xpcom/io/SlicedInputStream.h
author L10n Bumper Bot <release+l10nbumper@mozilla.com>
Thu, 08 Nov 2018 03:00:11 -0800
changeset 501100 1cd4f2d571554c4dc89cf1be1d98683c0d14f797
parent 500377 2da6504c901e9474566aa1663d907bd58bed9edb
child 508163 6f3709b3878117466168c40affa7bca0b60cf75b
permissions -rw-r--r--
no bug - Bumping Fennec l10n changesets r=release a=l10n-bump DONTBUILD an -> 336e061995b9 ar -> f6834a7d7374 as -> d2c76e616a66 ast -> fcb8f3455237 az -> c4caf3b07cf2 be -> 697eb1022498 bg -> 7bf1f448f743 bn-BD -> 5f7a87adee06 bn-IN -> 49ce3195c4c2 br -> 41cf35b7c5b5 bs -> 4a14aee27904 ca -> 9373e8ce86d4 cak -> a40d767541ba cs -> 4b99defb0525 cy -> 4c948fed2584 de -> 017a7e7a267a dsb -> aadebeccf5ba el -> 2d28a78dcef5 en-CA -> 55ad9171a9f0 en-GB -> 296422b495e9 en-ZA -> c1b5d2128914 eo -> c68e87667d9f es-AR -> bff0a788c711 es-CL -> 1d3efd2532ea es-ES -> 4d1feb70b0e2 es-MX -> fceda607d0f4 et -> 58a8262a0cc7 eu -> 7cebfd46208b fa -> cbc040d58476 ff -> 46f5aec275ea fi -> 235ab13d261e fr -> 8ee417b64f99

/* -*- 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 SlicedInputStream_h
#define SlicedInputStream_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 for a slice of an underlying input stream.

class SlicedInputStream final : public nsIAsyncInputStream
                              , public nsICloneableInputStream
                              , public nsIIPCSerializableInputStream
                              , public nsISeekableStream
                              , public nsIInputStreamCallback
                              , public nsIInputStreamLength
                              , public nsIAsyncInputStreamLength
                              , public nsIInputStreamLengthCallback
{
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
  NS_DECL_NSIASYNCINPUTSTREAMLENGTH
  NS_DECL_NSIINPUTSTREAMLENGTHCALLBACK

  // Create an input stream whose data comes from a slice of aInputStream.  The
  // slice begins at aStart bytes beyond aInputStream's current position, and
  // extends for a maximum of aLength bytes.  If aInputStream contains fewer
  // than aStart bytes, reading from SlicedInputStream returns no data.  If
  // aInputStream contains more than aStart bytes, but fewer than aStart +
  // aLength bytes, reading from SlicedInputStream returns as many bytes as can
  // be consumed from aInputStream after reading aLength bytes.
  //
  // aInputStream should not be read from after constructing a
  // SlicedInputStream wrapper around it.

  SlicedInputStream(already_AddRefed<nsIInputStream> aInputStream,
                    uint64_t aStart, uint64_t aLength);

  // This CTOR is meant to be used just for IPC.
  SlicedInputStream();

private:
  ~SlicedInputStream();

  void
  SetSourceStream(already_AddRefed<nsIInputStream> aInputStream);

  uint64_t
  AdjustRange(uint64_t aRange);

  nsCOMPtr<nsIInputStream> mInputStream;

  // Raw pointers because these are just QI of mInputStream.
  nsICloneableInputStream* mWeakCloneableInputStream;
  nsIIPCSerializableInputStream* mWeakIPCSerializableInputStream;
  nsISeekableStream* mWeakSeekableInputStream;
  nsITellableStream* mWeakTellableInputStream;
  nsIAsyncInputStream* mWeakAsyncInputStream;
  nsIInputStreamLength* mWeakInputStreamLength;
  nsIAsyncInputStreamLength* mWeakAsyncInputStreamLength;

  uint64_t mStart;
  uint64_t mLength;
  uint64_t mCurPos;

  bool mClosed;

  // These four are used for AsyncWait. They are protected by mutex because
  // touched on multiple threads.
  nsCOMPtr<nsIInputStreamCallback> mAsyncWaitCallback;
  nsCOMPtr<nsIEventTarget> mAsyncWaitEventTarget;
  uint32_t mAsyncWaitFlags;
  uint32_t mAsyncWaitRequestedCount;

  // This is use for nsIAsyncInputStreamLength::AsyncWait.
  // This is protected by mutex.
  nsCOMPtr<nsIInputStreamLengthCallback> mAsyncWaitLengthCallback;

  Mutex mMutex;
};

} // mozilla namespace

#endif // SlicedInputStream_h