forked from mirrors/gecko-dev
265e672179
# ignore-this-changeset --HG-- extra : amend_source : 4d301d3b0b8711c4692392aa76088ba7fd7d1022
89 lines
3.3 KiB
C++
89 lines
3.3 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_SnappyUncompressInputStream_h__
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#define mozilla_SnappyUncompressInputStream_h__
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#include "mozilla/Attributes.h"
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#include "mozilla/UniquePtr.h"
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#include "nsCOMPtr.h"
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#include "nsIInputStream.h"
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#include "nsISupportsImpl.h"
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#include "SnappyFrameUtils.h"
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namespace mozilla {
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class SnappyUncompressInputStream final : public nsIInputStream,
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protected detail::SnappyFrameUtils {
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public:
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// Construct a new blocking stream to uncompress the given base stream. The
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// base stream must also be blocking. The base stream does not have to be
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// buffered.
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explicit SnappyUncompressInputStream(nsIInputStream* aBaseStream);
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private:
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virtual ~SnappyUncompressInputStream();
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// Parse the next chunk of data. This may populate mBuffer and set
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// mBufferFillSize. This should not be called when mBuffer already
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// contains data.
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nsresult ParseNextChunk(uint32_t* aBytesReadOut);
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// Convenience routine to Read() from the base stream until we get
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// the given number of bytes or reach EOF.
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//
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// aBuf - The buffer to write the bytes into.
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// aCount - Max number of bytes to read. If the stream closes
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// fewer bytes my be read.
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// aMinValidCount - A minimum expected number of bytes. If we find
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// fewer than this many bytes, then return
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// NS_ERROR_CORRUPTED_CONTENT. If nothing was read due
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// due to EOF (aBytesReadOut == 0), then NS_OK is returned.
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// aBytesReadOut - An out parameter indicating how many bytes were read.
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nsresult ReadAll(char* aBuf, uint32_t aCount, uint32_t aMinValidCount,
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uint32_t* aBytesReadOut);
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// Convenience routine to determine how many bytes of uncompressed data
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// we currently have in our buffer.
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size_t UncompressedLength() const;
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nsCOMPtr<nsIInputStream> mBaseStream;
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// Buffer to hold compressed data. Must copy here since we need a large
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// flat buffer to run the uncompress process on. Always the same length
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// of SnappyFrameUtils::MaxCompressedBufferLength(snappy::kBlockSize)
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// bytes long.
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mozilla::UniquePtr<char[]> mCompressedBuffer;
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// Buffer storing the resulting uncompressed data. Exactly snappy::kBlockSize
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// bytes long.
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mozilla::UniquePtr<char[]> mUncompressedBuffer;
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// Number of bytes of uncompressed data in mBuffer.
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size_t mUncompressedBytes;
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// Next byte of mBuffer to return in ReadSegments(). Must be less than
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// mBufferFillSize
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size_t mNextByte;
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// Next chunk in the stream that has been parsed during read-ahead.
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ChunkType mNextChunkType;
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// Length of next chunk's length that has been determined during read-ahead.
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size_t mNextChunkDataLength;
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// The stream must begin with a StreamIdentifier chunk. Are we still
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// expecting it?
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bool mNeedFirstStreamIdentifier;
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public:
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NS_DECL_THREADSAFE_ISUPPORTS
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NS_DECL_NSIINPUTSTREAM
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};
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} // namespace mozilla
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#endif // mozilla_SnappyUncompressInputStream_h__
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