TempFile Class Reference

A temporary file that may optionally "shadow" another file. More...

#include <TempFile.h++>

Inheritance diagram for TempFile:

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Collaboration diagram for TempFile:

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List of all members.

Public Member Functions
	TempFile (const String &path=String::null)
	Construct a new TempFile.
	~TempFile () throw ()
	Destructor.
void	open () throw (IOException)
	Create and open the TempFile.
virtual void	close () throw ()
	Close (and delete) the temporary file.
virtual size_t	read (ByteBuffer &buffer) throw (IOException)
	Read data from the stream into a ByteBuffer.
virtual size_t	read (CharBuffer &buffer) throw (IOException)
	Read data from the stream into a CharBuffer.
template<typename T >
size_t	read (Buffer< T > &buffer, size_t &partial) throw (IOException)
	Read data from the stream into a Buffer of arbitrary type.
virtual size_t	read (byte_t *buffer, size_t buflen) throw (IOException)
	Read data from the stream into a raw buffer.
size_t	read (byte_t *buffer, size_t buflen, int64_t offset, AsyncIOTask &task) throw (IOException)
	Read data asynchronously from the stream into a raw buffer.
size_t	read (ByteBuffer &buffer, int64_t offset, AsyncIOTask &task) throw (IOException)
	Read data asynchronously from the stream into a Buffer.
virtual size_t	read (MemoryBlock *vec, uint_t count) throw (IOException)
	Read data from the stream into a series of I/O buffers.
size_t	write (const byte_t *buffer, size_t buflen, int64_t offset, AsyncIOTask &task) throw (IOException)
	Write data asynchronously to the stream from a raw buffer.
size_t	write (ByteBuffer &buffer, int64_t offset, AsyncIOTask &task) throw (IOException)
	Write data asynchronously to the stream from a Buffer.
virtual size_t	write (ByteBuffer &buffer) throw (IOException)
	Write data to the stream from a ByteBuffer.
virtual size_t	write (CharBuffer &buffer) throw (IOException)
	Write data to the stream from a CharBuffer.
template<typename T >
size_t	write (Buffer< T > &buffer, size_t &partial) throw (IOException)
	Write data to the stream from a Buffer of arbitrary type.
virtual size_t	write (const byte_t *buffer, size_t buflen) throw (IOException)
	Write data to the stream from a raw buffer, until either the entire buffer is written or an error or timeout occurs.
virtual size_t	write (const MemoryBlock *vec, uint_t count) throw (IOException)
	Write data to the stream from a series of I/O buffers.
virtual size_t	readFully (ByteBuffer &buffer, size_t count=0) throw (IOException)
	Read data from the stream into a ByteBuffer, until either the buffer is full or an error or timeout occurs.
virtual size_t	readFully (CharBuffer &buffer, size_t count=0) throw (IOException)
	Read data from the stream into a CharBuffer, until either the buffer is full or an error or timeout occurs.
template<typename T >
size_t	readFully (Buffer< T > &buffer, size_t &partial) throw (IOException)
	Read data from the stream into a Buffer of arbitrary type, until either the buffer is full or an error or timeout occurs.
virtual size_t	readFully (byte_t *buffer, size_t buflen) throw (IOException)
	Read data from the stream into a raw buffer, until either the buffer is full or an error or timeout occurs.
virtual size_t	writeFully (ByteBuffer &buffer) throw (IOException)
	Write data to the stream from a ByteBuffer, until either the entire buffer is written or an error or timeout occurs.
virtual size_t	writeFully (CharBuffer &buffer) throw (IOException)
	Write data to the stream from a CharBuffer, until either the entire buffer is written or an error or timeout occurs.
template<typename T >
size_t	writeFully (Buffer< T > &buffer, size_t &partial) throw (IOException)
	Write data to the stream from a Buffer of arbitrary type, until either the entire buffer is written or an error or timeout occurs.
virtual size_t	writeFully (const byte_t *buffer, size_t buflen) throw (IOException)
	Write data to the stream from a raw buffer.
virtual int64_t	seek (int64_t offset, SeekMode mode=SeekAbsolute) throw (IOException)
	Reposition the seek pointer in the stream.
virtual int64_t	tell () throw (IOException)
	Get the current (absolute) offset of the seek pointer.
bool	isOpen () const throw ()
	Test if the stream is open.
bool	isSeekable () const throw ()
	Test if the stream supports seeking.
bool	isReadable () const throw ()
	Test if the stream can be read from.
bool	isWritable () const throw ()
	Test if the stream can be written to.
bool	isFullDuplex () const throw ()
	Test if the stream is full-duplex (i.e., supports both reading and writing).
bool	isHalfDuplex () const throw ()
	Test if the stream is half-duplex (i.e., supports either reading or writing, but not both).
virtual void	close (IOMode mode=IOReadWrite) throw ()
	Close the stream for reading, writing, or both.
virtual void	setTimeout (int msec) throw (IOException)
	Set the stream I/O timeout, in milliseconds.
int	getTimeout () const throw ()
	Get the stream I/O timeout, in milliseconds.
Static Public Attributes
static const uint_t	MAX_IOBLOCK_COUNT = 16
	The maximum number of I/O buffers that can be passed to the vector I/O methods.
Protected Member Functions
void	_init (FileHandle handle, bool seekable, bool readable, bool writable)
	Initialize the stream for use with an open file.
Protected Attributes
bool	_seekable
bool	_canRead
bool	_canWrite
int	_timeout

