WebCore/loader/CachedResourceHandle.h
changeset 0 4f2f89ce4247
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/loader/CachedResourceHandle.h	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) 2008 Apple Inc. All Rights Reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#ifndef CachedResourceHandle_h
+#define CachedResourceHandle_h
+
+#include "CachedResource.h"
+
+namespace WebCore {
+
+    class CachedResourceHandleBase {
+    public:
+        ~CachedResourceHandleBase() { if (m_resource) m_resource->unregisterHandle(this); }
+        CachedResource* get() const { return m_resource; }
+        
+        bool operator!() const { return !m_resource; }
+        
+        // This conversion operator allows implicit conversion to bool but not to other integer types.
+        // Parenthesis is needed for winscw compiler to resolve class qualifier in this case.
+        typedef CachedResource* (CachedResourceHandleBase::*UnspecifiedBoolType);
+        operator UnspecifiedBoolType() const { return m_resource ? &CachedResourceHandleBase::m_resource : 0; }
+
+    protected:
+        CachedResourceHandleBase() : m_resource(0) {}
+        CachedResourceHandleBase(CachedResource* res) { m_resource = res; if (m_resource) m_resource->registerHandle(this); }
+        CachedResourceHandleBase(const CachedResourceHandleBase& o) : m_resource(o.m_resource) { if (m_resource) m_resource->registerHandle(this); }
+
+        void setResource(CachedResource*);
+        
+    private:
+        CachedResourceHandleBase& operator=(const CachedResourceHandleBase&) { return *this; } 
+        
+        friend class CachedResource;
+
+        CachedResource* m_resource;
+    };
+        
+    template <class R> class CachedResourceHandle : public CachedResourceHandleBase {
+    public: 
+        CachedResourceHandle() { }
+        CachedResourceHandle(R* res);
+        CachedResourceHandle(const CachedResourceHandle<R>& o) : CachedResourceHandleBase(o) { }
+
+        R* get() const { return reinterpret_cast<R*>(CachedResourceHandleBase::get()); }
+        R* operator->() const { return get(); }
+               
+        CachedResourceHandle& operator=(R* res) { setResource(res); return *this; } 
+        CachedResourceHandle& operator=(const CachedResourceHandle& o) { setResource(o.get()); return *this; }
+        bool operator==(const CachedResourceHandleBase& o) const { return get() == o.get(); }
+        bool operator!=(const CachedResourceHandleBase& o) const { return get() != o.get(); }
+    };
+
+    // Don't inline for winscw compiler to prevent the compiler aggressively resolving
+    // the base class of R* when CachedResourceHandler<T>(R*) is inlined.  The bug is
+    // reported at: https://xdabug001.ext.nokia.com/bugzilla/show_bug.cgi?id=9812.
+    template <class R>
+#if !COMPILER(WINSCW)
+    inline
+#endif
+    CachedResourceHandle<R>::CachedResourceHandle(R* res) : CachedResourceHandleBase(res) 
+    {
+    }
+    
+    template <class R, class RR> bool operator==(const CachedResourceHandle<R>& h, const RR* res) 
+    { 
+        return h.get() == res; 
+    }
+    template <class R, class RR> bool operator==(const RR* res, const CachedResourceHandle<R>& h) 
+    { 
+        return h.get() == res; 
+    }
+    template <class R, class RR> bool operator!=(const CachedResourceHandle<R>& h, const RR* res) 
+    { 
+        return h.get() != res; 
+    }
+    template <class R, class RR> bool operator!=(const RR* res, const CachedResourceHandle<R>& h) 
+    { 
+        return h.get() != res; 
+    }
+}
+
+#endif