MP cleanup

Expand the message union to provide member functions that return pointers into
the message buffer.

diff --git a/src/MultiPlayer/multiplaymgr.cxx b/src/MultiPlayer/multiplaymgr.cxx
index ee44918ebc473a854d73cfd625b2e48eb5ce137a..855969238e148d1b30777e3ab1defe7b291e3060 100644 (file)
--- a/src/MultiPlayer/multiplaymgr.cxx
+++ b/src/MultiPlayer/multiplaymgr.cxx
@@ -33,6 +33,7 @@
 
 #include <iostream>
 #include <algorithm>
+#include <cstring>
 #include <osg/Math>             // isNaN
 #include <plib/netSocket.h>
 
@@ -46,7 +47,7 @@
 #include "multiplaymgr.hxx"
 #include "mpmessages.hxx"
 
-using std::cerr;
+using namespace std;
 
 #define MAX_PACKET_SIZE 1200
 #define MAX_TEXT_SIZE 128
@@ -447,6 +448,78 @@ FGMultiplayMgr::Close (void)
 //  Description: Sends the position data for the local position.
 //
 //////////////////////////////////////////////////////////////////////
+
+/**
+ * The buffer that holds a multi-player message, suitably aligned.
+ */
+union FGMultiplayMgr::MsgBuf
+{
+    MsgBuf()
+    {
+        memset(&Msg, 0, sizeof(Msg));
+    }
+
+    T_MsgHdr* msgHdr()
+    {
+        return reinterpret_cast<T_MsgHdr*>(Msg);
+    }
+
+    const T_MsgHdr* msgHdr() const
+    {
+        return reinterpret_cast<const T_MsgHdr*>(Msg);
+    }
+
+    T_PositionMsg* posMsg()
+    {
+        return reinterpret_cast<T_PositionMsg*>(Msg + sizeof(T_MsgHdr));
+    }
+
+    const T_PositionMsg* posMsg() const
+    {
+        return reinterpret_cast<const T_PositionMsg*>(Msg + sizeof(T_MsgHdr));
+    }
+
+    xdr_data_t* properties()
+    {
+        return reinterpret_cast<xdr_data_t*>(Msg + sizeof(T_MsgHdr)
+                                             + sizeof(T_PositionMsg));
+    }
+
+    const xdr_data_t* properties() const
+    {
+        return reinterpret_cast<const xdr_data_t*>(Msg + sizeof(T_MsgHdr)
+                                                   + sizeof(T_PositionMsg));
+    }
+    /**
+     * The end of the properties buffer.
+     */
+    xdr_data_t* propsEnd()
+    {
+        return reinterpret_cast<xdr_data_t*>(Msg + MAX_PACKET_SIZE);
+    };
+
+    const xdr_data_t* propsEnd() const
+    {
+        return reinterpret_cast<const xdr_data_t*>(Msg + MAX_PACKET_SIZE);
+    };
+    /**
+     * The end of properties actually in the buffer. This assumes that
+     * the message header is valid.
+     */
+    xdr_data_t* propsRecvdEnd()
+    {
+        return reinterpret_cast<xdr_data_t*>(Msg + msgHdr()->MsgLen);
+    }
+
+    const xdr_data_t* propsRecvdEnd() const
+    {
+        return reinterpret_cast<const xdr_data_t*>(Msg + msgHdr()->MsgLen);
+    }
+    
+    xdr_data2_t double_val;
+    char Msg[MAX_PACKET_SIZE];
+};
+
 void
 FGMultiplayMgr::SendMyPosition(const FGExternalMotionData& motionInfo)
 {
@@ -457,42 +530,34 @@ FGMultiplayMgr::SendMyPosition(const FGExternalMotionData& motionInfo)
     return;
   }
 
-  T_PositionMsg PosMsg;
+  MsgBuf msgBuf;
+  T_PositionMsg* PosMsg = msgBuf.posMsg();
 
-  memset(&PosMsg, 0, sizeof(PosMsg));
-  strncpy(PosMsg.Model, fgGetString("/sim/model/path"), MAX_MODEL_NAME_LEN);
-  PosMsg.Model[MAX_MODEL_NAME_LEN - 1] = '\0';
+  strncpy(PosMsg->Model, fgGetString("/sim/model/path"), MAX_MODEL_NAME_LEN);
+  PosMsg->Model[MAX_MODEL_NAME_LEN - 1] = '\0';
   
