return static_cast< FinalT& >(*this); } }; //! An optimized composite logger version with no multithreading support template< typename CharT, typename FinalT, typename FeaturesT > class basic_composite_logger< CharT, FinalT, single_thread_model, FeaturesT > : public boost::log::sources::aux::inherit_features< basic_logger< CharT, FinalT, single_thread_model >, FeaturesT >::type { private: typedef typename boost::log::sources::aux::inherit_features< basic_logger< CharT, FinalT, single_thread_model >, FeaturesT >::type base_type; protected: typedef basic_composite_logger logger_base; BOOST_COPYABLE_AND_MOVABLE_ALT(logger_base) public: typedef typename base_type::threading_model threading_model; #endif // !defined(BOOST_LOG_NO_THREADS) public: basic_composite_logger() {} basic_composite_logger(basic_composite_logger const& that) : base_type(static_cast< base_type const& >(that)) { } basic_composite_logger(BOOST_RV_REF(logger_base) that) BOOST_NOEXCEPT_IF(boost::is_nothrow_move_constructible< base_type >::value) : base_type(boost::move(static_cast< base_type& >(that))) { } template< typename ArgsT > explicit basic_composite_logger(ArgsT const& args) : base_type(args) { } std::pair< attribute_set::iterator, bool > add_attribute(attribute_name const& name, attribute const& attr) { return base_type::add_attribute_unlocked(name, attr); } void remove_attribute(attribute_set::iterator it) { base_type::remove_attribute_unlocked(it); } void remove_all_attributes() { base_type::remove_all_attributes_unlocked(); } attribute_set get_attributes() const { return base_type::get_attributes_unlocked(); } void set_attributes(attribute_set const& attrs) { base_type::set_attributes_unlocked(attrs); } record open_record() { // Perform a quick check first if (this->core()->get_logging_enabled()) return base_type::open_record_unlocked(boost::log::aux::empty_arg_list()); else return record(); } template< typename ArgsT > record open_record(ArgsT const& args) { // Perform a quick check first if (this->core()->get_logging_enabled()) return base_type::open_record_unlocked(args); else return record(); } void push_record(BOOST_RV_REF(record) rec) { base_type::push_record_unlocked(boost::move(rec)); } void swap(basic_composite_logger& that) { base_type::swap_unlocked(static_cast< base_type& >(that)); } protected: FinalT& assign(FinalT that) { base_type::swap_unlocked(that); return static_cast< FinalT& >(*this); } }; #ifndef BOOST_LOG_DOXYGEN_PASS #define BOOST_LOG_FORWARD_LOGGER_CONSTRUCTORS_IMPL(class_type, typename_keyword)\ public:\ BOOST_DEFAULTED_FUNCTION(class_type(), {})\ class_type(class_type const& that) : class_type::logger_base(\ static_cast< typename_keyword() class_type::logger_base const& >(that)) {}\ class_type(BOOST_RV_REF(class_type) that) BOOST_NOEXCEPT_IF(boost::is_nothrow_move_constructible< typename_keyword() class_type::logger_base >::value) : class_type::logger_base(\ ::boost::move(static_cast< typename_keyword() class_type::logger_base& >(that))) {}\ BOOST_LOG_PARAMETRIZED_CONSTRUCTORS_FORWARD(class_type, class_type::logger_base)\ #endif // BOOST_LOG_DOXYGEN_PASS #define BOOST_LOG_FORWARD_LOGGER_CONSTRUCTORS(class_type)\ BOOST_LOG_FORWARD_LOGGER_CONSTRUCTORS_IMPL(class_type, BOOST_PP_EMPTY) #define BOOST_LOG_FORWARD_LOGGER_CONSTRUCTORS_TEMPLATE(class_type)\ BOOST_LOG_FORWARD_LOGGER_CONSTRUCTORS_IMPL(class_type, BOOST_PP_IDENTITY(typename)) #define BOOST_LOG_FORWARD_LOGGER_ASSIGNMENT(class_type)\ public:\ class_type& operator= (BOOST_COPY_ASSIGN_REF(class_type) that)\ {\ return class_type::logger_base::assign(static_cast< class_type const& >(that));\ }\ class_type& operator= (BOOST_RV_REF(class_type) that)\ {\ BOOST_LOG_EXPR_IF_MT(::boost::log::aux::exclusive_lock_guard< class_type::threading_model > lock(this->get_threading_model());)\ this->swap_unlocked(that);\ return *this;\ } #define BOOST_LOG_FORWARD_LOGGER_ASSIGNMENT_TEMPLATE(class_type)\ public:\ class_type& operator= (BOOST_COPY_ASSIGN_REF(class_type) that)\ {\ return class_type::logger_base::assign(static_cast< class_type