src/librustc_data_structures/sip128.rs

   1 //! This is a copy of `core::hash::sip` adapted to providing 128 bit hashes.
   2
   3 use std::cmp;
   4 use std::hash::Hasher;
   5 use std::slice;
   6 use std::ptr;
   7 use std::mem;
   8
   9 #[derive(Debug, Clone)]
  10 pub struct SipHasher128 {
  11     k0: u64,
  12     k1: u64,
  13     length: usize, // how many bytes we've processed
  14     state: State, // hash State
  15     tail: u64, // unprocessed bytes le
  16     ntail: usize, // how many bytes in tail are valid
  17 }
  18
  19 #[derive(Debug, Clone, Copy)]
  20 #[repr(C)]
  21 struct State {
  22     // v0, v2 and v1, v3 show up in pairs in the algorithm,
  23     // and simd implementations of SipHash will use vectors
  24     // of v02 and v13. By placing them in this order in the struct,
  25     // the compiler can pick up on just a few simd optimizations by itself.
  26     v0: u64,
  27     v2: u64,
  28     v1: u64,
  29     v3: u64,
  30 }
  31
  32 macro_rules! compress {
  33     ($state:expr) => ({
  34         compress!($state.v0, $state.v1, $state.v2, $state.v3)
  35     });
  36     ($v0:expr, $v1:expr, $v2:expr, $v3:expr) =>
  37     ({
  38         $v0 = $v0.wrapping_add($v1); $v1 = $v1.rotate_left(13); $v1 ^= $v0;
  39         $v0 = $v0.rotate_left(32);
  40         $v2 = $v2.wrapping_add($v3); $v3 = $v3.rotate_left(16); $v3 ^= $v2;
  41         $v0 = $v0.wrapping_add($v3); $v3 = $v3.rotate_left(21); $v3 ^= $v0;
  42         $v2 = $v2.wrapping_add($v1); $v1 = $v1.rotate_left(17); $v1 ^= $v2;
  43         $v2 = $v2.rotate_left(32);
  44     });
  45 }
  46
  47 /// Loads an integer of the desired type from a byte stream, in LE order. Uses
  48 /// `copy_nonoverlapping` to let the compiler generate the most efficient way
  49 /// to load it from a possibly unaligned address.
  50 ///
  51 /// Unsafe because: unchecked indexing at i..i+size_of(int_ty)
  52 macro_rules! load_int_le {
  53     ($buf:expr, $i:expr, $int_ty:ident) =>
  54     ({
  55        debug_assert!($i + mem::size_of::<$int_ty>() <= $buf.len());
  56        let mut data = 0 as $int_ty;
  57        ptr::copy_nonoverlapping($buf.get_unchecked($i),
  58                                 &mut data as *mut _ as *mut u8,
  59                                 mem::size_of::<$int_ty>());
  60        data.to_le()
  61     });
  62 }
  63
  64 /// Loads an u64 using up to 7 bytes of a byte slice.
  65 ///
  66 /// Unsafe because: unchecked indexing at start..start+len
  67 #[inline]
  68 unsafe fn u8to64_le(buf: &[u8], start: usize, len: usize) -> u64 {
  69     debug_assert!(len < 8);
  70     let mut i = 0; // current byte index (from LSB) in the output u64
  71     let mut out = 0;
  72     if i + 3 < len {
  73         out = load_int_le!(buf, start + i, u32) as u64;
  74         i += 4;
  75     }
  76     if i + 1 < len {
  77         out |= (load_int_le!(buf, start + i, u16) as u64) << (i * 8);
  78         i += 2
  79     }
  80     if i < len {
  81         out |= (*buf.get_unchecked(start + i) as u64) << (i * 8);
  82         i += 1;
  83     }
  84     debug_assert_eq!(i, len);
  85     out
  86 }
  87
  88
  89 impl SipHasher128 {
  90     #[inline]
  91     pub fn new_with_keys(key0: u64, key1: u64) -> SipHasher128 {
  92         let mut state = SipHasher128 {
  93             k0: key0,
  94             k1: key1,
  95             length: 0,
  96             state: State {
  97                 v0: 0,
  98                 v1: 0,
  99                 v2: 0,
 100                 v3: 0,
 101             },
 102             tail: 0,
 103             ntail: 0,
 104         };
 105         state.reset();
 106         state
 107     }
 108
 109     #[inline]
 110     fn reset(&mut self) {
 111         self.length = 0;
 112         self.state.v0 = self.k0 ^ 0x736f6d6570736575;
 113         self.state.v1 = self.k1 ^ 0x646f72616e646f6d;
 114         self.state.v2 = self.k0 ^ 0x6c7967656e657261;
 115         self.state.v3 = self.k1 ^ 0x7465646279746573;
 116         self.ntail = 0;
 117
 118         // This is only done in the 128 bit version:
 119         self.state.v1 ^= 0xee;
 120     }
 121
 122     // Specialized write function that is only valid for buffers with len <= 8.
