1 files changed, 88 insertions, 0 deletions
diff --git a/ipc/mscom/ProxyStream.h b/ipc/mscom/ProxyStream.h
new file mode 100644
index 0000000000..92b55745ca
--- /dev/null
+++ b/ipc/mscom/ProxyStream.h
@@ -0,0 +1,88 @@
+/* -*- 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_ProxyStream_h
+#define mozilla_mscom_ProxyStream_h
+
+#include "ipc/IPCMessageUtils.h"
+
+#include "mozilla/mscom/Ptr.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/TypedEnumBits.h"
+#include "mozilla/UniquePtr.h"
+
+namespace mozilla {
+namespace mscom {
+
+enum class ProxyStreamFlags : uint32_t {
+  eDefault = 0,
+  // When ePreservable is set on a ProxyStream, its caller *must* call
+  // GetPreservableStream() before the ProxyStream is destroyed.
+  ePreservable = 1
+};
+
+MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(ProxyStreamFlags);
+
+class ProxyStream final {
+ public:
+  class MOZ_RAII Environment {
+   public:
+    virtual ~Environment() = default;
+    virtual bool Push() = 0;
+    virtual bool Pop() = 0;
+  };
+
+  class MOZ_RAII DefaultEnvironment : public Environment {
+   public:
+    bool Push() override { return true; }
+    bool Pop() override { return true; }
+  };
+
+  ProxyStream();
+  ProxyStream(REFIID aIID, IUnknown* aObject, Environment* aEnv,
+              ProxyStreamFlags aFlags = ProxyStreamFlags::eDefault);
+  ProxyStream(REFIID aIID, const BYTE* aInitBuf, const int aInitBufSize,
+              Environment* aEnv);
+
+  ~ProxyStream();
+
+  // Not copyable because this would mess up the COM marshaling.
+  ProxyStream(const ProxyStream& aOther) = delete;
+  ProxyStream& operator=(const ProxyStream& aOther) = delete;
+
+  ProxyStream(ProxyStream&& aOther);
+  ProxyStream& operator=(ProxyStream&& aOther);
+
+  inline bool IsValid() const { return !(mUnmarshaledProxy && mStream); }
+
+  bool GetInterface(void** aOutInterface);
+  const BYTE* GetBuffer(int& aReturnedBufSize) const;
+
+  PreservedStreamPtr GetPreservedStream();
+
+  bool operator==(const ProxyStream& aOther) const { return this == &aOther; }
+
+ private:
+  RefPtr<IStream> mStream;
+  BYTE* mGlobalLockedBuf;
+  HGLOBAL mHGlobal;
+  int mBufSize;
+  ProxyUniquePtr<IUnknown> mUnmarshaledProxy;
+  bool mPreserveStream;
+};
+
+namespace detail {
+
+template <typename Interface>
+struct EnvironmentSelector {
+  typedef ProxyStream::DefaultEnvironment Type;
+};
+
+}  // namespace detail
+}  // namespace mscom
+}  // namespace mozilla
+
+#endif  // mozilla_mscom_ProxyStream_h