source: XMLIO_V2/external/src/POCO/Foundation.save/Poco/FileChannel.h @ 80

//
// FileChannel.h
//
// $Id: //poco/1.3/Foundation/include/Poco/FileChannel.h#2 $
//
// Library: Foundation
// Package: Logging
// Module:  FileChannel
//
// Definition of the FileChannel class.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
// 
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//


#ifndef Foundation_FileChannel_INCLUDED
#define Foundation_FileChannel_INCLUDED


#include "Poco/Foundation.h"
#include "Poco/Channel.h"
#include "Poco/Timestamp.h"
#include "Poco/Mutex.h"


namespace Poco {


class LogFile;
class RotateStrategy;
class ArchiveStrategy;
class PurgeStrategy;


class Foundation_API FileChannel: public Channel
        /// A Channel that writes to a file. This class supports
        /// flexible log file rotation and archiving, as well
        /// as automatic purging of archived log files.
        ///
        /// Only the message's text is written, followed
        /// by a newline.
        ///
        /// Chain this channel to a FormattingChannel with an
        /// appropriate Formatter to control what is in the text. 
        ///
        /// The FileChannel support log file rotation based
        /// on log file size or time intervals.
        /// Archived log files can be compressed in gzip format.
        /// Older archived files can be automatically deleted
        /// (purged).
        ///
        /// The rotation strategy can be specified with the
        /// "rotation" property, which can take one of the
        /// follwing values:
        ///
        ///   * never:         no log rotation
        ///   * [day,][hh]:mm: the file is rotated on specified day/time
        ///                    day - day is specified as long or short day name (Monday|Mon, Tuesday|Tue, ... );
        ///                          day can be omitted, in which case log is rotated every day
        ///                    hh  - valid hour range is 00-23;
        ///                          hour can be omitted, in which case log is rotated every hour
        ///                    mm  - valid minute range is 00-59;
        ///                          minute must be specified
        ///   * daily:         the file is rotated daily
        ///   * weekly:        the file is rotated every seven days
        ///   * monthly:       the file is rotated every 30 days
        ///   * <n> minutes:   the file is rotated every <n> minutes, 
        ///                    where <n> is an integer greater than zero.
        ///   * <n> hours:     the file is rotated every <n> hours, where
        ///                    <n> is an integer greater than zero.
        ///   * <n> days:      the file is rotated every <n> days, where
        ///                    <n> is an integer greater than zero.
        ///   * <n> weeks:     the file is rotated every <n> weeks, where
        ///                    <n> is an integer greater than zero.
        ///   * <n> months:    the file is rotated every <n> months, where
        ///                    <n> is an integer greater than zero and
        ///                    a month has 30 days.
        ///   * <n>:           the file is rotated when its size exceeds
        ///                    <n> bytes.
        ///   * <n> K:         the file is rotated when its size exceeds
        ///                    <n> Kilobytes.
        ///   * <n> M:         the file is rotated when its size exceeds
        ///                    <n> Megabytes.
        ///
        /// NOTE: For periodic log file rotation (daily, weekly, monthly, etc.),
        /// the date and time of log file creation or last rotation is
        /// written into the first line of the log file. This is because
        /// there is no reliable way to find out the real creation date of
        /// a file on many platforms (e.g., most Unix platforms do not
        /// provide the creation date, and Windows has its own issues
        /// with its "File System Tunneling Capabilities").
        ///
        /// Using the "archive" property it is possible to specify
        /// how archived log files are named. The following values
        /// for the "archive" property are supported:
        ///
        ///   * number:     A number, starting with 0, is appended to
        ///                 the name of archived log files. The newest
        ///                 archived log file always has the number 0.
        ///                 For example, if the log file is named
        ///                 "access.log", and it fulfils the criteria
        ///                 for rotation, the file is renamed to
        ///                 "access.log.0". If a file named "access.log.0"
        ///                 already exists, it is renamed to "access.log.1",
        ///                 and so on.
        ///   * timestamp:  A timestamp is appended to the log file name.
        ///                 For example, if the log file is named
        ///                 "access.log", and it fulfils the criteria
        ///                 for rotation, the file is renamed to
        ///                 "access.log.20050802110300".
        ///
        /// Using the "times" property it is possible to specify
        /// time mode for the day/time based rotation. The following values
        /// for the "times" property are supported:
        ///
        ///   * utc:        Rotation strategy is based on UTC time (default).
        ///   * local:      Rotation strategy is based on local time.
        ///
        /// Archived log files can be compressed using the gzip compression
        /// method. Compressing can be controlled with the "compression"
        /// property. The following values for the "compress" property
        /// are supported:
        ///
        ///   * true:       Compress archived log files.
        ///   * false:      Do not compress archived log files.
        ///
        /// Archived log files can be automatically purged, either if
        /// they reach a certain age, or if the number of archived
        /// log files reaches a given maximum number. This is 
        /// controlled by the purgeAge and purgeCount properties.
        ///
        /// The purgeAge property can have the following values:
        ///
        ///   * <n> [seconds]  the maximum age is <n> seconds.
        ///   * <n> minutes:   the maximum age is <n> minutes.
        ///   * <n> hours:     the maximum age is <n> hours.
        ///   * <n> days:      the maximum age is <n> days.
        ///   * <n> weeks:     the maximum age is <n> weeks.
        ///   * <n> months:    the maximum age is <n> months, where a month has 30 days.
        ///
        /// The purgeCount property has an integer value that
        /// specifies the maximum number of archived log files.
        /// If the number is exceeded, archived log files are 
        /// deleted, starting with the oldest.
        ///
        /// For a more lightweight file channel class, see SimpleFileChannel.
{
public:
        FileChannel();
                /// Creates the FileChannel.