 123     // It's used to force inlining of write_u8 and write_usize, those would normally be inlined
 124     // except for composite types (that includes slices and str hashing because of delimiter).
 125     // Without this extra push the compiler is very reluctant to inline delimiter writes,
 126     // degrading performance substantially for the most common use cases.
 127     #[inline]
 128     fn short_write(&mut self, msg: &[u8]) {
 129         debug_assert!(msg.len() <= 8);
 130         let length = msg.len();
 131         self.length += length;
 132
 133         let needed = 8 - self.ntail;
 134         let fill = cmp::min(length, needed);
 135         if fill == 8 {
 136             self.tail = unsafe { load_int_le!(msg, 0, u64) };
 137         } else {
 138             self.tail |= unsafe { u8to64_le(msg, 0, fill) } << (8 * self.ntail);
 139             if length < needed {
 140                 self.ntail += length;
 141                 return;
 142             }
 143         }
 144         self.state.v3 ^= self.tail;
 145         Sip24Rounds::c_rounds(&mut self.state);
 146         self.state.v0 ^= self.tail;
 147
 148         // Buffered tail is now flushed, process new input.
 149         self.ntail = length - needed;
 150         self.tail = unsafe { u8to64_le(msg, needed, self.ntail) };
 151     }
 152
 153     #[inline(always)]
 154     fn short_write_gen<T>(&mut self, x: T) {
 155         let bytes = unsafe {
 156             slice::from_raw_parts(&x as *const T as *const u8, mem::size_of::<T>())
 157         };
 158         self.short_write(bytes);
 159     }
 160
 161     #[inline]
 162     pub fn finish128(mut self) -> (u64, u64) {
 163         let b: u64 = ((self.length as u64 & 0xff) << 56) | self.tail;
 164
 165         self.state.v3 ^= b;
 166         Sip24Rounds::c_rounds(&mut self.state);
 167         self.state.v0 ^= b;
 168
 169         self.state.v2 ^= 0xee;
 170         Sip24Rounds::d_rounds(&mut self.state);
 171         let _0 = self.state.v0 ^ self.state.v1 ^ self.state.v2 ^ self.state.v3;
 172
 173         self.state.v1 ^= 0xdd;
 174         Sip24Rounds::d_rounds(&mut self.state);
 175         let _1 = self.state.v0 ^ self.state.v1 ^ self.state.v2 ^ self.state.v3;
 176         (_0, _1)
 177     }
 178 }
 179
 180 impl Hasher for SipHasher128 {
 181     #[inline]
 182     fn write_u8(&mut self, i: u8) {
 183         self.short_write_gen(i);
 184     }
 185
 186     #[inline]
 187     fn write_u16(&mut self, i: u16) {
 188         self.short_write_gen(i);
 189     }
 190
 191     #[inline]
 192     fn write_u32(&mut self, i: u32) {
 193         self.short_write_gen(i);
 194     }
 195
 196     #[inline]
 197     fn write_u64(&mut self, i: u64) {
 198         self.short_write_gen(i);
 199     }
 200
 201     #[inline]
 202     fn write_usize(&mut self, i: usize) {
 203         self.short_write_gen(i);
 204     }
 205
 206     #[inline]
 207     fn write_i8(&mut self, i: i8) {
 208         self.short_write_gen(i);
 209     }
 210
 211     #[inline]
 212     fn write_i16(&mut self, i: i16) {
 213         self.short_write_gen(i);
 214     }
 215
 216     #[inline]
 217     fn write_i32(&mut self, i: i32) {
 218         self.short_write_gen(i);
 219     }
 220
 221     #[inline]
 222     fn write_i64(&mut self, i: i64) {
 223         self.short_write_gen(i);
 224     }
 225
 226     #[inline]
 227     fn write_isize(&mut self, i: isize) {
 228         self.short_write_gen(i);
 229     }
 230
 231     #[inline]
 232     fn write(&mut self, msg: &[u8]) {
 233         let length = msg.len();
 234         self.length += length;
 235
 236         let mut needed = 0;
 237
 238         if self.ntail != 0 {
 239             needed = 8 - self.ntail;
 240             self.tail |= unsafe { u8to64_le(msg, 0, cmp::min(length, needed)) } << 8 * self.ntail;
 241             if length < needed {
 242                 self.ntail += length;
 243                 return
 244             } else {
 245                 self.state.v3 ^= self.tail;
 246                 Sip24Rounds::c_rounds(&mut self.state);
 247                 self.state.v0 ^= self.tail;
 248                 self.ntail = 0;
 249             }
 250         }
 251
 252         // Buffered tail is now flushed, process new input.
