Feed.h

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// Copyright Onix Solutions Limited [OnixS]. All rights reserved.
//
// This software owned by Onix Solutions Limited [OnixS] and is 
// protected by copyright law and international copyright treaties.
//
// Access to and use of the software is governed by the terms of the applicable 
// OnixS Software Services Agreement (the Agreement) and Customer end user license 
// agreements granting a non-assignable, non-transferable and non-exclusive license 
// to use the software for it's own data processing purposes under the terms defined 
// in the Agreement.
//
// Except as otherwise granted within the terms of the Agreement, copying or 
// reproduction of any part of this source code or associated reference material 
// to any other location for further reproduction or redistribution, and any 
// amendments to this copyright notice, are expressly prohibited.
//
// Any reproduction or redistribution for sale or hiring of the Software not in 
// accordance with the terms of the Agreement is a violation of copyright law.
//

#pragma once

#include <cassert>
#include <string>

#include <OnixS/CME/ConflatedUDP/Atomic.h>
#include <OnixS/CME/ConflatedUDP/Time.h>

#include <OnixS/CME/ConflatedUDP/FeedAttributes.h>
#include <OnixS/CME/ConflatedUDP/FeedConnection.h>

#include <OnixS/CME/ConflatedUDP/FeedLink.h>

ONIXS_CONFLATEDUDP_NAMESPACE_BEGIN

ONIXS_CONFLATEDUDP_EXPORTED_STRUCT_DECL
(
    NetFeedListener
);

ONIXS_CONFLATEDUDP_EXPORTED_CLASS_DECL
(
    NetFeedConsumer
);

/// Defines possible states for the feeds. 
ONIXS_CONFLATEDUDP_LTWT_STRUCT NetFeedState
{
    /// Defines possible states for the feeds. 
    enum Enum 
    { 
        Disconnected,
        Disconnecting,
        Connected,
        Connecting
    };
};

/// Base attributes of market data feed.
ONIXS_CONFLATEDUDP_LTWT_CLASS NetFeed
{
    typedef 
    Atomic<NetFeedState::Enum> 
    AtomicState;

    mutable volatile NetFeedState::Enum state_;

    NetFeedConsumer* consumer_;
    NetFeedListener* listener_;

    NetFeedLink* link_;

    TimeSpan receiveTimeout_;
    TimeSpan expirationTime_;

    NetFeedConnection connection_;

    NetFeedType::Enum type_;
    NetFeedRole::Enum role_;
    
    NetFeedId id_;

    NetFeed(
        const NetFeed&);
    
    NetFeed& 
    operator =(
        const NetFeed&);

public:
    /// Initializes the instance. 
    NetFeed()
        : state_(
            NetFeedState::Disconnected)
        , consumer_(NULL)
        , listener_(NULL)
        , link_(NULL)
    {
    }

    ~NetFeed()
    {
        assert(
            state() == 
            NetFeedState::Disconnected);

        if (link_) 
            link_->release(*this);
    }

    /// Identifier associated with feed. 
    const NetFeedId& id() const
    {
        return id_;
    }

    /// Assigns identifier. 
    void 
    id(
        const NetFeedId& id)
    {
        id_ = id;
    }

    /// Type of service (incremental, instrument, etc). 
    NetFeedType::Enum type() const
    {
        return type_;
    }

    /// Assigns feed service type. 
    void 
    type(
        NetFeedType::Enum type)
    {
        type_ = type;
    }

    /// Role in a service (primary, secondary). 
    NetFeedRole::Enum role() const
    {
        return role_;
    }

    /// Assigns feed service role. 
    void 
    role(
        NetFeedRole::Enum role)
    {
        role_ = role;
    }

    /// Connection attributes (overload for modifications). 
    NetFeedConnection& connection()
    {
        return connection_;
    }

    /// Connection attributes (read-only access). 
    const 
    NetFeedConnection& 
    connection() const
    {
        return connection_;
    }

    /// Life time for the feed. 
    ///
    /// If defined, the given time defines time period 
    /// during which the feed may receive the incoming 
    /// data and deliver it to the associate consumer. 
    /// After that, the feed stop receiving the data 
    /// while staying in the connected state. 
    const 
    TimeSpan& 
    expirationTime() const
    {
        return expirationTime_;
    }

    /// Defines life time for the feed in seconds. 
    ///
    /// The given attribute defines time period during 
    /// which the feed may receive the incoming data and 
    /// deliver it to the associate consumer. After that, 
    /// the feed stop receiving the data while staying 
    /// in the connected state. 
    void
    expirationTime(
        UInt32 expirationTime)
    {
        expirationTime_ = 
            TimeSpan(
                0, 
                0, 
                expirationTime, 
                0);
    }

    /// Maximal time interval between two packets transmitted. 
    const 
    TimeSpan& 
    receiveTimeout() const
    {
        return receiveTimeout_;
    }

    /// Updates time interval between two packets transmitted. 
    void
    receiveTimeout(
        UInt32 timeInterval)
    {
        receiveTimeout_ =
            TimeSpan(
                0,
                0, 
                timeInterval,
                0);
    }

    /// Indicates current state. 
    NetFeedState::Enum state() const
    {
        return AtomicState::read(state_);
    }

    /// Binds the given listener to the feed. 
    void 
    listener(
        NetFeedListener& listener)
    {
        assert(
            state() == 
            NetFeedState::Disconnected);

        listener_ = &listener;
    }

    /// An instance of data consumer associated 
    /// with the given feed if available. 
    NetFeedConsumer*
    consumer() const 
    {
        return consumer_;
    }

    /// Binds the given consumer to the feed. 
    void 
    consumer(
        NetFeedConsumer& consumer)
    {
        assert(
            state() == 
            NetFeedState::Disconnected);

        assert(NULL == link_);

        consumer_ = &consumer;
    }

    /// Associates the given link with the feed. 
    void 
    link(
        NetFeedLink& link)
    {
        assert(
            state() == 
            NetFeedState::Disconnected);

        NetFeedLink* old = link_;

        link_ = &link;

        if (old)
            old->release(*this);
    }

    /// Bring the given instance to the connected state. 
    ///
    /// Feed must be fully configured and a valid instance 
    /// of the NetFeedLink bound to the feed. Otherwise, an 
    /// exception will be thrown. 
    /// 
    /// Returns 'true' if the feed was connected. 
    /// 'False' is returned if the feed wasn't in the 
    /// disconnected state at the moment of invocation. 
    ONIXS_CONFLATEDUDP_LTWT_EXPORTED
    bool 
    connect(
        UInt32);

    /// Instructs the feed to stop delivering 
    /// packets to the associated consumer. 
    ///
    /// Returns 'true' if the feed was disconnected. 
    /// 'False' is returned if the feed wasn't previously 
    /// connected of was in the process of disconnecting. 
    ONIXS_CONFLATEDUDP_LTWT_EXPORTED
    bool 
    disconnect();

    /// Send the given message to the source from which the feed 
    /// receives data and delivers to the associated consumer. 
    ///
    /// @throw the exception if the operation is not supported or 
    /// the given message can't be delivered to the destination. 
    void  
    sendMessage(
        const void* message, 
        size_t length, 
        UInt32 timeout)
    {
        assert(NULL != link_);

        link_->send
        (
            *this, 
            message, 
            length,
            timeout
        );
    }
};

ONIXS_CONFLATEDUDP_NAMESPACE_END