diff options
Diffstat (limited to 'third_party/rust/ahash/src/fallback_hash.rs')
-rw-r--r-- | third_party/rust/ahash/src/fallback_hash.rs | 51 |
1 files changed, 13 insertions, 38 deletions
diff --git a/third_party/rust/ahash/src/fallback_hash.rs b/third_party/rust/ahash/src/fallback_hash.rs index aad9efc859..bc5cbfeeec 100644 --- a/third_party/rust/ahash/src/fallback_hash.rs +++ b/third_party/rust/ahash/src/fallback_hash.rs @@ -1,12 +1,11 @@ use crate::convert::*; use crate::operations::folded_multiply; use crate::operations::read_small; +use crate::operations::MULTIPLE; use crate::random_state::PI; use crate::RandomState; use core::hash::Hasher; -///This constant come from Kunth's prng (Empirically it works better than those from splitmix32). -pub(crate) const MULTIPLE: u64 = 6364136223846793005; const ROT: u32 = 23; //17 /// A `Hasher` for hashing an arbitrary stream of bytes. @@ -31,7 +30,7 @@ impl AHasher { /// Creates a new hasher keyed to the provided key. #[inline] #[allow(dead_code)] // Is not called if non-fallback hash is used. - pub fn new_with_keys(key1: u128, key2: u128) -> AHasher { + pub(crate) fn new_with_keys(key1: u128, key2: u128) -> AHasher { let pi: [u128; 2] = PI.convert(); let key1: [u64; 2] = (key1 ^ pi[0]).convert(); let key2: [u64; 2] = (key2 ^ pi[1]).convert(); @@ -57,8 +56,8 @@ impl AHasher { #[allow(dead_code)] // Is not called if non-fallback hash is used. pub(crate) fn from_random_state(rand_state: &RandomState) -> AHasher { AHasher { - buffer: rand_state.k0, - pad: rand_state.k1, + buffer: rand_state.k1, + pad: rand_state.k0, extra_keys: [rand_state.k2, rand_state.k3], } } @@ -93,19 +92,10 @@ impl AHasher { /// attacker somehow knew part of (but not all) the contents of the buffer before hand, /// they would not be able to predict any of the bits in the buffer at the end. #[inline(always)] - #[cfg(feature = "folded_multiply")] fn update(&mut self, new_data: u64) { self.buffer = folded_multiply(new_data ^ self.buffer, MULTIPLE); } - #[inline(always)] - #[cfg(not(feature = "folded_multiply"))] - fn update(&mut self, new_data: u64) { - let d1 = (new_data ^ self.buffer).wrapping_mul(MULTIPLE); - self.pad = (self.pad ^ d1).rotate_left(8).wrapping_mul(MULTIPLE); - self.buffer = (self.buffer ^ self.pad).rotate_left(24); - } - /// Similar to the above this function performs an update using a "folded multiply". /// However it takes in 128 bits of data instead of 64. Both halves must be masked. /// @@ -118,25 +108,16 @@ impl AHasher { /// can't be changed by the same set of input bits. To cancel this sequence with subsequent input would require /// knowing the keys. #[inline(always)] - #[cfg(feature = "folded_multiply")] fn large_update(&mut self, new_data: u128) { let block: [u64; 2] = new_data.convert(); let combined = folded_multiply(block[0] ^ self.extra_keys[0], block[1] ^ self.extra_keys[1]); self.buffer = (self.buffer.wrapping_add(self.pad) ^ combined).rotate_left(ROT); } - #[inline(always)] - #[cfg(not(feature = "folded_multiply"))] - fn large_update(&mut self, new_data: u128) { - let block: [u64; 2] = new_data.convert(); - self.update(block[0] ^ self.extra_keys[0]); - self.update(block[1] ^ self.extra_keys[1]); - } - #[inline] #[cfg(feature = "specialize")] fn short_finish(&self) -> u64 { - self.buffer.wrapping_add(self.pad) + folded_multiply(self.buffer, self.pad) } } @@ -170,7 +151,11 @@ impl Hasher for AHasher { } #[inline] - #[cfg(any(target_pointer_width = "64", target_pointer_width = "32", target_pointer_width = "16"))] + #[cfg(any( + target_pointer_width = "64", + target_pointer_width = "32", + target_pointer_width = "16" + ))] fn write_usize(&mut self, i: usize) { self.write_u64(i as u64); } @@ -208,18 +193,10 @@ impl Hasher for AHasher { } #[inline] - #[cfg(feature = "folded_multiply")] fn finish(&self) -> u64 { let rot = (self.buffer & 63) as u32; folded_multiply(self.buffer, self.pad).rotate_left(rot) } - - #[inline] - #[cfg(not(feature = "folded_multiply"))] - fn finish(&self) -> u64 { - let rot = (self.buffer & 63) as u32; - (self.buffer.wrapping_mul(MULTIPLE) ^ self.pad).rotate_left(rot) - } } #[cfg(feature = "specialize")] @@ -233,8 +210,8 @@ pub(crate) struct AHasherU64 { impl Hasher for AHasherU64 { #[inline] fn finish(&self) -> u64 { - let rot = (self.pad & 63) as u32; - self.buffer.rotate_left(rot) + folded_multiply(self.buffer, self.pad) + //self.buffer } #[inline] @@ -338,8 +315,7 @@ impl Hasher for AHasherStr { self.0.write(bytes) } else { let value = read_small(bytes); - self.0.buffer = folded_multiply(value[0] ^ self.0.buffer, - value[1] ^ self.0.extra_keys[1]); + self.0.buffer = folded_multiply(value[0] ^ self.0.buffer, value[1] ^ self.0.extra_keys[1]); self.0.pad = self.0.pad.wrapping_add(bytes.len() as u64); } } @@ -365,7 +341,6 @@ impl Hasher for AHasherStr { #[cfg(test)] mod tests { - use crate::convert::Convert; use crate::fallback_hash::*; #[test] |