 253         let len = length - needed;
 254         let left = len & 0x7;
 255
 256         let mut i = needed;
 257         while i < len - left {
 258             let mi = unsafe { load_int_le!(msg, i, u64) };
 259
 260             self.state.v3 ^= mi;
 261             Sip24Rounds::c_rounds(&mut self.state);
 262             self.state.v0 ^= mi;
 263
 264             i += 8;
 265         }
 266
 267         self.tail = unsafe { u8to64_le(msg, i, left) };
 268         self.ntail = left;
 269     }
 270
 271     fn finish(&self) -> u64 {
 272         panic!("SipHasher128 cannot provide valid 64 bit hashes")
 273     }
 274 }
 275
 276 #[derive(Debug, Clone, Default)]
 277 struct Sip24Rounds;
 278
 279 impl Sip24Rounds {
 280     #[inline]
 281     fn c_rounds(state: &mut State) {
 282         compress!(state);
 283         compress!(state);
 284     }
 285
 286     #[inline]
 287     fn d_rounds(state: &mut State) {
 288         compress!(state);
 289         compress!(state);
 290         compress!(state);
 291         compress!(state);
 292     }
 293 }
 294
 295 #[cfg(test)]
 296 mod test {
 297     use std::hash::{Hash, Hasher};
 298     use std::{slice, mem};
 299     use super::SipHasher128;
 300
 301     // Hash just the bytes of the slice, without length prefix
 302     struct Bytes<'a>(&'a [u8]);
 303
 304     impl<'a> Hash for Bytes<'a> {
 305         #[allow(unused_must_use)]
 306         fn hash<H: Hasher>(&self, state: &mut H) {
 307             for byte in self.0 {
 308                 state.write_u8(*byte);
 309             }
 310         }
 311     }
 312
 313     fn hash_with<T: Hash>(mut st: SipHasher128, x: &T) -> (u64, u64) {
 314         x.hash(&mut st);
 315         st.finish128()
 316     }
 317
 318     fn hash<T: Hash>(x: &T) -> (u64, u64) {
 319         hash_with(SipHasher128::new_with_keys(0, 0), x)
 320     }
 321
 322     const TEST_VECTOR : [[u8; 16]; 64] = [
 323         [0xa3,0x81,0x7f,0x04,0xba,0x25,0xa8,0xe6,0x6d,0xf6,0x72,0x14,0xc7,0x55,0x02,0x93],
 324         [0xda,0x87,0xc1,0xd8,0x6b,0x99,0xaf,0x44,0x34,0x76,0x59,0x11,0x9b,0x22,0xfc,0x45],
 325         [0x81,0x77,0x22,0x8d,0xa4,0xa4,0x5d,0xc7,0xfc,0xa3,0x8b,0xde,0xf6,0x0a,0xff,0xe4],
