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//
// FileChannel.h
//
// Library: Foundation
// Package: Logging
// Module: FileChannel
//
// Definition of the FileChannel class.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#ifndef Foundation_FileChannel_INCLUDED
#define Foundation_FileChannel_INCLUDED
#include "Poco/Foundation.h"
#include "Poco/Channel.h"
#include "Poco/Timestamp.h"
#include "Poco/Timespan.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 "compress"
/// 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. When "none" or empty string are
/// supplied, they reset purgeCount to none (no purging).
///
/// 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.
///
/// The rotateOnOpen property specifies whether an existing log file should be
/// rotated (and archived) when the channel is opened. Valid values are:
///
/// * true: The log file is rotated (and archived) when the channel is opened.
/// * false: Log messages will be appended to an existing log file,
/// if it exists (unless other conditions for a rotation are met).
/// This is the default.
///
/// 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.
/// * flush: Specifies whether messages are immediately
/// flushed to the log file. See the FileChannel class
/// for details.
/// * rotateOnOpen: Specifies whether an existing log file should be
/// rotated and archived when the channel is opened.
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;
static const std::string PROP_FLUSH;
static const std::string PROP_ROTATEONOPEN;
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 setFlush(const std::string& flush);
void setRotateOnOpen(const std::string& rotateOnOpen);
void purge();
void unsafeOpen();
private:
bool setNoPurge(const std::string& value);
int extractDigit(const std::string& value, std::string::const_iterator* nextToDigit = NULL) const;
void setPurgeStrategy(PurgeStrategy* strategy);
Timespan::TimeDiff extractFactor(const std::string& value, std::string::const_iterator start) const;
std::string _path;
std::string _times;
std::string _rotation;
std::string _archive;
bool _compress;
std::string _purgeAge;
std::string _purgeCount;
bool _flush;
bool _rotateOnOpen;
LogFile* _pFile;
RotateStrategy* _pRotateStrategy;
ArchiveStrategy* _pArchiveStrategy;
PurgeStrategy* _pPurgeStrategy;
FastMutex _mutex;
};
} // namespace Poco
#endif // Foundation_FileChannel_INCLUDED
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