move crc to ckum and add ADLER function
parent
bf8fa42e26
commit
7d02f6460f
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@ -3,7 +3,7 @@
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fn crc_accum(a: u32, _: u32) -> u32
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{
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if a & 1 == 1 {
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0xEDB8_8320 ^ a >> 1
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ISO_3309_POLYNOMIAL ^ a >> 1
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} else {
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a >> 1
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}
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@ -18,13 +18,36 @@ fn crc_init() -> [u32; 256]
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t
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}
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/// Creates an ADLER32 of all bytes in `b`.
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///
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/// # Examples
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///
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/// ```
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/// use maraiah::durandal::cksum::adler32;
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///
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/// assert_eq!(adler32(b"Lorem ipsum dolor sit amet"), 0x83D5_09C5);
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/// ```
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pub fn adler32(b: &[u8]) -> u32
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{
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let mut x = 1;
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let mut y = 0;
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for &z in b {
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let z = u32::from(z);
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x = (x + z) % ADLER32_MODULO;
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y = (y + x) % ADLER32_MODULO;
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}
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(y << 16) | x
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}
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/// Creates a CRC-32 of all bytes in `b` with the starting sum `s`. The
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/// polynomial used is the one from ISO-3309.
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///
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/// # Examples
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///
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/// ```
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/// use maraiah::durandal::crc::crc32;
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/// use maraiah::durandal::cksum::crc32;
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///
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/// assert_eq!(crc32(b"Lorem ipsum dolor sit amet", !0), 0x5F29_D461);
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/// ```
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@ -34,4 +57,7 @@ pub fn crc32(b: &[u8], s: u32) -> u32
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!b.iter().fold(s, |a, &o| a >> 8 ^ t[usize::from(a as u8 ^ o)])
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}
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const ISO_3309_POLYNOMIAL: u32 = 0xEDB8_8320;
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const ADLER32_MODULO: u32 = 65521;
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// EOF
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@ -8,7 +8,7 @@ pub mod cenum;
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pub mod bin;
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pub mod bit;
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pub mod crc;
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pub mod cksum;
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pub mod file;
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pub mod fixed;
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pub mod image;
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