        FileChannel(const std::string& path);
                /// Creates the FileChannel for a file with the given path.

        void open();
                /// Opens the FileChannel and creates the log file if necessary.
                
        void close();
                /// Closes the FileChannel.

        void log(const Message& msg);
                /// Logs the given message to the file.
                
        void setProperty(const std::string& name, const std::string& value);
                /// Sets the property with the given name. 
                /// 
                /// The following properties are supported:
                ///   * path:       The log file's path.
                ///   * rotation:   The log file's rotation mode. See the 
                ///                 FileChannel class for details.
                ///   * archive:    The log file's archive mode. See the
                ///                 FileChannel class for details.
                ///   * times:      The log file's time mode. See the
                ///                 FileChannel class for details.
                ///   * compress:   Enable or disable compression of
                ///                 archived files. See the FileChannel class
                ///                 for details.
                ///   * purgeAge:   Maximum age of an archived log file before
                ///                 it is purged. See the FileChannel class for
                ///                 details.
                ///   * purgeCount: Maximum number of archived log files before
                ///                 files are purged. See the FileChannel class
                ///                 for details.

        std::string getProperty(const std::string& name) const;
                /// Returns the value of the property with the given name.
                /// See setProperty() for a description of the supported
                /// properties.

        Timestamp creationDate() const;
                /// Returns the log file's creation date.
                
        UInt64 size() const;
                /// Returns the log file's current size in bytes.

        const std::string& path() const;
                /// Returns the log file's path.

        static const std::string PROP_PATH;
        static const std::string PROP_ROTATION;
        static const std::string PROP_ARCHIVE;
        static const std::string PROP_TIMES;
        static const std::string PROP_COMPRESS;
        static const std::string PROP_PURGEAGE;
        static const std::string PROP_PURGECOUNT;

protected:
        ~FileChannel();
        void setRotation(const std::string& rotation);
        void setArchive(const std::string& archive);
        void setCompress(const std::string& compress);
        void setPurgeAge(const std::string& age);
        void setPurgeCount(const std::string& count);
        void purge();

private:
        std::string      _path;
        std::string      _times;
        std::string      _rotation;
        std::string      _archive;
        bool             _compress;
        std::string      _purgeAge;
        std::string      _purgeCount;
        LogFile*         _pFile;
        RotateStrategy*  _pRotateStrategy;
        ArchiveStrategy* _pArchiveStrategy;
        PurgeStrategy*   _pPurgeStrategy;
        FastMutex        _mutex;
};


} // namespace Poco


#endif // Foundation_FileChannel_INCLUDED