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/*
* 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_