ConnFactory.hpp

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/***************************************************************************
  tag: Peter Soetens  Thu Oct 22 11:59:08 CEST 2009  ConnFactory.hpp

                        ConnFactory.hpp -  description
                           -------------------
    begin                : Thu October 22 2009
    copyright            : (C) 2009 Peter Soetens
    email                : peter@thesourcworks.com

 ***************************************************************************
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#ifndef ORO_CONN_FACTORY_HPP
#define ORO_CONN_FACTORY_HPP

#include <string>
#include "Channels.hpp"
#include "ConnInputEndPoint.hpp"
#include "ConnOutputEndPoint.hpp"
#include "SharedConnection.hpp"
#include "../base/PortInterface.hpp"
#include "../base/InputPortInterface.hpp"
#include "../base/OutputPortInterface.hpp"
#include "../DataFlowInterface.hpp"

#include "../base/DataObject.hpp"
#include "../base/DataObjectUnSync.hpp"
#include "../base/Buffer.hpp"
#include "../base/BufferUnSync.hpp"
#include "../Logger.hpp"

#include "../rtt-config.h"

namespace RTT
{ namespace internal {

    struct LocalConnID : public ConnID
    {
        base::PortInterface const* ptr;
        LocalConnID(base::PortInterface const* obj)
            : ptr(obj) {}
        virtual ConnID* clone() const;
        virtual bool isSameID(ConnID const& id) const;
    };

    struct RTT_API StreamConnID : public ConnID
    {
        std::string name_id;
        StreamConnID(const std::string& name)
            : name_id(name) {}
        virtual ConnID* clone() const;
        virtual bool isSameID(ConnID const& id) const;
    };


    class RTT_API ConnFactory
    {
    public:
        virtual ~ConnFactory() {}

        virtual base::InputPortInterface* inputPort(std::string const& name) const = 0;

        virtual base::OutputPortInterface* outputPort(std::string const& name) const = 0;

        virtual base::ChannelElementBase::shared_ptr buildDataStorage(ConnPolicy const& policy) const = 0;

        virtual base::ChannelElementBase::shared_ptr buildChannelOutput(base::InputPortInterface& port, ConnPolicy const& policy) const = 0;

        virtual base::ChannelElementBase::shared_ptr buildChannelInput(base::OutputPortInterface& port, ConnPolicy const& policy) const = 0;

        virtual internal::SharedConnectionBase::shared_ptr buildSharedConnection(base::OutputPortInterface *output_port, base::InputPortInterface *input_port, ConnPolicy const& policy) const = 0;

        template<typename T>
        static base::ChannelElement<T>* buildDataStorage(ConnPolicy const& policy, const T& initial_value = T())
        {
            if (policy.type == ConnPolicy::DATA)
            {
                typename base::DataObjectInterface<T>::shared_ptr data_object;
                switch (policy.lock_policy)
                {
#ifndef OROBLD_OS_NO_ASM
                case ConnPolicy::LOCK_FREE:
                    data_object.reset( new base::DataObjectLockFree<T>(initial_value, policy) );
                    break;
#else
                case ConnPolicy::LOCK_FREE:
                    RTT::log(Warning) << "lock free connection policy is unavailable on this system, defaulting to LOCKED" << RTT::endlog();
#endif
                case ConnPolicy::LOCKED:
                    data_object.reset( new base::DataObjectLocked<T>(initial_value) );
                    break;
                case ConnPolicy::UNSYNC:
                    data_object.reset( new base::DataObjectUnSync<T>(initial_value) );
                    break;
                }
                return new ChannelDataElement<T>(data_object, policy);
            }
            else if (policy.type == ConnPolicy::BUFFER || policy.type == ConnPolicy::CIRCULAR_BUFFER)
            {
                typename base::BufferInterface<T>::shared_ptr buffer_object;
                switch (policy.lock_policy)
                {
#ifndef OROBLD_OS_NO_ASM
                case ConnPolicy::LOCK_FREE:
                    buffer_object.reset(new base::BufferLockFree<T>(policy.size, initial_value, policy));
                    break;
#else
                case ConnPolicy::LOCK_FREE:
                    RTT::log(Warning) << "lock free connection policy is unavailable on this system, defaulting to LOCKED" << RTT::endlog();
#endif
                case ConnPolicy::LOCKED:
                    buffer_object.reset(new base::BufferLocked<T>(policy.size, initial_value, policy));
                    break;
                case ConnPolicy::UNSYNC:
                    buffer_object.reset(new base::BufferUnSync<T>(policy.size, initial_value, policy));
                    break;
                }
                return new ChannelBufferElement<T>(buffer_object, policy);
            }
            return NULL;
        }

