Add m-esr52 at 52.6.0

1 files changed, 332 insertions, 0 deletions

diff --git a/dom/base/StructuredCloneHolder.h b/dom/base/StructuredCloneHolder.h
new file mode 100644
index 000000000..e6953d0f3
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+++ b/dom/base/StructuredCloneHolder.h
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+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_StructuredCloneHolder_h
+#define mozilla_dom_StructuredCloneHolder_h
+
+#include "jsapi.h"
+#include "js/StructuredClone.h"
+#include "mozilla/Move.h"
+#include "mozilla/UniquePtr.h"
+#include "mozilla/dom/BindingDeclarations.h"
+#include "nsISupports.h"
+#include "nsTArray.h"
+
+#ifdef DEBUG
+#include "nsIThread.h"
+#endif
+
+namespace mozilla {
+class ErrorResult;
+namespace layers {
+class Image;
+}
+
+namespace gfx {
+class DataSourceSurface;
+}
+
+namespace dom {
+
+class StructuredCloneHolderBase
+{
+public:
+  typedef JS::StructuredCloneScope StructuredCloneScope;
+
+  StructuredCloneHolderBase(StructuredCloneScope aScope = StructuredCloneScope::SameProcessSameThread);
+  virtual ~StructuredCloneHolderBase();
+
+  StructuredCloneHolderBase(StructuredCloneHolderBase&& aOther) = default;
+
+  // These methods should be implemented in order to clone data.
+  // Read more documentation in js/public/StructuredClone.h.
+
+  virtual JSObject* CustomReadHandler(JSContext* aCx,
+                                      JSStructuredCloneReader* aReader,
+                                      uint32_t aTag,
+                                      uint32_t aIndex) = 0;
+
+  virtual bool CustomWriteHandler(JSContext* aCx,
+                                  JSStructuredCloneWriter* aWriter,
+                                  JS::Handle<JSObject*> aObj) = 0;
+
+  // This method has to be called when this object is not needed anymore.
+  // It will free memory and the buffer. This has to be called because
+  // otherwise the buffer will be freed in the DTOR of this class and at that
+  // point we cannot use the overridden methods.
+  void Clear();
+
+  // If these 3 methods are not implement, transfering objects will not be
+  // allowed. Otherwise only arrayBuffers will be transferred.
+
+  virtual bool
+  CustomReadTransferHandler(JSContext* aCx,
+                            JSStructuredCloneReader* aReader,
+                            uint32_t aTag,
+                            void* aContent,
+                            uint64_t aExtraData,
+                            JS::MutableHandleObject aReturnObject);
+
+  virtual bool
+  CustomWriteTransferHandler(JSContext* aCx,
+                             JS::Handle<JSObject*> aObj,
+                             // Output:
+                             uint32_t* aTag,
+                             JS::TransferableOwnership* aOwnership,
+                             void** aContent,
+                             uint64_t* aExtraData);
+
+  virtual void
+  CustomFreeTransferHandler(uint32_t aTag,
+                            JS::TransferableOwnership aOwnership,
+                            void* aContent,
+                            uint64_t aExtraData);
+
+  // These methods are what you should use to read/write data.
+
+  // Execute the serialization of aValue using the Structured Clone Algorithm.
+  // The data can read back using Read().
+  bool Write(JSContext* aCx,
+             JS::Handle<JS::Value> aValue);
+
+  // Like Write() but it supports the transferring of objects and handling
+  // of cloning policy.
+  bool Write(JSContext* aCx,
+             JS::Handle<JS::Value> aValue,
+             JS::Handle<JS::Value> aTransfer,
+             JS::CloneDataPolicy cloneDataPolicy);
+
+  // If Write() has been called, this method retrieves data and stores it into
+  // aValue.
+  bool Read(JSContext* aCx,
+            JS::MutableHandle<JS::Value> aValue);
+
+  bool HasData() const
+  {
+    return !!mBuffer;
+  }
+
+  JSStructuredCloneData& BufferData() const
+  {
+    MOZ_ASSERT(mBuffer, "Write() has never been called.");
+    return mBuffer->data();
+  }
+
+protected:
+  UniquePtr<JSAutoStructuredCloneBuffer> mBuffer;
+
+  StructuredCloneScope mStructuredCloneScope;
+
+#ifdef DEBUG
+  bool mClearCalled;
+#endif
+};
+
+class BlobImpl;
+class MessagePort;
+class MessagePortIdentifier;
+
+class StructuredCloneHolder : public StructuredCloneHolderBase
+{
+public:
+  enum CloningSupport
+  {
+    CloningSupported,
+    CloningNotSupported
+  };
+
+  enum TransferringSupport
+  {
+    TransferringSupported,
+    TransferringNotSupported
+  };
+
+  // If cloning is supported, this object will clone objects such as Blobs,
+  // FileList, ImageData, etc.
+  // If transferring is supported, we will transfer MessagePorts and in the
+  // future other transferrable objects.
+  // The StructuredCloneScope is useful to know where the cloned/transferred
+  // data can be read and written. Additional checks about the nature of the
+  // objects will be done based on this scope value because not all the
+  // objects can be sent between threads or processes.
+  explicit StructuredCloneHolder(CloningSupport aSupportsCloning,
+                                 TransferringSupport aSupportsTransferring,
+                                 StructuredCloneScope aStructuredCloneScope);
+  virtual ~StructuredCloneHolder();
+
+  StructuredCloneHolder(StructuredCloneHolder&& aOther) = default;
+
+  // Normally you should just use Write() and Read().
+
+  void Write(JSContext* aCx,
+             JS::Handle<JS::Value> aValue,
+             ErrorResult &aRv);
+
+  void Write(JSContext* aCx,
+             JS::Handle<JS::Value> aValue,
+             JS::Handle<JS::Value> aTransfer,
+             JS::CloneDataPolicy cloneDataPolicy,
+             ErrorResult &aRv);
+
+  void Read(nsISupports* aParent,
+            JSContext* aCx,
+            JS::MutableHandle<JS::Value> aValue,
+            ErrorResult &aRv);
+
+  // Call this method to know if this object is keeping some DOM object alive.
+  bool HasClonedDOMObjects() const
+  {
+    return !mBlobImplArray.IsEmpty() ||
+           !mWasmModuleArray.IsEmpty() ||
+           !mClonedSurfaces.IsEmpty();
+  }
+
+  nsTArray<RefPtr<BlobImpl>>& BlobImpls()
+  {
+    MOZ_ASSERT(mSupportsCloning, "Blobs cannot be taken/set if cloning is not supported.");
+    return mBlobImplArray;
+  }
+
+  nsTArray<RefPtr<JS::WasmModule>>& WasmModules()
+  {
+    MOZ_ASSERT(mSupportsCloning, "WasmModules cannot be taken/set if cloning is not supported.");
+    return mWasmModuleArray;
+  }
+
+  StructuredCloneScope CloneScope() const
+  {
+    return mStructuredCloneScope;
+  }
+
+  // The parent object is set internally just during the Read(). This method
+  // can be used by read functions to retrieve it.
+  nsISupports* ParentDuringRead() const
+  {
+    return mParent;
+  }
+
+  // This must be called if the transferring has ports generated by Read().
+  // MessagePorts are not thread-safe and they must be retrieved in the thread
+  // where they are created.
+  nsTArray<RefPtr<MessagePort>>&& TakeTransferredPorts()
+  {
+    MOZ_ASSERT(mSupportsTransferring);
+    return Move(mTransferredPorts);
+  }
+
+  // This method uses TakeTransferredPorts() to populate a sequence of
+  // MessagePorts for WebIDL binding classes.
+  bool
+  TakeTransferredPortsAsSequence(Sequence<OwningNonNull<mozilla::dom::MessagePort>>& aPorts);
+
+  nsTArray<MessagePortIdentifier>& PortIdentifiers() const
+  {
+    MOZ_ASSERT(mSupportsTransferring);
+    return mPortIdentifiers;
+  }
+
+  nsTArray<RefPtr<gfx::DataSourceSurface>>& GetSurfaces()
+  {
+    return mClonedSurfaces;
+  }
+
+  // Implementations of the virtual methods to allow cloning of objects which
+  // JS engine itself doesn't clone.
+
+  virtual JSObject* CustomReadHandler(JSContext* aCx,
+                                      JSStructuredCloneReader* aReader,
+                                      uint32_t aTag,
+                                      uint32_t aIndex) override;
+
+  virtual bool CustomWriteHandler(JSContext* aCx,
+                                  JSStructuredCloneWriter* aWriter,
+                                  JS::Handle<JSObject*> aObj) override;
+
+  virtual bool CustomReadTransferHandler(JSContext* aCx,
+                                         JSStructuredCloneReader* aReader,
+                                         uint32_t aTag,
+                                         void* aContent,
+                                         uint64_t aExtraData,
+                                         JS::MutableHandleObject aReturnObject) override;
+
+  virtual bool CustomWriteTransferHandler(JSContext* aCx,
+                                          JS::Handle<JSObject*> aObj,
+                                          uint32_t* aTag,
+                                          JS::TransferableOwnership* aOwnership,
+                                          void** aContent,
+                                          uint64_t* aExtraData) override;
+
+  virtual void CustomFreeTransferHandler(uint32_t aTag,
+                                         JS::TransferableOwnership aOwnership,
+                                         void* aContent,
+                                         uint64_t aExtraData) override;
+
+  // These 2 static methods are useful to read/write fully serializable objects.
+  // They can be used by custom StructuredCloneHolderBase classes to
+  // serialize objects such as ImageData, CryptoKey, RTCCertificate, etc.
+
+  static JSObject* ReadFullySerializableObjects(JSContext* aCx,
+                                                JSStructuredCloneReader* aReader,
+                                                uint32_t aTag);
+
+  static bool  WriteFullySerializableObjects(JSContext* aCx,
+                                             JSStructuredCloneWriter* aWriter,
+                                             JS::Handle<JSObject*> aObj);
+
+  static const JSStructuredCloneCallbacks sCallbacks;
+
+protected:
+  // If you receive a buffer from IPC, you can use this method to retrieve a
+  // JS::Value. It can happen that you want to pre-populate the array of Blobs
+  // and/or the PortIdentifiers.
+  void ReadFromBuffer(nsISupports* aParent,
+                      JSContext* aCx,
+                      JSStructuredCloneData& aBuffer,
+                      JS::MutableHandle<JS::Value> aValue,
+                      ErrorResult &aRv);
+
+  void ReadFromBuffer(nsISupports* aParent,
+                      JSContext* aCx,
+                      JSStructuredCloneData& aBuffer,
+                      uint32_t aAlgorithmVersion,
+                      JS::MutableHandle<JS::Value> aValue,
+                      ErrorResult &aRv);
+
+  bool mSupportsCloning;
+  bool mSupportsTransferring;
+
+  // Used for cloning blobs in the structured cloning algorithm.
+  nsTArray<RefPtr<BlobImpl>> mBlobImplArray;
+
+  // Used for cloning JS::WasmModules in the structured cloning algorithm.
+  nsTArray<RefPtr<JS::WasmModule>> mWasmModuleArray;
+
+  // This is used for sharing the backend of ImageBitmaps.
+  // The DataSourceSurface object must be thread-safely reference-counted.
+  // The DataSourceSurface object will not be written ever via any ImageBitmap
+  // instance, so no race condition will occur.
+  nsTArray<RefPtr<gfx::DataSourceSurface>> mClonedSurfaces;
+
+  // This raw pointer is only set within ::Read() and is unset by the end.
+  nsISupports* MOZ_NON_OWNING_REF mParent;
+
+  // This array contains the ports once we've finished the reading. It's
+  // generated from the mPortIdentifiers array.
+  nsTArray<RefPtr<MessagePort>> mTransferredPorts;
+
+  // This array contains the identifiers of the MessagePorts. Based on these we
+  // are able to reconnect the new transferred ports with the other
+  // MessageChannel ports.
+  mutable nsTArray<MessagePortIdentifier> mPortIdentifiers;
+
+#ifdef DEBUG
+  nsCOMPtr<nsIThread> mCreationThread;
+#endif
+};
+
+} // dom namespace
+} // mozilla namespace
+
+#endif // mozilla_dom_StructuredCloneHolder_h