cwUi.cpp : Improve websocket msg buffering.

cwUi.cpp

@@ -89,6 +89,7 @@ namespace cw
       char*                recvBuf;
       unsigned             recvBufN;
       unsigned             recvBufIdx;
+      unsigned             recvShiftN;
       
       unsigned*            sessA;       // sessA[ sessN ] array of wsSessId's
       unsigned             sessN;
@@ -1048,6 +1049,49 @@ namespace cw
       return _setPropertyValue( h, propertyStr,uuId,enableFl ? 1 : 0 );
     }
 
+    rc_t _copy_msg_to_recv_buffer( ui_t* p, const void* msg, unsigned msgByteN )
+    {
+      rc_t rc;
+      
+      if( p->recvBufIdx + msgByteN > p->recvBufN )
+        rc = cwLogError(kBufTooSmallRC,"The UI input buffer (%i) is too small.", p->recvBufN);
+      else
+      {
+        memcpy(p->recvBuf + p->recvBufIdx, msg, msgByteN );
+        p->recvBufIdx += msgByteN;
+      }
+      
+      return rc;
+    }
+
+    const char* _get_msg_from_recv_buffer( ui_t* p )
+    {
+      const char* msg = nullptr;
+      unsigned i;
+
+      // shift off the previous msg
+      if( p->recvShiftN > 0 )
+      {
+        memmove(p->recvBuf, p->recvBuf+p->recvShiftN, p->recvBufIdx - p->recvShiftN );
+        p->recvShiftN = 0;
+      }
+
+      // locate the end of the next msg.
+      for(i=0; p->recvBuf[i]!=0 and i<p->recvBufIdx; ++i)
+      {}
+
+      // if the end of the next msg was found
+      if( p->recvBuf[i] == 0 )
+      {
+        p->recvShiftN = i+1;
+        msg = p->recvBuf;
+      }
+  
+      return msg;
+    }
+
+    
+    
   }
 }
 
@@ -1089,6 +1133,7 @@ cw::rc_t cw::ui::create(
   p->recvBuf    = mem::allocZ<char>(fmtBufByteN);
   p->recvBufN   = fmtBufByteN;
   p->recvBufIdx = 0;
+  p->recvShiftN = 0;
   
   // create the root element
   if((ele = _createBaseEle(p, nullptr, kRootAppId, kInvalidId, "uiDivId" )) == nullptr || ele->uuId != kRootUuId )
@@ -1194,9 +1239,11 @@ cw::rc_t cw::ui::onReceive( handle_t h, unsigned wsSessId, const void* void_msg,
   rc_t        rc   = kOkRC;
   ui_t*       p    = _handleToPtr(h);
   opId_t      opId = kInvalidOpId;
+  ele_t*      ele  = nullptr;
+  const char* msg  = nullptr;
   value_t     value;
-  ele_t*  ele;
   
+  /*
   const char* src_msg = (const char*)void_msg;
   const char* msg = src_msg;
 
@@ -1233,6 +1280,15 @@ cw::rc_t cw::ui::onReceive( handle_t h, unsigned wsSessId, const void* void_msg,
   // the message is being processed so the buffer will end up empty
   // (if it was being used)
   p->recvBufIdx = 0;
+  */
+
+  // buffer the incoming msg
+  if((rc = _copy_msg_to_recv_buffer( p, void_msg, msgByteN )) != kOkRC )
+    goto errLabel;
+
+  // remove and and act on each buffered msg
+  while( (msg = _get_msg_from_recv_buffer(p)) != NULL )
+  {
 
     // parse the 'opId' from the message
     opId = _labelToOpId(msg);
@@ -1306,7 +1362,8 @@ cw::rc_t cw::ui::onReceive( handle_t h, unsigned wsSessId, const void* void_msg,
         break;
                 
     } // switch opId
-
+  }
+ errLabel:
   return rc;
 }