        template<typename T>
        static base::ChannelElementBase::shared_ptr buildChannelInput(OutputPort<T>& port, ConnPolicy const& policy, bool force_unbuffered = false)
        {
            typename internal::ConnInputEndpoint<T>::shared_ptr endpoint = port.getEndpoint();
            typename base::ChannelElement<T>::shared_ptr buffer = port.getSharedBuffer();

            // Note: PerInputPort implies PUSH and PerOutputPort implies PULL
            bool pull = policy.pull;
            if (policy.buffer_policy == PerInputPort) pull = ConnPolicy::PUSH;
            if (policy.buffer_policy == PerOutputPort) pull = ConnPolicy::PULL;

            if (pull == ConnPolicy::PULL && !force_unbuffered) {
                if (!buffer) {
                    buffer = buildDataStorage<T>(policy, port.getLastWrittenValue());
                    if (!buffer) return typename internal::ConnOutputEndpoint<T>::shared_ptr();

                    if (policy.buffer_policy == PerOutputPort) {
                        // For PerOutputPort connections, the buffer is installed BEFORE the input endpoint!
                        if (endpoint->connected()) {
                            log(Error) << "You tried to create a shared output buffer connection for output port " << port.getName() << ", "
                                       << "but the port already has at least one incompatible outgoing connection." << endlog();
                            return typename internal::ConnOutputEndpoint<T>::shared_ptr();
                        }
                        return buffer->connectTo(endpoint) ? endpoint : typename internal::ConnInputEndpoint<T>::shared_ptr();
                    } else {
                        return endpoint->connectTo(buffer, policy.mandatory) ? buffer : typename internal::ConnInputEndpoint<T>::shared_ptr();
                    }

                } else if (policy.buffer_policy == PerOutputPort) {
                    // check that the existing buffer type is compatible to the new ConnPolicy
                    assert(buffer->getConnPolicy());
                    ConnPolicy buffer_policy = *(buffer->getConnPolicy());

                    if (
                        (buffer_policy.type != policy.type) ||
                        (buffer_policy.size != policy.size) ||
                        (buffer_policy.lock_policy != policy.lock_policy)
                       )
                    {
                        log(Error) << "You mixed incompatible connection policies for the shared output buffer of port " << port.getName() << ": "
                                   << "The new connection requests a " << policy << " connection, "
                                   << "but the port already has a " << buffer_policy << " buffer." << endlog();
                        return typename internal::ConnOutputEndpoint<T>::shared_ptr();
                    }

                    return endpoint;
                }
            }

            if (buffer) {
                // The new connection requires an unbuffered channel input or a per-connection buffer, but this port already has a shared output buffer!
                assert(buffer->getConnPolicy());
                ConnPolicy buffer_policy = *(buffer->getConnPolicy());

                log(Error) << "You mixed incompatible connection policies for output port " << port.getName() << ": "
                           << "The new connection requests a " << policy << " connection, "
                           << "but the port already has a " << buffer_policy << " buffer." << endlog();
                return typename internal::ConnOutputEndpoint<T>::shared_ptr();
            }

            return endpoint;
        }

        template<typename T>
        static base::ChannelElementBase::shared_ptr buildChannelOutput(InputPort<T>& port, ConnPolicy const& policy, T const& initial_value = T() )
        {
            typename internal::ConnOutputEndpoint<T>::shared_ptr endpoint = port.getEndpoint();
            typename base::ChannelElement<T>::shared_ptr buffer = port.getSharedBuffer();

