comparison DEPENDENCIES/generic/include/boost/log/sinks/text_file_backend.hpp @ 16:2665513ce2d3

Add boost headers

+/*
+ *          Copyright Andrey Semashev 2007 - 2013.
+ * 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   text_file_backend.hpp
+ * \author Andrey Semashev
+ * \date   09.06.2009
+ *
+ * The header contains implementation of a text file sink backend.
+ */
+
+#ifndef BOOST_LOG_SINKS_TEXT_FILE_BACKEND_HPP_INCLUDED_
+#define BOOST_LOG_SINKS_TEXT_FILE_BACKEND_HPP_INCLUDED_
+
+#include <ios>
+#include <string>
+#include <ostream>
+#include <boost/limits.hpp>
+#include <boost/cstdint.hpp>
+#include <boost/smart_ptr/shared_ptr.hpp>
+#include <boost/date_time/date_defs.hpp>
+#include <boost/date_time/special_defs.hpp>
+#include <boost/date_time/gregorian/greg_day.hpp>
+#include <boost/date_time/posix_time/posix_time_types.hpp>
+#include <boost/filesystem/path.hpp>
+#include <boost/log/keywords/max_size.hpp>
+#include <boost/log/keywords/min_free_space.hpp>
+#include <boost/log/keywords/target.hpp>
+#include <boost/log/keywords/file_name.hpp>
+#include <boost/log/keywords/open_mode.hpp>
+#include <boost/log/keywords/auto_flush.hpp>
+#include <boost/log/keywords/rotation_size.hpp>
+#include <boost/log/keywords/time_based_rotation.hpp>
+#include <boost/log/detail/config.hpp>
+#include <boost/log/detail/light_function.hpp>
+#include <boost/log/detail/parameter_tools.hpp>
+#include <boost/log/sinks/basic_sink_backend.hpp>
+#include <boost/log/sinks/frontend_requirements.hpp>
+#include <boost/log/detail/header.hpp>
+
+#ifdef BOOST_HAS_PRAGMA_ONCE
+#pragma once
+#endif
+
+namespace boost {
+
+BOOST_LOG_OPEN_NAMESPACE
+
+namespace sinks {
+
+namespace file {
+
+//! The enumeration of the stored files scan methods
+enum scan_method
+{
+    no_scan,        //!< Don't scan for stored files
+    scan_matching,  //!< Scan for files with names matching the specified mask
+    scan_all        //!< Scan for all files in the directory
+};
+
+/*!
+ * \brief Base class for file collectors
+ *
+ * All file collectors, supported by file sink backends, should inherit this class.
+ */
+struct BOOST_LOG_NO_VTABLE collector
+{
+    /*!
+     * Default constructor
+     */
+    BOOST_DEFAULTED_FUNCTION(collector(), {})
+
+    /*!
+     * Virtual destructor
+     */
+    virtual ~collector() {}
+
+    /*!
+     * The function stores the specified file in the storage. May lead to an older file
+     * deletion and a long file moving.
+     *
+     * \param src_path The name of the file to be stored
+     */
+    virtual void store_file(filesystem::path const& src_path) = 0;
+
+    /*!
+     * Scans the target directory for the files that have already been stored. The found
+     * files are added to the collector in order to be tracked and erased, if needed.
+     *
+     * The function may scan the directory in two ways: it will either consider every
+     * file in the directory a log file, or will only consider files with names that
+     * match the specified pattern. The pattern may contain the following placeholders:
+     *
+     * \li %y, %Y, %m, %d - date components, in Boost.DateTime meaning.
+     * \li %H, %M, %S, %f - time components, in Boost.DateTime meaning.
+     * \li %N - numeric file counter. May also contain width specification
+     *     in printf-compatible form (e.g. %5N). The resulting number will always be zero-filled.
+     * \li %% - a percent sign
+     *
+     * All other placeholders are not supported.
+     *
+     * \param method The method of scanning. If \c no_scan is specified, the call has no effect.