-  PosMsg.time = XDR_encode_double (motionInfo.time);
-  PosMsg.lag = XDR_encode_double (motionInfo.lag);
+  PosMsg->time = XDR_encode_double (motionInfo.time);
+  PosMsg->lag = XDR_encode_double (motionInfo.lag);
   for (unsigned i = 0 ; i < 3; ++i)
-    PosMsg.position[i] = XDR_encode_double (motionInfo.position(i));
+    PosMsg->position[i] = XDR_encode_double (motionInfo.position(i));
   SGVec3f angleAxis;
   motionInfo.orientation.getAngleAxis(angleAxis);
   for (unsigned i = 0 ; i < 3; ++i)
-    PosMsg.orientation[i] = XDR_encode_float (angleAxis(i));
+    PosMsg->orientation[i] = XDR_encode_float (angleAxis(i));
   for (unsigned i = 0 ; i < 3; ++i)
-    PosMsg.linearVel[i] = XDR_encode_float (motionInfo.linearVel(i));
+    PosMsg->linearVel[i] = XDR_encode_float (motionInfo.linearVel(i));
   for (unsigned i = 0 ; i < 3; ++i)
-    PosMsg.angularVel[i] = XDR_encode_float (motionInfo.angularVel(i));
+    PosMsg->angularVel[i] = XDR_encode_float (motionInfo.angularVel(i));
   for (unsigned i = 0 ; i < 3; ++i)
-    PosMsg.linearAccel[i] = XDR_encode_float (motionInfo.linearAccel(i));
+    PosMsg->linearAccel[i] = XDR_encode_float (motionInfo.linearAccel(i));
   for (unsigned i = 0 ; i < 3; ++i)
-    PosMsg.angularAccel[i] = XDR_encode_float (motionInfo.angularAccel(i));
-  // ensure alignment of message buffer
-  union {
-    xdr_data2_t double_val;
-    char Msg[MAX_PACKET_SIZE];
-  } msgBuf;
-  memcpy(msgBuf.Msg + sizeof(T_MsgHdr), &PosMsg, sizeof(T_PositionMsg));
+    PosMsg->angularAccel[i] = XDR_encode_float (motionInfo.angularAccel(i));
   
-  xdr_data_t* ptr = reinterpret_cast<xdr_data_t*>(msgBuf.Msg + sizeof(T_MsgHdr)
-                                                  + sizeof(T_PositionMsg));
+  xdr_data_t* ptr = msgBuf.properties();
   std::vector<FGPropertyData*>::const_iterator it;
   it = motionInfo.properties.begin();
   //cout << "OUTPUT PROPERTIES\n";
-  xdr_data_t* msgEnd = reinterpret_cast<xdr_data_t*>(msgBuf.Msg
-                                                     + MAX_PACKET_SIZE);
+  xdr_data_t* msgEnd = msgBuf.propsEnd();
   while (it != motionInfo.properties.end() && ptr + 2 < msgEnd) {
     
     // First element is the ID. Write it out when we know we have room for
@@ -583,15 +648,12 @@ FGMultiplayMgr::SendMyPosition(const FGExternalMotionData& motionInfo)
     ++it;
   }
 escape:
-  
-  T_MsgHdr MsgHdr;
   unsigned msgLen = reinterpret_cast<char*>(ptr) - msgBuf.Msg;
-  FillMsgHdr(&MsgHdr, POS_DATA_ID, msgLen);
-  memcpy(msgBuf.Msg, &MsgHdr, sizeof(T_MsgHdr));
-
+  FillMsgHdr(msgBuf.msgHdr(), POS_DATA_ID, msgLen);
   mSocket->sendto(msgBuf.Msg, msgLen, 0, &mServer);
   SG_LOG(SG_NETWORK, SG_DEBUG, "FGMultiplayMgr::SendMyPosition");
 } // FGMultiplayMgr::SendMyPosition()
+
 //////////////////////////////////////////////////////////////////////
 
