Engine directory for ticket #1

Engine/source/sim/connectionStringTable.h

@@ -0,0 +1,109 @@
+//-----------------------------------------------------------------------------
+// Copyright (c) 2012 GarageGames, LLC
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to
+// deal in the Software without restriction, including without limitation the
+// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+// sell copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+// IN THE SOFTWARE.
+//-----------------------------------------------------------------------------
+
+#ifndef _H_CONNECTIONSTRINGTABLE
+#define _H_CONNECTIONSTRINGTABLE
+
+/// Maintain a table of strings which are shared across the network.
+///
+/// This allows us to reference strings in our network streams more efficiently.
+class ConnectionStringTable
+{
+public:
+   enum Constants {
+      EntryCount = 32,
+      EntryBitSize = 5,
+      InvalidEntryId = 32,
+   };
+private:
+   struct Entry {
+      NetStringHandle string;   ///< Global string table entry of this string
+                             ///  will be 0 if this string is unused.
+
+      U32 index;             ///< index of this entry
+      Entry *nextHash;       ///< the next hash entry for this id
+      Entry *nextLink;       ///< the next in the LRU list
+      Entry *prevLink;       ///< the prev entry in the LRU list
+      bool receiveConfirmed; ///< The other side now has this string.
+   };
+
+   Entry mEntryTable[EntryCount];
+   Entry *mHashTable[EntryCount];
+   NetStringHandle mRemoteStringTable[EntryCount];
+   Entry mLRUHead, mLRUTail;
+
+   /// Connection over which we are maintaining this string table.
+   NetConnection *mParent;
+
+   inline void pushBack(Entry *entry) // pushes an entry to the back of the LRU list
+   {
+      entry->prevLink->nextLink = entry->nextLink;
+      entry->nextLink->prevLink = entry->prevLink;
+      entry->nextLink = &mLRUTail;
+      entry->prevLink = mLRUTail.prevLink;
+      entry->nextLink->prevLink = entry;
+      entry->prevLink->nextLink = entry;
+   }
+
+public:
+   /// Initialize the connection string table.
+   ///
+   /// @param  parent   Connection over which we are maintaining this string table.
+   ConnectionStringTable(NetConnection *parent);
+
+   /// Has the specified string been received on the other side?
+   inline void confirmStringReceived(NetStringHandle &string, U32 index)
+   {
+      if(mEntryTable[index].string == string)
+         mEntryTable[index].receiveConfirmed = true;
+   }
+
+   U32 checkString(NetStringHandle &stringTableId, bool *stringOnOtherSide = NULL);  ///< Checks if the global string ID is
+                                                                                  ///  currently valid for this connection
+                                                                                  ///  and returns the table ID.
+                                                                                  ///  Sends a string event to the other side
+                                                                                  ///  if it is not active.
+                                                                                  ///  It will fill in stringOnOtherSide.
+
+   U32 getNetSendId(NetStringHandle &stringTableId); ///< Same return value as checkString
+                                                  ///  but will assert if the string is not
+                                                  ///  valid.
+
+   void mapString(U32 netId, NetStringHandle &string); ///< Maps a string that
+                                                    ///  was just sent over the net
+                                                    ///  to the corresponding net ID.
+
+   inline NetStringHandle lookupString(U32 netId) ///< looks up the string ID and returns
+   {                                           /// the global string table ID for that string.
+      return mRemoteStringTable[netId];
+   }
+
+   /// @name Demo functionality
+   /// @{
+
+   void readDemoStartBlock(BitStream *stream);
+   void writeDemoStartBlock(ResizeBitStream *stream);
+   /// @}
+};
+
+#endif
+