SC::AsyncWritableStream Struct Reference

Async destination abstraction where bytes can be written to. More...

#include <AsyncStreams.h>

Inheritance diagram for SC::AsyncWritableStream:

Classes
struct	Request

Public Member Functions
Result	init (AsyncBuffersPool &buffersPool, Span< Request > requests)
	Emitted when no more data can be written. More...
Result	write (AsyncBufferView::ID bufferID, Function< void(AsyncBufferView::ID)> cb={})
	Writes a buffer (that must be allocated by the AsyncBuffersPool passed in AsyncWritableStream) When the buffer it will be actually written, AsyncWritableStream::eventWritten will be raised and its reference count will be decreased. More...
Result	write (Span< const char > data, Function< void(AsyncBufferView::ID)> cb={})
	Try requesting a buffer big enough and copy data into it. More...
template<size_t N>
Result	write (const char(&str)[N])
	Write a C-string literal in the stream. More...
void	end ()
	Ends the writable stream, waiting for all in-flight and queued writes to finish. More...
AsyncBuffersPool &	getBuffersPool ()
	Obtains the buffers pool to access its data. More...
void	finishedWriting (AsyncBufferView::ID bufferID, Function< void(AsyncBufferView::ID)> &&cb, Result res)
	Signals that the given buffer (previously queued by write) has been fully written. More...

Public Attributes
Function< Result(AsyncBufferView::ID, Function< void(AsyncBufferView::ID)>)>	asyncWrite
	Function that every stream must define to implement its custom write operation. More...
Event< MaxListeners, Result >	eventError
Event< MaxListeners >	eventDrain
	Emitted when an error occurs. More...
Event< MaxListeners >	eventFinish
	Emitted when write queue is empty. More...

Static Public Attributes
static constexpr int	MaxListeners = 8

Detailed Description

Async destination abstraction where bytes can be written to.

When buffers are pushed faster than the stream can handle, they will get queued. Queuing process happens with a linked list stored in the AsyncBufferView itself. As AsyncBufferView contains a fixed (at init) number of buffers, the queue is bounded by the fact that user will be unable to allocate buffers to write until at least one will be made available again (i.e. a write finishes). User can listen to AsyncWritableStream::eventWritten to know when a buffer is written (and its refcount decreased) or AsyncWritableStream::eventDrain when the queue is empty.

Member Function Documentation

end()

void SC::AsyncWritableStream::end

(

)

Ends the writable stream, waiting for all in-flight and queued writes to finish.

After this happens, AsyncWritableStream::eventFinished will be raised

finishedWriting()

void SC::AsyncWritableStream::finishedWriting	(	AsyncBufferView::ID	bufferID,
		Function< void(AsyncBufferView::ID)> &&	cb,
		Result	res
	)

Signals that the given buffer (previously queued by write) has been fully written.

getBuffersPool()

AsyncBuffersPool & SC::AsyncWritableStream::getBuffersPool

(

)

Obtains the buffers pool to access its data.

init()

Result SC::AsyncWritableStream::init	(	AsyncBuffersPool &	buffersPool,
		Span< Request >	requests
	)

Emitted when no more data can be written.

Inits the writable stream

Parameters

buffersPool	An instance of AsyncBuffersPool providing write buffers
requests	User owned memory to hold a circular buffer for write requests

write() [1/3]

Result SC::AsyncWritableStream::write	(	AsyncBufferView::ID	bufferID,
		Function< void(AsyncBufferView::ID)>	cb = {}
	)

Writes a buffer (that must be allocated by the AsyncBuffersPool passed in AsyncWritableStream) When the buffer it will be actually written, AsyncWritableStream::eventWritten will be raised and its reference count will be decreased.

Parameters

bufferID	Buffer allocated from the associated AsyncBuffersPool (AsyncWritableStream::getBuffersPool)
cb	Callback that will be invoked when the write is finished

Returns

Invalid Result if write queue is full

write() [2/3]

template<size_t N>

Result SC::AsyncWritableStream::write ( const char(&)  str[N] )

inline

Write a C-string literal in the stream.

Returns

Invalid Result if write queue is full or if there are no available buffers in the pool

write() [3/3]

Result SC::AsyncWritableStream::write	(	Span< const char >	data,
		Function< void(AsyncBufferView::ID)>	cb = {}
	)

Try requesting a buffer big enough and copy data into it.

Returns

Invalid Result if write queue is full or if there are no available buffers in the pool

Member Data Documentation

asyncWrite

Function<Result(AsyncBufferView::ID, Function<void(AsyncBufferView::ID)>)> SC::AsyncWritableStream::asyncWrite

Function that every stream must define to implement its custom write operation.

eventDrain

Event<MaxListeners> SC::AsyncWritableStream::eventDrain

Emitted when an error occurs.

eventFinish

Event<MaxListeners> SC::AsyncWritableStream::eventFinish

Emitted when write queue is empty.

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

• AsyncStreams.h