 //////////////////////////////////////////////////////////////////////
@@ -657,11 +719,7 @@ FGMultiplayMgr::Update(void)
   //////////////////////////////////////////////////
   int bytes;
   do {
-    // ensure alignment
-    union {
-      xdr_data2_t doubleVal;
-      char Msg[MAX_PACKET_SIZE];
-    } msgBuf;
+    MsgBuf msgBuf;
     //////////////////////////////////////////////////
     //  Although the recv call asks for 
     //  MAX_PACKET_SIZE of data, the number of bytes
@@ -687,7 +745,7 @@ FGMultiplayMgr::Update(void)
     //////////////////////////////////////////////////
     //  Read header
     //////////////////////////////////////////////////
-    T_MsgHdr* MsgHdr = reinterpret_cast<T_MsgHdr *>(msgBuf.Msg);
+    T_MsgHdr* MsgHdr = msgBuf.msgHdr();
     MsgHdr->Magic       = XDR_decode_uint32 (MsgHdr->Magic);
     MsgHdr->Version     = XDR_decode_uint32 (MsgHdr->Version);
     MsgHdr->MsgId       = XDR_decode_uint32 (MsgHdr->MsgId);
@@ -714,10 +772,10 @@ FGMultiplayMgr::Update(void)
     //////////////////////////////////////////////////
     switch (MsgHdr->MsgId) {
     case CHAT_MSG_ID:
-      ProcessChatMsg(msgBuf.Msg, SenderAddress);
+      ProcessChatMsg(msgBuf, SenderAddress);
       break;
     case POS_DATA_ID:
-      ProcessPosMsg(msgBuf.Msg, SenderAddress, bytes, stamp);
+      ProcessPosMsg(msgBuf, SenderAddress, stamp);
       break;
     case UNUSABLE_POS_DATA_ID:
     case OLD_OLD_POS_DATA_ID:
@@ -751,17 +809,16 @@ FGMultiplayMgr::Update(void)
 //
 //////////////////////////////////////////////////////////////////////
 void
-FGMultiplayMgr::ProcessPosMsg(const char *Msg, netAddress & SenderAddress,
-                              unsigned len, long stamp)
+FGMultiplayMgr::ProcessPosMsg(const FGMultiplayMgr::MsgBuf& Msg,
+                              const netAddress& SenderAddress, long stamp)
 {
-  const T_MsgHdr* MsgHdr = reinterpret_cast<const T_MsgHdr *>(Msg);
+  const T_MsgHdr* MsgHdr = Msg.msgHdr();
   if (MsgHdr->MsgLen < sizeof(T_MsgHdr) + sizeof(T_PositionMsg)) {
     SG_LOG( SG_NETWORK, SG_ALERT, "FGMultiplayMgr::MP_ProcessData - "
             << "Position message received with insufficient data" );
     return;
   }
-  const T_PositionMsg* PosMsg
-    = reinterpret_cast<const T_PositionMsg *>(Msg + sizeof(T_MsgHdr));
+  const T_PositionMsg* PosMsg = Msg.posMsg();
   FGExternalMotionData motionInfo;
   motionInfo.time = XDR_decode_double(PosMsg->time);
   motionInfo.lag = XDR_decode_double(PosMsg->lag);
@@ -782,7 +839,7 @@ FGMultiplayMgr::ProcessPosMsg(const char *Msg, netAddress & SenderAddress,
 
 
   //cout << "INPUT MESSAGE\n";
-  const xdr_data_t* xdr = (xdr_data_t*)(Msg + sizeof(T_MsgHdr) + sizeof(T_PositionMsg));
+
   // There was a bug in 1.9.0 and before: T_PositionMsg was 196 bytes
   // on 32 bit architectures and 200 bytes on 64 bit, and this
   // structure is put directly on the wire. By looking at the padding,
@@ -798,15 +855,14 @@ FGMultiplayMgr::ProcessPosMsg(const char *Msg, netAddress & SenderAddress,
   // There is a chance that we could be fooled by garbage in the
   // padding looking like a valid property, so verifyProperties() is
   // strict about the validity of the property values.
+  const xdr_data_t* xdr = Msg.properties();
   if (PosMsg->pad != 0) {
-    if (verifyProperties(&PosMsg->pad,
-                         reinterpret_cast<const xdr_data_t*>(Msg + len)))
+    if (verifyProperties(&PosMsg->pad, Msg.propsRecvdEnd()))
       xdr = &PosMsg->pad;
-    else if (!verifyProperties(xdr,
-                               reinterpret_cast<const xdr_data_t*>(Msg + len)))
+    else if (!verifyProperties(xdr, Msg.propsRecvdEnd()))
       goto noprops;
   }
-  while ((char*)xdr < Msg + len) {
+  while (xdr < Msg.propsRecvdEnd()) {
     FGPropertyData* pData = new FGPropertyData;
     SGPropertyNode::Type type = SGPropertyNode::UNSPECIFIED;
     
