51 lines
1.7 KiB
C++
51 lines
1.7 KiB
C++
/* -*- 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
|