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

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//
// SimpleFileChannel.h
//
// $Id: //poco/1.4/Foundation/include/Poco/SimpleFileChannel.h#1 $
//
// Library: Foundation
// Package: Logging
// Module: SimpleFileChannel
//
// Definition of the SimpleFileChannel class.
//
// Copyright (c) 2005-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#ifndef Foundation_SimpleFileChannel_INCLUDED
#define Foundation_SimpleFileChannel_INCLUDED
#include "Poco/Foundation.h"
#include "Poco/Channel.h"
#include "Poco/Timestamp.h"
#include "Poco/Mutex.h"
namespace Poco {
class LogFile;
class Foundation_API SimpleFileChannel: public Channel
/// A Channel that writes to a file. This class only
/// supports simple log file rotation.
///
/// For more features, see the FileChannel class.
///
/// 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.
///
/// Log file rotation based on log file size is supported.
///
/// If rotation is enabled, the SimpleFileChannel will
/// alternate between two log files. If the size of
/// the primary log file exceeds a specified limit,
/// the secondary log file will be used, and vice
/// versa.
///
/// Log rotation is configured with the "rotation"
/// property, which supports the following values:
/// * never: no log rotation
/// * <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.
///
/// The path of the (primary) log file can be specified with
/// the "path" property. Optionally, the path of the secondary
/// log file can be specified with the "secondaryPath" property.
///
/// If no secondary path is specified, the secondary path will
/// default to <primaryPath>.1.
///
/// The flush property specifies whether each log message is flushed
/// immediately to the log file (which may hurt application performance,
/// but ensures that everything is in the log in case of a system crash),
// or whether it's allowed to stay in the system's file buffer for some time.
/// Valid values are:
///
/// * true: Every essages is immediately flushed to the log file (default).
/// * false: Messages are not immediately flushed to the log file.
///
{
public:
SimpleFileChannel();
/// Creates the FileChannel.
SimpleFileChannel(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 primary log file's path.
/// * secondaryPath: The secondary log file's path.
/// * rotation: The log file's rotation mode. See the
/// SimpleFileChannel class for details.
/// * flush: Specifies whether messages are immediately
/// flushed to the log file. See the SimpleFileChannel
/// 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 primary path.
const std::string& secondaryPath() const;
/// Returns the log file's secondary path.
static const std::string PROP_PATH;
static const std::string PROP_SECONDARYPATH;
static const std::string PROP_ROTATION;
static const std::string PROP_FLUSH;
protected:
~SimpleFileChannel();
void setRotation(const std::string& rotation);
void setFlush(const std::string& flush);
void rotate();
private:
std::string _path;
std::string _secondaryPath;
std::string _rotation;
UInt64 _limit;
bool _flush;
LogFile* _pFile;
FastMutex _mutex;
};
} // namespace Poco
#endif // Foundation_SimpleFileChannel_INCLUDED