@@ -903,25 +959,29 @@ FGMultiplayMgr::ProcessPosMsg(const char *Msg, netAddress & SenderAddress,
 //
 //////////////////////////////////////////////////////////////////////
 void
-FGMultiplayMgr::ProcessChatMsg(const char *Msg, netAddress& SenderAddress)
+FGMultiplayMgr::ProcessChatMsg(const MsgBuf& Msg,
+                               const netAddress& SenderAddress)
 {
-  T_MsgHdr* MsgHdr = (T_MsgHdr *)Msg;
+  const T_MsgHdr* MsgHdr = Msg.msgHdr();
   if (MsgHdr->MsgLen < sizeof(T_MsgHdr) + 1) {
     SG_LOG( SG_NETWORK, SG_ALERT, "FGMultiplayMgr::MP_ProcessData - "
             << "Chat message received with insufficient data" );
     return;
   }
   
-  char *MsgBuf = new char[MsgHdr->MsgLen - sizeof(T_MsgHdr)];
-  strncpy(MsgBuf, ((T_ChatMsg *)(Msg + sizeof(T_MsgHdr)))->Text,
+  char *chatStr = new char[MsgHdr->MsgLen - sizeof(T_MsgHdr)];
+  strncpy(chatStr,
+          (reinterpret_cast<const T_ChatMsg *>(Msg.Msg + sizeof(T_MsgHdr)))
+          ->Text,
           MsgHdr->MsgLen - sizeof(T_MsgHdr));
-  MsgBuf[MsgHdr->MsgLen - sizeof(T_MsgHdr) - 1] = '\0';
+  chatStr[MsgHdr->MsgLen - sizeof(T_MsgHdr) - 1] = '\0';
   
-  T_ChatMsg* ChatMsg = (T_ChatMsg *)(Msg + sizeof(T_MsgHdr));
+  const T_ChatMsg* ChatMsg
+      = reinterpret_cast<const T_ChatMsg *>(Msg.Msg + sizeof(T_MsgHdr));
   SG_LOG (SG_NETWORK, SG_ALERT, "Chat [" << MsgHdr->Callsign << "]"
-           << " " << MsgBuf);
+           << " " << chatStr);
 
-  delete [] MsgBuf;
+  delete [] chatStr;
 } // FGMultiplayMgr::ProcessChatMsg ()
 //////////////////////////////////////////////////////////////////////
 

diff --git a/src/MultiPlayer/multiplaymgr.hxx b/src/MultiPlayer/multiplaymgr.hxx
index 2cca356c571c575c12894fa02b3f00e3ada4acd3..ab110ed3b565ca53f681ea1d6e90b0a350298ab3 100644 (file)
--- a/src/MultiPlayer/multiplaymgr.hxx
+++ b/src/MultiPlayer/multiplaymgr.hxx
@@ -72,18 +72,18 @@ public:
   // transmitter
   void SendMyPosition(const FGExternalMotionData& motionInfo);
   void SendTextMessage(const string &sMsgText);
-  void FillMsgHdr(T_MsgHdr *MsgHdr, int iMsgId, unsigned _len = 0u);
-  
   // receiver
-  void ProcessPosMsg(const char *Msg, netAddress & SenderAddress,
-                     unsigned len, long stamp);
-  void ProcessChatMsg(const char *Msg, netAddress & SenderAddress);
   void Update(void);
   
 private:
+  union MsgBuf;
   FGAIMultiplayer* addMultiplayer(const std::string& callsign,
                                   const std::string& modelName);
   FGAIMultiplayer* getMultiplayer(const std::string& callsign);
+  void FillMsgHdr(T_MsgHdr *MsgHdr, int iMsgId, unsigned _len = 0u);
+  void ProcessPosMsg(const MsgBuf& Msg, const netAddress& SenderAddress,
+                     long stamp);
+  void ProcessChatMsg(const MsgBuf& Msg, const netAddress& SenderAddress);
 
   /// maps from the callsign string to the FGAIMultiplayer
   typedef std::map<std::string, osg::ref_ptr<FGAIMultiplayer> > MultiPlayerMap;