use crate::util::crc64;
use crc_catalog::Algorithm;
mod bytewise;
mod nolookup;
mod slice16;
const fn init(algorithm: &Algorithm<u64>, initial: u64) -> u64 {
if algorithm.refin {
initial.reverse_bits() >> (64u8 - algorithm.width)
} else {
initial << (64u8 - algorithm.width)
}
}
const fn finalize(algorithm: &Algorithm<u64>, mut crc: u64) -> u64 {
if algorithm.refin ^ algorithm.refout {
crc = crc.reverse_bits();
}
if !algorithm.refout {
crc >>= 64u8 - algorithm.width;
}
crc ^ algorithm.xorout
}
const fn update_nolookup(mut crc: u64, algorithm: &Algorithm<u64>, bytes: &[u8]) -> u64 {
let poly = if algorithm.refin {
let poly = algorithm.poly.reverse_bits();
poly >> (64u8 - algorithm.width)
} else {
algorithm.poly << (64u8 - algorithm.width)
};
let mut i = 0;
if algorithm.refin {
while i < bytes.len() {
let to_crc = (crc ^ bytes[i] as u64) & 0xFF;
crc = crc64(poly, algorithm.refin, to_crc) ^ (crc >> 8);
i += 1;
}
} else {
while i < bytes.len() {
let to_crc = ((crc >> 56) ^ bytes[i] as u64) & 0xFF;
crc = crc64(poly, algorithm.refin, to_crc) ^ (crc << 8);
i += 1;
}
}
crc
}
const fn update_bytewise(mut crc: u64, reflect: bool, table: &[u64; 256], bytes: &[u8]) -> u64 {
let mut i = 0;
let len = bytes.len();
if reflect {
while i < len {
let table_index = ((crc ^ bytes[i] as u64) & 0xFF) as usize;
crc = table[table_index] ^ (crc >> 8);
i += 1;
}
} else {
while i < len {
let table_index = (((crc >> 56) ^ bytes[i] as u64) & 0xFF) as usize;
crc = table[table_index] ^ (crc << 8);
i += 1;
}
}
crc
}
const fn update_slice16(
mut crc: u64,
reflect: bool,
table: &[[u64; 256]; 16],
bytes: &[u8],
) -> u64 {
let mut i = 0;
let len = bytes.len();
if reflect {
while i + 16 <= len {
let current0 = bytes[i] ^ crc as u8;
let current1 = bytes[i + 1] ^ (crc >> 8) as u8;
let current2 = bytes[i + 2] ^ (crc >> 16) as u8;
let current3 = bytes[i + 3] ^ (crc >> 24) as u8;
let current4 = bytes[i + 4] ^ (crc >> 32) as u8;
let current5 = bytes[i + 5] ^ (crc >> 40) as u8;
let current6 = bytes[i + 6] ^ (crc >> 48) as u8;
let current7 = bytes[i + 7] ^ (crc >> 56) as u8;
crc = table[0][bytes[i + 15] as usize]
^ table[1][bytes[i + 14] as usize]
^ table[2][bytes[i + 13] as usize]
^ table[3][bytes[i + 12] as usize]
^ table[4][bytes[i + 11] as usize]
^ table[5][bytes[i + 10] as usize]
^ table[6][bytes[i + 9] as usize]
^ table[7][bytes[i + 8] as usize]
^ table[8][current7 as usize]
^ table[9][current6 as usize]
^ table[10][current5 as usize]
^ table[11][current4 as usize]
^ table[12][current3 as usize]
^ table[13][current2 as usize]
^ table[14][current1 as usize]
^ table[15][current0 as usize];
i += 16;
}
while i < len {
let table_index = ((crc ^ bytes[i] as u64) & 0xFF) as usize;
crc = table[0][table_index] ^ (crc >> 8);
i += 1;
}
} else {
while i + 16 <= len {
let current0 = bytes[i] ^ (crc >> 56) as u8;
let current1 = bytes[i + 1] ^ (crc >> 48) as u8;
let current2 = bytes[i + 2] ^ (crc >> 40) as u8;
let current3 = bytes[i + 3] ^ (crc >> 32) as u8;
let current4 = bytes[i + 4] ^ (crc >> 24) as u8;
let current5 = bytes[i + 5] ^ (crc >> 16) as u8;
let current6 = bytes[i + 6] ^ (crc >> 8) as u8;
let current7 = bytes[i + 7] ^ crc as u8;
crc = table[0][bytes[i + 15] as usize]
^ table[1][bytes[i + 14] as usize]
^ table[2][bytes[i + 13] as usize]
^ table[3][bytes[i + 12] as usize]
^ table[4][bytes[i + 11] as usize]
^ table[5][bytes[i + 10] as usize]
^ table[6][bytes[i + 9] as usize]
^ table[7][bytes[i + 8] as usize]
^ table[8][current7 as usize]
^ table[9][current6 as usize]
^ table[10][current5 as usize]
^ table[11][current4 as usize]
^ table[12][current3 as usize]
^ table[13][current2 as usize]
^ table[14][current1 as usize]
^ table[15][current0 as usize];
i += 16;
}
while i < len {
let table_index = (((crc >> 56) ^ bytes[i] as u64) & 0xFF) as usize;
crc = table[0][table_index] ^ (crc << 8);
i += 1;
}
}
crc
}
#[cfg(test)]
mod test {
use crate::*;
use crc_catalog::{Algorithm, CRC_64_ECMA_182};
#[test]
fn correctness() {
let data: &[&str] = &[
"",
"1",
"1234",
"123456789",
"0123456789ABCDE",
"01234567890ABCDEFGHIJK",
"01234567890ABCDEFGHIJK01234567890ABCDEFGHIJK01234567890ABCDEFGHIJK01234567890ABCDEFGHIJK01234567890ABCDEFGHIJK01234567890ABCDEFGHIJK01234567890ABCDEFGHIJK01234567890ABCDEFGHIJK01234567890ABCDEFGHIJK01234567890ABCDEFGHIJK01234567890ABCDEFGHIJK01234567890ABCDEFGHIJK",
];
pub const CRC_64_ECMA_182_REFLEX: Algorithm<u64> = Algorithm {
width: 64,
poly: 0x42f0e1eba9ea3693,
init: 0x0000000000000000,
refin: true,
refout: false,
xorout: 0x0000000000000000,
check: 0x6c40df5f0b497347,
residue: 0x0000000000000000,
};
let algs_to_test = [&CRC_64_ECMA_182, &CRC_64_ECMA_182_REFLEX];
for alg in algs_to_test {
for data in data {
let crc_slice16 = Crc::<u64, Table<16>>::new(alg);
let crc_nolookup = Crc::<u64, NoTable>::new(alg);
let expected = Crc::<u64, Table<1>>::new(alg).checksum(data.as_bytes());
assert_eq!(crc_slice16.checksum(data.as_bytes()), expected);
assert_eq!(crc_nolookup.checksum(data.as_bytes()), expected);
let mut digest = crc_slice16.digest();
digest.update(data.as_bytes());
assert_eq!(digest.finalize(), expected);
let mut digest = crc_nolookup.digest();
digest.update(data.as_bytes());
assert_eq!(digest.finalize(), expected);
if data.len() > 2 {
let data = data.as_bytes();
let data1 = &data[..data.len() / 2];
let data2 = &data[data.len() / 2..];
let mut digest = crc_slice16.digest();
digest.update(data1);
digest.update(data2);
assert_eq!(digest.finalize(), expected);
let mut digest = crc_nolookup.digest();
digest.update(data1);
digest.update(data2);
assert_eq!(digest.finalize(), expected);
}
}
}
}
}