 326         [0x9c,0x70,0xb6,0x0c,0x52,0x67,0xa9,0x4e,0x5f,0x33,0xb6,0xb0,0x29,0x85,0xed,0x51],
 327         [0xf8,0x81,0x64,0xc1,0x2d,0x9c,0x8f,0xaf,0x7d,0x0f,0x6e,0x7c,0x7b,0xcd,0x55,0x79],
 328         [0x13,0x68,0x87,0x59,0x80,0x77,0x6f,0x88,0x54,0x52,0x7a,0x07,0x69,0x0e,0x96,0x27],
 329         [0x14,0xee,0xca,0x33,0x8b,0x20,0x86,0x13,0x48,0x5e,0xa0,0x30,0x8f,0xd7,0xa1,0x5e],
 330         [0xa1,0xf1,0xeb,0xbe,0xd8,0xdb,0xc1,0x53,0xc0,0xb8,0x4a,0xa6,0x1f,0xf0,0x82,0x39],
 331         [0x3b,0x62,0xa9,0xba,0x62,0x58,0xf5,0x61,0x0f,0x83,0xe2,0x64,0xf3,0x14,0x97,0xb4],
 332         [0x26,0x44,0x99,0x06,0x0a,0xd9,0xba,0xab,0xc4,0x7f,0x8b,0x02,0xbb,0x6d,0x71,0xed],
 333         [0x00,0x11,0x0d,0xc3,0x78,0x14,0x69,0x56,0xc9,0x54,0x47,0xd3,0xf3,0xd0,0xfb,0xba],
 334         [0x01,0x51,0xc5,0x68,0x38,0x6b,0x66,0x77,0xa2,0xb4,0xdc,0x6f,0x81,0xe5,0xdc,0x18],
 335         [0xd6,0x26,0xb2,0x66,0x90,0x5e,0xf3,0x58,0x82,0x63,0x4d,0xf6,0x85,0x32,0xc1,0x25],
 336         [0x98,0x69,0xe2,0x47,0xe9,0xc0,0x8b,0x10,0xd0,0x29,0x93,0x4f,0xc4,0xb9,0x52,0xf7],
 337         [0x31,0xfc,0xef,0xac,0x66,0xd7,0xde,0x9c,0x7e,0xc7,0x48,0x5f,0xe4,0x49,0x49,0x02],
 338         [0x54,0x93,0xe9,0x99,0x33,0xb0,0xa8,0x11,0x7e,0x08,0xec,0x0f,0x97,0xcf,0xc3,0xd9],
 339         [0x6e,0xe2,0xa4,0xca,0x67,0xb0,0x54,0xbb,0xfd,0x33,0x15,0xbf,0x85,0x23,0x05,0x77],
 340         [0x47,0x3d,0x06,0xe8,0x73,0x8d,0xb8,0x98,0x54,0xc0,0x66,0xc4,0x7a,0xe4,0x77,0x40],
 341         [0xa4,0x26,0xe5,0xe4,0x23,0xbf,0x48,0x85,0x29,0x4d,0xa4,0x81,0xfe,0xae,0xf7,0x23],
 342         [0x78,0x01,0x77,0x31,0xcf,0x65,0xfa,0xb0,0x74,0xd5,0x20,0x89,0x52,0x51,0x2e,0xb1],
 343         [0x9e,0x25,0xfc,0x83,0x3f,0x22,0x90,0x73,0x3e,0x93,0x44,0xa5,0xe8,0x38,0x39,0xeb],
 344         [0x56,0x8e,0x49,0x5a,0xbe,0x52,0x5a,0x21,0x8a,0x22,0x14,0xcd,0x3e,0x07,0x1d,0x12],
 345         [0x4a,0x29,0xb5,0x45,0x52,0xd1,0x6b,0x9a,0x46,0x9c,0x10,0x52,0x8e,0xff,0x0a,0xae],
 346         [0xc9,0xd1,0x84,0xdd,0xd5,0xa9,0xf5,0xe0,0xcf,0x8c,0xe2,0x9a,0x9a,0xbf,0x69,0x1c],
 347         [0x2d,0xb4,0x79,0xae,0x78,0xbd,0x50,0xd8,0x88,0x2a,0x8a,0x17,0x8a,0x61,0x32,0xad],
 348         [0x8e,0xce,0x5f,0x04,0x2d,0x5e,0x44,0x7b,0x50,0x51,0xb9,0xea,0xcb,0x8d,0x8f,0x6f],
 349         [0x9c,0x0b,0x53,0xb4,0xb3,0xc3,0x07,0xe8,0x7e,0xae,0xe0,0x86,0x78,0x14,0x1f,0x66],
