1 files changed, 188 insertions, 0 deletions
diff --git a/ipc/glue/DataPipe.h b/ipc/glue/DataPipe.h
new file mode 100644
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+++ b/ipc/glue/DataPipe.h
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+/* -*- 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 https://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_ipc_DataPipe_h
+#define mozilla_ipc_DataPipe_h
+
+#include "mozilla/ipc/SharedMemoryBasic.h"
+#include "mozilla/ipc/NodeController.h"
+#include "nsIAsyncInputStream.h"
+#include "nsIAsyncOutputStream.h"
+#include "nsIIPCSerializableInputStream.h"
+#include "nsISupports.h"
+
+namespace mozilla {
+namespace ipc {
+
+namespace data_pipe_detail {
+
+class DataPipeAutoLock;
+class DataPipeLink;
+
+class DataPipeBase {
+ public:
+  DataPipeBase(const DataPipeBase&) = delete;
+  DataPipeBase& operator=(const DataPipeBase&) = delete;
+
+ protected:
+  explicit DataPipeBase(bool aReceiverSide, nsresult aError);
+  DataPipeBase(bool aReceiverSide, ScopedPort aPort, SharedMemory* aShmem,
+               uint32_t aCapacity, nsresult aPeerStatus, uint32_t aOffset,
+               uint32_t aAvailable);
+
+  void CloseInternal(DataPipeAutoLock&, nsresult aStatus) MOZ_REQUIRES(*mMutex);
+
+  void AsyncWaitInternal(already_AddRefed<nsIRunnable> aCallback,
+                         already_AddRefed<nsIEventTarget> aTarget,
+                         bool aClosureOnly) MOZ_EXCLUDES(*mMutex);
+
+  // Like `nsWriteSegmentFun` or `nsReadSegmentFun`.
+  using ProcessSegmentFun =
+      FunctionRef<nsresult(Span<char> aSpan, uint32_t aProcessedThisCall,
+                           uint32_t* aProcessedCount)>;
+  nsresult ProcessSegmentsInternal(uint32_t aCount,
+                                   ProcessSegmentFun aProcessSegment,
+                                   uint32_t* aProcessedCount)
+      MOZ_EXCLUDES(*mMutex);
+
+  nsresult CheckStatus(DataPipeAutoLock&) MOZ_REQUIRES(*mMutex);
+
+  nsCString Describe(DataPipeAutoLock&) MOZ_REQUIRES(*mMutex);
+
+  // Thread safety helper to tell the analysis that `mLink->mMutex` is held when
+  // `mMutex` is held.
+  void AssertSameMutex(const std::shared_ptr<Mutex>& aMutex)
+      MOZ_REQUIRES(*mMutex) MOZ_ASSERT_CAPABILITY(*aMutex) {
+    MOZ_ASSERT(mMutex == aMutex);
+  }
+
+  virtual ~DataPipeBase();
+
+  const std::shared_ptr<Mutex> mMutex;
+  nsresult mStatus MOZ_GUARDED_BY(*mMutex) = NS_OK;
+  RefPtr<DataPipeLink> mLink MOZ_GUARDED_BY(*mMutex);
+};
+
+template <typename T>
+void DataPipeWrite(IPC::MessageWriter* aWriter, T* aParam);
+
+template <typename T>
+bool DataPipeRead(IPC::MessageReader* aReader, RefPtr<T>* aResult);
+
+}  // namespace data_pipe_detail
+
+class DataPipeSender;
+class DataPipeReceiver;
+
+#define NS_DATAPIPESENDER_IID                        \
+  {                                                  \
+    0x6698ed77, 0x9fff, 0x425d, {                    \
+      0xb0, 0xa6, 0x1d, 0x30, 0x66, 0xee, 0xb8, 0x16 \
+    }                                                \
+  }
+
+// Helper class for streaming data to another process.
