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authorMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
committerMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
commit5f8de423f190bbb79a62f804151bc24824fa32d8 (patch)
tree10027f336435511475e392454359edea8e25895d /xpcom/io/SnappyUncompressInputStream.h
parent49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff)
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Add m-esr52 at 52.6.0
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diff --git a/xpcom/io/SnappyUncompressInputStream.h b/xpcom/io/SnappyUncompressInputStream.h
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+/* -*- 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 mozilla_SnappyUncompressInputStream_h__
+#define mozilla_SnappyUncompressInputStream_h__
+
+#include "mozilla/Attributes.h"
+#include "mozilla/UniquePtr.h"
+#include "nsCOMPtr.h"
+#include "nsIInputStream.h"
+#include "nsISupportsImpl.h"
+#include "SnappyFrameUtils.h"
+
+namespace mozilla {
+
+class SnappyUncompressInputStream final : public nsIInputStream
+ , protected detail::SnappyFrameUtils
+{
+public:
+ // Construct a new blocking stream to uncompress the given base stream. The
+ // base stream must also be blocking. The base stream does not have to be
+ // buffered.
+ explicit SnappyUncompressInputStream(nsIInputStream* aBaseStream);
+
+private:
+ virtual ~SnappyUncompressInputStream();
+
+ // Parse the next chunk of data. This may populate mBuffer and set
+ // mBufferFillSize. This should not be called when mBuffer already
+ // contains data.
+ nsresult ParseNextChunk(uint32_t* aBytesReadOut);
+
+ // Convenience routine to Read() from the base stream until we get
+ // the given number of bytes or reach EOF.
+ //
+ // aBuf - The buffer to write the bytes into.
+ // aCount - Max number of bytes to read. If the stream closes
+ // fewer bytes my be read.
+ // aMinValidCount - A minimum expected number of bytes. If we find
+ // fewer than this many bytes, then return
+ // NS_ERROR_CORRUPTED_CONTENT. If nothing was read due
+ // due to EOF (aBytesReadOut == 0), then NS_OK is returned.
+ // aBytesReadOut - An out parameter indicating how many bytes were read.
+ nsresult ReadAll(char* aBuf, uint32_t aCount, uint32_t aMinValidCount,
+ uint32_t* aBytesReadOut);
+
+ // Convenience routine to determine how many bytes of uncompressed data
+ // we currently have in our buffer.
+ size_t UncompressedLength() const;
+
+ nsCOMPtr<nsIInputStream> mBaseStream;
+
+ // Buffer to hold compressed data. Must copy here since we need a large
+ // flat buffer to run the uncompress process on. Always the same length
+ // of SnappyFrameUtils::MaxCompressedBufferLength(snappy::kBlockSize)
+ // bytes long.
+ mozilla::UniquePtr<char[]> mCompressedBuffer;
+
+ // Buffer storing the resulting uncompressed data. Exactly snappy::kBlockSize
+ // bytes long.
+ mozilla::UniquePtr<char[]> mUncompressedBuffer;
+
+ // Number of bytes of uncompressed data in mBuffer.
+ size_t mUncompressedBytes;
+
+ // Next byte of mBuffer to return in ReadSegments(). Must be less than
+ // mBufferFillSize
+ size_t mNextByte;
+
+ // Next chunk in the stream that has been parsed during read-ahead.
+ ChunkType mNextChunkType;
+
+ // Length of next chunk's length that has been determined during read-ahead.
+ size_t mNextChunkDataLength;
+
+ // The stream must begin with a StreamIdentifier chunk. Are we still
+ // expecting it?
+ bool mNeedFirstStreamIdentifier;
+
+public:
+ NS_DECL_THREADSAFE_ISUPPORTS
+ NS_DECL_NSIINPUTSTREAM
+};
+
+} // namespace mozilla
+
+#endif // mozilla_SnappyUncompressInputStream_h__