+     * \param pattern The file name pattern if \a method is \c scan_matching. Otherwise the parameter
+     *                is not used.
+     * \param counter If not \c NULL and \a method is \c scan_matching, the method suggests initial value
+     *                of a file counter that may be used in the file name pattern. The parameter
+     *                is not used otherwise.
+     * \return The number of found files.
+     *
+     * \note In case if \a method is \c scan_matching the effect of this function is highly dependent
+     *       on the \a pattern definition. It is recommended to choose patterns with easily
+     *       distinguished placeholders (i.e. having delimiters between them). Otherwise
+     *       either some files can be mistakenly found or not found, which in turn may lead
+     *       to an incorrect file deletion.
+     */
+    virtual uintmax_t scan_for_files(
+        scan_method method, filesystem::path const& pattern = filesystem::path(), unsigned int* counter = 0) = 0;
+
+    BOOST_DELETED_FUNCTION(collector(collector const&))
+    BOOST_DELETED_FUNCTION(collector& operator= (collector const&))
+};
+
+namespace aux {
+
+    //! Creates and returns a file collector with the specified parameters
+    BOOST_LOG_API shared_ptr< collector > make_collector(
+        filesystem::path const& target_dir,
+        uintmax_t max_size,
+        uintmax_t min_free_space
+    );
+    template< typename ArgsT >
+    inline shared_ptr< collector > make_collector(ArgsT const& args)
+    {
+        return aux::make_collector(
+            filesystem::path(args[keywords::target]),
+            args[keywords::max_size | (std::numeric_limits< uintmax_t >::max)()],
+            args[keywords::min_free_space | static_cast< uintmax_t >(0)]);
+    }
+
+} // namespace aux
+
+#ifndef BOOST_LOG_DOXYGEN_PASS
+
+template< typename T1 >
+inline shared_ptr< collector > make_collector(T1 const& a1)
+{
+    return aux::make_collector(a1);
+}
+template< typename T1, typename T2 >
+inline shared_ptr< collector > make_collector(T1 const& a1, T2 const& a2)
+{
+    return aux::make_collector((a1, a2));
+}
+template< typename T1, typename T2, typename T3 >
+inline shared_ptr< collector > make_collector(T1 const& a1, T2 const& a2, T3 const& a3)
+{
+    return aux::make_collector((a1, a2, a3));
+}
+
+#else
+
+/*!
+ * The function creates a file collector for the specified target directory.
+ * Each target directory is managed by a single file collector, so if
+ * this function is called several times for the same directory,
+ * it will return a reference to the same file collector. It is safe
+ * to use the same collector in different sinks, even in a multithreaded
+ * application.
+ *
+ * One can specify certain restrictions for the stored files, such as
+ * maximum total size or minimum free space left in the target directory.
+ * If any of the specified restrictions is not met, the oldest stored file
+ * is deleted. If the same collector is requested more than once with
+ * different restrictions, the collector will act according to the most strict
+ * combination of all specified restrictions.
+ *
+ * The following named parameters are supported:
+ *
+ * \li \c target - Specifies the target directory for the files being stored in. This parameter
+ *                 is mandatory.
+ * \li \c max_size - Specifies the maximum total size, in bytes, of stored files that the collector
+ *                   will try not to exceed. If the size exceeds this threshold the oldest file(s) is
+ *                   deleted to free space. Note that the threshold may be exceeded if the size of
+ *                   individual files exceed the \c max_size value. The threshold is not maintained,
+ *                   if not specified.
+ * \li \c min_free_space - Specifies the minimum free space, in bytes, in the target directory that
+ *                         the collector tries to maintain. If the threshold is exceeded, the oldest
+ *                         file(s) is deleted to free space. The threshold is not maintained, if not
+ *                         specified.
+ *
+ * \return The file collector.
+ */
+template< typename... ArgsT >
+shared_ptr< collector > make_collector(ArgsT... const& args);
+
+#endif // BOOST_LOG_DOXYGEN_PASS
+
+/*!
