SocketFeedEngine.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 <OnixS/CME/MDH/Watch.h>
#include <OnixS/CME/MDH/PacketTraits.h>
#include <OnixS/CME/MDH/FeedEngine.h>

ONIXS_CMEMDH_NAMESPACE_BEGIN

/// Represents a collection of settings affecting
/// the behavior of the multi-threaded feed engine
/// while working with network-related services.
class ONIXS_CMEMDH_LTWT SocketFeedEngineSettings
{
public:
    /// Initializes the given instance of the
    /// network settings with the default values.
    SocketFeedEngineSettings()
        : packetMaxSize_(1420)
        , watch_(&UtcWatch::service())
        , socketBufferSize_(8 * 1024 * 1024)
        , dataWaitTime_(10)
    {
    }

    /// Cleans everything up.
    ~SocketFeedEngineSettings() {}

    /// Max size for network packet transmitted by MDP.
    ///
    /// @note Default value is '1420'.
    PacketSize packetMaxSize() const
    {
        return packetMaxSize_;
    }

    /// Max size for network packet transmitted by MDP.
    void packetMaxSize(PacketSize value)
    {
        packetMaxSize_ = value;
    }

    /// Watch service to be used by Feed Engine.
    ///
    /// Watch is used by Feed Engine to assign time
    /// points to packets received from the feeds.
    ///
    /// @note By default, UTC watch service is used.
    WatchService& watch() const
    {
        return *watch_;
    }

    /// Watch service to be used by Feed Engine.
    ///
    /// If no instance associated, UTC watch is used.
    void watch(WatchService& watch)
    {
        watch_ = &watch;
    }

    /// Defines size of receiving buffer in bytes for sockets.
    ///
    /// @note Default value is 8 MiB.
    UInt32 socketBufferSize() const
    {
        return socketBufferSize_;
    }

    /// Sets socketBufferSize. @see socketBufferSize.
    void socketBufferSize(UInt32 value)
    {
        socketBufferSize_ = value;
    }

    /// Defines amount of time Feed Engine spends on socket
    /// waiting for I/O while running master processing loop.
    ///
    /// Time is measured in milliseconds.
    ///
    /// @note Default value is '10'.
    ///
    /// @warning The given parameter significantly affects
    /// responsiveness of the Handler and load onto CPU.
    UInt32 dataWaitTime() const
    {
        return dataWaitTime_;
    }

    /// Sets dataWaitTime. @see dataWaitTime.
    void dataWaitTime(UInt32 value)
    {
        dataWaitTime_ = value;
    }

private:
    PacketSize packetMaxSize_;
    WatchService* watch_;

    UInt32 socketBufferSize_;
    UInt32 dataWaitTime_;
};

/// Serializes feed engine settings into a string.
ONIXS_CMEMDH_EXPORTED
void toStr(std::string&, const SocketFeedEngineSettings&);

/// Serializes feed engine settings into a string.
inline std::string toStr(const SocketFeedEngineSettings& settings)
{
    std::string str;

    toStr(str, settings);

    return str;
}

/// The given class implements feed engine concept
/// using pool of working threads and standard socket
/// API.
class ONIXS_CMEMDH_EXPORTED SocketFeedEngine : public NetFeedEngine
{
public:
    /// Initializes the engine according to the given configuration.
    SocketFeedEngine(const SocketFeedEngineSettings&);

    /// Initializes the engine with the default settings
    SocketFeedEngine();

    /// Destructs the given instance.
    ~SocketFeedEngine() ONIXS_CMEMDH_OVERRIDE;

    /// Appends information on the given
    /// implementation to the given string.
    void info(std::string&) ONIXS_CMEMDH_OVERRIDE;

    /// Allocates a link for the given feed.
    NetFeedLink& allocate(const NetFeed&) ONIXS_CMEMDH_OVERRIDE;

    /// Exposes an instance of the watch service
    /// used while manipulating the feed links.
    WatchService& watch() ONIXS_CMEMDH_OVERRIDE;

    /// Carries out pending actions like
    /// data retrieval and event dispatching.
    ///
    /// The returned value indicates whether any
    /// events have been handled by the engine.
    NetFeedEngineProcessResult process() ONIXS_CMEMDH_OVERRIDE;

private:
    // The workhorse for the multi-threaded
    // feed engine based on the standard socket
    // API and a pool of threads.
    class Workhorse;

    Workhorse* workhorse_;
};

ONIXS_CMEMDH_NAMESPACE_END