WIP don't review: Implement Future

Source/core/dom/Future.h

+/*
+ * Copyright (C) 2013 Google 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:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * 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.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "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 THE COPYRIGHT
+ * OWNER 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 Future_h
+#define Future_h
+
+#include "bindings/v8/ScriptValue.h"
+#include "core/dom/ActiveDOMObject.h"
+#include "core/dom/AnyCallback.h"
+#include "core/dom/FutureInit.h"
+#include "core/dom/FutureResolver.h"
+#include "wtf/PassRefPtr.h"
+#include "wtf/RefCounted.h"
+#include "wtf/RefPtr.h"
+#include "wtf/Vector.h"
+
+namespace WebCore {
+
+// Needed due to circular dependency.
+class AnyCallback;
+class FutureInit;
+
+class Future : public RefCounted<Future>, public ActiveDOMObject {
+public:
+    enum State {
+        Pending,
+        Accepted,
+        Rejected
+    };
+
+    static PassRefPtr<Future> createAndRunInit(PassRefPtr<FutureInit>);
+
+    static PassRefPtr<Future> accept(const ScriptValue&);
+    static PassRefPtr<Future> resolve(const ScriptValue&);
+    static PassRefPtr<Future> reject(const ScriptValue&);
+
+    static PassRefPtr<Future> anyof(Vector<ScriptValue>&);
+    static PassRefPtr<Future> every(Vector<ScriptValue>&);
+    static PassRefPtr<Future> some(Vector<ScriptValue>&);
+
+    PassRefPtr<Future> then(PassRefPtr<AnyCallback>, PassRefPtr<AnyCallback>);
+    void done(PassRefPtr<AnyCallback>, PassRefPtr<AnyCallback>);
+
+    void then(PassRefPtr<Future>);
+
+    void setResolver(PassRefPtr<FutureResolver> resolver) { m_resolver = resolver; }
+    PassRefPtr<FutureResolver> getResolver() { return m_resolver; }
+
+    // Methods for m_resolver to modify the associated Future instance.
+
+    void setState(State state) { m_state = state; }
+    void setResult(const ScriptValue& result) { m_result = result; }
+
+    void processAcceptCallbacks(const ScriptValue&);
+    void queueProcessAcceptCallbacksTask(const ScriptValue&);
+    void processRejectCallbacks(const ScriptValue&);
+    void queueProcessRejectCallbacksTask(const ScriptValue&);
+
+    // For RefCounted<Future>.
+    virtual ~Future();
+
+private:
+    class FutureCallback : public RefCounted<FutureCallback> {
+    public:
+        enum Algorithm {
+            NoAlgorithm,
+            WrapperAlgorithm,
+            AcceptAlgorithm,
+            ResolveAlgorithm,
+            RejectAlgorithm
+        };
+
+        static PassRefPtr<FutureCallback> create(Algorithm algorithm, PassRefPtr<FutureResolver> resolver, PassRefPtr<AnyCallback> callback)
+        {
+            return adoptRef(new FutureCallback(algorithm, resolver, callback));
+        }
+
+        void invoke(const ScriptValue&);
+
+    private:
+        FutureCallback(Algorithm algorithm, PassRefPtr<FutureResolver> resolver, PassRefPtr<AnyCallback> callback)
+            : m_algorithm(algorithm)
+            , m_resolver(resolver)
+            , m_callback(callback)
+        {
+        }
+
+        Algorithm m_algorithm;
+        RefPtr<FutureResolver> m_resolver;
+        RefPtr<AnyCallback> m_callback;
+    };
+
+    static PassRefPtr<Future> create();
+
+    explicit Future(ScriptExecutionContext*);
+
+    void appendCallbacks(PassRefPtr<FutureCallback> acceptCallback, PassRefPtr<FutureCallback> rejectCallback);
+
+    Vector<RefPtr<FutureCallback> > m_acceptCallbacks;
+    Vector<RefPtr<FutureCallback> > m_rejectCallbacks;
+    State m_state;
+    ScriptValue m_result;

[abarth-chromium, 2013/05/23 17:56:47]

We should talk more about the general approach.  Using ScriptValue is going to
lead to many memory leaks.

+
+    // The associated FutureResolver instance.
+    RefPtr<FutureResolver> m_resolver;
+};
+
+} // namespace WebCore
+
+#endif // Future_h