Detailed Description

A temporary file that may optionally "shadow" another file.

When it is opened, the temporary file is created with a unique name in the host platform's designated temporary directory. When the temporary file is closed, its contents are copied to the shadowed file, if one has been specified, and then the temporary file is deleted. TempFile can thus be used to safely update an existing file.

Author:: Mark Lindner

Constructor & Destructor Documentation

TempFile ( const String & path = String::null )

Construct a new TempFile.

Parameters:

path

The path to the file being shadowed, if any.

~TempFile ( ) throw ()

Destructor.

Member Function Documentation

void _init	(	FileHandle	handle,
		bool	seekable,
		bool	readable,
		bool	writable
	)			`[protected, inherited]`

Initialize the stream for use with an open file.

Parameters:

	handle	The handle to an open file.
	seekable	A flag indicating whether the stream is seekable.
	readable	A flag indicating whether the stream is readable.
	writable	A flag indicating whether the stream is writable.

void close ( IOMode mode = IOReadWrite ) throw () [virtual, inherited]

Close the stream for reading, writing, or both.

Parameters:

mode

The close mode.

Reimplemented in StreamPipe, and StreamSocket.

void close ( ) throw () [virtual]

Close (and delete) the temporary file.

If the temporary file is shadowing another file, its contents are copied to that file before the temporary file is deleted.

int getTimeout ( ) const throw () [inline, inherited]

Get the stream I/O timeout, in milliseconds.

bool isFullDuplex ( ) const throw () [inline, inherited]

Test if the stream is full-duplex (i.e., supports both reading and writing).

bool isHalfDuplex ( ) const throw () [inline, inherited]

Test if the stream is half-duplex (i.e., supports either reading or writing, but not both).

bool isOpen ( ) const throw () [inline, inherited]

Test if the stream is open.

bool isReadable ( ) const throw () [inline, inherited]

Test if the stream can be read from.

bool isSeekable ( ) const throw () [inline, inherited]

Test if the stream supports seeking.

bool isWritable ( ) const throw () [inline, inherited]

Test if the stream can be written to.

void open ( ) throw (IOException)

Create and open the TempFile.

Exceptions:

IOException

If the file could not be created and/or opened.

size_t read	(	MemoryBlock *	vec,
		uint_t	count
	)			throw (IOException) `[virtual, inherited]`

Read data from the stream into a series of I/O buffers.

This operation is known as "vector read" or "scatter read." The buffers are read into in order. On systems that support it, the operation is performed with a single system call.

Parameters:

	vec	An array of buffers to read into.
	count	The number of buffers in the array.

Exceptions:

IOException

If the end-of-file was reached or some other I/O error occurred.

Reimplemented in StreamSocket.

size_t read	(	ByteBuffer &	buffer,
		int64_t	offset,
		AsyncIOTask &	task
	)			throw (IOException) `[inherited]`

Read data asynchronously from the stream into a Buffer.

