ClickHouse/contrib/libpoco/Foundation/include/Poco/ArchiveStrategy.h

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//
// ArchiveStrategy.h
//
// $Id: //poco/1.4/Foundation/include/Poco/ArchiveStrategy.h#1 $
//
// Library: Foundation
// Package: Logging
// Module: FileChannel
//
// Definition of the ArchiveStrategy class and subclasses.
//
// Copyright (c) 2004-2008, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#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