Cpl::Io::AtomicOutputApi< CONTEXT > Class Template Reference

This abstract template class defines a interface for an Atomic outputs to a stream. More...

Detailed Description

template<class CONTEXT>
class Cpl::Io::AtomicOutputApi< CONTEXT >

This abstract template class defines a interface for an Atomic outputs to a stream.

The AtomicOutputApi interface is intended to be used in an multi threaded environment and provides a mechanism for many clients to write to a single output stream in manner where each client's output is atomic with respect to other clients.

The interface provides two paradigms:

1) An atomic output of a single a 'chunk' of data, i.e. each write()
   call on the Output is an atomic operation.
2) A Callback mechanism that allows outputting many 'chunks'
   a single atomic operation.

The template arg - CONTEXT - is the class that implements the callback when requestOutputs() is called.

#include <AtomicOutputApi.h>

Inheritance diagram for Cpl::Io::AtomicOutputApi< CONTEXT >:

Collaboration diagram for Cpl::Io::AtomicOutputApi< CONTEXT >:

Public Types
typedef bool(CONTEXT::*	OutputsFunction_T) (Output &)
	Definition of the call-back method that is used by the client/context to atomically publish many output operations.

Public Member Functions
virtual bool	requestOutputs (CONTEXT &client, OutputsFunction_T clientsMethod)=0
	This method is used to output a series of output operations to the stream as a single atomic operation.
Public Member Functions inherited from Cpl::Io::Output
virtual bool	write (char c)
	Writes a single byte to the stream.
virtual bool	write (const char *string)
	Writes a string to the stream.
virtual bool	write (const Cpl::Text::String &string)
	Writes a string to the stream.
virtual bool	write (Cpl::Text::String &formatBuffer, const char *format,...)
	Formatted write to the stream.
virtual bool	vwrite (Cpl::Text::String &formatBuffer, const char *format, va_list ap)
	Same as write( String& formatBuffer, const char* format,...), except that it is called with a va_list instead of a variable number of arguments.
virtual bool	write (const void *buffer, int numBytes)
	Writes the content of the buffer to the stream.
virtual bool	write (const void *buffer, int maxBytes, int &bytesWritten)=0
	Writes the content of the buffer to the stream.
virtual void	flush ()=0
	Forces all buffered data (if any) to be written to the stream media.
virtual	~Output ()
	Lets the make the destructor virtual.
Public Member Functions inherited from Cpl::Io::Close
virtual void	close ()=0
	This method will close the stream.
virtual	~Close ()
	Lets the make the destructor virtual.
Public Member Functions inherited from Cpl::Container::Item
bool	insert_ (void *newContainerPtr)
	Helper method to trap when inserting an item in multiple containers.
bool	isInContainer_ (const void *containerPtr) const noexcept
	Returns 'true' if the instance is in the specified container.
Public Member Functions inherited from Cpl::Io::IsEos
virtual bool	isEos ()=0
	This method returns true if End-of-Stream was encountered on the stream.
virtual	~IsEos ()
	Lets the make the destructor virtual.

Additional Inherited Members
Static Public Member Functions inherited from Cpl::Container::Item
static void	remove_ (Item *itemPtr) noexcept
	Helper method to do the proper 'clean-up' for the multiple-containers-error-trap when removing an item from a container.
Public Attributes inherited from Cpl::Container::Item
void *	m_nextPtr_
	The link field.
void *	m_inListPtr_
	Debug field.
Protected Member Functions inherited from Cpl::Container::Item
	Item ()
	Constructor.
	Item (const char *)
	Constructor used ONLY with the child class MapItem: -->special constructor to allow a Map to be statically allocated.

Member Typedef Documentation

OutputsFunction_T

template<class CONTEXT >

typedef bool(CONTEXT::* Cpl::Io::AtomicOutputApi< CONTEXT >::OutputsFunction_T) (Output &)

Definition of the call-back method that is used by the client/context to atomically publish many output operations.

The callback is required to return the OR'd return codes from all of the operations called on the Output stream.

Member Function Documentation

requestOutputs()

template<class CONTEXT >

virtual bool Cpl::Io::AtomicOutputApi< CONTEXT >::requestOutputs ( CONTEXT &  client, OutputsFunction_T  clientsMethod  )

pure virtual

This method is used to output a series of output operations to the stream as a single atomic operation.

A callback mechanism is used and all output operations performed in the callback are atomic with respect to the Output Stream. This method returns false if a error occur on the Output Stream; else true is returned.

NOTE: The callback client should keep the amount of work/duration of callback to a MINIMUM. All other clients attempting to publish to the same Output stream will be BLOCKED until this method returns.

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

• Cpl/Io/AtomicOutputApi.h