Parameters:

	buffer	The Buffer to read into. This object must not be destroyed before the asynchronous I/O operation is completed or cancelled.
	offset	The file offset to read from.
	task	The async I/O control block for monitoring the operation.

Returns:: The number of bytes actually read, if the operation completed immediately, otherwise 0 to indicate that the operation has begun.

Exceptions:

IOException

If an I/O error occurred.

Reimplemented in StreamSocket.

size_t read	(	byte_t *	buffer,
		size_t	buflen,
		int64_t	offset,
		AsyncIOTask &	task
	)			throw (IOException) `[inherited]`

Read data asynchronously from the stream into a raw buffer.

Parameters:

	buffer	The buffer to read into.
	buflen	The number of bytes to read.
	offset	The file offset to read from.
	task	The async I/O control block for monitoring the operation.

Returns:: The number of bytes actually read, if the operation completed immediately, otherwise 0 to indicate that the operation has begun.

Exceptions:

IOException

If an I/O error occurred.

Reimplemented in StreamSocket.

size_t read	(	byte_t *	buffer,
		size_t	buflen
	)			throw (IOException) `[virtual, inherited]`

Read data from the stream into a raw buffer.

Parameters:

	buffer	The buffer to read into.
	buflen	The number of bytes to read.

Returns:: The number of bytes actually read.

Exceptions:

IOException

If the end-of-file was reached or some other I/O error occurred.

Reimplemented in StreamSocket.

size_t read	(	Buffer< T > &	buffer,
		size_t &	partial
	)			throw (IOException) `[inline, inherited]`

Read data from the stream into a Buffer of arbitrary type.

If sizeof(T) is greater than 1 byte, then there can be no guarantee that the number of bytes read before a timeout or error occurs will be evenly divisible by sizeof(T). If the final element was partially read, the number of bytes of the element that were read will be stored in partial; this value should be passed unmodified to the next invocation of this method to continue reading from the appropriate offset within the partially-read element.

Parameters:

	buffer	The buffer to read into.
	partial	The number of bytes remaining to read for a partially-read element; on return, the number of bytes read of a partially-read element, or 0 if the last element was read completely. Should be set to 0 prior to the first call to this method for a fresh buffer.

Returns:: The number of whole elements actually read.

Exceptions:

IOException

If the end-of-file was reached or some other I/O error occurred.

size_t read ( CharBuffer & buffer ) throw (IOException) [virtual, inherited]

Read data from the stream into a CharBuffer.

Parameters:

buffer

The buffer to read into.

Returns:: The number of characters actually read.

Exceptions:

IOException

If the end-of-file was reached or some other I/O error occurred.

Reimplemented in StreamSocket.

size_t read ( ByteBuffer & buffer ) throw (IOException) [virtual, inherited]

Read data from the stream into a ByteBuffer.

Parameters:

buffer

The buffer to read into.

Returns:: The number of bytes actually read.

Exceptions:

IOException

If the end-of-file was reached or some other I/O error occurred.

Reimplemented in StreamSocket.

size_t readFully	(	byte_t *	buffer,
		size_t	buflen
	)			throw (IOException) `[virtual, inherited]`

Read data from the stream into a raw buffer, until either the buffer is full or an error or timeout occurs.

Parameters:

	buffer	The buffer to read into.
	buflen	The number of bytes to read.

Returns:: The number of bytes actually read.

Exceptions:

IOException

If the end-of-file was reached or some other I/O error occurred.

size_t readFully	(	Buffer< T > &	buffer,
		size_t &	partial
	)			throw (IOException) `[inline, inherited]`

Read data from the stream into a Buffer of arbitrary type, until either the buffer is full or an error or timeout occurs.

If sizeof(T) is greater than 1 byte, then there can be no guarantee that the number of bytes read before a timeout or error occurs will be evenly divisible by sizeof(T). If the final element was partially read, the number of bytes of the element that were read will be stored in partial; this value should be passed unmodified to the next invocation of this method to continue reading from the appropriate offset within the partially-read element.

