CPN::QueueWriter Class Reference

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

#include <QueueWriter.h>

Collaboration diagram for CPN::QueueWriter:

Public Member Functions
	QueueWriter (QueueReleaser *qr, shared_ptr< QueueBase >)
	~QueueWriter ()
void *	GetRawEnqueuePtr (unsigned thresh, unsigned chan=0)
void	Enqueue (unsigned count)
void	RawEnqueue (const void *data, unsigned count, unsigned numChans, unsigned chanStride)
void	RawEnqueue (const void *data, unsigned count)
void	Flush ()
bool	Flushed () const
unsigned	NumChannels () const
unsigned	MaxThreshold () const
unsigned	QueueLength () const
unsigned	Freespace () const
bool	Full () const
unsigned	ChannelStride () const
const std::string &	GetDatatype () 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 writer portion of the CPN queue class.

Definition at line 37 of file QueueWriter.h.

Constructor & Destructor Documentation

CPN::QueueWriter::QueueWriter	(	QueueReleaser *	qr,
		shared_ptr< QueueBase >	q
	)

Definition at line 31 of file QueueWriter.cc.

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

CPN::QueueWriter::~QueueWriter

(

)

Definition at line 36 of file QueueWriter.cc.

References queue.

                              {
        queue->ShutdownWriter();
    }

Member Function Documentation

unsigned CPN::QueueWriter::ChannelStride

(

)

const

Returns

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

Definition at line 67 of file QueueWriter.cc.

References queue.

{ return queue->EnqueueChannelStride(); }

void CPN::QueueWriter::Enqueue

(

unsigned

count

)

This function is used to release the buffer obtained with GetRawEnqueuePtr. The count specifies the number of entries that we want to be placed in the buffer.

Note

A call to this function without an accompanying call to GetRawEnqueuePtr is undefined.

Parameters

count

the number of bytes to be placed in the buffer

Invariant

count <= thresh from GetRawEnqueuePtr

Definition at line 42 of file QueueWriter.cc.

References queue.

{ queue->Enqueue(count); }

void CPN::QueueWriter::Flush

(

)

Definition at line 53 of file QueueWriter.cc.

References queue.

{ queue->Flush(); }

bool CPN::QueueWriter::Flushed

(

)

const

Definition at line 55 of file QueueWriter.cc.

References queue.

{ return queue->Flushed(); }

unsigned CPN::QueueWriter::Freespace

(

)

const

Get the space available in elements.

Warning

This function violates the rules of CPN.

Returns

the number of bytes we can add to the queue without blocking.

Definition at line 63 of file QueueWriter.cc.

References queue.

{ return queue->Freespace(); }

bool CPN::QueueWriter::Full

(

)

const

Test if the queue is currently full.

Warning

This function violates the rules of CPN.

Returns

true if the queue is full, false otherwise

Definition at line 65 of file QueueWriter.cc.

References queue.

{ return queue->Full(); }

const std::string & CPN::QueueWriter::GetDatatype

(

)

const

Returns

the typename for this queue

Definition at line 69 of file QueueWriter.cc.

References queue.

{ return queue->GetDatatype(); }

Key_t CPN::QueueWriter::GetKey

(

)

const

Returns

the key associated with this endpoint

Definition at line 71 of file QueueWriter.cc.

References queue.

Referenced by Release().

{ return queue->GetWriterKey(); }

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

inline

Definition at line 156 of file QueueWriter.h.

{ return queue; }

void * CPN::QueueWriter::GetRawEnqueuePtr	(	unsigned	thresh,
		unsigned	chan = 0
	)

Return a pointer to a buffer of memory that contains thresh entries that we can write into.

Note

A call to this function without an accompanying call to Enqueue is undefined.

An access to the memory locations defined by the return value is undefined after a call to Enqueue.

Parameters

thresh	the number bytes we need in the returned buffer.
chan	the channel to use

Returns

void* to a block of memory at least thresh bytes long, blocks until thresh bytes available

Exceptions

BrokenQueueException

if the reader is released

Definition at line 39 of file QueueWriter.cc.

References queue.

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

unsigned CPN::QueueWriter::MaxThreshold

(

)

const

Returns

the maximum threshold this queue supports.

Definition at line 59 of file QueueWriter.cc.

References queue.

{ return queue->MaxThreshold(); }

void CPN::QueueWriter::NotifyTerminate

(

)

Called by the node.

Definition at line 73 of file QueueWriter.cc.

References queue.

{ queue->NotifyTerminate(); }

unsigned CPN::QueueWriter::NumChannels

(

)

const

Returns

the number of channels supported by this queue.

Definition at line 57 of file QueueWriter.cc.

References queue.

{ return queue->NumChannels(); }

unsigned CPN::QueueWriter::QueueLength

(

)

const

Definition at line 61 of file QueueWriter.cc.

References queue.

{ return queue->QueueLength(); }

void CPN::QueueWriter::RawEnqueue	(	const void *	data,
		unsigned	count,
		unsigned	numChans,
		unsigned	chanStride
	)

This function shall be equivalent to a call to GetRqwEnqueuePtr and a memcpy and then a call to Enqueue

The underlying implementatin may implement ether the GetRawEnqueuePtr and Enqueue or RawEnqueue and then implement the other in terms of the one implemented.

Parameters

data	pointer to the memory to enqueue
count	the number of bytes to enqueue
numChans	the number of channels to write to
chanStride	the distance in bytes between the beginning of the channels in data.

Exceptions

BrokenQueueException

if the reader is released

Definition at line 44 of file QueueWriter.cc.

References queue.

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

void CPN::QueueWriter::RawEnqueue	(	const void *	data,
		unsigned	count
	)

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

Parameters

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

Exceptions

BrokenQueueException

if the reader is released

Definition at line 49 of file QueueWriter.cc.

References queue.

                                                                 {
        queue->RawEnqueue(data, count);
    }

void CPN::QueueWriter::Release

(

)

Release this queue, will start releasing the resources used.

Definition at line 75 of file QueueWriter.cc.

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

                              {
        queue->ShutdownWriter();
        releaser->ReleaseWriter(GetKey());
    }

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Member Data Documentation

shared_ptr<QueueBase> CPN::QueueWriter::queue

private

Definition at line 159 of file QueueWriter.h.

Referenced by ChannelStride(), Enqueue(), Flush(), Flushed(), Freespace(), Full(), GetDatatype(), GetKey(), GetRawEnqueuePtr(), MaxThreshold(), NotifyTerminate(), NumChannels(), QueueLength(), RawEnqueue(), Release(), and ~QueueWriter().

QueueReleaser* CPN::QueueWriter::releaser

private

Definition at line 158 of file QueueWriter.h.

Referenced by Release().

---

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

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