DcmOutputStream Class Reference

base class for output streams. More...

Inheritance diagram for DcmOutputStream:

List of all members.

Public Member Functions
virtual	~DcmOutputStream ()
	destructor
virtual OFBool	good () const
	returns the status of the stream.
virtual OFCondition	status () const
	returns the status of the consumer as an OFCondition object.
virtual OFBool	isFlushed () const
	returns true if the stream is flushed, i.e.
virtual offile_off_t	avail () const
	returns the minimum number of bytes that can be written with the next call to write().
virtual offile_off_t	write (const void *buf, offile_off_t buflen)
	processes as many bytes as possible from the given input block.
virtual void	flush ()
	instructs the stream to flush its internal content until either the stream becomes "flushed" or I/O suspension occurs.
virtual offile_off_t	tell () const
	returns the total number of bytes written to the stream so far
virtual OFCondition	installCompressionFilter (E_StreamCompression filterType)
	installs a compression filter for the given stream compression type, which should be neither ESC_none nor ESC_unsupported.
Protected Member Functions
	DcmOutputStream (DcmConsumer *initial)
	protected constructor, to be called from derived class constructor
Private Member Functions
	DcmOutputStream (const DcmOutputStream &)
	private unimplemented copy constructor
DcmOutputStream &	operator= (const DcmOutputStream &)
	private unimplemented copy assignment operator
Private Attributes
DcmConsumer *	current_
	pointer to first node in filter chain
DcmOutputFilter *	compressionFilter_
	pointer to compression filter, NULL if no compression
offile_off_t	tell_
	counter for number of bytes written so far

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Detailed Description

base class for output streams.

This class cannot be instantiated since the constructor is protected.

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Constructor & Destructor Documentation

DcmOutputStream::DcmOutputStream

(

DcmConsumer *

initial

)

[protected]

protected constructor, to be called from derived class constructor

Parameters:

initial

initial pointer to first node in filter chain The pointer is not dereferenced in the constructor, so the object pointed to may be initialized later in the subclass constructor.

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Member Function Documentation

virtual offile_off_t DcmOutputStream::avail

(

)

const [virtual]

returns the minimum number of bytes that can be written with the next call to write().

The DcmObject write methods rely on avail to return a value > 0 if there is no I/O suspension since certain data such as tag and length are only written "en bloc", i.e. all or nothing.

Returns:

minimum of space available in stream

virtual void DcmOutputStream::flush

(

)

[virtual]

instructs the stream to flush its internal content until either the stream becomes "flushed" or I/O suspension occurs.

After a call to flush(), a call to write() will produce undefined behaviour.

virtual OFBool DcmOutputStream::good

(

)

const [virtual]

returns the status of the stream.

Unless the status is good, the stream will not permit any operation.

Returns:

status, true if good

virtual OFCondition DcmOutputStream::installCompressionFilter

(

E_StreamCompression

filterType

)

[virtual]

installs a compression filter for the given stream compression type, which should be neither ESC_none nor ESC_unsupported.

Once a compression filter is active, it cannot be deactivated or replaced during the lifetime of the stream.

Parameters:

filterType

type of compression filter

Returns:

EC_Normal if successful, an error code otherwise

virtual OFBool DcmOutputStream::isFlushed

(

)

const [virtual]

returns true if the stream is flushed, i.e.

has no more data pending in it's internal state that needs to be flushed before the stream is closed.

Returns:

true if stream is flushed, false otherwise

virtual OFCondition DcmOutputStream::status

(

)

const [virtual]

returns the status of the consumer as an OFCondition object.

Unless the status is good, the consumer will not permit any operation.

Returns:

status, EC_Normal if good

virtual offile_off_t DcmOutputStream::tell

(

)

const [virtual]

returns the total number of bytes written to the stream so far

Returns:

total number of bytes written to the stream

virtual offile_off_t DcmOutputStream::write	(	const void *	buf,
		offile_off_t	buflen
	)		[virtual]

processes as many bytes as possible from the given input block.

Parameters:

buf	pointer to memory block, must not be NULL
buflen	length of memory block

Returns:

number of bytes actually processed.

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

• dcmdata/include/dcmtk/dcmdata/dcostrma.h