wangle::OutputBufferingHandler Class Reference

#include <OutputBufferingHandler.h>

Inheritance diagram for wangle::OutputBufferingHandler:

Public Member Functions
folly::Future< folly::Unit >	write (Context *ctx, std::unique_ptr< folly::IOBuf > buf) override
void	runLoopCallback () noexceptoverride
void	cleanUp ()
folly::Future< folly::Unit >	close (Context *ctx) override
Public Member Functions inherited from wangle::OutboundHandler< Win, Wout >
	~OutboundHandler () override=default
virtual folly::Future< folly::Unit >	write (Context *ctx, Win msg)=0
virtual folly::Future< folly::Unit >	writeException (Context *ctx, folly::exception_wrapper e)
Public Member Functions inherited from wangle::HandlerBase< OutboundHandlerContext< Wout > >
virtual	~HandlerBase ()=default
virtual void	attachPipeline (OutboundHandlerContext< Wout > *)
virtual void	detachPipeline (OutboundHandlerContext< Wout > *)
OutboundHandlerContext< Wout > *	getContext ()

Public Attributes
folly::SharedPromise< folly::Unit >	sharedPromise_
std::unique_ptr< folly::IOBuf >	sends_ {nullptr}
bool	queueSends_ {true}

Additional Inherited Members
Public Types inherited from wangle::OutboundHandler< Win, Wout >
typedef folly::Unit	rin
typedef folly::Unit	rout
typedef Win	win
typedef Wout	wout
typedef OutboundHandlerContext< Wout >	Context
Static Public Attributes inherited from wangle::OutboundHandler< Win, Wout >
static const HandlerDir	dir = HandlerDir::OUT
Protected Member Functions inherited from folly::EventBase::LoopCallback
virtual	~LoopCallback ()=default
void	cancelLoopCallback ()
bool	isLoopCallbackScheduled () const

Detailed Description

Definition at line 34 of file OutputBufferingHandler.h.

Member Function Documentation

void wangle::OutputBufferingHandler::cleanUp ( )

inline

Definition at line 69 of file OutputBufferingHandler.h.

References folly::EventBase::LoopCallback::cancelLoopCallback(), folly::EventBase::LoopCallback::isLoopCallbackScheduled(), sends_, and sharedPromise_.

                 {
    if (isLoopCallbackScheduled()) {
      cancelLoopCallback();
    }

    sends_.reset();
    sharedPromise_ = folly::SharedPromise<folly::Unit>();
  }

folly::Future<folly::Unit> wangle::OutputBufferingHandler::close ( Context *  ctx )

inlineoverridevirtual

Reimplemented from wangle::OutboundHandler< Win, Wout >.

Definition at line 78 of file OutputBufferingHandler.h.

References folly::EventBase::LoopCallback::cancelLoopCallback(), wangle::OutboundHandlerContext< Out >::fireClose(), folly::EventBase::LoopCallback::isLoopCallbackScheduled(), sends_, folly::SharedPromise< T >::setException(), and sharedPromise_.

                                                      {
    if (isLoopCallbackScheduled()) {
      cancelLoopCallback();
    }

    // If there are sends queued, cancel them
    sharedPromise_.setException(
      folly::make_exception_wrapper<std::runtime_error>(
        "close() called while sends still pending"));
    sends_.reset();
    sharedPromise_ = folly::SharedPromise<folly::Unit>();
    return ctx->fireClose();
  }

void wangle::OutputBufferingHandler::runLoopCallback ( )

inlineoverridevirtualnoexcept

Implements folly::EventBase::LoopCallback.

Definition at line 58 of file OutputBufferingHandler.h.

References wangle::OutboundHandlerContext< Out >::fireWrite(), wangle::HandlerBase< OutboundHandlerContext< Wout > >::getContext(), folly::gen::move, sends_, folly::SharedPromise< T >::setTry(), sharedPromise_, folly::f14::swap(), and folly::pushmi::detail::t.

                                           {
    folly::SharedPromise<folly::Unit> sharedPromise;
    std::swap(sharedPromise, sharedPromise_);
    getContext()
        ->fireWrite(std::move(sends_))
        .thenTry([sharedPromise = std::move(sharedPromise)](
                     folly::Try<folly::Unit> t) mutable {
          sharedPromise.setTry(std::move(t));
        });
  }

folly::Future<folly::Unit> wangle::OutputBufferingHandler::write ( Context *  ctx, std::unique_ptr< folly::IOBuf >  buf  )

inlineoverride

Definition at line 37 of file OutputBufferingHandler.h.

References wangle::OutboundHandlerContext< Out >::fireWrite(), folly::SharedPromise< T >::getFuture(), wangle::OutboundHandlerContext< Out >::getTransport(), folly::EventBase::LoopCallback::isLoopCallbackScheduled(), folly::gen::move, queueSends_, sends_, and sharedPromise_.

                                              {
    CHECK(buf);
    if (!queueSends_) {
      return ctx->fireWrite(std::move(buf));
    } else {
      // Delay sends to optimize for fewer syscalls
      if (!sends_) {
        DCHECK(!isLoopCallbackScheduled());
        // Buffer all the sends, and call writev once per event loop.
        sends_ = std::move(buf);
        ctx->getTransport()->getEventBase()->runInLoop(this);
      } else {
        DCHECK(isLoopCallbackScheduled());
        sends_->prependChain(std::move(buf));
      }
      return sharedPromise_.getFuture();
    }
  }

Member Data Documentation

bool wangle::OutputBufferingHandler::queueSends_ {true}

Definition at line 94 of file OutputBufferingHandler.h.

Referenced by write().

std::unique_ptr<folly::IOBuf> wangle::OutputBufferingHandler::sends_ {nullptr}

Definition at line 93 of file OutputBufferingHandler.h.

Referenced by cleanUp(), close(), runLoopCallback(), and write().

folly::SharedPromise<folly::Unit> wangle::OutputBufferingHandler::sharedPromise_

Definition at line 92 of file OutputBufferingHandler.h.

Referenced by cleanUp(), close(), runLoopCallback(), and write().

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

• proxygen/wangle/wangle/channel/OutputBufferingHandler.h