boost/log/core/core.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 core/core.hpp * \author Andrey Semashev * \date 19.04.2007 * * This header contains logging core class definition. */ #ifndef BOOST_LOG_CORE_CORE_HPP_INCLUDED_ #define BOOST_LOG_CORE_CORE_HPP_INCLUDED_ #include <utility> #include <boost/smart_ptr/shared_ptr.hpp> #include <boost/move/core.hpp> #include <boost/log/detail/config.hpp> #include <boost/log/detail/light_function.hpp> #include <boost/log/core/record.hpp> #include <boost/log/attributes/attribute_set.hpp> #include <boost/log/attributes/attribute_name.hpp> #include <boost/log/attributes/attribute.hpp> #include <boost/log/attributes/attribute_value_set.hpp> #include <boost/log/expressions/filter.hpp> #include <boost/log/detail/header.hpp> #ifdef BOOST_HAS_PRAGMA_ONCE #pragma once #endif namespace boost { BOOST_LOG_OPEN_NAMESPACE #ifndef BOOST_LOG_DOXYGEN_PASS namespace sinks { class sink; } // namespace sinks #endif // BOOST_LOG_DOXYGEN_PASS class core; typedef shared_ptr< core > core_ptr; /*! * \brief Logging library core class * * The logging core is used to interconnect log sources and sinks. It also provides * a number of basic features, like global filtering and global and thread-specific attribute storage. * * The logging core is a singleton. Users can acquire the core instance by calling the static method <tt>get</tt>. */ class core { public: //! Exception handler function type typedef boost::log::aux::light_function< void () > exception_handler_type; private: //! Implementation type struct implementation; friend struct implementation; private: //! A pointer to the implementation implementation* m_impl; private: //! \cond core(); //! \endcond public: /*! * Destructor. Destroys the core, releases any sinks and attributes that were registered. */ ~core(); /*! * \return The method returns a pointer to the logging core singleton instance. */ BOOST_LOG_API static core_ptr get(); /*! * The method enables or disables logging. * * Setting this status to \c false allows you to completely wipe out any logging activity, including * filtering and generation of attribute values. It is useful if you want to completely disable logging * in a running application. The state of logging does not alter any other properties of the logging * library, such as filters or sinks, so you can enable logging with the very same settings that you had * when the logging was disabled. * This feature may also be useful if you want to perform major changes to logging configuration and * don't want your application to block on opening or pushing a log record. * * By default logging is enabled. * * \param enabled The actual flag of logging activity. * \return The previous value of enabled/disabled logging flag */ BOOST_LOG_API bool set_logging_enabled(bool enabled = true); /*! * The method allows to detect if logging is enabled. See the comment for \c set_logging_enabled. */ BOOST_LOG_API bool get_logging_enabled() const; /*! * The method sets the global logging filter. The filter is applied to every log record that is processed. * * \param filter The filter function object to be installed. */ BOOST_LOG_API void set_filter(filter const& filter); /*! * The method removes the global logging filter. All log records are passed to sinks without global filtering applied. */ BOOST_LOG_API void reset_filter(); /*! * The method adds a new sink. The sink is included into logging process immediately after being added and until being removed. * No sink can be added more than once at the same time. If the sink is already registered, the call is ignored. * * \param s The sink to be registered. */ BOOST_LOG_API void add_sink(shared_ptr< sinks::sink > const& s); /*! * The method removes the sink from the output. The sink will not receive any log records after removal. * The call has no effect if the sink is not registered. * * \param s The sink to be unregistered. */ BOOST_LOG_API void remove_sink(shared_ptr< sinks::sink > const& s); /*! * The method removes all registered sinks from the output. The sinks will not receive any log records after removal. */ BOOST_LOG_API void remove_all_sinks(); /*! * The method performs flush on all registered sinks. * * \note This method may take long time to complete as it may block until all sinks manage to process all buffered log records. * The call will also block all logging attempts until the operation completes. */ BOOST_LOG_API void flush(); /*! * The method adds an attribute to the global attribute set. The attribute will be implicitly added to every log record. * * \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. */ BOOST_LOG_API std::pair< attribute_set::iterator, bool > add_global_attribute(attribute_name const& name, attribute const& attr); /*! * The method removes an attribute from the global attribute set. * * \pre The attribute was added with the \c add_global_attribute call. * \post The attribute is no longer registered as a global attribute. The iterator is invalidated after removal. * * \param it Iterator to the previously added attribute. */ BOOST_LOG_API void remove_global_attribute(attribute_set::iterator it); /*! * The method returns a copy of the complete set of currently registered global attributes. */ BOOST_LOG_API attribute_set get_global_attributes() const; /*! * The method replaces the complete set of currently registered global attributes with the provided set. * * \note The method invalidates all iterators and references that may have been returned * from the \c add_global_attribute method. * * \param attrs The set of attributes to be installed. */ BOOST_LOG_API void set_global_attributes(attribute_set const& attrs); /*! * The method adds an attribute to the thread-specific attribute set. The attribute will be implicitly added to * every log record made in the current thread. * * \note In single-threaded build the effect is the same as adding the attribute globally. This, however, does * not imply that iterators to thread-specific and global attributes are interchangeable. * * \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. */ BOOST_LOG_API std::pair< attribute_set::iterator, bool > add_thread_attribute(attribute_name const& name, attribute const& attr); /*! * The method removes an attribute from the thread-specific attribute set. * * \pre The attribute was added with the \c add_thread_attribute call. * \post The attribute is no longer registered as a thread-specific attribute. The iterator is invalidated after removal. * * \param it Iterator to the previously added attribute. */ BOOST_LOG_API void remove_thread_attribute(attribute_set::iterator it); /*! * The method returns a copy of the complete set of currently registered thread-specific attributes. */ BOOST_LOG_API attribute_set get_thread_attributes() const; /*! * The method replaces the complete set of currently registered thread-specific attributes with the provided set. * * \note The method invalidates all iterators and references that may have been returned * from the \c add_thread_attribute method. * * \param attrs The set of attributes to be installed. */ BOOST_LOG_API void set_thread_attributes(attribute_set const& attrs); /*! * The method sets exception handler function. The function will be called with no arguments * in case if an exception occurs during either \c open_record or \c push_record method * execution. Since exception handler is called from a \c catch statement, the exception * can be rethrown in order to determine its type. * * By default no handler is installed, thus any exception is propagated as usual. * * \sa See also: <tt>utility/exception_handler.hpp</tt> * \param handler Exception handling function * * \note The exception handler can be invoked in several threads concurrently. * Thread interruptions are not affected by exception handlers. */ BOOST_LOG_API void set_exception_handler(exception_handler_type const& handler); /*! * The method attempts to open a new record to be written. While attempting to open a log record all filtering is applied. * A successfully opened record can be pushed further to sinks by calling the \c push_record method or simply destroyed by * destroying the returned object. * * More than one open records are allowed, such records exist independently. All attribute values are acquired during opening * the record and do not interact between records. * * The returned records can be copied, however, they must not be passed between different threads. * * \param source_attributes The set of source-specific attributes to be attached to the record to be opened. * \return A valid log record if the record is opened, an invalid record object if not (e.g. because it didn't pass filtering). * * \b Throws: If an exception handler is installed, only throws if the handler throws. Otherwise may * throw if one of the sinks throws, or some system resource limitation is reached. */ BOOST_LOG_API record open_record(attribute_set const& source_attributes); /*! * The method attempts to open a new record to be written. While attempting to open a log record all filtering is applied. * A successfully opened record can be pushed further to sinks by calling the \c push_record method or simply destroyed by * destroying the returned object. * * More than one open records are allowed, such records exist independently. All attribute values are acquired during opening * the record and do not interact between records. * * The returned records can be copied, however, they must not be passed between different threads. * * \param source_attributes The set of source-specific attribute values to be attached to the record to be opened. * \return A valid log record if the record is opened, an invalid record object if not (e.g. because it didn't pass filtering). * * \b Throws: If an exception handler is installed, only throws if the handler throws. Otherwise may * throw if one of the sinks throws, or some system resource limitation is reached. */ BOOST_LOG_API record open_record(attribute_value_set const& source_attributes); /*! * The method attempts to open a new record to be written. While attempting to open a log record all filtering is applied. * A successfully opened record can be pushed further to sinks by calling the \c push_record method or simply destroyed by * destroying the returned object. * * More than one open records are allowed, such records exist independently. All attribute values are acquired during opening * the record and do not interact between records. * * The returned records can be copied, however, they must not be passed between different threads. * * \param source_attributes The set of source-specific attribute values to be attached to the record to be opened. The contents * of this container are unspecified after this call. * \return A valid log record if the record is opened, an invalid record object if not (e.g. because it didn't pass filtering). * * \b Throws: If an exception handler is installed, only throws if the handler throws. Otherwise may * throw if one of the sinks throws, or some system resource limitation is reached. */ BOOST_FORCEINLINE record open_record(BOOST_RV_REF(attribute_value_set) source_attributes) { return open_record_move(static_cast< attribute_value_set& >(source_attributes)); } /*! * The method pushes the record to sinks. The record is moved from in the process. * * \pre <tt>!!rec == true</tt> * \post <tt>!rec == true</tt> * \param rec A previously successfully opened log record. * * \b Throws: If an exception handler is installed, only throws if the handler throws. Otherwise may * throw if one of the sinks throws. */ BOOST_FORCEINLINE void push_record(BOOST_RV_REF(record) rec) { push_record_move(static_cast< record& >(rec)); } BOOST_DELETED_FUNCTION(core(core const&)) BOOST_DELETED_FUNCTION(core& operator= (core const&)) #ifndef BOOST_LOG_DOXYGEN_PASS private: //! Opens log record. This function is mostly needed to maintain ABI stable between C++03 and C++11. BOOST_LOG_API record open_record_move(attribute_value_set& source_attributes); //! The method pushes the record to sinks. BOOST_LOG_API void push_record_move(record& rec); #endif // BOOST_LOG_DOXYGEN_PASS }; BOOST_LOG_CLOSE_NAMESPACE // namespace log } // namespace boost #include <boost/log/detail/footer.hpp> #endif // BOOST_LOG_CORE_CORE_HPP_INCLUDED_