зеркало из https://github.com/mozilla/gecko-dev.git
92 строки
3.4 KiB
C++
92 строки
3.4 KiB
C++
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* vim: set ts=8 sts=2 et sw=2 tw=80: */
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#ifndef mozilla_SeekableStreamWrapper_h
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#define mozilla_SeekableStreamWrapper_h
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#include "mozilla/Assertions.h"
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#include "mozilla/Mutex.h"
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#include "nsCOMPtr.h"
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#include "nsIAsyncInputStream.h"
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#include "nsISeekableStream.h"
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#include "nsICloneableInputStream.h"
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#include "nsIIPCSerializableInputStream.h"
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#include "nsIInputStreamLength.h"
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#include "nsIBufferedStreams.h"
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namespace mozilla {
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// Adapter class which converts an input stream implementing
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// `nsICloneableInputStream`, such as `nsPipe`, into a stream implementing
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// `nsISeekableStream`. This is done by keeping a clone of the original unwound
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// input stream to allow rewinding the stream back to its original position.
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class SeekableStreamWrapper final : public nsIAsyncInputStream,
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public nsISeekableStream,
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public nsICloneableInputStream,
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public nsIInputStreamLength,
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public nsIAsyncInputStreamLength,
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public nsIIPCSerializableInputStream,
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public nsIBufferedInputStream {
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NS_DECL_THREADSAFE_ISUPPORTS
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NS_DECL_NSIINPUTSTREAM
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NS_DECL_NSIASYNCINPUTSTREAM
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NS_DECL_NSITELLABLESTREAM
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NS_DECL_NSISEEKABLESTREAM
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NS_DECL_NSICLONEABLEINPUTSTREAM
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NS_DECL_NSIINPUTSTREAMLENGTH
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NS_DECL_NSIASYNCINPUTSTREAMLENGTH
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NS_DECL_NSIIPCSERIALIZABLEINPUTSTREAM
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NS_DECL_NSIBUFFEREDINPUTSTREAM
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public:
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/**
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* This function returns a nsIInputStream which is known to implement
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* nsISeekableStream. This will return |aSource| if it already implements
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* nsISeekableStream, and will wrap it if it does not.
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*
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* If the original stream implements `nsICloneableInputStream`, this will be
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* used to implement the rewinding functionality necessary for
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* `nsISeekableStream`, otherwise it will be copied into a `nsPipe`.
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*/
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static nsresult MaybeWrap(already_AddRefed<nsIInputStream> aOriginal,
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nsIInputStream** aResult);
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private:
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SeekableStreamWrapper(nsICloneableInputStream* aOriginal,
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nsIInputStream* aCurrent)
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: mOriginal(aOriginal), mCurrent(aCurrent) {
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MOZ_ASSERT(mOriginal->GetCloneable());
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}
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~SeekableStreamWrapper() = default;
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template <typename T>
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nsCOMPtr<T> StreamAs();
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template <typename M>
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void SerializeInternal(mozilla::ipc::InputStreamParams& aParams,
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FileDescriptorArray& aFileDescriptors,
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bool aDelayedStart, uint32_t aMaxSize,
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uint32_t* aSizeUsed, M* aManager);
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bool IsAsyncInputStream();
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bool IsInputStreamLength();
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bool IsAsyncInputStreamLength();
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bool IsIPCSerializableInputStream();
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bool IsBufferedInputStream();
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// mOriginal is immutable after creation, and is not guarded by `mMutex`.
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nsCOMPtr<nsICloneableInputStream> mOriginal;
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// This mutex guards `mCurrent`.
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Mutex mMutex MOZ_UNANNOTATED{"SeekableStreamWrapper"};
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nsCOMPtr<nsIInputStream> mCurrent;
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};
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} // namespace mozilla
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#endif // mozilla_SeekableStreamWrapper_h
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