WebCrypto: Add interfaces for importKey().

Source/modules/crypto/CryptoOperation.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
@@ skipping 20 matching lines @@
 #ifndef CryptoOperation_h
 #define CryptoOperation_h
 
 #include "bindings/v8/ScriptObject.h"
 #include "bindings/v8/ScriptWrappable.h"
 #include "modules/crypto/Algorithm.h"
 #include "public/platform/WebCrypto.h"
 #include "public/platform/WebCryptoAlgorithm.h"
 #include "wtf/Forward.h"
 #include "wtf/PassRefPtr.h"
-#include "wtf/RefCounted.h"
+#include "wtf/ThreadSafeRefCounted.h"
 
 namespace WebCore {
 
 class ScriptPromiseResolver;
 class ExceptionState;
 
-class CryptoOperation : public ScriptWrappable, public WebKit::WebCryptoOperationResult, public RefCounted<CryptoOperation> {
+typedef int ExceptionCode;
+
+// CryptoOperation vs CryptoOperationImpl:
+//
+// A CryptoOperation corresponds with the request from JavaScript to start a
+// multi-part cryptographic operation. This is forwarded to the Platform layer,
+// which creates a WebCryptoOperation. When the WebCryptoOperation eventually
+// completes, it resolves a Promise.
+//
+// To avoid a reference cycle between WebCryptoOperation and CryptoOperation,
+// WebCryptoOperation's result handle holds a reference to
+// CryptoOperationImpl rather than CryptoOperation. This prevents extending the
+// lifetime of CryptoOperation beyond JavaScript garbage collection, which is
+// important since:
+//
+//   * When JavaScript garbage collects CryptoOperation and finish() has NOT
+//     been called on it, the Platform operation can no longer complete and
+//     should therefore be aborted.
+//   * The WebCryptoOperation may outlive CryptoOperation if finish() was
+//     called, as the result is delivered to a separate Promise (this is
+//     different than what the current version of the spec says).
+
+class CryptoOperationImpl : public WebKit::WebCryptoOperationResultPrivate, public ThreadSafeRefCounted<CryptoOperationImpl> {
 public:
-    ~CryptoOperation();
-    static PassRefPtr<CryptoOperation> create(const WebKit::WebCryptoAlgorithm&, ExceptionState*);
+    static PassRefPtr<CryptoOperationImpl> create() { return adoptRef(new CryptoOperationImpl); }
 
-    CryptoOperation* process(ArrayBuffer* data);
-    CryptoOperation* process(ArrayBufferView* data);
+    bool throwInitializationError(ExceptionState&);
+
+    // The CryptoOperation which started the request is getting destroyed.
+    void detach();
+
+    void process(const void* bytes, size_t);
 
     ScriptObject finish();
     ScriptObject abort();
 
-    Algorithm* algorithm();
-
-    // Implementation of WebKit::WebCryptoOperationResult.
+    // WebCryptoOperationResultPrivate implementation.
     virtual void initializationFailed() OVERRIDE;
-    virtual void initializationSucceded(WebKit::WebCryptoOperation*) OVERRIDE;
+    virtual void initializationSucceeded(WebKit::WebCryptoOperation*) OVERRIDE;
     virtual void completeWithError() OVERRIDE;
     virtual void completeWithArrayBuffer(const WebKit::WebArrayBuffer&) OVERRIDE;
+    virtual void ref() OVERRIDE;
+    virtual void deref() OVERRIDE;
 
 private:
     enum State {
-        // Constructing the WebCryptoOperation.
+        // Constructing the WebCryptoOperationImpl.
         Initializing,
 
         // Accepting calls to process().
         Processing,
 
         // finish() has been called, but the Promise has not been resolved yet.
         Finishing,
 
         // The operation either:
         //  - completed successfully
         //  - failed
         //  - was aborted
         Done,
     };
 
-    CryptoOperation(const WebKit::WebCryptoAlgorithm&, ExceptionState*);
-
-    void process(const unsigned char*, size_t);
-
-    // Aborts and clears m_impl. If the operation has already comleted then
-    // returns false.
-    bool abortImpl();
+    CryptoOperationImpl();
 
     ScriptPromiseResolver* promiseResolver();
 
-    WebKit::WebCryptoAlgorithm m_algorithm;
-    WebKit::WebCryptoOperation* m_impl;
-    RefPtr<Algorithm> m_algorithmNode;
     State m_state;
 
+    WebKit::WebCryptoOperation* m_impl;
     RefPtr<ScriptPromiseResolver> m_promiseResolver;
+    ExceptionCode m_initializationError;
+};
 
-    ExceptionState* m_exceptionState;
+class CryptoOperation : public ScriptWrappable, public RefCounted<CryptoOperation> {
+public:
+    ~CryptoOperation();
+    static PassRefPtr<CryptoOperation> create(const WebKit::WebCryptoAlgorithm&, CryptoOperationImpl*);
+
+    CryptoOperation* process(ArrayBuffer* data);
+    CryptoOperation* process(ArrayBufferView* data);
+
+    ScriptObject finish();
+    ScriptObject abort();
+
+    Algorithm* algorithm();
+
+    CryptoOperationImpl* impl() { return m_impl.get(); }
+
+private:
+    explicit CryptoOperation(const WebKit::WebCryptoAlgorithm&, CryptoOperationImpl*);
+
+    WebKit::WebCryptoAlgorithm m_algorithm;
+    RefPtr<Algorithm> m_algorithmNode;
+
+    RefPtr<CryptoOperationImpl> m_impl;
 };
 
 } // namespace WebCore
 
 #endif