+ * The class represents the time point of log file rotation. One can specify one of three
+ * types of time point based rotation:
+ *
+ * \li rotation takes place every day, at the specified time
+ * \li rotation takes place on the specified day of every week, at the specified time
+ * \li rotation takes place on the specified day of every month, at the specified time
+ *
+ * The time points are considered to be local time.
+ */
+class rotation_at_time_point
+{
+public:
+    typedef bool result_type;
+
+private:
+    enum day_kind
+    {
+        not_specified,
+        weekday,
+        monthday
+    };
+
+    day_kind m_DayKind : 2;
+    unsigned char m_Day : 6;
+    unsigned char m_Hour, m_Minute, m_Second;
+
+    mutable posix_time::ptime m_Previous;
+
+public:
+    /*!
+     * Creates a rotation time point of every day at the specified time
+     *
+     * \param hour The rotation hour, should be within 0 and 23
+     * \param minute The rotation minute, should be within 0 and 59
+     * \param second The rotation second, should be within 0 and 59
+     */
+    BOOST_LOG_API explicit rotation_at_time_point(unsigned char hour, unsigned char minute, unsigned char second);
+
+    /*!
+     * Creates a rotation time point of each specified weekday at the specified time
+     *
+     * \param wday The weekday of the rotation
+     * \param hour The rotation hour, should be within 0 and 23
+     * \param minute The rotation minute, should be within 0 and 59
+     * \param second The rotation second, should be within 0 and 59
+     */
+    BOOST_LOG_API explicit rotation_at_time_point(
+        date_time::weekdays wday,
+        unsigned char hour = 0,
+        unsigned char minute = 0,
+        unsigned char second = 0);
+
+    /*!
+     * Creates a rotation time point of each specified day of month at the specified time
+     *
+     * \param mday The monthday of the rotation, should be within 1 and 31
+     * \param hour The rotation hour, should be within 0 and 23
+     * \param minute The rotation minute, should be within 0 and 59
+     * \param second The rotation second, should be within 0 and 59
+     */
+    BOOST_LOG_API explicit rotation_at_time_point(
+        gregorian::greg_day mday,
+        unsigned char hour = 0,
+        unsigned char minute = 0,
+        unsigned char second = 0);
+
+    /*!
+     * Checks if it's time to rotate the file
+     */
+    BOOST_LOG_API bool operator() () const;
+};
+
+/*!
+ * The class represents the time interval of log file rotation. The log file will be rotated
+ * after the specified time interval has passed.
+ */
+class rotation_at_time_interval
+{
+public:
+    typedef bool result_type;
+
+private:
+    posix_time::time_duration m_Interval;
+    mutable posix_time::ptime m_Previous;
+
+public:
+    /*!
+     * Creates a rotation time interval of the specified duration
+     *
+     * \param interval The interval of the rotation, should be no less than 1 second
+     */
+    explicit rotation_at_time_interval(posix_time::time_duration const& interval) :
+        m_Interval(interval)
+    {
+        BOOST_ASSERT(!interval.is_special());
+        BOOST_ASSERT(interval.total_seconds() > 0);
+    }
+
+    /*!
+     * Checks if it's time to rotate the file
+     */
+    BOOST_LOG_API bool operator() () const;
+};
+
+} // namespace file
+
+
+/*!
+ * \brief An implementation of a text file logging sink backend
+ *
+ * The sink backend puts formatted log records to a text file.
+ * The sink supports file rotation and advanced file control, such as
+ * size and file count restriction.
