knowrob::TokenBuffer Class Reference

#include <TokenBuffer.h>

Inheritance diagram for knowrob::TokenBuffer:

Collaboration diagram for knowrob::TokenBuffer:

Public Member Functions
	TokenBuffer ()
void	stopBuffering ()
std::shared_ptr< TokenQueue >	createQueue ()
	TokenBuffer ()
void	stopBuffering ()
std::shared_ptr< TokenQueue >	createQueue ()
Public Member Functions inherited from knowrob::TokenBroadcaster
	TokenBroadcaster ()
	~TokenBroadcaster () override
void	addSubscriber (const std::shared_ptr< Channel > &subscriber)
void	removeSubscriber (const std::shared_ptr< Channel > &subscriber)
	TokenBroadcaster ()
	~TokenBroadcaster () override
void	addSubscriber (const std::shared_ptr< Channel > &subscriber)
void	removeSubscriber (const std::shared_ptr< Channel > &subscriber)
Public Member Functions inherited from knowrob::TokenStream
	TokenStream ()
virtual	~TokenStream ()
	TokenStream (const TokenStream &)=delete
virtual void	close ()
bool	isOpened () const
	TokenStream ()
virtual	~TokenStream ()
	TokenStream (const TokenStream &)=delete
virtual void	close ()
bool	isOpened () const

Protected Member Functions
void	push (const TokenPtr &tok) override
void	push (const TokenPtr &tok) override
Protected Member Functions inherited from knowrob::TokenBroadcaster
virtual void	pushToBroadcast (const TokenPtr &tok)
virtual void	pushToBroadcast (const TokenPtr &tok)
Protected Member Functions inherited from knowrob::TokenStream
virtual void	push (Channel &channel, const TokenPtr &tok)
virtual void	push (Channel &channel, const TokenPtr &tok)

Protected Attributes
std::mutex	bufferMutex_
std::atomic< bool >	isBuffering_
std::list< TokenPtr >	buffer_
Protected Attributes inherited from knowrob::TokenBroadcaster
std::list< std::shared_ptr< Channel > >	subscribers_
std::mutex	mtx_
Protected Attributes inherited from knowrob::TokenStream
std::list< std::shared_ptr< Channel > >	channels_
std::atomic< bool >	isOpened_
std::mutex	channel_mutex_

Detailed Description

A token stream that buffers all input until stopBuffering() is called. The main purpose is to avoid losing messages while building a pipeline, such that pipeline can be partially active during construction. Also TokenBuffer provides an easy exit point for a pipeline by creating a queue.

Definition at line 19 of file TokenBuffer.h.

Constructor & Destructor Documentation

TokenBuffer() [1/2]

TokenBuffer::TokenBuffer

(

)

Definition at line 15 of file TokenBuffer.cpp.

        : TokenBroadcaster(), isBuffering_(true) {}

TokenBuffer() [2/2]

knowrob::TokenBuffer::TokenBuffer

(

)

Member Function Documentation

createQueue() [1/2]

std::shared_ptr< TokenQueue > TokenBuffer::createQueue

(

)

Create a queue that will receive all output tokens of this stream.

Returns

a queue of tokens.

Definition at line 39 of file TokenBuffer.cpp.

                                                   {
    auto queue = std::make_shared<TokenQueue>();
    addSubscriber(Channel::create(queue));
    stopBuffering();
    return queue;
}

createQueue() [2/2]

std::shared_ptr<TokenQueue> knowrob::TokenBuffer::createQueue

(

)

Create a queue that will receive all output tokens of this stream.

Returns

a queue of tokens.

push() [1/2]

void TokenBuffer::push ( const TokenPtr &  tok )

overrideprotectedvirtual

Reimplemented from knowrob::TokenBroadcaster.

Definition at line 46 of file TokenBuffer.cpp.

                                          {
    {
        std::lock_guard<std::mutex> lock(bufferMutex_);
        if (isBuffering_) {
            buffer_.push_back(tok);
            return;
        }
    }
    TokenBroadcaster::push(tok);
}

push() [2/2]

void knowrob::TokenBuffer::push ( const TokenPtr &  tok )

overrideprotectedvirtual

Reimplemented from knowrob::TokenBroadcaster.

stopBuffering() [1/2]

void TokenBuffer::stopBuffering

(

)

Stop buffering and forward all buffered tokens to subscribers.

Definition at line 18 of file TokenBuffer.cpp.

                                {
    if (!isBuffering_) return;
    TokenPtr next;
 
    while (true) {
        {
            // acquire lock, pop first element and lift the lock before pushing to the broadcaster.
            // this is done such that other threads may still push to the buffer while we are broadcasting.
            std::lock_guard<std::mutex> lock(bufferMutex_);
            if (buffer_.empty()) {
                isBuffering_ = false;
                break;
            } else {
                next = buffer_.front();
                buffer_.pop_front();
            }
        }
        TokenBroadcaster::push(next);
    }
}

stopBuffering() [2/2]

void knowrob::TokenBuffer::stopBuffering

(

)

Stop buffering and forward all buffered tokens to subscribers.

Member Data Documentation

buffer_

std::list< TokenPtr > knowrob::TokenBuffer::buffer_

protected

Definition at line 37 of file TokenBuffer.h.

bufferMutex_

std::mutex knowrob::TokenBuffer::bufferMutex_

protected

Definition at line 35 of file TokenBuffer.h.

isBuffering_

std::atomic< bool > knowrob::TokenBuffer::isBuffering_

protected

Definition at line 36 of file TokenBuffer.h.

---

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

• build/_CPack_Packages/Linux/DEB/knowrob-2.1.0-Linux/usr/include/knowrob/queries/TokenBuffer.h
• src/queries/TokenBuffer.cpp