Engine directory for ticket #1

Engine/source/console/simObjectMemento.cpp

@@ -0,0 +1,155 @@
+//-----------------------------------------------------------------------------
+// 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.
+//-----------------------------------------------------------------------------
+
+#include "platform/platform.h"
+#include "console/simObjectMemento.h"
+
+#include "console/simObject.h"
+#include "console/simDatablock.h"
+#include "core/stream/memStream.h"
+
+
+SimObjectMemento::SimObjectMemento()
+   : mState( NULL ),
+		mIsDatablock( false )
+{
+}
+
+SimObjectMemento::~SimObjectMemento()
+{
+   dFree( mState );
+}
+
+void SimObjectMemento::save( SimObject *object )
+{
+   // Cleanup any existing state data.
+   dFree( mState );
+   mObjectName = String::EmptyString;
+
+	// Use a stream to save the state.
+   MemStream stream( 256 );
+
+   U32 writeFlags = 0;
+	SimDataBlock* db = dynamic_cast<SimDataBlock*>(object);
+	if( !db )
+		stream.write( sizeof( "return " ) - 1, "return " );
+	else
+   {
+		mIsDatablock = true;
+
+      // Cull the datablock name from the output so that
+      // we can easily replace it in case the datablock's name
+      // is already taken when we call restore().  We can't use the same
+      // setup as with non-datablock classes as the return semantics
+      // are not the same.
+
+      writeFlags |= SimObject::NoName;
+   }
+	
+   object->write( stream, 0, writeFlags );
+   stream.write( (UTF8)0 );
+
+   // Steal the data away from the stream.
+   mState = (UTF8*)stream.takeBuffer();
+   mObjectName = object->getName();
+}
+
+SimObject *SimObjectMemento::restore() const
+{
+   // Make sure we have data to restore.
+   if ( !mState )
+      return NULL;
+
+   // TODO: We could potentially make this faster by
+   // caching the CodeBlock generated from the string
+
+	SimObject* object;
+	if( !mIsDatablock )
+	{
+      // Set the redefine behavior to automatically giving
+      // the new objects unique names.  This will restore the
+      // old names if they are still available or give reasonable
+      // approximations if not.
+
+      const char* oldRedefineBehavior = Con::getVariable( "$Con::redefineBehavior" );
+      Con::setVariable( "$Con::redefineBehavior", "renameNew" );
+
+      // Read the object.
+
+		const UTF8* result = Con::evaluate( mState );
+
+      // Restore the redefine behavior.
+
+      Con::setVariable( "$Con::redefineBehavior", oldRedefineBehavior );
+
+		if ( !result || !result[ 0 ] )
+			return NULL;
+
+      // Look up the object.
+
+		U32 objectId = dAtoi( result );
+		object = Sim::findObject( objectId );
+	}
+	else
+	{
+      String objectName = mObjectName;
+
+      // For datablocks, it's getting a little complicated.  Datablock definitions cannot be used
+      // as expressions and thus we can't get to the datablock object we create by using the
+      // Con::evaluate() return value.  Instead, we need to rely on the object name.  However, if
+      // the name is already taken and needs to be changed, we need to manually do that.  To complicate
+      // this further, we cannot rely on automatic renaming since then we don't know by what name
+      // the newly created object actually goes.  So what we do is we alter the source text snapshot
+      // and substitute a name in case the old object name is actually taken now.
+
+      char* tempBuffer;
+      if( !Sim::findObject( objectName ) )
+         tempBuffer = mState;
+      else
+      {
+         String uniqueName = Sim::getUniqueName( objectName );
+         U32 uniqueNameLen = uniqueName.length();
+
+         char* pLeftParen = dStrchr( mState, '(' );
+         if( pLeftParen == NULL )
+            return NULL;
+         U32 numCharsToLeftParen = pLeftParen - mState;
+
+         tempBuffer = ( char* ) dMalloc( dStrlen( mState ) + uniqueNameLen + 1 );
+         dMemcpy( tempBuffer, mState, numCharsToLeftParen );
+         dMemcpy( &tempBuffer[ numCharsToLeftParen ], uniqueName, uniqueNameLen );
+         dStrcpy( &tempBuffer[ numCharsToLeftParen + uniqueNameLen ], &mState[ numCharsToLeftParen ] );
+      }
+
+		Con::evaluate( tempBuffer );
+
+      if( tempBuffer != mState )
+         dFree( tempBuffer );
+
+      if( objectName == String::EmptyString )
+			return NULL;
+
+		object = Sim::findObject( objectName );
+	}
+
+   return object;
+}