gecko-dev/xpcom/io/SlicedInputStream.h

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1.7 KiB
C
Исходник Обычный вид История

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* 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 "nsCOMPtr.h"
#include "nsIAsyncInputStream.h"
#include "nsICloneableInputStream.h"
// A wrapper for a slice of an underlying input stream.
class SlicedInputStream final : public nsIAsyncInputStream
, public nsICloneableInputStream
{
public:
NS_DECL_THREADSAFE_ISUPPORTS
NS_DECL_NSIINPUTSTREAM
NS_DECL_NSICLONEABLEINPUTSTREAM
NS_DECL_NSIASYNCINPUTSTREAM
// 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(nsIInputStream* aInputStream,
uint64_t aStart, uint64_t aLength);
private:
~SlicedInputStream();
nsCOMPtr<nsIInputStream> mInputStream;
uint64_t mStart;
uint64_t mLength;
uint64_t mCurPos;
bool mClosed;
};
#endif // SlicedInputStream_h