diff options
Diffstat (limited to 'users/fogti/store-ref-scanner/src/hbm.rs')
| -rw-r--r-- | users/fogti/store-ref-scanner/src/hbm.rs | 167 |
1 files changed, 167 insertions, 0 deletions
diff --git a/users/fogti/store-ref-scanner/src/hbm.rs b/users/fogti/store-ref-scanner/src/hbm.rs new file mode 100644 index 0000000000..2520efd836 --- /dev/null +++ b/users/fogti/store-ref-scanner/src/hbm.rs @@ -0,0 +1,167 @@ +#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)] +pub struct HalfBytesMask(pub [u8; 16]); + +#[allow(clippy::as_conversions, clippy::zero_prefixed_literal)] +impl HalfBytesMask { + pub const B32_REVSHA256: HalfBytesMask = + HalfBytesMask([0, 0, 0, 0, 0, 0, 255, 3, 0, 0, 0, 0, 222, 127, 207, 7]); + + pub const B64_BLAKE2B256: HalfBytesMask = HalfBytesMask([ + 0, 0, 0, 0, 0, 8, 255, 3, 254, 255, 255, 135, 254, 255, 255, 7, + ]); + + pub const DFL_REST: HalfBytesMask = HalfBytesMask([ + 0, 0, 0, 0, 0, 104, 255, 163, 254, 255, 255, 135, 254, 255, 255, 7, + ]); + + #[inline] + pub const fn from_expanded(x: [bool; 128]) -> Self { + let mut ret = [0u8; 16]; + let mut idx = 0; + while idx < 16 { + let fin = idx * 8; + let mut idx2 = 0; + while idx2 < 8 { + if x[fin + idx2] { + ret[idx] += (1 << idx2) as u8; + } + idx2 += 1; + } + idx += 1; + } + Self(ret) + } + + /// create a mask by allowing all characters via the mask which are included in the given string + pub fn from_bytes(s: &[u8]) -> Self { + s.iter().fold(Self([0u8; 16]), |mut ret, &i| { + ret.set(i, true); + ret + }) + } + + pub const fn into_expanded(self) -> [bool; 128] { + let Self(ihbm) = self; + let mut ret = [false; 128]; + let mut idx = 0; + while idx < 16 { + let fin = idx * 8; + let curi = ihbm[idx]; + let mut idx2 = 0; + while idx2 < 8 { + ret[fin + idx2] = (curi >> idx2) & 0b1 != 0; + idx2 += 1; + } + idx += 1; + } + ret + } + + pub fn contains(&self, byte: u8) -> bool { + if byte >= 0x80 { + false + } else { + (self.0[usize::from(byte / 8)] >> u32::from(byte % 8)) & 0b1 != 0 + } + } + + pub fn set(&mut self, byte: u8, allow: bool) { + if byte >= 0x80 { + if cfg!(debug_assertions) { + panic!( + "tried to manipulate invalid byte {:?} in HalfBytesMask", + byte + ); + } else { + return; + } + } + let block = &mut self.0[usize::from(byte / 8)]; + let bitpat = (1 << u32::from(byte % 8)) as u8; + if allow { + *block |= bitpat; + } else { + *block &= !bitpat; + } + } + + #[cfg(test)] + fn count_ones(&self) -> u8 { + self.0 + .iter() + .map(|i| i.count_ones()) + .sum::<u32>() + .try_into() + .unwrap() + } +} + +#[cfg(test)] +mod tests { + use super::*; + + #[test] + fn maskbase() { + assert_eq!(HalfBytesMask::B32_REVSHA256.count_ones(), 32); + assert_eq!(HalfBytesMask::B64_BLAKE2B256.count_ones(), 64); + } + + #[test] + fn non_ascii() { + for i in 0x80..=0xff { + assert!(!HalfBytesMask::DFL_REST.contains(i)); + } + } + + #[test] + fn dflmask() { + assert_eq!( + HalfBytesMask::from_expanded( + [ + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + ] + .map(|i| i != 0) + ), + Default::default(), + ); + + assert_eq!( + HalfBytesMask::from_expanded( + [ + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, + ] + .map(|i| i != 0) + ), + HalfBytesMask::B32_REVSHA256, + ); + + assert_eq!( + HalfBytesMask::from_expanded( + [ + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, + 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, + ] + .map(|i| i != 0) + ), + HalfBytesMask::B64_BLAKE2B256, + ); + + assert_eq!( + HalfBytesMask::from_bytes( + b"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+-._?=" + ), + HalfBytesMask::DFL_REST, + ); + } +} |