i2pd/core/NetDbRequests.cpp

#include "util/Log.h"
#include "I2NPProtocol.h"
#include "transport/Transports.h"
#include "NetworkDatabase.h"
#include "NetDbRequests.h"

namespace i2p
{
namespace data
{
    std::shared_ptr<I2NPMessage> RequestedDestination::CreateRequestMessage (std::shared_ptr<const RouterInfo> router,
        std::shared_ptr<const i2p::tunnel::InboundTunnel> replyTunnel)
    {
        auto msg = i2p::CreateRouterInfoDatabaseLookupMsg (m_Destination, 
            replyTunnel->GetNextIdentHash (), replyTunnel->GetNextTunnelID (), m_IsExploratory, 
            &m_ExcludedPeers);
        m_ExcludedPeers.insert (router->GetIdentHash ());
        m_CreationTime = i2p::util::GetSecondsSinceEpoch ();
        return msg;
    }   

    std::shared_ptr<I2NPMessage> RequestedDestination::CreateRequestMessage (const IdentHash& floodfill)
    {
        auto msg = i2p::CreateRouterInfoDatabaseLookupMsg (m_Destination, 
            i2p::context.GetRouterInfo ().GetIdentHash () , 0, false, &m_ExcludedPeers);
        m_ExcludedPeers.insert (floodfill);
        m_CreationTime = i2p::util::GetSecondsSinceEpoch ();
        return msg;
    }   

    void RequestedDestination::ClearExcludedPeers ()
    {
        m_ExcludedPeers.clear ();
    }   
    
    void RequestedDestination::Success (std::shared_ptr<RouterInfo> r)
    {
        if (m_RequestComplete)
        {
            m_RequestComplete (r);
            m_RequestComplete = nullptr;
        }
    }

    void RequestedDestination::Fail ()
    {
        if (m_RequestComplete)
        {
            m_RequestComplete (nullptr);
            m_RequestComplete = nullptr;
        }
    }

    void NetDbRequests::Start ()
    {
    }

    void NetDbRequests::Stop ()
    {
        m_RequestedDestinations.clear ();
    }


    std::shared_ptr<RequestedDestination> NetDbRequests::CreateRequest (const IdentHash& destination, bool isExploratory, RequestedDestination::RequestComplete requestComplete)
    {
        // request RouterInfo directly
        auto dest = std::make_shared<RequestedDestination> (destination, isExploratory); 
        dest->SetRequestComplete (requestComplete);
        {
            std::unique_lock<std::mutex> l(m_RequestedDestinationsMutex);
            if (!m_RequestedDestinations.insert (std::make_pair (destination, 
                std::shared_ptr<RequestedDestination> (dest))).second) // not inserted
                return nullptr; 
        }
        return dest;
    }   

    void NetDbRequests::RequestComplete (const IdentHash& ident, std::shared_ptr<RouterInfo> r)
    {
        auto it = m_RequestedDestinations.find (ident);
        if (it != m_RequestedDestinations.end ())
        {   
            if (r)
                it->second->Success (r);
            else
                it->second->Fail ();
            std::unique_lock<std::mutex> l(m_RequestedDestinationsMutex);
            m_RequestedDestinations.erase (it);
        }   
    }

    std::shared_ptr<RequestedDestination> NetDbRequests::FindRequest (const IdentHash& ident) const
    {
        auto it = m_RequestedDestinations.find (ident);
        if (it != m_RequestedDestinations.end ())
            return it->second;
        return nullptr;
    }   

    void NetDbRequests::ManageRequests ()
    {
        uint64_t ts = i2p::util::GetSecondsSinceEpoch ();   
        std::unique_lock<std::mutex> l(m_RequestedDestinationsMutex);   
        for (auto it = m_RequestedDestinations.begin (); it != m_RequestedDestinations.end ();)
        {
            auto& dest = it->second;
            bool done = false;
            if (ts < dest->GetCreationTime () + 60) // request is worthless after 1 minute
            {
                if (ts > dest->GetCreationTime () + 5) // no response for 5 seconds
                {
                    auto count = dest->GetExcludedPeers ().size ();
                    if (!dest->IsExploratory () && count < 7)
                    {
                        auto pool = i2p::tunnel::tunnels.GetExploratoryPool ();
                        auto outbound = pool->GetNextOutboundTunnel ();
                        auto inbound = pool->GetNextInboundTunnel ();   
                        auto nextFloodfill = netdb.GetClosestFloodfill (dest->GetDestination (), dest->GetExcludedPeers ());
                        if (nextFloodfill && outbound && inbound)
                            outbound->SendTunnelDataMsg (nextFloodfill->GetIdentHash (), 0,
                                dest->CreateRequestMessage (nextFloodfill, inbound));
                        else
                        {
                            done = true;
                            if (!inbound) LogPrint (eLogWarning, "No inbound tunnels"); 
                            if (!outbound) LogPrint (eLogWarning, "No outbound tunnels");
                            if (!nextFloodfill) LogPrint (eLogWarning, "No more floodfills");   
                        }
                    }   
                    else
                    {
                        if (!dest->IsExploratory ())
                            LogPrint (eLogWarning, dest->GetDestination ().ToBase64 (), " not found after 7 attempts"); 
                        done = true;
                    }    
                }   
            }   
            else // delete obsolete request
                done = true;

            if (done)
                it = m_RequestedDestinations.erase (it);
            else
                it++;
        }   
    }
}
}