Parameters:

	buffer	The buffer to read into.
	partial	The number of bytes remaining to read for a partially-read element; on return, the number of bytes read of a partially-read element, or 0 if the last element was read completely. Should be set to 0 prior to the first call to this method for a fresh buffer.

Returns:: The number of whole elements actually read.

Exceptions:

IOException

If the end-of-file was reached or some other I/O error occurred.

size_t readFully	(	CharBuffer &	buffer,
		size_t	count = `0`
	)			throw (IOException) `[virtual, inherited]`

Read data from the stream into a CharBuffer, until either the buffer is full or an error or timeout occurs.

Parameters:

	buffer	The buffer to read into.
	count	The number of characters to read. If 0 or greater than the number of bytes between the position and the limit, reads up to the limit.

Returns:: The number of bytes actually read.

Exceptions:

IOException

If the end-of-file was reached or some other I/O error occurred.

size_t readFully	(	ByteBuffer &	buffer,
		size_t	count = `0`
	)			throw (IOException) `[virtual, inherited]`

Read data from the stream into a ByteBuffer, until either the buffer is full or an error or timeout occurs.

Parameters:

	buffer	The buffer to read into.
	count	The number of bytes to read. If 0 or greater than the number of bytes between the position and the limit, reads up to the limit.

Returns:: The number of bytes actually read.

Exceptions:

IOException

If the end-of-file was reached or some other I/O error occurred.

int64_t seek	(	int64_t	offset,
		SeekMode	mode = `SeekAbsolute`
	)			throw (IOException) `[virtual, inherited]`

Reposition the seek pointer in the stream.

Parameters:

	offset	The new offset.
	mode	The seek mode.

Returns:: The new position of the seek pointer.

Exceptions:

IOException

If the stream does not support seeking, or if some other I/O error occurred.

void setTimeout ( int msec ) throw (IOException) [virtual, inherited]

Set the stream I/O timeout, in milliseconds.

A timeout of 0 indicates no timeout, and a timeout of -1 indicates infinite timeout (blocking I/O).

Reimplemented in SerialPort, and StreamSocket.

int64_t tell ( ) throw (IOException) [virtual, inherited]

Get the current (absolute) offset of the seek pointer.

Returns:: The current offset, from the beginning of the stream.

Exceptions:

IOException

If the stream does not support seeking, or if some other I/O error occurred.

size_t write	(	const MemoryBlock *	vec,
		uint_t	count
	)			throw (IOException) `[virtual, inherited]`

Write data to the stream from a series of I/O buffers.

This operation is known as "vector write" or "gather write." The buffers are written in order. On systems that support it, the operation is performed with a single system call.

Parameters:

	vec	An array of buffers to write.
	count	The number of buffers in the array.

Exceptions:

IOException

If an I/O error occurred.

Reimplemented in StreamSocket.

size_t write	(	const byte_t *	buffer,
		size_t	buflen
	)			throw (IOException) `[virtual, inherited]`

Write data to the stream from a raw buffer, until either the entire buffer is written or an error or timeout occurs.

Parameters:

	buffer	A pointer to the buffer.
	buflen	The number of bytes to write.

Returns:: The number of bytes actually written.

Exceptions:

IOException

If an I/O error occurred.

Reimplemented in StreamSocket.

size_t write	(	Buffer< T > &	buffer,
		size_t &	partial
	)			throw (IOException) `[inline, inherited]`

Write data to the stream from a Buffer of arbitrary type.

If sizeof(T) is greater than 1 byte, then there can be no guarantee that the number of bytes written before a timeout or error occurs will be evenly divisible by sizeof(T). If the final element was partially written, the number of bytes of the element that were written will be stored in partial; this value should be passed unmodified to the next invocation of this method to continue writing from the appropriate offset within the partially-written element.

Parameters:

	buffer	The buffer to write.
	partial	The number of bytes remaining to write for a partially-written element; on return, the number of bytes written of a partially-written element, or 0 if the last element was written completely. Should be set to 0 prior to the first call to this method for a fresh buffer.

Returns:: The number of whole elements actually written.

Exceptions:

IOException

If an I/O error occurred.

size_t write ( CharBuffer & buffer ) throw (IOException) [virtual, inherited]

Write data to the stream from a CharBuffer.