+class DataPipeSender final : public nsIAsyncOutputStream,
+                             public data_pipe_detail::DataPipeBase {
+ public:
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_DATAPIPESENDER_IID)
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIOUTPUTSTREAM
+  NS_DECL_NSIASYNCOUTPUTSTREAM
+
+ private:
+  friend nsresult NewDataPipe(uint32_t, DataPipeSender**, DataPipeReceiver**);
+  friend void data_pipe_detail::DataPipeWrite<DataPipeSender>(
+      IPC::MessageWriter* aWriter, DataPipeSender* aParam);
+  friend bool data_pipe_detail::DataPipeRead<DataPipeSender>(
+      IPC::MessageReader* aReader, RefPtr<DataPipeSender>* aResult);
+
+  explicit DataPipeSender(nsresult aError)
+      : data_pipe_detail::DataPipeBase(/* aReceiverSide */ false, aError) {}
+  DataPipeSender(ScopedPort aPort, SharedMemory* aShmem, uint32_t aCapacity,
+                 nsresult aPeerStatus, uint32_t aOffset, uint32_t aAvailable)
+      : data_pipe_detail::DataPipeBase(/* aReceiverSide */ false,
+                                       std::move(aPort), aShmem, aCapacity,
+                                       aPeerStatus, aOffset, aAvailable) {}
+
+  ~DataPipeSender() = default;
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(DataPipeSender, NS_DATAPIPESENDER_IID)
+
+#define NS_DATAPIPERECEIVER_IID                      \
+  {                                                  \
+    0x0a185f83, 0x499e, 0x450c, {                    \
+      0x95, 0x82, 0x27, 0x67, 0xad, 0x6d, 0x64, 0xb5 \
+    }                                                \
+  }
+
+// Helper class for streaming data from another process.
+class DataPipeReceiver final : public nsIAsyncInputStream,
+                               public nsIIPCSerializableInputStream,
+                               public data_pipe_detail::DataPipeBase {
+ public:
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_DATAPIPERECEIVER_IID)
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIINPUTSTREAM
+  NS_DECL_NSIASYNCINPUTSTREAM
+  NS_DECL_NSIIPCSERIALIZABLEINPUTSTREAM
+
+ private:
+  friend nsresult NewDataPipe(uint32_t, DataPipeSender**, DataPipeReceiver**);
+  friend void data_pipe_detail::DataPipeWrite<DataPipeReceiver>(
+      IPC::MessageWriter* aWriter, DataPipeReceiver* aParam);
+  friend bool data_pipe_detail::DataPipeRead<DataPipeReceiver>(
+      IPC::MessageReader* aReader, RefPtr<DataPipeReceiver>* aResult);
+
+  explicit DataPipeReceiver(nsresult aError)
+      : data_pipe_detail::DataPipeBase(/* aReceiverSide */ true, aError) {}
+  DataPipeReceiver(ScopedPort aPort, SharedMemory* aShmem, uint32_t aCapacity,
+                   nsresult aPeerStatus, uint32_t aOffset, uint32_t aAvailable)
+      : data_pipe_detail::DataPipeBase(/* aReceiverSide */ true,
+                                       std::move(aPort), aShmem, aCapacity,
+                                       aPeerStatus, aOffset, aAvailable) {}
+
+  ~DataPipeReceiver() = default;
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(DataPipeReceiver, NS_DATAPIPERECEIVER_IID)
+
+constexpr uint32_t kDefaultDataPipeCapacity = 64 * 1024;
+
+/**
+ * Create a new DataPipe pair. The sender and receiver ends of the pipe may be
+ * used to transfer data between processes. |aCapacity| is the capacity of the
+ * underlying ring buffer. If `0` is passed, `kDefaultDataPipeCapacity` will be
+ * used.
+ */
+nsresult NewDataPipe(uint32_t aCapacity, DataPipeSender** aSender,
+                     DataPipeReceiver** aReceiver);
+
+}  // namespace ipc
+}  // namespace mozilla
+
+namespace IPC {
+
+template <>
+struct ParamTraits<mozilla::ipc::DataPipeSender*> {
+  static void Write(MessageWriter* aWriter,
+                    mozilla::ipc::DataPipeSender* aParam);
+  static bool Read(MessageReader* aReader,
+                   RefPtr<mozilla::ipc::DataPipeSender>* aResult);
+};
+
+template <>
+struct ParamTraits<mozilla::ipc::DataPipeReceiver*> {
+  static void Write(MessageWriter* aWriter,
+                    mozilla::ipc::DataPipeReceiver* aParam);
+  static bool Read(MessageReader* aReader,
+                   RefPtr<mozilla::ipc::DataPipeReceiver>* aResult);
+};
+
+}  // namespace IPC
+
+#endif  // mozilla_ipc_DataPipe_h