source: XMLIO_V2/external/include/Poco/ArchiveStrategy.h @ 80

//
// ArchiveStrategy.h
//
// $Id: //poco/1.3/Foundation/include/Poco/ArchiveStrategy.h#5 $
//
// Library: Foundation
// Package: Logging
// Module:  FileChannel
//
// Definition of the ArchiveStrategy class and subclasses.
//
// Copyright (c) 2004-2008, 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_ArchiveStrategy_INCLUDED
#define Foundation_ArchiveStrategy_INCLUDED


#include "Poco/Foundation.h"
#include "Poco/LogFile.h"
#include "Poco/File.h"
#include "Poco/DateTimeFormatter.h"
#include "Poco/NumberFormatter.h"


namespace Poco {


class ArchiveCompressor;


class Foundation_API ArchiveStrategy
        /// The ArchiveStrategy is used by FileChannel 
        /// to rename a rotated log file for archiving.
        ///
        /// Archived files can be automatically compressed,
        /// using the gzip file format.
{
public:
        ArchiveStrategy();
        virtual ~ArchiveStrategy();

        virtual LogFile* archive(LogFile* pFile) = 0;
                /// Renames the given log file for archiving
                /// and creates and returns a new log file.
                /// The given LogFile object is deleted.

        void compress(bool flag = true);
                /// Enables or disables compression of archived files.  

protected:
        void moveFile(const std::string& oldName, const std::string& newName);
        bool exists(const std::string& name);
        
private:
        ArchiveStrategy(const ArchiveStrategy&);
        ArchiveStrategy& operator = (const ArchiveStrategy&);
        
        bool _compress;
        ArchiveCompressor* _pCompressor;
};


class Foundation_API ArchiveByNumberStrategy: public ArchiveStrategy
        /// A monotonic increasing number is appended to the
        /// log file name. The most recent archived file
        /// always has the number zero.
{
public:
        ArchiveByNumberStrategy();
        ~ArchiveByNumberStrategy();
        LogFile* archive(LogFile* pFile);
};


template <class DT>
class ArchiveByTimestampStrategy: public ArchiveStrategy
        /// A timestamp (YYYYMMDDhhmmssiii) is appended to archived
        /// log files.
{
public:
        ArchiveByTimestampStrategy()
        {
        }
        
        ~ArchiveByTimestampStrategy()
        {
        }
        
        LogFile* archive(LogFile* pFile)
                /// Archives the file by appending the current timestamp to the
                /// file name. If the new file name exists, additionally a monotonic
                /// increasing number is appended to the log file name.
        {
                std::string path = pFile->path();
                delete pFile;
                std::string archPath = path;
                archPath.append(".");
                DateTimeFormatter::append(archPath, DT().timestamp(), "%Y%m%d%H%M%S%i");
                
                if (exists(archPath)) archiveByNumber(archPath);
                else moveFile(path, archPath);

                return new LogFile(path);
        }

private:
        void archiveByNumber(const std::string& basePath)
                /// A monotonic increasing number is appended to the
                /// log file name. The most recent archived file
                /// always has the number zero.
        {
                int n = -1;
                std::string path;
                do
                {
                        path = basePath;
                        path.append(".");
                        NumberFormatter::append(path, ++n);
                }
                while (exists(path));
                
                while (n >= 0)
                {
                        std::string oldPath = basePath;
                        if (n > 0)
                        {
                                oldPath.append(".");
                                NumberFormatter::append(oldPath, n - 1);
                        }
                        std::string newPath = basePath;
                        newPath.append(".");
                        NumberFormatter::append(newPath, n);
                        moveFile(oldPath, newPath);
                        --n;
                }
        }
};


} // namespace Poco


#endif // Foundation_ArchiveStrategy_INCLUDED