1 files changed, 101 insertions, 0 deletions

diff --git a/src/sharedcore.h b/src/sharedcore.h
new file mode 100644
index 0000000..9f42345
--- /dev/null
+++ b/src/sharedcore.h
@@ -0,0 +1,101 @@
+/*
+ * Copyright (C) 2007-2008 Xagasoft, All rights reserved.
+ *
+ * This file is part of the libbu++ library and is released under the
+ * terms of the license contained in the file LICENSE.
+ */
+
+#ifndef BU_SHARED_CORE_H
+#define BU_SHARED_CORE_H
+
+#include "bu/util.h"
+#include "bu/sio.h"
+
+namespace Bu
+{
+        template<typename Core>
+        class SharedCore
+        {
+                typedef class SharedCore<Core> _SharedType;
+        public:
+                SharedCore() :
+                        data( new Core ),
+                        iRefCount( new int(1) )
+                {
+                }
+
+                SharedCore( const _SharedType &rSrc ) :
+                        data( NULL ),
+                        iRefCount( NULL )
+                {
+                        _softCopy( rSrc );
+                }
+
+                virtual ~SharedCore()
+                {
+                        _deref();
+                }
+
+                SharedCore &operator=( const SharedCore &rhs )
+                {
+                        _softCopy( rhs );
+                        return *this;
+                }
+
+                int getRefCount() const
+                {
+                        return *iRefCount;
+                }
+
+        protected:
+                Core *data;
+                void _hardCopy()
+                {
+                        if( !data || !iRefCount )
+                                return;
+                        sio << "_hardCopy()" << sio.nl;
+                        Core *copy = new Core( *data );
+                        _deref();
+                        data = copy;
+                        iRefCount = new int( 1 );
+                }
+
+        private:
+                void _deref()
+                {
+                        sio << "_deref()" << sio.nl;
+                        if( (--(*iRefCount)) == 0 )
+                        {
+                                sio << " --> iRefCount == 0, cleaning up." << sio.nl;
+                                delete data;
+                                delete iRefCount;
+                        }
+                        else
+                                sio << " --> iRefCount == " << *iRefCount << sio.nl;
+                        data = NULL;
+                        iRefCount = NULL;
+                }
+
+                void _incRefCount()
+                {
+                        sio << "_incRefCount()" << sio.nl;
+                        if( iRefCount && data )
+                                ++(*iRefCount);
+                        sio << " --> iRefCount == " << *iRefCount << sio.nl;
+                }
+
+                void _softCopy( const _SharedType &rSrc )
+                {
+                        sio << "_softCopy()" << sio.nl;
+                        if( data )
+                                _deref();
+                        data = rSrc.data;
+                        iRefCount = rSrc.iRefCount;
+                        _incRefCount();
+                }
+
+                int *iRefCount;
+        };
+};
+
+#endif