File indexing completed on 2024-04-28 16:06:18

 /* AUDEX CDDA EXTRACTOR
  * SPDX-FileCopyrightText: Copyright (C) 2007 Marco Nelles
  * <https://userbase.kde.org/Audex>
  *
  * SPDX-License-Identifier: GPL-3.0-or-later
  */
 
 #include "crc32hash.h"
 
 #include <QDebug>
 
 #define MASK1 0x00FFFFFF
 #define MASK2 0xFFFFFFFF
 #define POLYNOMIAL 0xEDB88320
 
 CRC32Hash::CRC32Hash(const quint32 initial_value)
 {
     p_initial_value = initial_value;
     init(initial_value);
 }
 
 CRC32Hash::CRC32Hash(const CRC32Hash &other)
 {
     crc32_accum = other.crc32_accum;
     memcpy(crc32_table, other.crc32_table, 256);
 }
 
 CRC32Hash &CRC32Hash::operator=(const CRC32Hash &other)
 {
     crc32_accum = other.crc32_accum;
     memcpy(crc32_table, other.crc32_table, 256);
     return *this;
 }
 
 bool CRC32Hash::operator==(const CRC32Hash &other) const
 {
     return result() == other.result();
 }
 
 bool CRC32Hash::operator!=(const CRC32Hash &other) const
 {
     return result() != other.result();
 }
 
 CRC32Hash::~CRC32Hash()
 {
 }
 
 void CRC32Hash::addData(const QByteArray &ba)
 {
     int length = ba.length();
     const unsigned char *buffer = reinterpret_cast<const unsigned char *>(ba.constData());
     while (length-- > 0)
         crc32_accum = ((crc32_accum >> 8) & MASK1) ^ crc32_table[(crc32_accum & 0xff) ^ *buffer++];
 }
 
 quint32 CRC32Hash::result() const
 {
     return (~crc32_accum) & MASK2;
 }
 
 void CRC32Hash::clear()
 {
     crc32_accum = p_initial_value;
 }
 
 void CRC32Hash::init(const quint32 initial_value)
 {
     crc32_accum = initial_value;
 
     for (int byte = 0; byte != 256; byte++) {
         quint32 data = byte;
 
         for (int i = 8; i > 0; --i)
             data = data & 1 ? (data >> 1) ^ POLYNOMIAL : data >> 1;
 
         crc32_table[byte] = data;
     }
 }