pure virtual abstract base class for producers, i.e. More...
Inheritance diagram for DcmProducer:
Public Member Functions | |
| virtual | ~DcmProducer () |
| destructor | |
| virtual OFBool | good () const =0 |
| returns the status of the producer. | |
| virtual OFCondition | status () const =0 |
| returns the status of the producer as an OFCondition object. | |
| virtual OFBool | eos ()=0 |
| returns true if the producer is at the end of stream. | |
| virtual offile_off_t | avail ()=0 |
| returns the minimum number of bytes that can be read with the next call to read(). | |
| virtual offile_off_t | read (void *buf, offile_off_t buflen)=0 |
| reads as many bytes as possible into the given block. | |
| virtual offile_off_t | skip (offile_off_t skiplen)=0 |
| skips over the given number of bytes (or less) | |
| virtual void | putback (offile_off_t num)=0 |
| resets the stream to the position by the given number of bytes. | |
Detailed Description
pure virtual abstract base class for producers, i.e.
the initial node of a filter chain in an input stream.
Member Function Documentation
| virtual offile_off_t DcmProducer::avail | ( | ) | [pure 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
Implemented in DcmZLibInputFilter, DcmFileProducer, and DcmBufferProducer.
| virtual OFBool DcmProducer::eos | ( | ) | [pure virtual] |
returns true if the producer is at the end of stream.
- Returns:
- true if end of stream, false otherwise
Implemented in DcmZLibInputFilter, DcmFileProducer, and DcmBufferProducer.
| virtual OFBool DcmProducer::good | ( | ) | const [pure virtual] |
returns the status of the producer.
Unless the status is good, the producer will not permit any operation.
- Returns:
- status, true if good
Implemented in DcmZLibInputFilter, DcmFileProducer, and DcmBufferProducer.
| virtual void DcmProducer::putback | ( | offile_off_t | num | ) | [pure 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.
Implemented in DcmZLibInputFilter, DcmFileProducer, and DcmBufferProducer.
| virtual offile_off_t DcmProducer::read | ( | void * | buf, |
| offile_off_t | buflen | ||
| ) | [pure 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.
Implemented in DcmZLibInputFilter, DcmFileProducer, and DcmBufferProducer.
| virtual offile_off_t DcmProducer::skip | ( | offile_off_t | skiplen | ) | [pure virtual] |
skips over the given number of bytes (or less)
- Parameters:
-
skiplen number of bytes to skip
- Returns:
- number of bytes actually skipped.
Implemented in DcmZLibInputFilter, DcmFileProducer, and DcmBufferProducer.
| virtual OFCondition DcmProducer::status | ( | ) | const [pure 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
Implemented in DcmZLibInputFilter, DcmFileProducer, and DcmBufferProducer.
The documentation for this class was generated from the following file:
- dcmdata/include/dcmtk/dcmdata/dcistrma.h