//
// PurgeStrategy.h
//
// $Id: //poco/svn/Foundation/include/Poco/PurgeStrategy.h#2 $
//
// Library: Foundation
// Package: Logging
// Module:  FileChannel
//
// Definition of the PurgeStrategy 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_PurgeStrategy_INCLUDED
#define Foundation_PurgeStrategy_INCLUDED


#include "Poco/Foundation.h"
#include "Poco/File.h"
#include "Poco/Timespan.h"
#include <vector>


namespace Poco {


class Foundation_API PurgeStrategy
	/// The PurgeStrategy is used by FileChannel
	/// to purge archived log files.
{
public:
	PurgeStrategy();
	virtual ~PurgeStrategy();

	virtual void purge(const std::string& path) = 0;
		/// Purges archived log files. The path to the
		/// current "hot" log file is given.
		/// To find archived log files, look for files
		/// with a name consisting of the given path 
		/// plus any suffix (e.g., .1, .20050929081500, .1.gz).
		/// A list of archived files can be obtained by calling
		/// the list() method.

protected:
	void list(const std::string& path, std::vector<File>& files);
		/// Fills the given vector with a list of archived log
		/// files. The path of the current "hot" log file is
		/// given in path.
		///
		/// All files with the same name as the one given in path,
		/// plus some suffix (e.g., .1, .20050929081500, .1.gz) are
		/// considered archived files.

private:
	PurgeStrategy(const PurgeStrategy&);
	PurgeStrategy& operator = (const PurgeStrategy&);
};


class Foundation_API PurgeByAgeStrategy: public PurgeStrategy
	/// This purge strategy purges all files that have
	/// exceeded a given age (given in seconds).
{
public:
	PurgeByAgeStrategy(const Timespan& age);
	~PurgeByAgeStrategy();
	
	void purge(const std::string& path);
	
private:
	Timespan _age;
};


class Foundation_API PurgeByCountStrategy: public PurgeStrategy
	/// This purge strategy ensures that a maximum number
	/// of archived files is not exceeded. Files are deleted
	/// based on their age, with oldest files deleted first.
{
public:
	PurgeByCountStrategy(int count);
	~PurgeByCountStrategy();
	
	void purge(const std::string& path);
	
private:
	int _count;
};


} // namespace Poco


#endif // Foundation_PurgeStrategy_INCLUDED