CPN::QueueReader Class Reference

Definition of the reader portion of the CPN queue class. More...

#include <QueueReader.h>

Collaboration diagram for CPN::QueueReader:

Public Member Functions
	QueueReader (QueueReleaser *n, shared_ptr< QueueBase > q)
	~QueueReader ()
const void *	GetRawDequeuePtr (unsigned thresh, unsigned chan=0)
void	Dequeue (unsigned count)
bool	RawDequeue (void *data, unsigned count, unsigned numChans, unsigned chanStride)
bool	RawDequeue (void *data, unsigned count)
void	Reset ()
bool	Flushed () const
unsigned	NumChannels () const
unsigned	MaxThreshold () const
unsigned	QueueLength () const
unsigned	Count () const
bool	Empty () const
const std::string &	GetDatatype () const
unsigned	ChannelStride () const
Key_t	GetKey () const
void	Release ()
void	NotifyTerminate ()
	Called by the node. More...
shared_ptr< QueueBase >	GetQueue ()

Private Attributes
QueueReleaser *	releaser
shared_ptr< QueueBase >	queue

Detailed Description

Definition of the reader portion of the CPN queue class.

Definition at line 37 of file QueueReader.h.

Constructor & Destructor Documentation

CPN::QueueReader::QueueReader	(	QueueReleaser *	n,
		shared_ptr< QueueBase >	q
	)

Definition at line 31 of file QueueReader.cc.

        : releaser(qr), queue(q)
    {
    }

CPN::QueueReader::~QueueReader

(

)

Definition at line 36 of file QueueReader.cc.

References queue.

                              {
        queue->ShutdownReader();
    }

Member Function Documentation

unsigned CPN::QueueReader::ChannelStride

(

)

const

Returns

The current channel stride, the returned value is only guaranteed to be consistent when called between calls to GetRawDequeuePtr and Dequeue.

Definition at line 73 of file QueueReader.cc.

References queue.

{ return queue->DequeueChannelStride(); }

unsigned CPN::QueueReader::Count

(

)

const

An accessor method for the number of elements currently in the queue.

Warning

This function violates the rules of CPN.

Returns

the number of elements in the queue.

Definition at line 65 of file QueueReader.cc.

References queue.

{ return queue->Count(); }

void CPN::QueueReader::Dequeue

(

unsigned

count

)

This function is used to remove elements from the queue. count elements will be removed from the queue when this function is called.

Parameters

count

the number of bytes to remove from the queue

Invariant

count <= thresh from GetRawDequeuePtr

Definition at line 44 of file QueueReader.cc.

References queue.

{ queue->Dequeue(count); }

bool CPN::QueueReader::Empty

(

)

const

Warning

This function violates the rules of CPN.

Returns

true if the queue is empty

Definition at line 67 of file QueueReader.cc.

References queue.

{ return queue->Empty(); }

bool CPN::QueueReader::Flushed

(

)

const

Definition at line 57 of file QueueReader.cc.

References queue.

{ return queue->Flushed(); }

const std::string & CPN::QueueReader::GetDatatype

(

)

const

Returns

the typename for this queue

Definition at line 69 of file QueueReader.cc.

References queue.

                                                    {
        return queue->GetDatatype();
    }

Key_t CPN::QueueReader::GetKey

(

)

const

Returns

the key associated with this endpoint

Definition at line 75 of file QueueReader.cc.

References queue.

Referenced by Release().

{ return queue->GetReaderKey(); }

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shared_ptr<QueueBase> CPN::QueueReader::GetQueue ( )

inline

Definition at line 150 of file QueueReader.h.

{ return queue; }

const void * CPN::QueueReader::GetRawDequeuePtr	(	unsigned	thresh,
		unsigned	chan = 0
	)

Get a pointer to a buffer containing elements.

Note

access to the memory locations pointed to by the returned pointer after Dequeue has been called is undefined.

Parameters

thresh	the number of bytes to get
chan	the channel to use

Returns

A void* to a block of memory thresh bytes long blocks until threshold bytes available 0 if the writer has disconnected and there is not enough data to fill the request.

Definition at line 40 of file QueueReader.cc.

References queue.

                                                                            {
        return queue->GetRawDequeuePtr(thresh, chan);
    }

unsigned CPN::QueueReader::MaxThreshold

(

)

const

Returns

the maximum threshold this queue supports.

Definition at line 61 of file QueueReader.cc.

References queue.

{ return queue->MaxThreshold(); }

void CPN::QueueReader::NotifyTerminate

(

)

Called by the node.

Definition at line 77 of file QueueReader.cc.

References queue.

{ queue->NotifyTerminate(); }

unsigned CPN::QueueReader::NumChannels

(

)

const

Returns

the number of channels supported by this queue.

Definition at line 59 of file QueueReader.cc.

References queue.

{ return queue->NumChannels(); }

unsigned CPN::QueueReader::QueueLength

(

)

const

Definition at line 63 of file QueueReader.cc.

References queue.

{ return queue->QueueLength(); }

bool CPN::QueueReader::RawDequeue	(	void *	data,
		unsigned	count,
		unsigned	numChans,
		unsigned	chanStride
	)

Dequeue data from the queue directly into the memory pointed to by data. This function shall be equivalent to a call to GetRawDequeuePtr then a memcpy and then a call to Dequeue.

Parameters

data	poiner to memory to dequeue to
count	the number of bytes to copy into data
numChans	the number of channels to write to
chanStride	the distance in bytes between the beginning of the channels in data.

Returns

true on success or false if the writer has disconnected and there is not enough data to fill the request.

Definition at line 46 of file QueueReader.cc.

References queue.

                                                    {
        return queue->RawDequeue(data, count, numChans, chanStride);
    }

bool CPN::QueueReader::RawDequeue	(	void *	data,
		unsigned	count
	)

A version of RawDequeue to use when there is only 1 channel.

Parameters

data	the data to enqueue
count	the number of bytes to enqueue

Returns

true on success or false if the writer has disconnected and there is not enough data to fill the request.

Definition at line 51 of file QueueReader.cc.

References queue.

                                                           {
        return queue->RawDequeue(data, count);
    }

void CPN::QueueReader::Release

(

)

Release the reader and reclame resources, all futher operations are invalid.

Definition at line 79 of file QueueReader.cc.

References GetKey(), queue, releaser, and CPN::QueueReleaser::ReleaseReader().

                              {
        queue->ShutdownReader();
        releaser->ReleaseReader(GetKey());
    }

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void CPN::QueueReader::Reset

(

)

Definition at line 55 of file QueueReader.cc.

References queue.

{ queue->Reset(); }

Member Data Documentation

shared_ptr<QueueBase> CPN::QueueReader::queue

private

Definition at line 153 of file QueueReader.h.

Referenced by ChannelStride(), Count(), Dequeue(), Empty(), Flushed(), GetDatatype(), GetKey(), GetRawDequeuePtr(), MaxThreshold(), NotifyTerminate(), NumChannels(), QueueLength(), RawDequeue(), Release(), Reset(), and ~QueueReader().

QueueReleaser* CPN::QueueReader::releaser

private

Definition at line 152 of file QueueReader.h.

Referenced by Release().

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

• include/cpn/bits/QueueReader.h
• lib/QueueReader.cc