JackRequest: Make ReadType method static

Therefore no object of the class has to be created to detect the type only.
In addition the member variable fType can be const.

Change-Id: Ib9c484964a93d4f25ca0a354d6852c03a7b33896
Signed-off-by: Timo Wischer <twischer@de.adit-jv.com>

common/JackRequest.h

@@ -105,9 +105,11 @@ struct JackRequest
     virtual ~JackRequest()
     {}
 
-    virtual int Read(detail::JackChannelTransactionInterface* trans)
+    static int ReadType(detail::JackChannelTransactionInterface* trans, RequestType& type)
     {
-        return trans->Read(&fType, sizeof(RequestType));
+        type = (RequestType)0;
+        CheckRes(trans->Read(&type, sizeof(fType)));
+        return 0;
     }
 
     virtual int Write(detail::JackChannelTransactionInterface* trans) { return -1; }

common/JackRequestDecoder.cpp

@@ -58,9 +58,9 @@ int JackRequestDecoder::HandleRequest(detail::JackChannelTransactionInterface* s
             CheckWriteName("JackRequest::ClientCheck", socket);
             // Atomic ClientCheck followed by ClientOpen on same socket
             if (req.fOpen) {
-                JackRequest header;
-                header.Read(socket);
-                return HandleRequest(socket, header.fType);
+                JackRequest::RequestType type;
+                JackRequest::ReadType(socket, type);
+                return HandleRequest(socket, type);
             }
             break;
         }

posix/JackSocketServerChannel.cpp

@@ -235,14 +235,14 @@ bool JackSocketServerChannel::Execute()
                 } else if (fPollTable[i].revents & POLLIN) {
                     JackClientSocket* socket = fSocketTable[fd].second;
                     // Decode header
-                    JackRequest header;
-                    if (header.Read(socket) < 0) {
+                    JackRequest::RequestType type;
+                    if (JackRequest::ReadType(socket, type) < 0) {
                         jack_log("JackSocketServerChannel::Execute : cannot decode header");
                         ClientKill(fd);
                     // Decode request
                     } else {
                         // Result is not needed here
-                        fDecoder->HandleRequest(socket, header.fType);
+                        fDecoder->HandleRequest(socket, type);
                     }
                 }
             }

windows/JackWinNamedPipeServerChannel.cpp

@@ -83,8 +83,8 @@ bool JackClientPipeThread::Execute()
     try {
 
         jack_log("JackClientPipeThread::Execute %x", this);
-        JackRequest header;
-        int res = header.Read(fPipe);
+        JackRequest::RequestType type;
+        int res = JackRequest::ReadType(fPipe, type);
         bool ret = true;
 
         // Lock the global mutex
@@ -98,7 +98,7 @@ bool JackClientPipeThread::Execute()
             ClientKill();
             ret = false;
         // Decode request
-        } else if (fDecoder->HandleRequest(fPipe, header.fType) < 0) {
+        } else if (fDecoder->HandleRequest(fPipe, type) < 0) {
             ret = false;
         }