1 files changed, 85 insertions, 0 deletions
diff --git a/xpcom/io/NonBlockingAsyncInputStream.h b/xpcom/io/NonBlockingAsyncInputStream.h
new file mode 100644
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+++ b/xpcom/io/NonBlockingAsyncInputStream.h
@@ -0,0 +1,85 @@
+/* -*- Mode: C++; tab-width: 4; 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 NonBlockingAsyncInputStream_h
+#define NonBlockingAsyncInputStream_h
+
+#include "mozilla/Attributes.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/Mutex.h"
+#include "nsCOMPtr.h"
+#include "nsIAsyncInputStream.h"
+#include "nsICloneableInputStream.h"
+#include "nsIIPCSerializableInputStream.h"
+#include "nsISeekableStream.h"
+
+// This class aims to wrap a non-blocking and non-async inputStream and expose
+// it as nsIAsyncInputStream.
+// Probably you don't want to use this class directly. Instead use
+// NS_MakeAsyncNonBlockingInputStream() as it will handle different stream
+// variants without requiring you to special-case them yourself.
+
+namespace mozilla {
+
+class NonBlockingAsyncInputStream final : public nsIAsyncInputStream,
+                                          public nsICloneableInputStream,
+                                          public nsIIPCSerializableInputStream,
+                                          public nsISeekableStream {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIINPUTSTREAM
+  NS_DECL_NSIASYNCINPUTSTREAM
+  NS_DECL_NSICLONEABLEINPUTSTREAM
+  NS_DECL_NSIIPCSERIALIZABLEINPUTSTREAM
+  NS_DECL_NSISEEKABLESTREAM
+  NS_DECL_NSITELLABLESTREAM
+
+  // |aInputStream| must be a non-blocking, non-async inputSteam.
+  static nsresult Create(already_AddRefed<nsIInputStream> aInputStream,
+                         nsIAsyncInputStream** aAsyncInputStream);
+
+ private:
+  explicit NonBlockingAsyncInputStream(
+      already_AddRefed<nsIInputStream> aInputStream);
+  ~NonBlockingAsyncInputStream();
+
+  class AsyncWaitRunnable;
+
+  void RunAsyncWaitCallback(AsyncWaitRunnable* aRunnable,
+                            already_AddRefed<nsIInputStreamCallback> aCallback);
+
+  nsCOMPtr<nsIInputStream> mInputStream;
+
+  // Raw pointers because these are just QI of mInputStream.
+  nsICloneableInputStream* MOZ_NON_OWNING_REF mWeakCloneableInputStream;
+  nsIIPCSerializableInputStream* MOZ_NON_OWNING_REF
+      mWeakIPCSerializableInputStream;
+  nsISeekableStream* MOZ_NON_OWNING_REF mWeakSeekableInputStream;
+  nsITellableStream* MOZ_NON_OWNING_REF mWeakTellableInputStream;
+
+  Mutex mLock;
+
+  struct WaitClosureOnly {
+    WaitClosureOnly(AsyncWaitRunnable* aRunnable, nsIEventTarget* aEventTarget);
+
+    RefPtr<AsyncWaitRunnable> mRunnable;
+    nsCOMPtr<nsIEventTarget> mEventTarget;
+  };
+
+  // This is set when AsyncWait is called with a callback and with
+  // WAIT_CLOSURE_ONLY as flag.
+  // This is protected by mLock.
+  Maybe<WaitClosureOnly> mWaitClosureOnly MOZ_GUARDED_BY(mLock);
+
+  // This is protected by mLock.
+  RefPtr<AsyncWaitRunnable> mAsyncWaitCallback MOZ_GUARDED_BY(mLock);
+
+  // This is protected by mLock.
+  bool mClosed MOZ_GUARDED_BY(mLock);
+};
+
+}  // namespace mozilla
+
+#endif  // NonBlockingAsyncInputStream_h