| 898 | #define CRC_BUFFER_SIZE 5000 |
| 899 | |
| 900 | uint32_t cf_CalculateFileCRC(CFILE *infile) { |
| 901 | int i, j; |
| 902 | uint8_t crcbuf[CRC_BUFFER_SIZE]; |
| 903 | static bool Cfile_crc_calculated = false; |
| 904 | static uint32_t CRCTable[256]; |
| 905 | uint32_t crc; |
| 906 | uint32_t temp1; |
| 907 | uint32_t temp2; |
| 908 | uint32_t readlen; |
| 909 | |
| 910 | // Only make the lookup table once |
| 911 | if (!Cfile_crc_calculated) { |
| 912 | Cfile_crc_calculated = true; |
| 913 | |
| 914 | for (i = 0; i <= 255; i++) { |
| 915 | crc = i; |
| 916 | for (j = 8; j > 0; j--) { |
| 917 | if (crc & 1) |
| 918 | crc = (crc >> 1) ^ CRC32_POLYNOMIAL; |
| 919 | else |
| 920 | crc >>= 1; |
| 921 | } |
| 922 | CRCTable[i] = crc; |
| 923 | } |
| 924 | } |
| 925 | |
| 926 | crc = 0xffffffffl; |
| 927 | while (!cfeof(infile)) { |
| 928 | if ((infile->size - infile->position) < CRC_BUFFER_SIZE) |
| 929 | readlen = infile->size - infile->position; |
| 930 | else |
| 931 | readlen = CRC_BUFFER_SIZE; |
| 932 | if (!cf_ReadBytes(crcbuf, readlen, infile)) { |
| 933 | // Doh, error time! |
| 934 | Int3(); |
| 935 | return 0xFFFFFFFF; |
| 936 | } |
| 937 | for (uint32_t a = 0; a < readlen; a++) { |
| 938 | temp1 = (crc >> 8) & 0x00FFFFFFL; |
| 939 | temp2 = CRCTable[((int)crc ^ crcbuf[a]) & 0xff]; |
| 940 | crc = temp1 ^ temp2; |
| 941 | } |
| 942 | } |
| 943 | |
| 944 | return crc ^ 0xffffffffl; |
| 945 | } |
| 946 | |
| 947 | uint32_t cf_GetfileCRC(const std::filesystem::path &src) { |
| 948 | CFILE *infile = cfopen(src, "rb"); |