const& >(that));\ }\ class_type& operator= (BOOST_RV_REF(class_type) that)\ {\ BOOST_LOG_EXPR_IF_MT(::boost::log::aux::exclusive_lock_guard< typename class_type::threading_model > lock(this->get_threading_model());)\ this->swap_unlocked(that);\ return *this;\ } #define BOOST_LOG_FORWARD_LOGGER_MEMBERS(class_type)\ BOOST_COPYABLE_AND_MOVABLE(class_type)\ BOOST_LOG_FORWARD_LOGGER_CONSTRUCTORS(class_type)\ BOOST_LOG_FORWARD_LOGGER_ASSIGNMENT(class_type) #define BOOST_LOG_FORWARD_LOGGER_MEMBERS_TEMPLATE(class_type)\ BOOST_COPYABLE_AND_MOVABLE(class_type)\ BOOST_LOG_FORWARD_LOGGER_CONSTRUCTORS_TEMPLATE(class_type)\ BOOST_LOG_FORWARD_LOGGER_ASSIGNMENT_TEMPLATE(class_type) } // namespace sources BOOST_LOG_CLOSE_NAMESPACE // namespace log } // namespace boost /*! * \brief The macro declares a logger class that inherits a number of base classes * * \param type_name The name of the logger class to declare * \param char_type The character type of the logger. Either char or wchar_t expected. * \param base_seq A Boost.Preprocessor sequence of type identifiers of the base classes templates * \param threading A threading model class */ #define BOOST_LOG_DECLARE_LOGGER_TYPE(type_name, char_type, base_seq, threading)\ class type_name :\ public ::boost::log::sources::basic_composite_logger<\ char_type,\ type_name,\ threading,\ ::boost::log::sources::features< BOOST_PP_SEQ_ENUM(base_seq) >\ >\ {\ BOOST_LOG_FORWARD_LOGGER_MEMBERS(type_name)\ } #ifdef BOOST_LOG_USE_CHAR /*! * \brief The macro declares a narrow-char logger class that inherits a number of base classes * * Equivalent to BOOST_LOG_DECLARE_LOGGER_TYPE(type_name, char, base_seq, single_thread_model) * * \param type_name The name of the logger class to declare * \param base_seq A Boost.Preprocessor sequence of type identifiers of the base classes templates */ #define BOOST_LOG_DECLARE_LOGGER(type_name, base_seq)\ BOOST_LOG_DECLARE_LOGGER_TYPE(type_name, char, base_seq, ::boost::log::sources::single_thread_model) #if !defined(BOOST_LOG_NO_THREADS) /*! * \brief The macro declares a narrow-char thread-safe logger class that inherits a number of base classes * * Equivalent to <tt>BOOST_LOG_DECLARE_LOGGER_TYPE(type_name, char, base_seq, multi_thread_model< shared_mutex >)</tt> * * \param type_name The name of the logger class to declare * \param base_seq A Boost.Preprocessor sequence of type identifiers of the base classes templates */ #define BOOST_LOG_DECLARE_LOGGER_MT(type_name, base_seq)\ BOOST_LOG_DECLARE_LOGGER_TYPE(type_name, char, base_seq,\ ::boost::log::sources::multi_thread_model< ::boost::shared_mutex >) #endif // !defined(BOOST_LOG_NO_THREADS) #endif // BOOST_LOG_USE_CHAR #ifdef BOOST_LOG_USE_WCHAR_T /*! * \brief The macro declares a wide-char logger class that inherits a number of base classes * * Equivalent to BOOST_LOG_DECLARE_LOGGER_TYPE(type_name, wchar_t, base_seq, single_thread_model) * * \param type_name The name of the logger class to declare * \param base_seq A Boost.Preprocessor sequence of type identifiers of the base classes templates */ #define BOOST_LOG_DECLARE_WLOGGER(type_name, base_seq)\ BOOST_LOG_DECLARE_LOGGER_TYPE(type_name, wchar_t, base_seq, ::boost::log::sources::single_thread_model) #if !defined(BOOST_LOG_NO_THREADS) /*! * \brief The macro declares a wide-char thread-safe logger class that inherits a number of base classes * * Equivalent to <tt>BOOST_LOG_DECLARE_LOGGER_TYPE(type_name, wchar_t, base_seq, multi_thread_model< shared_mutex >)</tt> * * \param type_name The name of the logger class to declare * \param base_seq A Boost.Preprocessor sequence of type identifiers of the base classes templates */ #define BOOST_LOG_DECLARE_WLOGGER_MT(type_name, base_seq)\ BOOST_LOG_DECLARE_LOGGER_TYPE(type_name, wchar_t, base_seq,\ ::boost::log::sources::multi_thread_model< ::boost::shared_mutex >) #endif // !defined(BOOST_LOG_NO_THREADS) #endif // BOOST_LOG_USE_WCHAR_T #include <boost/log/detail/footer.hpp> #endif // BOOST_LOG_SOURCES_BASIC_LOGGER_HPP_INCLUDED_