+ */
+class text_file_backend :
+    public basic_formatted_sink_backend<
+        char,
+        combine_requirements< synchronized_feeding, flushing >::type
+    >
+{
+    //! Base type
+    typedef basic_formatted_sink_backend<
+        char,
+        combine_requirements< synchronized_feeding, flushing >::type
+    > base_type;
+
+public:
+    //! Character type
+    typedef base_type::char_type char_type;
+    //! String type to be used as a message text holder
+    typedef base_type::string_type string_type;
+    //! Stream type
+    typedef std::basic_ostream< char_type > stream_type;
+
+    //! File open handler
+    typedef boost::log::aux::light_function< void (stream_type&) > open_handler_type;
+    //! File close handler
+    typedef boost::log::aux::light_function< void (stream_type&) > close_handler_type;
+
+    //! Predicate that defines the time-based condition for file rotation
+    typedef boost::log::aux::light_function< bool () > time_based_rotation_predicate;
+
+private:
+    //! \cond
+
+    struct implementation;
+    implementation* m_pImpl;
+
+    //! \endcond
+
+public:
+    /*!
+     * Default constructor. The constructed sink backend uses default values of all the parameters.
+     */
+    BOOST_LOG_API text_file_backend();
+
+    /*!
+     * Constructor. Creates a sink backend with the specified named parameters.
+     * The following named parameters are supported:
+     *
+     * \li \c file_name - Specifies the file name pattern where logs are actually written to. The pattern may
+     *                    contain directory and file name portions, but only the file name may contain
+     *                    placeholders. The backend supports Boost.DateTime placeholders for injecting
+     *                    current time and date into the file name. Also, an additional %N placeholder is
+     *                    supported, it will be replaced with an integral increasing file counter. The placeholder
+     *                    may also contain width specification in the printf-compatible form (e.g. %5N). The
+     *                    printed file counter will always be zero-filled. If \c file_name is not specified,
+     *                    pattern "%5N.log" will be used.
+     * \li \c open_mode - File open mode. The mode should be presented in form of mask compatible to
+     *                    <tt>std::ios_base::openmode</tt>. If not specified, <tt>trunc | out</tt> will be used.
+     * \li \c rotation_size - Specifies the approximate size, in characters written, of the temporary file
+     *                        upon which the file is passed to the file collector. Note the size does
+     *                        not count any possible character conversions that may take place during
+     *                        writing to the file. If not specified, the file won't be rotated upon reaching
+     *                        any size.
+     * \li \c time_based_rotation - Specifies the predicate for time-based file rotation.
+     *                              No time-based file rotations will be performed, if not specified.
+     * \li \c auto_flush - Specifies a flag, whether or not to automatically flush the file after each
+     *                     written log record. By default, is \c false.
+     *
+     * \note Read the caution note regarding file name pattern in the <tt>sinks::file::collector::scan_for_files</tt>
+     *       documentation.
+     */
+#ifndef BOOST_LOG_DOXYGEN_PASS
+    BOOST_LOG_PARAMETRIZED_CONSTRUCTORS_CALL(text_file_backend, construct)
+#else
+    template< typename... ArgsT >
+    explicit text_file_backend(ArgsT... const& args);
+#endif
+
+    /*!
+     * Destructor
+     */
+    BOOST_LOG_API ~text_file_backend();
+
+    /*!
+     * The method sets file name wildcard for the files being written. The wildcard supports
+     * date and time injection into the file name.
+     *
+     * \param pattern The name pattern for the file being written.
+     */
+    template< typename PathT >
+    void set_file_name_pattern(PathT const& pattern)
+    {
+        set_file_name_pattern_internal(filesystem::path(pattern));
+    }
+
+    /*!
+     * The method sets the file open mode
+     *
+     * \param mode File open mode
+     */
+    BOOST_LOG_API void set_open_mode(std::ios_base::openmode mode);
+
+    /*!
+     * The method sets the log file collector function. The function is called
+     * on file rotation and is being passed the written file name.
+     *
+     * \param collector The file collector function object
+     */
+    BOOST_LOG_API void set_file_collector(shared_ptr< file::collector > const& collector);
+
+    /*!
+     * The method sets file opening handler. The handler will be called every time
+     * the backend opens a new temporary file. The handler may write a header to the
+     * opened file in order to maintain file validity.
+     *
+     * \param handler The file open handler function object
+     */
+    BOOST_LOG_API void set_open_handler(open_handler_type const& handler);
+
+    /*!
