summaryrefslogtreecommitdiffstats
path: root/tools/source/zcodec
diff options
context:
space:
mode:
Diffstat (limited to '')
-rw-r--r--tools/source/zcodec/zcodec.cxx364
1 files changed, 364 insertions, 0 deletions
diff --git a/tools/source/zcodec/zcodec.cxx b/tools/source/zcodec/zcodec.cxx
new file mode 100644
index 000000000..80daa1507
--- /dev/null
+++ b/tools/source/zcodec/zcodec.cxx
@@ -0,0 +1,364 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * 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/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed
+ * with this work for additional information regarding copyright
+ * ownership. The ASF licenses this file to you under the Apache
+ * License, Version 2.0 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#include <sal/config.h>
+
+#include <algorithm>
+
+#include <tools/stream.hxx>
+
+#include <zlib.h>
+
+#include <tools/zcodec.hxx>
+#include <tools/long.hxx>
+
+/* gzip flag byte */
+// GZ_ASCII_FLAG 0x01 /* bit 0 set: file probably ascii text */
+#define GZ_HEAD_CRC 0x02 /* bit 1 set: header CRC present */
+#define GZ_EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
+#define GZ_ORIG_NAME 0x08 /* bit 3 set: original file name present */
+#define GZ_COMMENT 0x10 /* bit 4 set: file comment present */
+#define GZ_RESERVED 0xE0 /* bits 5..7: reserved */
+
+constexpr sal_uInt16 GZ_MAGIC_BYTES_LE = 0x8B1F; /* gzip magic bytes, little endian */
+
+ZCodec::ZCodec( size_t nInBufSize, size_t nOutBufSize )
+ : meState(STATE_INIT)
+ , mbStatus(false)
+ , mbFinish(false)
+ , mnInBufSize(nInBufSize)
+ , mnInToRead(0)
+ , mpOStm(nullptr)
+ , mnOutBufSize(nOutBufSize)
+ , mnCompressLevel(0)
+ , mbGzLib(false)
+{
+ mpsC_Stream = new z_stream;
+}
+
+ZCodec::~ZCodec()
+{
+ auto pStream = static_cast<z_stream*>(mpsC_Stream);
+ delete pStream;
+}
+
+bool ZCodec::IsZCompressed( SvStream& rIStm )
+{
+ sal_uInt64 nCurPos = rIStm.Tell();
+ rIStm.Seek( 0 );
+ sal_uInt16 nFirstTwoBytes = 0;
+ rIStm.ReadUInt16( nFirstTwoBytes );
+ rIStm.Seek( nCurPos );
+ return nFirstTwoBytes == GZ_MAGIC_BYTES_LE;
+}
+
+void ZCodec::BeginCompression( int nCompressLevel, bool gzLib )
+{
+ assert(meState == STATE_INIT);
+ mbStatus = true;
+ mbFinish = false;
+ mpOStm = nullptr;
+ mnInToRead = 0xffffffff;
+ mpInBuf.reset();
+ mpOutBuf.reset();
+ auto pStream = static_cast<z_stream*>(mpsC_Stream);
+ pStream->total_out = pStream->total_in = 0;
+ mnCompressLevel = nCompressLevel;
+ mbGzLib = gzLib;
+ pStream->zalloc = nullptr;
+ pStream->zfree = nullptr;
+ pStream->opaque = nullptr;
+ pStream->avail_out = pStream->avail_in = 0;
+}
+
+tools::Long ZCodec::EndCompression()
+{
+ tools::Long retvalue = 0;
+ auto pStream = static_cast<z_stream*>(mpsC_Stream);
+
+ if (meState != STATE_INIT)
+ {
+ if (meState == STATE_COMPRESS)
+ {
+ if (mbStatus)
+ {
+ do
+ {
+ ImplWriteBack();
+ }
+ while ( deflate( pStream, Z_FINISH ) != Z_STREAM_END );
+
+ ImplWriteBack();
+ }
+
+ retvalue = pStream->total_in;
+ deflateEnd( pStream );
+ }
