DcmBufferProducer Class Reference

producer class that reads data from a buffer provided by the caller. More...

Inheritance diagram for DcmBufferProducer:

Public Member Functions
	DcmBufferProducer ()
	constructor
virtual	~DcmBufferProducer ()
	destructor
virtual OFBool	good () const
	returns the status of the producer. More...
virtual OFCondition	status () const
	returns the status of the producer as an OFCondition object. More...
virtual OFBool	eos ()
	returns true if the producer is at the end of stream. More...
virtual offile_off_t	avail ()
	returns the minimum number of bytes that can be read with the next call to read(). More...
virtual offile_off_t	read (void *buf, offile_off_t buflen)
	reads as many bytes as possible into the given block. More...
virtual offile_off_t	skip (offile_off_t skiplen)
	skips over the given number of bytes (or less) More...
virtual void	putback (offile_off_t num)
	resets the stream to the position by the given number of bytes. More...
virtual void	setBuffer (const void *buf, offile_off_t buflen)
	adds the content of the given buffer to the input stream. More...
virtual void	releaseBuffer ()
	releases the current buffer. More...
virtual void	setEos ()
	marks the end of stream, i.e. More...
Public Member Functions inherited from DcmProducer
virtual	~DcmProducer ()
	destructor

Private Member Functions
	DcmBufferProducer (const DcmBufferProducer &)
	private unimplemented copy constructor
DcmBufferProducer &	operator= (const DcmBufferProducer &)
	private unimplemented copy assignment operator

Private Attributes
unsigned char *	buffer_
	the user buffer we're actually reading from
unsigned char *	backup_
	the backup buffer
offile_off_t	bufSize_
	size of the user buffer, in bytes
offile_off_t	bufIndex_
	number of bytes read from the user buffer
offile_off_t	backupIndex_
	number of bytes read from the backup buffer
offile_off_t	backupStart_
	index of first valid byte in backup buffer, for putback
OFCondition	status_
	status
OFBool	eosflag_
	true if setEos has been called before

Detailed Description

producer class that reads data from a buffer provided by the caller.

Used for DICOM network communication.

Member Function Documentation

avail()

virtual offile_off_t DcmBufferProducer::avail ( )

virtual

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

The DcmObject read 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 read "en bloc", i.e. all or nothing.

Returns

minimum of data available in producer

Implements DcmProducer.

eos()

virtual OFBool DcmBufferProducer::eos ( )

virtual

returns true if the producer is at the end of stream.

Returns

true if end of stream, false otherwise

Implements DcmProducer.

good()

virtual OFBool DcmBufferProducer::good ( ) const

virtual

returns the status of the producer.

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

Returns

status, true if good

Implements DcmProducer.

putback()

virtual void DcmBufferProducer::putback ( offile_off_t  num )

virtual

resets the stream to the position by the given number of bytes.

Parameters

num	number of bytes to putback. If the putback operation fails, the producer status becomes bad.

Implements DcmProducer.

read()

virtual offile_off_t DcmBufferProducer::read ( void *  buf, offile_off_t  buflen  )

virtual

reads as many bytes as possible into the given block.

Parameters

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

Returns

number of bytes actually read.

Implements DcmProducer.

releaseBuffer()

virtual void DcmBufferProducer::releaseBuffer ( )

virtual

releases the current buffer.

Should only be called when the content of the buffer has been read as far as possible. Pending input from the buffer is copied into an internal backup buffer if necessary. If an overflow condition occurs, the producer status becomes bad.

setBuffer()

virtual void DcmBufferProducer::setBuffer ( const void *  buf, offile_off_t  buflen  )

virtual

adds the content of the given buffer to the input stream.

Parameters

buf	buffer from which data is read. Must be allocated by caller and remain valid until releaseBuffer() is called
buflen	buffer length, must be even number > 0.

setEos()

virtual void DcmBufferProducer::setEos ( )

virtual

marks the end of stream, i.e.

the data provided with the last call to setBuffer is the last data available in the stream.

skip()

virtual offile_off_t DcmBufferProducer::skip ( offile_off_t  skiplen )

virtual

skips over the given number of bytes (or less)

Parameters

skiplen

number of bytes to skip

Returns

number of bytes actually skipped.

Implements DcmProducer.

status()

virtual OFCondition DcmBufferProducer::status ( ) const

virtual

returns the status of the producer as an OFCondition object.

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

Returns

status, EC_Normal if good

Implements DcmProducer.

---

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

• dcmdata/include/dcmtk/dcmdata/dcistrmb.h