From 36d22d82aa202bb199967e9512281e9a53db42c9 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 21:33:14 +0200 Subject: Adding upstream version 115.7.0esr. Signed-off-by: Daniel Baumann --- xpcom/io/SnappyCompressOutputStream.h | 68 +++++++++++++++++++++++++++++++++++ 1 file changed, 68 insertions(+) create mode 100644 xpcom/io/SnappyCompressOutputStream.h (limited to 'xpcom/io/SnappyCompressOutputStream.h') diff --git a/xpcom/io/SnappyCompressOutputStream.h b/xpcom/io/SnappyCompressOutputStream.h new file mode 100644 index 0000000000..895691034b --- /dev/null +++ b/xpcom/io/SnappyCompressOutputStream.h @@ -0,0 +1,68 @@ +/* -*- 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_SnappyCompressOutputStream_h__ +#define mozilla_SnappyCompressOutputStream_h__ + +#include "mozilla/Attributes.h" +#include "mozilla/UniquePtr.h" +#include "nsCOMPtr.h" +#include "nsIOutputStream.h" +#include "nsISupportsImpl.h" +#include "SnappyFrameUtils.h" + +namespace mozilla { + +class SnappyCompressOutputStream final : public nsIOutputStream, + protected detail::SnappyFrameUtils { + public: + // Maximum compression block size. + static const size_t kMaxBlockSize; + + // Construct a new blocking output stream to compress data to + // the given base stream. The base stream must also be blocking. + // The compression block size may optionally be set to a value + // up to kMaxBlockSize. + explicit SnappyCompressOutputStream(nsIOutputStream* aBaseStream, + size_t aBlockSize = kMaxBlockSize); + + // The compression block size. To optimize stream performance + // try to write to the stream in segments at least this size. + size_t BlockSize() const; + + private: + virtual ~SnappyCompressOutputStream(); + + nsresult FlushToBaseStream(); + nsresult MaybeFlushStreamIdentifier(); + nsresult WriteAll(const char* aBuf, uint32_t aCount, + uint32_t* aBytesWrittenOut); + + nsCOMPtr mBaseStream; + const size_t mBlockSize; + + // Buffer holding copied uncompressed data. This must be copied here + // so that the compression can be performed on a single flat buffer. + mozilla::UniquePtr mBuffer; + + // The next byte in the uncompressed data to copy incoming data to. + size_t mNextByte; + + // Buffer holding the resulting compressed data. + mozilla::UniquePtr mCompressedBuffer; + size_t mCompressedBufferLength; + + // The first thing written to the stream must be a stream identifier. + bool mStreamIdentifierWritten; + + public: + NS_DECL_THREADSAFE_ISUPPORTS + NS_DECL_NSIOUTPUTSTREAM +}; + +} // namespace mozilla + +#endif // mozilla_SnappyCompressOutputStream_h__ -- cgit v1.2.3