            // Note: PerInputPort implies PUSH and PerOutputPort implies PULL
            bool pull = policy.pull;
            if (policy.buffer_policy == PerInputPort) pull = ConnPolicy::PUSH;
            if (policy.buffer_policy == PerOutputPort) pull = ConnPolicy::PULL;

            if (pull == ConnPolicy::PUSH) {
                if (!buffer) {
                    buffer = buildDataStorage<T>(policy, initial_value);
                    if (!buffer) return typename internal::ConnOutputEndpoint<T>::shared_ptr();

                    if (policy.buffer_policy == PerInputPort) {
                        // For PerInputPort connections, the buffer is installed AFTER the output endpoint!
                        if (endpoint->connected()) {
                            log(Error) << "You tried to create a shared input buffer connection for input port " << port.getName() << ", "
                                       << "but the port already has at least one incompatible incoming connection." << endlog();
                            return typename internal::ConnOutputEndpoint<T>::shared_ptr();
                        }
                        return endpoint->connectTo(buffer) ? endpoint : typename internal::ConnOutputEndpoint<T>::shared_ptr();
                    } else {
                        return buffer->connectTo(endpoint) ? buffer : typename internal::ConnOutputEndpoint<T>::shared_ptr();
                    }

                } else if (policy.buffer_policy == PerInputPort) {
                    // check that the existing buffer type is compatible to the new ConnPolicy
                    assert(buffer->getConnPolicy());
                    ConnPolicy buffer_policy = *(buffer->getConnPolicy());

                    if (
                        (buffer_policy.type != policy.type) ||
                        (buffer_policy.size != policy.size) ||
                        (buffer_policy.lock_policy != policy.lock_policy)
                       )
                    {
                        log(Error) << "You mixed incompatible connection policies for the shared input buffer of port " << port.getName() << ": "
                                   << "The new connection requests a " << policy << " connection, "
                                   << "but the port already has a " << buffer_policy << " buffer." << endlog();
                        return typename internal::ConnOutputEndpoint<T>::shared_ptr();
                    }

                    return endpoint;
                }
            }

            if (buffer) {
                // The new connection requires an unbuffered channel output or a per-connection buffer, but this port already has a shared input buffer!
                assert(buffer->getConnPolicy());
                ConnPolicy buffer_policy = *(buffer->getConnPolicy());

                log(Error) << "You mixed incompatible connection policies for input port " << port.getName() << ": "
                           << "The new connection requests a " << policy << " connection, "
                           << "but the port already has a " << buffer_policy << " buffer." << endlog();
                return typename internal::ConnOutputEndpoint<T>::shared_ptr();
            }

            return endpoint;
        }

        static bool findSharedConnection(base::OutputPortInterface *output_port, base::InputPortInterface *input_port, ConnPolicy const& policy, SharedConnectionBase::shared_ptr &shared_connection);

        template <typename T>
        static SharedConnectionBase::shared_ptr buildSharedConnection(OutputPort<T> *output_port, base::InputPortInterface *input_port, ConnPolicy const& policy)
        {
            // try to find an existing shared connection first
            SharedConnectionBase::shared_ptr shared_connection;

            // abort if an incompatible connection has been found or one of the ports is already connected to another shared connection
            if (findSharedConnection(output_port, input_port, policy, shared_connection) && !shared_connection) {
                return SharedConnectionBase::shared_ptr();
            }

            // for remote input ports, and if we can derive the type from the output port, build the shared buffer at the remote side and only generate a proxy here:
            if (input_port && !input_port->isLocal()) {
                if (!output_port) {
                    log(Error) << "Cannot create a shared connection for a remote input port or a non-standard transport without knowing the local output port." << endlog();
                    return SharedConnectionBase::shared_ptr();
                }