+     * The method sets file closing handler. The handler will be called every time
+     * the backend closes a temporary file. The handler may write a footer to the
+     * opened file in order to maintain file validity.
+     *
+     * \param handler The file close handler function object
+     */
+    BOOST_LOG_API void set_close_handler(close_handler_type const& handler);
+
+    /*!
+     * The method sets maximum file size. When the size is reached, file rotation is performed.
+     *
+     * \note The size does not count any possible character translations that may happen in
+     *       the underlying API. This may result in greater actual sizes of the written files.
+     *
+     * \param size The maximum file size, in characters.
+     */
+    BOOST_LOG_API void set_rotation_size(uintmax_t size);
+
+    /*!
+     * The method sets the predicate that defines the time-based condition for file rotation.
+     *
+     * \note The rotation always occurs on writing a log record, so the rotation is
+     *       not strictly bound to the specified condition.
+     *
+     * \param predicate The predicate that defines the time-based condition for file rotation.
+     *                  If empty, no time-based rotation will take place.
+     */
+    BOOST_LOG_API void set_time_based_rotation(time_based_rotation_predicate const& predicate);
+
+    /*!
+     * Sets the flag to automatically flush buffers of all attached streams after each log record
+     */
+    BOOST_LOG_API void auto_flush(bool f = true);
+
+    /*!
+     * Performs scanning of the target directory for log files that may have been left from
+     * previous runs of the application. The found files are considered by the file collector
+     * as if they were rotated.
+     *
+     * The file scan can be performed in two ways: either all files in the target directory will
+     * be considered as log files, or only those files that satisfy the file name pattern.
+     * See documentation on <tt>sinks::file::collector::scan_for_files</tt> for more information.
+     *
+     * \pre File collector and the proper file name pattern have already been set.
+     *
+     * \param method File scanning method
+     * \param update_counter If \c true and \a method is \c scan_matching, the method attempts
+     *        to update the internal file counter according to the found files. The counter
+     *        is unaffected otherwise.
+     * \return The number of files found.
+     *
+     * \note The method essentially delegates to the same-named function of the file collector.
+     */
+    BOOST_LOG_API uintmax_t scan_for_files(
+        file::scan_method method = file::scan_matching, bool update_counter = true);
+
+    /*!
+     * The method writes the message to the sink
+     */
+    BOOST_LOG_API void consume(record_view const& rec, string_type const& formatted_message);
+
+    /*!
+     * The method flushes the currently open log file
+     */
+    BOOST_LOG_API void flush();
+
+    /*!
+     * The method rotates the file
+     */
+    BOOST_LOG_API void rotate_file();
+
+private:
+#ifndef BOOST_LOG_DOXYGEN_PASS
+    //! Constructor implementation
+    template< typename ArgsT >
+    void construct(ArgsT const& args)
+    {
+        construct(
+            filesystem::path(args[keywords::file_name | filesystem::path()]),
+            args[keywords::open_mode | (std::ios_base::trunc | std::ios_base::out)],
+            args[keywords::rotation_size | (std::numeric_limits< uintmax_t >::max)()],
+            args[keywords::time_based_rotation | time_based_rotation_predicate()],
+            args[keywords::auto_flush | false]);
+    }
+    //! Constructor implementation
+    BOOST_LOG_API void construct(
+        filesystem::path const& pattern,
+        std::ios_base::openmode mode,
+        uintmax_t rotation_size,
+        time_based_rotation_predicate const& time_based_rotation,
+        bool auto_flush);
+
+    //! The method sets file name mask
+    BOOST_LOG_API void set_file_name_pattern_internal(filesystem::path const& pattern);
+#endif // BOOST_LOG_DOXYGEN_PASS
+};
+
+} // namespace sinks
+
+BOOST_LOG_CLOSE_NAMESPACE // namespace log
+
+} // namespace boost
+
+#include <boost/log/detail/footer.hpp>
+
+#endif // BOOST_LOG_SINKS_TEXT_FILE_BACKEND_HPP_INCLUDED_