/* -*- 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 <package/Deflater.hxx>

#include <zlib.h>

#include <com/sun/star/packages/zip/ZipConstants.hpp>

#include <osl/diagnose.h>

#include <string.h>

using namespace com::sun::star::packages::zip::ZipConstants;

using namespace com::sun::star;

using namespace ZipUtils;

/** Provides general purpose compression using the ZLIB compression

 * library.

 */

Deflater::~Deflater()

{

    end();

}

void Deflater::init (sal_Int32 nLevelArg, bool bNowrap)

{

    pStream.reset(new z_stream);

    /* Memset it to 0...sets zalloc/zfree/opaque to NULL */

    memset (pStream.get(), 0, sizeof(*pStream));

    switch (deflateInit2(pStream.get(), nLevelArg, Z_DEFLATED, bNowrap? -MAX_WBITS : MAX_WBITS,

                DEF_MEM_LEVEL, DEFAULT_STRATEGY))

    {

        case Z_OK:

            break;

        case Z_MEM_ERROR:

        case Z_STREAM_ERROR:

            pStream.reset();

            break;

        default:

             break;

    }

}

Deflater::Deflater(sal_Int32 nSetLevel, bool bNowrap)

: bFinish(false)

, bFinished(false)

, nOffset(0)

, nLength(0)

, nTotalOut64(0)

, nTotalIn64(0)

{

    init(nSetLevel, bNowrap);

}

sal_Int32 Deflater::doDeflateBytes (uno::Sequence < sal_Int8 > &rBuffer, sal_Int32 nNewOffset, sal_Int32 nNewLength)

{

    sal_Int32 nResult;

    pStream->next_in   = reinterpret_cast<const unsigned char*>( sInBuffer.getConstArray() + nOffset );

    pStream->next_out  = reinterpret_cast<unsigned char*>(rBuffer.getArray())+nNewOffset;

    pStream->avail_in  = nLength;

    pStream->avail_out = nNewLength;

    auto nLastTotalIn = pStream->total_in;

    auto nLastTotalOut = pStream->total_out;

#if !defined Z_PREFIX

    nResult = deflate(pStream.get(), bFinish ? Z_FINISH : Z_NO_FLUSH);

#else

    nResult = z_deflate(pStream.get(), bFinish ? Z_FINISH : Z_NO_FLUSH);

#endif

    // total_in / total_out may stored only in 32bit, and can overflow during deflate

    // 1 deflate call, uncompress only a few data, so only 1 overflow can happen at once.

    if (pStream->total_in < nLastTotalIn)

    {

        nTotalIn64 += 0x100000000;

    }

    if (pStream->total_out < nLastTotalOut)

    {

        nTotalOut64 += 0x100000000;

    }

    switch (nResult)

    {

        case Z_STREAM_END:

            bFinished = true;

            [[fallthrough]];

        case Z_OK:

            nOffset += nLength - pStream->avail_in;

            nLength = pStream->avail_in;

            return nNewLength - pStream->avail_out;

        default:

            return 0;

    }

}

void Deflater::setInputSegment( const uno::Sequence< sal_Int8 >& rBuffer )

{

    sInBuffer = rBuffer;

    nOffset = 0;

    nLength = rBuffer.getLength();

}

bool Deflater::needsInput() const

{

    return nLength <=0;

}

void Deflater::finish(  )

{

    bFinish = true;

}

sal_Int32 Deflater::doDeflateSegment( uno::Sequence< sal_Int8 >& rBuffer, sal_Int32 nNewLength )

{

    OSL_ASSERT( !(nNewLength < 0 || nNewLength > rBuffer.getLength()));

    return doDeflateBytes(rBuffer, /*nNewOffset*/0, nNewLength);

}

sal_Int64 Deflater::getTotalIn() const

{

    return pStream->total_in + nTotalIn64;

}

sal_Int64 Deflater::getTotalOut() const

{

    return pStream->total_out + nTotalOut64;

}

void Deflater::reset(  )

{

#if !defined Z_PREFIX

    deflateReset(pStream.get());

#else

    z_deflateReset(pStream.get());

#endif

    bFinish = false;

    bFinished = false;

    nOffset = nLength = 0;

}

void Deflater::end(  )

{

    if (pStream)

    {

#if !defined Z_PREFIX

        deflateEnd(pStream.get());

#else

        z_deflateEnd(pStream.get());

#endif

        pStream.reset();

    }

}

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