                // If no existing shared connection has been found, ask the remote side to build a shared channel output and create a local proxy.
                if (!shared_connection) {
                    base::ChannelElementBase::shared_ptr output_half = buildRemoteChannelOutput( *output_port, *input_port, policy);
                    if (!output_half) {
                        log(Error) << "Could not create a shared remote connection for input port '" << input_port->getName() << "'." << endlog();
                        return SharedConnectionBase::shared_ptr();
                    }

                    shared_connection = new SharedRemoteConnection<T>(policy);
                    shared_connection->connectTo(output_half, policy.mandatory);

                // ...or only ask the remote side to connect the additional input port to an existing remote shared connection
                } else {
//                    typename SharedRemoteConnection<T>::shared_ptr shared_remote_connection = boost::dynamic_pointer_cast<SharedRemoteConnection<T> >(shared_connection);

//                    if (!shared_remote_connection) {
//                        log(Error) << "Cannot create a shared connection for a remote input port because the local output port is already connected to a local shared connection." << endlog();
//                        return SharedConnectionBase::shared_ptr();
//                    }

//                    if (!input_port->createConnection(shared_remote_connection, policy)) {
                    if (!input_port->createConnection(shared_connection, policy)) {
                        log(Error) << "The remote side refused to connect the input port '" << input_port->getName() << "' to the existing shared connection '" << shared_connection->getName() << "'." << endlog();
                        return SharedConnectionBase::shared_ptr();
                    }
                }
            }

            // create a new shared connection instance
            if (!shared_connection) {
                RTT::OutputPort<T> *output_p = dynamic_cast<RTT::OutputPort<T> *>(output_port);
                typename base::ChannelElement<T>::shared_ptr buffer = buildDataStorage<T>(policy, (output_p ? output_p->getLastWrittenValue() : T()));
                if (!buffer) return SharedConnectionBase::shared_ptr();
                shared_connection.reset(new SharedConnection<T>(buffer.get(), policy));
            }

            return shared_connection;
        }

        template<typename T>
        static bool createConnection(OutputPort<T>& output_port, base::InputPortInterface& input_port, ConnPolicy const& policy)
        {
            if ( !output_port.isLocal() ) {
                log(Error) << "Need a local OutputPort to create connections." <<endlog();
                return false;
            }

            if (output_port.connectedTo(&input_port)) {
                log(Info) << "OutputPort " << output_port.getName() << " is already connected to " << input_port.getName() << ", ignoring new connection." << endlog();
                return true;
            }

            InputPort<T>* input_p = dynamic_cast<InputPort<T>*>(&input_port);

            // Shared push connection? => forward to createAndCheckSharedConnection()
            if (policy.buffer_policy == Shared) {
                return createAndCheckSharedConnection(&output_port, &input_port, buildSharedConnection<T>(&output_port, &input_port, policy), policy);
            }

            // This is the input and output channel element of the output half
            base::ChannelElementBase::shared_ptr output_half;
            if (input_port.isLocal() && policy.transport == 0)
            {
                // Local connection
                if (!input_p)
                {
                    log(Error) << "Port " << input_port.getName() << " is not compatible with " << output_port.getName() << endlog();
                    return false;
                }

                // local ports, create buffer here.
                output_half = buildChannelOutput<T>(*input_p, policy, output_port.getLastWrittenValue());
            }
            else
            {
                // if the input is not local, this is a pure remote connection,
                // if the input *is* local, the user requested to use a different transport
                // than plain memory, rare case, but we accept it. The unit tests use this for example
                // to test the OOB transports.
                if ( !input_port.isLocal() ) {
                    output_half = buildRemoteChannelOutput( output_port, input_port, policy);
                } else if (input_p) {
                    return createOutOfBandConnection<T>( output_port, *input_p, policy);
                } else {
                    log(Error) << "Port " << input_port.getName() << " is not compatible with " << output_port.getName() << endlog();
                    return false;
                }
            }

            if (!output_half)
                return false;