+ else
+ {
+ retvalue = pStream->total_out;
+ inflateEnd( pStream );
+ }
+ mpOutBuf.reset();
+ mpInBuf.reset();
+ meState = STATE_INIT;
+ }
+ return mbStatus ? retvalue : -1;
+}
+
+void ZCodec::Compress( SvStream& rIStm, SvStream& rOStm )
+{
+ assert(meState == STATE_INIT);
+ mpOStm = &rOStm;
+ InitCompress();
+ mpInBuf.reset(new sal_uInt8[ mnInBufSize ]);
+ auto pStream = static_cast<z_stream*>(mpsC_Stream);
+ for (;;)
+ {
+ pStream->next_in = mpInBuf.get();
+ pStream->avail_in = rIStm.ReadBytes( mpInBuf.get(), mnInBufSize );
+ if (pStream->avail_in == 0)
+ break;
+ if ( pStream->avail_out == 0 )
+ ImplWriteBack();
+ if ( deflate( pStream, Z_NO_FLUSH ) < 0 )
+ {
+ mbStatus = false;
+ break;
+ }
+ };
+}
+
+tools::Long ZCodec::Decompress( SvStream& rIStm, SvStream& rOStm )
+{
+ int err;
+ size_t nInToRead;
+ auto pStream = static_cast<z_stream*>(mpsC_Stream);
+ tools::Long nOldTotal_Out = pStream->total_out;
+
+ assert(meState == STATE_INIT);
+ mpOStm = &rOStm;
+ InitDecompress(rIStm);
+ pStream->avail_out = mnOutBufSize;
+ mpOutBuf.reset(new sal_uInt8[ pStream->avail_out ]);
+ pStream->next_out = mpOutBuf.get();
+ do
+ {
+ if ( pStream->avail_out == 0 ) ImplWriteBack();
+ if ( pStream->avail_in == 0 && mnInToRead )
+ {
+ nInToRead = std::min( mnInBufSize, mnInToRead );
+ pStream->next_in = mpInBuf.get();
+ pStream->avail_in = rIStm.ReadBytes(mpInBuf.get(), nInToRead);
+ mnInToRead -= nInToRead;
+ }
+ err = mbStatus ? inflate(pStream, Z_NO_FLUSH) : Z_ERRNO;
+ if (err < 0 || err == Z_NEED_DICT)
+ {
+ mbStatus = false;
+ break;
+ }
+
+ }
+ while ( ( err != Z_STREAM_END) && ( pStream->avail_in || mnInToRead ) );
+ ImplWriteBack();
+
+ return mbStatus ? static_cast<tools::Long>(pStream->total_out - nOldTotal_Out) : -1;
+}
+
+void ZCodec::Write( SvStream& rOStm, const sal_uInt8* pData, sal_uInt32 nSize )
+{
+ if (meState == STATE_INIT)
+ {
+ mpOStm = &rOStm;
+ InitCompress();
+ }
+ assert(&rOStm == mpOStm);
+
+ auto pStream = static_cast<z_stream*>(mpsC_Stream);
+ pStream->avail_in = nSize;
+ pStream->next_in = pData;
+
+ while ( pStream->avail_in || ( pStream->avail_out == 0 ) )
+ {
+ if ( pStream->avail_out == 0 )
+ ImplWriteBack();
+
+ if ( deflate( pStream, Z_NO_FLUSH ) < 0 )
+ {
+ mbStatus = false;
+ break;
+ }
+ }
+}
+
+tools::Long ZCodec::Read( SvStream& rIStm, sal_uInt8* pData, sal_uInt32 nSize )
+{
+ int err;
+ size_t nInToRead;
+
+ if ( mbFinish )
+ return 0; // pStream->total_out;
+
+ if (meState == STATE_INIT)
+ {
+ InitDecompress(rIStm);
+ }
+ auto pStream = static_cast<z_stream*>(mpsC_Stream);
+ pStream->avail_out = nSize;
+ pStream->next_out = pData;
+ do
+ {
+ if ( pStream->avail_in == 0 && mnInToRead )
+ {
+ nInToRead = std::min(mnInBufSize, mnInToRead);
+ pStream->next_in = mpInBuf.get();
+ pStream->avail_in = rIStm.ReadBytes(mpInBuf.get(), nInToRead);
+ mnInToRead -= nInToRead;
+ }
+ err = mbStatus ? inflate(pStream, Z_NO_FLUSH) : Z_ERRNO;
+ if (err < 0 || err == Z_NEED_DICT)
+ {
+ // Accept Z_BUF_ERROR as EAGAIN or EWOULDBLOCK.
