1 files changed, 134 insertions, 0 deletions
diff --git a/ipc/mscom/oop/Handler.h b/ipc/mscom/oop/Handler.h
new file mode 100644
index 0000000000..a723064e5e
--- /dev/null
+++ b/ipc/mscom/oop/Handler.h
@@ -0,0 +1,134 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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_mscom_Handler_h
+#define mozilla_mscom_Handler_h
+
+#if defined(MOZILLA_INTERNAL_API)
+#  error This code is NOT for internal Gecko use!
+#endif  // defined(MOZILLA_INTERNAL_API)
+
+#include <objidl.h>
+
+#include "mozilla/mscom/Aggregation.h"
+#include "mozilla/NotNull.h"
+#include "mozilla/RefPtr.h"
+
+/* WARNING! The code in this file may be loaded into the address spaces of other
+   processes! It MUST NOT link against xul.dll or other Gecko binaries! Only
+   inline code may be included! */
+
+namespace mozilla {
+namespace mscom {
+
+class Handler : public IMarshal {
+ public:
+  // IMarshal
+  STDMETHODIMP GetUnmarshalClass(REFIID riid, void* pv, DWORD dwDestContext,
+                                 void* pvDestContext, DWORD mshlflags,
+                                 CLSID* pCid) override;
+  STDMETHODIMP GetMarshalSizeMax(REFIID riid, void* pv, DWORD dwDestContext,
+                                 void* pvDestContext, DWORD mshlflags,
+                                 DWORD* pSize) override;
+  STDMETHODIMP MarshalInterface(IStream* pStm, REFIID riid, void* pv,
+                                DWORD dwDestContext, void* pvDestContext,
+                                DWORD mshlflags) override;
+  STDMETHODIMP UnmarshalInterface(IStream* pStm, REFIID riid,
+                                  void** ppv) override;
+  STDMETHODIMP ReleaseMarshalData(IStream* pStm) override;
+  STDMETHODIMP DisconnectObject(DWORD dwReserved) override;
+
+  /**
+   * This method allows the handler to return its own interfaces that override
+   * those interfaces that are exposed by the underlying COM proxy.
+   * @param aProxyUnknown is the IUnknown of the underlying COM proxy. This is
+   *                      provided to give the handler implementation an
+   *                      opportunity to acquire interfaces to the underlying
+   *                      remote object, if needed.
+   * @param aIid Interface requested, similar to IUnknown::QueryInterface
+   * @param aOutInterface Outparam for the resulting interface to return to the
+   *                      client.
+   * @return The usual HRESULT codes similarly to IUnknown::QueryInterface.
+   *         If E_NOINTERFACE is returned, the proxy will be queried.
+   *         If the handler is certain that this interface is not available,
+   *         it can return S_FALSE to avoid querying the proxy. This will be
+   *         translated to E_NOINTERFACE before it is returned to the client.
+   */
+  virtual HRESULT QueryHandlerInterface(IUnknown* aProxyUnknown, REFIID aIid,
+                                        void** aOutInterface) = 0;
+  /**
+   * Called when the implementer should deserialize data in aStream.
+   * @return S_OK on success;
+   *         S_FALSE if the deserialization was successful but there was no
+   * data; HRESULT error code otherwise.
+   */
+  virtual HRESULT ReadHandlerPayload(IStream* aStream, REFIID aIid) {
+    return S_FALSE;
+  }
+
+  /**
+   * Unfortunately when COM marshals a proxy, it doesn't implicitly marshal
+   * the payload that was originally sent with the proxy. We must implement
+   * that code in the handler in order to make this happen.
+   */
+
+  /**
+   * This function allows the implementer to substitute a different interface
+   * for marshaling than the one that COM is intending to marshal. For example,
+   * the implementer might want to marshal a proxy for an interface that is
+   * derived from the requested interface.
+   *
+   * The default implementation is the identity function.
+   */
+  virtual REFIID MarshalAs(REFIID aRequestedIid) { return aRequestedIid; }
+
+  virtual HRESULT GetMarshalInterface(REFIID aMarshalAsIid,
+                                      NotNull<IUnknown*> aProxy,
+                                      NotNull<IID*> aOutIid,
+                                      NotNull<IUnknown**> aOutUnk);
+
+  /**
+   * Called when the implementer must provide the size of the payload.
+   */
+  virtual HRESULT GetHandlerPayloadSize(REFIID aIid, DWORD* aOutPayloadSize) {
+    if (!aOutPayloadSize) {
+      return E_INVALIDARG;
+    }
+    *aOutPayloadSize = 0;
+    return S_OK;
+  }
+
+  /**
+   * Called when the implementer should serialize the payload data into aStream.
+   */
+  virtual HRESULT WriteHandlerPayload(IStream* aStream, REFIID aIid) {
+    return S_OK;
+  }
+
+  IUnknown* GetProxy() const { return mInnerUnk; }
+
+  static HRESULT Register(REFCLSID aClsid);
+  static HRESULT Unregister(REFCLSID aClsid);
+
+ protected:
+  Handler(IUnknown* aOuter, HRESULT* aResult);
+  virtual ~Handler() {}
+  bool HasPayload() const { return mHasPayload; }
+  IUnknown* GetOuter() const { return mOuter; }
+
+ private:
+  ULONG mRefCnt;
+  IUnknown* mOuter;
+  RefPtr<IUnknown> mInnerUnk;
+  IMarshal* mUnmarshal;  // WEAK
+  bool mHasPayload;
+  DECLARE_AGGREGATABLE(Handler);
+};
+
+}  // namespace mscom
+}  // namespace mozilla
+
+#endif  // mozilla_mscom_Handler_h