WebRequestServiceBackendImpl.h

// Copyright eeGeo Ltd (2012-2014), All Rights Reserved

#pragma once

#include "Types.h"
#include "Web.h"
#include "Tasks.h"
#include "Helpers.h"
#include "Web.h"
#include "BidirectionalWebIOBus.h"
#include "WebMessages.h"
#include "WebIOConfig.h"

#include <curl.h>
#include <uv.h>

#include <string>
#include <deque>
#include <list>
#include <vector>

namespace Eegeo
{
    namespace Web
    {
        // we use this to marry up a curl socket & a uv poll handle
        struct AppCurlContext
        {
            // uv_poll_t must be the first field; do not re-order or it'll break everything!
            uv_poll_t pollHandle;
            curl_socket_t sockfd;
            void* data; // expect this to be an instance of WebRequestServiceBackendImpl
        };

        // pimpl class to avoid pulling in various headers & causing include chaos
        class WebRequestServiceBackendImpl : public Eegeo::NonCopyable
        {
        public:
            WebRequestServiceBackendImpl(const WebIOConfig& config, Eegeo::Web::TMessageBus& webMessageBus);

            ~WebRequestServiceBackendImpl();

            bool Update();
        private:
            void StartWebRequest(InFlightWebRequest* request, Eegeo::Web::WebRequestHandle* requestHandle);
            void IssueWebLoadRequests();
            void SendResponse(InFlightWebRequest& completedWebRequest);
            void SendFallBackToCacheMessage(const TWebRequestId requestId);
            void CheckMultiInfo();

            void ResetHandle(WebRequestHandle* pWebRequestHandle);

            void OnWebPauseMessage(const Eegeo::Web::WebPauseMessage& message);
            void OnWebResumeMessage(const Eegeo::Web::WebResumeMessage& message);
            void OnWebRequestLoadMessage(const Eegeo::Web::WebRequestLoadMessage& message);
            void OnWebRequestCancelMessage(const Eegeo::Web::WebRequestCancelMessage& message);
            void OnWebStopWorkMessage(const Eegeo::Web::WebStopWorkMessage& message);

            // libcurl callbacks
            static int CurlSocketCallbackWrapper(CURL* easy, curl_socket_t s, int action, void* userp, void* socketp);
            int CurlSocketCallBack(CURL* easy, curl_socket_t s, int action, void* socketp);

            static int CurlTimeoutCallbackWrapper(CURLM* multi, long timeout_ms, void* userp);
            int CurlTimeoutCallback(CURLM* multi, long timeout_ms);

            // libuv callbacks
            // (static) callback that is invoked by libuv when changes are detected on a socket it is monitoring.
            static void UVCallbackPollWrapper(uv_poll_t* req, int status, int events);
            void UVCallbackPoll(AppCurlContext* pAppCurlContext, int status, int events);

            // (static) callback invoked by libuv when a timeout occurs
            static void UVCallbackTimeoutWrapper(uv_timer_t* handle);
            void UVCallbackTimeout(uv_timer_t* handle);

            const WebIOConfig m_config;
            int m_threadSleepDurationMilliseconds;
            Eegeo::Web::TMessageBus& m_webMessageBus;

            CURLM * m_curlMultiHandle;
            WebRequestHandlePool* m_pWebLoadHandlePool;
            std::vector<WebRequestHandle*> m_inFlightWebRequestHandles;
            std::list<InFlightWebRequest*> m_pendingWebRequests;

            int m_stillRunning;
            bool m_webLoadPoolExhaustedLastFrame;

            uv_timer_t m_uvTimer;
            uv_loop_t* m_pUvLoop;

            Eegeo::Helpers::TCallback1<WebRequestServiceBackendImpl, const WebPauseMessage&> m_webPauseMessageHandler;
            Eegeo::Helpers::TCallback1<WebRequestServiceBackendImpl, const WebResumeMessage&> m_webResumeMessageHandler;
            Eegeo::Helpers::TCallback1<WebRequestServiceBackendImpl, const WebRequestLoadMessage&> m_webRequestLoadMessageHandler;
            Eegeo::Helpers::TCallback1<WebRequestServiceBackendImpl, const WebRequestCancelMessage&> m_webRequestCancelMessageHandler;
            Eegeo::Helpers::TCallback1<WebRequestServiceBackendImpl, const WebStopWorkMessage&> m_webRequestStopWorkMessageHandler;

            bool m_continueRunning;
        };
    }
}