+ mbStatus = (err == Z_BUF_ERROR);
+ break;
+ }
+ }
+ while ( (err != Z_STREAM_END) &&
+ (pStream->avail_out != 0) &&
+ (pStream->avail_in || mnInToRead) );
+ if ( err == Z_STREAM_END )
+ mbFinish = true;
+
+ return (mbStatus ? static_cast<tools::Long>(nSize - pStream->avail_out) : -1);
+}
+
+void ZCodec::ImplWriteBack()
+{
+ auto pStream = static_cast<z_stream*>(mpsC_Stream);
+ size_t nAvail = mnOutBufSize - pStream->avail_out;
+
+ if ( nAvail > 0 )
+ {
+ pStream->next_out = mpOutBuf.get();
+ mpOStm->WriteBytes( mpOutBuf.get(), nAvail );
+ pStream->avail_out = mnOutBufSize;
+ }
+}
+
+void ZCodec::InitCompress()
+{
+ assert(meState == STATE_INIT);
+ meState = STATE_COMPRESS;
+ auto pStream = static_cast<z_stream*>(mpsC_Stream);
+ mbStatus = deflateInit2_(
+ pStream, mnCompressLevel, Z_DEFLATED, MAX_WBITS, MAX_MEM_LEVEL,
+ Z_DEFAULT_STRATEGY, ZLIB_VERSION, sizeof (z_stream)) >= 0;
+ mpOutBuf.reset(new sal_uInt8[mnOutBufSize]);
+ pStream->next_out = mpOutBuf.get();
+ pStream->avail_out = mnOutBufSize;
+}
+
+void ZCodec::InitDecompress(SvStream & inStream)
+{
+ assert(meState == STATE_INIT);
+ auto pStream = static_cast<z_stream*>(mpsC_Stream);
+ if ( mbStatus && mbGzLib )
+ {
+ sal_uInt8 j, nMethod, nFlags;
+ sal_uInt16 nFirstTwoBytes;
+ inStream.Seek( 0 );
+ inStream.ReadUInt16( nFirstTwoBytes );
+ if ( nFirstTwoBytes != GZ_MAGIC_BYTES_LE )
+ mbStatus = false;
+ inStream.ReadUChar( nMethod );
+ inStream.ReadUChar( nFlags );
+ if ( nMethod != Z_DEFLATED )
+ mbStatus = false;
+ if ( ( nFlags & GZ_RESERVED ) != 0 )
+ mbStatus = false;
+ /* Discard time, xflags and OS code: */
+ inStream.SeekRel( 6 );
+ /* skip the extra field */
+ if ( nFlags & GZ_EXTRA_FIELD )
+ {
+ sal_uInt8 n1, n2;
+ inStream.ReadUChar( n1 ).ReadUChar( n2 );
+ inStream.SeekRel( n1 + ( n2 << 8 ) );
+ }
+ /* skip the original file name */
+ if ( nFlags & GZ_ORIG_NAME)
+ {
+ do
+ {
+ inStream.ReadUChar( j );
+ }
+ while ( j && !inStream.eof() );
+ }
+ /* skip the .gz file comment */
+ if ( nFlags & GZ_COMMENT )
+ {
+ do
+ {
+ inStream.ReadUChar( j );
+ }
+ while ( j && !inStream.eof() );
+ }
+ /* skip the header crc */
+ if ( nFlags & GZ_HEAD_CRC )
+ inStream.SeekRel( 2 );
+ if ( mbStatus )
+ mbStatus = inflateInit2( pStream, -MAX_WBITS) == Z_OK;
+ }
+ else
+ {
+ mbStatus = ( inflateInit( pStream ) >= 0 );
+ }
+ if ( mbStatus )
+ meState = STATE_DECOMPRESS;
+ mpInBuf.reset(new sal_uInt8[ mnInBufSize ]);
+}
+
+bool ZCodec::AttemptDecompression(SvStream& rIStm, SvStream& rOStm)
+{
+ assert(meState == STATE_INIT);
+ sal_uInt64 nStreamPos = rIStm.Tell();
+ BeginCompression(ZCODEC_DEFAULT_COMPRESSION, true/*gzLib*/);
+ InitDecompress(rIStm);
+ EndCompression();
+ if ( !mbStatus || rIStm.GetError() )
+ {
+ rIStm.Seek(nStreamPos);
+ return false;
+ }
+ rIStm.Seek(nStreamPos);
+ BeginCompression(ZCODEC_DEFAULT_COMPRESSION, true/*gzLib*/);
+ Decompress(rIStm, rOStm);
+ EndCompression();
+ if( !mbStatus || rIStm.GetError() || rOStm.GetError() )
+ {
+ rIStm.Seek(nStreamPos);
+ return false;
+ }
+ rIStm.Seek(nStreamPos);
+ rOStm.Seek(0);
+ return true;
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */