WebCore/dom/MessagePortChannel.h
changeset 0 4f2f89ce4247
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/dom/MessagePortChannel.h	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,114 @@
+/*
+ * Copyright (C) 2009 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 MessagePortChannel_h
+#define MessagePortChannel_h
+
+#include "PlatformString.h"
+
+#include "SerializedScriptValue.h"
+
+#include <wtf/OwnPtr.h>
+#include <wtf/PassOwnPtr.h>
+#include <wtf/PassRefPtr.h>
+#include <wtf/RefCounted.h>
+#include <wtf/RefPtr.h>
+
+namespace WebCore {
+
+    class MessagePort;
+    class MessagePortChannel;
+    class PlatformMessagePortChannel;
+    class ScriptExecutionContext;
+    class SerializedScriptValue;
+    class String;
+
+    // The overwhelmingly common case is sending a single port, so handle that efficiently with an inline buffer of size 1.
+    typedef Vector<OwnPtr<MessagePortChannel>, 1> MessagePortChannelArray;
+
+    // MessagePortChannel is a platform-independent interface to the remote side of a message channel.
+    // It acts as a wrapper around the platform-dependent PlatformMessagePortChannel implementation which ensures that the platform-dependent close() method is invoked before destruction.
+    class MessagePortChannel : public Noncopyable {
+    public:
+        static void createChannel(PassRefPtr<MessagePort>, PassRefPtr<MessagePort>);
+
+        // Creates a new wrapper for the passed channel.
+        static PassOwnPtr<MessagePortChannel> create(PassRefPtr<PlatformMessagePortChannel>);
+
+        // Entangles the channel with a port (called when a port has been cloned, after the clone has been marshaled to its new owning thread and is ready to receive messages).
+        // Returns false if the entanglement failed because the port was closed.
+        bool entangleIfOpen(MessagePort*);
+
+        // Disentangles the channel from a given port so it no longer forwards messages to the port. Called when the port is being cloned and no new owning thread has yet been established.
+        void disentangle();
+
+        // Closes the port (ensures that no further messages can be added to either queue).
+        void close();
+
+        // Used by MessagePort.postMessage() to prevent callers from passing a port's own entangled port.
+        bool isConnectedTo(MessagePort*);
+
+        // Returns true if the proxy currently contains messages for this port.
+        bool hasPendingActivity();
+
+        class EventData : public Noncopyable {
+        public:
+            static PassOwnPtr<EventData> create(PassRefPtr<SerializedScriptValue>, PassOwnPtr<MessagePortChannelArray>);
+
+            SerializedScriptValue* message() { return m_message.get(); }
+            PassOwnPtr<MessagePortChannelArray> channels() { return m_channels.release(); }
+
+        private:
+            EventData(PassRefPtr<SerializedScriptValue> message, PassOwnPtr<MessagePortChannelArray>);
+            RefPtr<SerializedScriptValue> m_message;
+            OwnPtr<MessagePortChannelArray> m_channels;
+        };
+
+        // Sends a message and optional cloned port to the remote port.
+        void postMessageToRemote(PassOwnPtr<EventData>);
+
+        // Extracts a message from the message queue for this port.
+        bool tryGetMessageFromRemote(OwnPtr<EventData>&);
+
+        // Returns the entangled port if run by the same thread (see MessagePort::locallyEntangledPort() for more details).
+        MessagePort* locallyEntangledPort(const ScriptExecutionContext*);
+
+        ~MessagePortChannel();
+
+        PlatformMessagePortChannel* channel() const { return m_channel.get(); }
+
+    private:
+        MessagePortChannel(PassRefPtr<PlatformMessagePortChannel>);
+        RefPtr<PlatformMessagePortChannel> m_channel;
+    };
+
+} // namespace WebCore
+
+#endif // MessagePortChannel_h