            // Since output is local, buildChannelInput is local as well.
            // This this the input channel element of the whole connection
            base::ChannelElementBase::shared_ptr channel_input;
            channel_input = buildChannelInput<T>(output_port, policy);

            if (!channel_input) {
                output_half->disconnect(true);
                return false;
            }

            // NOTE: channel_input and output_half are not yet connected!
            return createAndCheckConnection(output_port, input_port, channel_input, output_half, policy);
        }

        template<class T>
        static bool createStream(OutputPort<T>& output_port, ConnPolicy const& policy)
        {
            StreamConnID *sid = new StreamConnID(policy.name_id);
            // Stream channel inputs are always unbuffered (push). It's the transport that has to add a buffer element if required.
            RTT::base::ChannelElementBase::shared_ptr chan = buildChannelInput( output_port, policy, /* force_unbuffered = */ true );
            if (!chan) return false;
            return bool(createAndCheckStream(output_port, policy, chan, sid));
        }

        template<class T>
        static bool createStream(InputPort<T>& input_port, ConnPolicy const& policy)
        {
            StreamConnID *sid = new StreamConnID(policy.name_id);
            RTT::base::ChannelElementBase::shared_ptr outhalf = buildChannelOutput( input_port, policy );
            if (!outhalf) return false;
            return bool(createAndCheckStream(input_port, policy, outhalf, sid));
        }

        static bool createAndCheckSharedConnection(base::OutputPortInterface* output_port, base::InputPortInterface* input_port, SharedConnectionBase::shared_ptr shared_connection, ConnPolicy const& policy);

    protected:
        static bool createAndCheckConnection(base::OutputPortInterface& output_port, base::InputPortInterface& input_port, base::ChannelElementBase::shared_ptr channel_input, base::ChannelElementBase::shared_ptr channel_output, ConnPolicy const& policy);

        static base::ChannelElementBase::shared_ptr createAndCheckStream(base::OutputPortInterface& output_port, ConnPolicy const& policy, base::ChannelElementBase::shared_ptr channel_input, StreamConnID* conn_id);

        static base::ChannelElementBase::shared_ptr createAndCheckStream(base::InputPortInterface& input_port, ConnPolicy const& policy, base::ChannelElementBase::shared_ptr channel_output, StreamConnID* conn_id);

        static base::ChannelElementBase::shared_ptr buildRemoteChannelOutput(base::OutputPortInterface& output_port, base::InputPortInterface& input_port, ConnPolicy const& policy);

        template<class T>
        static bool createOutOfBandConnection(OutputPort<T>& output_port, InputPort<T>& input_port, ConnPolicy const& policy) {
            // constructs an out-of-band channel:
            // output_port -> channel_input -> stream_input -> (out-of-band transport of data) -> stream_output -> channel_output -> input_port
            //                                           |-- (direct connection for coordination) --^
            //

            // Stream channel inputs are always unbuffered (push). It's the transport that has to add a buffer element if required.
            RTT::base::ChannelElementBase::shared_ptr channel_input = buildChannelInput( output_port, policy, /* force_unbuffered = */ true );
            if (!channel_input) return false;

            RTT::base::ChannelElementBase::shared_ptr stream_input = createAndCheckStream(output_port, policy, channel_input, new StreamConnID(policy.name_id));
            if (!stream_input) return false;

            RTT::base::ChannelElementBase::shared_ptr channel_output = ConnFactory::buildChannelOutput<T>(input_port, policy, output_port.getLastWrittenValue());
            if (!channel_output) return false;

            RTT::base::ChannelElementBase::shared_ptr stream_output = createAndCheckStream(input_port, policy, channel_output, new StreamConnID(policy.name_id));
            if (!stream_output) return false;

            return stream_input->getOutputEndPoint()->connectTo(stream_output->getInputEndPoint(), policy.mandatory);
        }

    };

    typedef boost::shared_ptr<ConnFactory> ConnFactoryPtr;

}}

#endif