Parameters:

buffer

The buffer to write.

Returns:: The number of characters actually written.

Exceptions:

IOException

If an I/O error occurred.

Reimplemented in StreamSocket.

size_t write ( ByteBuffer & buffer ) throw (IOException) [virtual, inherited]

Write data to the stream from a ByteBuffer.

Parameters:

buffer

The buffer to write.

Returns:: The number of bytes actually written.

Exceptions:

IOException

If an I/O error occurred.

Reimplemented in StreamSocket.

size_t write	(	ByteBuffer &	buffer,
		int64_t	offset,
		AsyncIOTask &	task
	)			throw (IOException) `[inherited]`

Write data asynchronously to the stream from a Buffer.

Parameters:

	buffer	The Buffer to write. This object must not be destroyed before the asynchronous I/O operation is completed or cancelled.
	offset	The file offset to write to.
	task	The async I/O control block for monitoring the operation.

Returns:: The number of bytes actually written, if the operation completed immediately, otherwise 0 to indicate that the operation has begun.

Exceptions:

IOException

If an I/O error occurred.

Reimplemented in StreamSocket.

size_t write	(	const byte_t *	buffer,
		size_t	buflen,
		int64_t	offset,
		AsyncIOTask &	task
	)			throw (IOException) `[inherited]`

Write data asynchronously to the stream from a raw buffer.

Parameters:

	buffer	The buffer to write.
	buflen	The number of bytes to write.
	offset	The file offset to write to.
	task	The async I/O control block for monitoring the operation.

Returns:: The number of bytes actually written, if the operation completed immediately, otherwise 0 to indicate that the operation has begun.

Exceptions:

IOException

If an I/O error occurred.

Reimplemented in StreamSocket.

size_t writeFully	(	const byte_t *	buffer,
		size_t	buflen
	)			throw (IOException) `[virtual, inherited]`

Write data to the stream from a raw buffer.

Parameters:

	buffer	A pointer to the buffer.
	buflen	The number of bytes to write.

Returns:: The number of bytes actually written.

Exceptions:

IOException

If an I/O error occurred.

size_t writeFully	(	Buffer< T > &	buffer,
		size_t &	partial
	)			throw (IOException) `[inline, inherited]`

Write data to the stream from a Buffer of arbitrary type, until either the entire buffer is written or an error or timeout occurs.

If sizeof(T) is greater than 1 byte, then there can be no guarantee that the number of bytes written before a timeout or error occurs will be evenly divisible by sizeof(T). If the final element was partially written, the number of bytes of the element that were written will be stored in partial; this value should be passed unmodified to the next invocation of this method to continue writing from the appropriate offset within the partially-written element.

Parameters:

	buffer	The buffer to write.
	partial	The number of bytes remaining to write for a partially-written element; on return, the number of bytes written of a partially-written element, or 0 if the last element was written completely. Should be set to 0 prior to the first call to this method for a fresh buffer.

Returns:: The number of whole elements actually written.

Exceptions:

IOException

If an I/O error occurred.

size_t writeFully ( CharBuffer & buffer ) throw (IOException) [virtual, inherited]

Write data to the stream from a CharBuffer, until either the entire buffer is written or an error or timeout occurs.

Parameters:

buffer

The buffer to write.

Returns:: The number of bytes actually written.

Exceptions:

IOException

If an I/O error occurred.

size_t writeFully ( ByteBuffer & buffer ) throw (IOException) [virtual, inherited]

Write data to the stream from a ByteBuffer, until either the entire buffer is written or an error or timeout occurs.

Parameters:

buffer

The buffer to write.

Returns:: The number of bytes actually written.

Exceptions:

IOException

If and I/O error occurred.

Member Data Documentation

bool _canRead [protected, inherited]

bool _canWrite [protected, inherited]

bool _seekable [protected, inherited]

int _timeout [protected, inherited]

const uint_t MAX_IOBLOCK_COUNT = 16 [static, inherited]

The maximum number of I/O buffers that can be passed to the vector I/O methods.

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

TempFile Class Reference

Public Member Functions

Static Public Attributes

Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation