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access CRC tab directly

This commit is contained in:
Martchus 2015-10-16 21:34:58 +02:00
parent 4e359bdfea
commit cd01df9c64
2 changed files with 47 additions and 54 deletions
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11
io/binaryreader.cpp
View File

@ -275,7 +275,6 @@ string BinaryReader::readMultibyteTerminatedStringLE(size_t maxBytesToRead, uint
*/ */
uint32 BinaryReader::readCrc32(size_t length) uint32 BinaryReader::readCrc32(size_t length)
{ {
uint32 *crc32Table = BinaryReader::crc32Table();
uint32 crc = 0x00; uint32 crc = 0x00;
for(uint32 i = 0; i < length; ++i) { for(uint32 i = 0; i < length; ++i) {
crc = (crc << 8) ^ crc32Table[((crc >> 24) & 0xff) ^ static_cast<byte>(m_stream->get())]; crc = (crc << 8) ^ crc32Table[((crc >> 24) & 0xff) ^ static_cast<byte>(m_stream->get())];
@ -284,15 +283,11 @@ uint32 BinaryReader::readCrc32(size_t length)
} }
/*! /*!
* \brief Returns a CRC-32 table. * \brief CRC-32 table.
*
* \remarks Internally used by readCrc32() method. * \remarks Internally used by readCrc32() method.
*
* \sa readCrc32() * \sa readCrc32()
*/ */
uint32 *BinaryReader::crc32Table() const uint32 BinaryReader::crc32Table[] = {
{
static uint32 table[] = {
0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b, 0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b,
0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61, 0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61,
0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd, 0x4c11db70, 0x48d0c6c7, 0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd, 0x4c11db70, 0x48d0c6c7,
@ -337,6 +332,4 @@ uint32 *BinaryReader::crc32Table()
0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668, 0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668,
0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4 0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4
}; };
return table;
}

2
io/binaryreader.h
View File

@ -75,8 +75,8 @@ public:
float32 readFixed8LE(); float32 readFixed8LE();
float32 readFixed16LE(); float32 readFixed16LE();
uint32 readCrc32(std::size_t length); uint32 readCrc32(std::size_t length);
static uint32 *crc32Table();
static uint32 computeCrc32(const char *buffer, std::size_t length); static uint32 computeCrc32(const char *buffer, std::size_t length);
static const uint32 crc32Table[];
private: private:
std::istream *m_stream; std::istream *m_stream;