libreoffice/package/source/zipapi/CRC32.cxx

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#include <CRC32.hxx>
#include <PackageConstants.hxx>
#include <rtl/crc.h>
#include <com/sun/star/io/XInputStream.hpp>

using namespace com::sun::star::uno;
using namespace com::sun::star::io;

/** A class to compute the CRC32 value of a data stream
 */

CRC32::CRC32()
: nCRC(0)
{
}
CRC32::~CRC32()
{
}
void SAL_CALL CRC32::reset()
    throw(RuntimeException)
{
    nCRC=0;
}
sal_Int32 SAL_CALL CRC32::getValue()
    throw(RuntimeException)
{
    return nCRC & 0xFFFFFFFFL;
}
/** Update CRC32 with specified sequence of bytes
 */
void SAL_CALL CRC32::updateSegment(const Sequence< sal_Int8 > &b,
                                    sal_Int32 off,
                                    sal_Int32 len)
        throw(RuntimeException)
{
    nCRC = rtl_crc32(nCRC, b.getConstArray()+off, len );
}
/** Update CRC32 with specified sequence of bytes
 */
void SAL_CALL CRC32::update(const Sequence< sal_Int8 > &b)
        throw(RuntimeException)
{
    nCRC = rtl_crc32(nCRC, b.getConstArray(),b.getLength());
}

sal_Int32 SAL_CALL CRC32::updateStream( Reference < XInputStream > & xStream )
    throw ( RuntimeException )
{
    sal_Int32 nLength, nTotal = 0;
    Sequence < sal_Int8 > aSeq ( n_ConstBufferSize );
    do
    {
        nLength = xStream->readBytes ( aSeq, n_ConstBufferSize );
        updateSegment ( aSeq, 0, nLength );
        nTotal += nLength;
    }
    while ( nLength == n_ConstBufferSize );

    return nTotal;
}

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