1 files changed, 136 insertions, 0 deletions
diff --git a/ipc/glue/SendStreamParent.cpp b/ipc/glue/SendStreamParent.cpp
new file mode 100644
index 000000000..3ed2d1b2b
--- /dev/null
+++ b/ipc/glue/SendStreamParent.cpp
@@ -0,0 +1,136 @@
+/* -*- 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/. */
+
+#include "mozilla/ipc/SendStream.h"
+
+#include "mozilla/Unused.h"
+#include "nsIAsyncInputStream.h"
+#include "nsIAsyncOutputStream.h"
+#include "nsIPipe.h"
+
+namespace mozilla {
+namespace ipc {
+
+namespace {
+
+class SendStreamParentImpl final : public SendStreamParent
+{
+public:
+  SendStreamParentImpl(nsIAsyncInputStream* aReader,
+                        nsIAsyncOutputStream* aWriter);
+  ~SendStreamParentImpl();
+
+private:
+  // PSendStreamParentImpl methods
+  virtual void
+  ActorDestroy(ActorDestroyReason aReason) override;
+
+  // SendStreamparent methods
+  already_AddRefed<nsIInputStream>
+  TakeReader() override;
+
+  virtual bool
+  RecvBuffer(const nsCString& aBuffer) override;
+
+  virtual bool
+  RecvClose(const nsresult& aRv) override;
+
+  nsCOMPtr<nsIAsyncInputStream> mReader;
+  nsCOMPtr<nsIAsyncOutputStream> mWriter;
+
+  NS_DECL_OWNINGTHREAD
+};
+
+SendStreamParentImpl::~SendStreamParentImpl()
+{
+}
+
+already_AddRefed<nsIInputStream>
+SendStreamParentImpl::TakeReader()
+{
+  MOZ_ASSERT(mReader);
+  return mReader.forget();
+}
+
+void
+SendStreamParentImpl::ActorDestroy(ActorDestroyReason aReason)
+{
+  // If we were gracefully closed we should have gotten RecvClose().  In
+  // that case, the writer will already be closed and this will have no
+  // effect.  This just aborts the writer in the case where the child process
+  // crashes.
+  mWriter->CloseWithStatus(NS_ERROR_ABORT);
+}
+
+bool
+SendStreamParentImpl::RecvBuffer(const nsCString& aBuffer)
+{
+  uint32_t numWritten = 0;
+
+  // This should only fail if we hit an OOM condition.
+  nsresult rv = mWriter->Write(aBuffer.get(), aBuffer.Length(), &numWritten);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    Unused << SendRequestClose(rv);
+  }
+
+  return true;
+}
+
+bool
+SendStreamParentImpl::RecvClose(const nsresult& aRv)
+{
+  mWriter->CloseWithStatus(aRv);
+  Unused << Send__delete__(this);
+  return true;
+}
+
+SendStreamParentImpl::SendStreamParentImpl(nsIAsyncInputStream* aReader,
+                                             nsIAsyncOutputStream* aWriter)
+  : mReader(aReader)
+  , mWriter(aWriter)
+{
+  MOZ_ASSERT(mReader);
+  MOZ_ASSERT(mWriter);
+}
+
+} // anonymous namespace
+
+SendStreamParent::~SendStreamParent()
+{
+}
+
+PSendStreamParent*
+AllocPSendStreamParent()
+{
+  // use async versions for both reader and writer even though we are
+  // opening the writer as an infinite stream.  We want to be able to
+  // use CloseWithStatus() to communicate errors through the pipe.
+  nsCOMPtr<nsIAsyncInputStream> reader;
+  nsCOMPtr<nsIAsyncOutputStream> writer;
+
+  // Use an "infinite" pipe because we cannot apply back-pressure through
+  // the async IPC layer at the moment.  Blocking the IPC worker thread
+  // is not desirable, either.
+  nsresult rv = NS_NewPipe2(getter_AddRefs(reader),
+                            getter_AddRefs(writer),
+                            true, true,   // non-blocking
+                            0,            // segment size
+                            UINT32_MAX);  // "infinite" pipe
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return nullptr;
+  }
+
+  return new SendStreamParentImpl(reader, writer);
+}
+
+void
+DeallocPSendStreamParent(PSendStreamParent* aActor)
+{
+  delete aActor;
+}
+
+} // namespace ipc
+} // namespace mozilla