From d01bed9bd969a77b0a8092b1612ee8b225861c5b Mon Sep 17 00:00:00 2001
From: narspt <narspt@users.noreply.github.com>
Date: Wed, 14 Apr 2021 00:59:43 +0100
Subject: [PATCH 1/2] Update cdextraprotocol.h

---
 src/cdextraprotocol.h | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/cdextraprotocol.h b/src/cdextraprotocol.h
index 3c623fc..8ebc81c 100644
--- a/src/cdextraprotocol.h
+++ b/src/cdextraprotocol.h
@@ -55,6 +55,15 @@
 ////////////////////////////////////////////////////////////////////////////////////////
 // class
 
+class CDextraStreamCacheItem
+{
+public:
+    CDextraStreamCacheItem()     {}
+    ~CDextraStreamCacheItem()    {}
+    
+    CDvHeaderPacket m_dvHeader;
+};
+
 class CDextraProtocol : public CProtocol
 {
 public:
@@ -101,6 +110,9 @@ protected:
 protected:
     // time
     CTimePoint          m_LastKeepaliveTime;
+    
+    // for queue header caches
+    std::array<CDextraStreamCacheItem, NB_OF_MODULES>    m_StreamsCache;
 };
 
 ////////////////////////////////////////////////////////////////////////////////////////

From e6a5c7aed110a1605abef216393cb54c2a1e2119 Mon Sep 17 00:00:00 2001
From: narspt <narspt@users.noreply.github.com>
Date: Wed, 14 Apr 2021 01:55:26 +0100
Subject: [PATCH 2/2] Update cdextraprotocol.cpp

---
 src/cdextraprotocol.cpp | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/src/cdextraprotocol.cpp b/src/cdextraprotocol.cpp
index 8aa88ab..4b05e57 100644
--- a/src/cdextraprotocol.cpp
+++ b/src/cdextraprotocol.cpp
@@ -118,6 +118,27 @@ void CDextraProtocol::Task(void)
                     // acknowledge the request
                     EncodeConnectAckPacket(&Buffer, ProtRev);
                     m_Socket.Send(Buffer, Ip);
+
+                    // check if any client currently streaming on the module
+                    CClients *clients = g_Reflector.GetClients();
+                    for ( int i = 0; i < clients->GetSize(); i++ )
+                    {
+                        if ( clients->GetClient(i)->IsAMaster() && (clients->GetClient(i)->GetReflectorModule() == ToLinkModule) )
+                        {
+                            // found a client streaming on the module, encode a copy of the cached header packet
+                            CBuffer buffer2;
+                            if ( EncodeDvPacket(m_StreamsCache[g_Reflector.GetModuleIndex(ToLinkModule)].m_dvHeader, &buffer2) )
+                            {
+                                // and send it to the connecting client, so it can listen the already streaming client
+                                for ( int j = 0; j < 5; j++ )
+                                {
+                                    m_Socket.Send(buffer2, Ip);
+                                }
+                            }
+                            break; // done, stop here
+                        }
+                    }
+                    g_Reflector.ReleaseClients();
                     
                     // create the client
                     CDextraClient *client = new CDextraClient(Callsign, Ip, ToLinkModule, ProtRev);
@@ -216,6 +237,16 @@ void CDextraProtocol::HandleQueue(void)
         CPacket *packet = m_Queue.front();
         m_Queue.pop();
         
+        // get our sender's id
+        int iModId = g_Reflector.GetModuleIndex(packet->GetModuleId());
+        
+        // check if it's header and update cache
+        if ( packet->IsDvHeader() )
+        {
+            // this relies on queue feeder setting valid module id
+            m_StreamsCache[iModId].m_dvHeader = CDvHeaderPacket((const CDvHeaderPacket &)*packet);
+        }
+
         // encode it
         CBuffer buffer;
         if ( EncodeDvPacket(*packet, &buffer) )