FileLoggerDevice Class Reference

An implementation of QIODevice that writes lines of text to a rotating list of files. More...

#include <FileLoggerDevice.h++>

Inheritance diagram for FileLoggerDevice:

Public Member Functions
	FileLoggerDevice (const QString &directory, const QString &fileName, qint64 maxFileSize=1024 *1024, int numBacklogFiles=2)
	Constructs a new FileLoggerDevice with the specified attributes. More...
virtual	~FileLoggerDevice ()
	Destructor. More...
virtual bool	open (OpenMode mode)
	Specified by QIODevice. More...
virtual void	close ()
	Closes the currently open log file. More...
virtual bool	isSequential () const
	Specified by QIODevice. More...
virtual qint64	bytesAvailable () const
	Specified by QIODevice. More...

Static Public Attributes
static const char *	LOG_FILE_EXTENSION
	The file extension for the log files created by this object. More...

Protected Member Functions
virtual qint64	readData (char *data, qint64 maxlen)
	Specified by QIODevice. More...
virtual qint64	writeData (const char *data, qint64 maxSize)
	Specified by QIODevice. More...

Detailed Description

An implementation of QIODevice that writes lines of text to a rotating list of files.

Intended for use with QDebug as a rotating log. The class writes data to a "current" file as long as the size of the file would not exceed the specified limit. Once the limit is reached, all existing log files are rotated. If the maximum number of log files already exists, the oldest log file is deleted. A new "current" file is then opened, and writing continues.

Author

Mark Lindner

Constructor & Destructor Documentation

FileLoggerDevice()

FileLoggerDevice	(	const QString &	directory,
		const QString &	fileName,
		qint64	maxFileSize = 1024 *1024,
		int	numBacklogFiles = 2
	)

Constructs a new FileLoggerDevice with the specified attributes.

Parameters

directory	The path to the directory in which the rotating log files will be created.
fileName	The base name for the log files.
maxFileSize	The maximum size of a log file, in bytes.
numBacklogFiles	The number of "backlog" files that will be created in addition to the "current" log file.

~FileLoggerDevice()

virtual ~FileLoggerDevice ( )

virtual

Destructor.

Closes the currently-open log file.

Member Function Documentation

bytesAvailable()

virtual qint64 bytesAvailable ( ) const

virtual

Specified by QIODevice.

Always returns 0.

close()

virtual void close ( )

virtual

Closes the currently open log file.

isSequential()

virtual bool isSequential ( ) const

virtual

Specified by QIODevice.

Always returns true.

open()

virtual bool open ( OpenMode  mode )

virtual

Specified by QIODevice.

Parameters

mode	The open mode. Only the following options are supported: QIODevice::WriteOnly, QIODevice::Truncate, QIODevice::Text, QIODevice::Unbuffered, QIODevice::Append.

Returns

true if a log file was successfully opened, false otherwise.

readData()

virtual qint64 readData ( char *  data, qint64  maxlen  )

protectedvirtual

Specified by QIODevice.

Does nothing and returns -1.

writeData()

virtual qint64 writeData ( const char *  data, qint64  maxSize  )

protectedvirtual

Specified by QIODevice.

Writes data to the log file. Writes newline-terminated lines from the data into the log file as long as the log file remains below the maximum file size. If the next line to be written would increase the file size beyond this limit, the logs are rotated, and then writing continues.

Parameters

data	The text data to be written.
maxSize	The maximum number of bytes to write.

Returns

The number of bytes actually written.

Member Data Documentation

LOG_FILE_EXTENSION

const char* LOG_FILE_EXTENSION

static

The file extension for the log files created by this object.

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The documentation for this class was generated from the following file:

• FileLoggerDevice.h++