1 files changed, 84 insertions, 0 deletions
diff --git a/xpcom/io/InputStreamLengthWrapper.h b/xpcom/io/InputStreamLengthWrapper.h
new file mode 100644
index 0000000000..a11a808fa7
--- /dev/null
+++ b/xpcom/io/InputStreamLengthWrapper.h
@@ -0,0 +1,84 @@
+/* -*- 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 InputStreamLengthWrapper_h
+#define InputStreamLengthWrapper_h
+
+#include "mozilla/Attributes.h"
+#include "mozilla/Mutex.h"
+#include "nsCOMPtr.h"
+#include "nsIAsyncInputStream.h"
+#include "nsICloneableInputStream.h"
+#include "nsIIPCSerializableInputStream.h"
+#include "nsISeekableStream.h"
+#include "nsIInputStreamLength.h"
+
+namespace mozilla {
+
+// A wrapper keeps an inputStream together with its length.
+// This class can be used for nsIInputStreams that do not implement
+// nsIInputStreamLength.
+
+class InputStreamLengthWrapper final : public nsIAsyncInputStream,
+                                       public nsICloneableInputStream,
+                                       public nsIIPCSerializableInputStream,
+                                       public nsISeekableStream,
+                                       public nsIInputStreamCallback,
+                                       public nsIInputStreamLength {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIINPUTSTREAM
+  NS_DECL_NSIASYNCINPUTSTREAM
+  NS_DECL_NSICLONEABLEINPUTSTREAM
+  NS_DECL_NSIIPCSERIALIZABLEINPUTSTREAM
+  NS_DECL_NSISEEKABLESTREAM
+  NS_DECL_NSITELLABLESTREAM
+  NS_DECL_NSIINPUTSTREAMCALLBACK
+  NS_DECL_NSIINPUTSTREAMLENGTH
+
+  // This method creates a InputStreamLengthWrapper around aInputStream if
+  // this doesn't implement nsIInputStreamLength or
+  // nsIInputStreamAsyncLength interface, but it implements
+  // nsIAsyncInputStream. For this kind of streams,
+  // InputStreamLengthHelper is not able to retrieve the length. This
+  // method will make such streams ready to be used with
+  // InputStreamLengthHelper.
+  static already_AddRefed<nsIInputStream> MaybeWrap(
+      already_AddRefed<nsIInputStream> aInputStream, int64_t aLength);
+
+  // The length here will be used when nsIInputStreamLength::Length() is called.
+  InputStreamLengthWrapper(already_AddRefed<nsIInputStream> aInputStream,
+                           int64_t aLength);
+
+  // This CTOR is meant to be used just for IPC.
+  InputStreamLengthWrapper();
+
+ private:
+  ~InputStreamLengthWrapper();
+
+  void SetSourceStream(already_AddRefed<nsIInputStream> aInputStream);
+
+  nsCOMPtr<nsIInputStream> mInputStream;
+
+  // Raw pointers because these are just QI of mInputStream.
+  nsICloneableInputStream* mWeakCloneableInputStream;
+  nsIIPCSerializableInputStream* mWeakIPCSerializableInputStream;
+  nsISeekableStream* mWeakSeekableInputStream;
+  nsITellableStream* mWeakTellableInputStream;
+  nsIAsyncInputStream* mWeakAsyncInputStream;
+
+  int64_t mLength;
+  bool mConsumed;
+
+  mozilla::Mutex mMutex;
+
+  // This is used for AsyncWait and it's protected by mutex.
+  nsCOMPtr<nsIInputStreamCallback> mAsyncWaitCallback MOZ_GUARDED_BY(mMutex);
+};
+
+}  // namespace mozilla
+
+#endif  // InputStreamLengthWrapper_h