 350         [0xab,0xf2,0x48,0xaf,0x69,0xa6,0xea,0xe4,0xbf,0xd3,0xeb,0x2f,0x12,0x9e,0xeb,0x94],
 351         [0x06,0x64,0xda,0x16,0x68,0x57,0x4b,0x88,0xb9,0x35,0xf3,0x02,0x73,0x58,0xae,0xf4],
 352         [0xaa,0x4b,0x9d,0xc4,0xbf,0x33,0x7d,0xe9,0x0c,0xd4,0xfd,0x3c,0x46,0x7c,0x6a,0xb7],
 353         [0xea,0x5c,0x7f,0x47,0x1f,0xaf,0x6b,0xde,0x2b,0x1a,0xd7,0xd4,0x68,0x6d,0x22,0x87],
 354         [0x29,0x39,0xb0,0x18,0x32,0x23,0xfa,0xfc,0x17,0x23,0xde,0x4f,0x52,0xc4,0x3d,0x35],
 355         [0x7c,0x39,0x56,0xca,0x5e,0xea,0xfc,0x3e,0x36,0x3e,0x9d,0x55,0x65,0x46,0xeb,0x68],
 356         [0x77,0xc6,0x07,0x71,0x46,0xf0,0x1c,0x32,0xb6,0xb6,0x9d,0x5f,0x4e,0xa9,0xff,0xcf],
 357         [0x37,0xa6,0x98,0x6c,0xb8,0x84,0x7e,0xdf,0x09,0x25,0xf0,0xf1,0x30,0x9b,0x54,0xde],
 358         [0xa7,0x05,0xf0,0xe6,0x9d,0xa9,0xa8,0xf9,0x07,0x24,0x1a,0x2e,0x92,0x3c,0x8c,0xc8],
 359         [0x3d,0xc4,0x7d,0x1f,0x29,0xc4,0x48,0x46,0x1e,0x9e,0x76,0xed,0x90,0x4f,0x67,0x11],
 360         [0x0d,0x62,0xbf,0x01,0xe6,0xfc,0x0e,0x1a,0x0d,0x3c,0x47,0x51,0xc5,0xd3,0x69,0x2b],
 361         [0x8c,0x03,0x46,0x8b,0xca,0x7c,0x66,0x9e,0xe4,0xfd,0x5e,0x08,0x4b,0xbe,0xe7,0xb5],
 362         [0x52,0x8a,0x5b,0xb9,0x3b,0xaf,0x2c,0x9c,0x44,0x73,0xcc,0xe5,0xd0,0xd2,0x2b,0xd9],
 363         [0xdf,0x6a,0x30,0x1e,0x95,0xc9,0x5d,0xad,0x97,0xae,0x0c,0xc8,0xc6,0x91,0x3b,0xd8],
 364         [0x80,0x11,0x89,0x90,0x2c,0x85,0x7f,0x39,0xe7,0x35,0x91,0x28,0x5e,0x70,0xb6,0xdb],
 365         [0xe6,0x17,0x34,0x6a,0xc9,0xc2,0x31,0xbb,0x36,0x50,0xae,0x34,0xcc,0xca,0x0c,0x5b],
 366         [0x27,0xd9,0x34,0x37,0xef,0xb7,0x21,0xaa,0x40,0x18,0x21,0xdc,0xec,0x5a,0xdf,0x89],
 367         [0x89,0x23,0x7d,0x9d,0xed,0x9c,0x5e,0x78,0xd8,0xb1,0xc9,0xb1,0x66,0xcc,0x73,0x42],
 368         [0x4a,0x6d,0x80,0x91,0xbf,0x5e,0x7d,0x65,0x11,0x89,0xfa,0x94,0xa2,0x50,0xb1,0x4c],
 369         [0x0e,0x33,0xf9,0x60,0x55,0xe7,0xae,0x89,0x3f,0xfc,0x0e,0x3d,0xcf,0x49,0x29,0x02],
 370         [0xe6,0x1c,0x43,0x2b,0x72,0x0b,0x19,0xd1,0x8e,0xc8,0xd8,0x4b,0xdc,0x63,0x15,0x1b],
 371         [0xf7,0xe5,0xae,0xf5,0x49,0xf7,0x82,0xcf,0x37,0x90,0x55,0xa6,0x08,0x26,0x9b,0x16],
 372         [0x43,0x8d,0x03,0x0f,0xd0,0xb7,0xa5,0x4f,0xa8,0x37,0xf2,0xad,0x20,0x1a,0x64,0x03],
 373         [0xa5,0x90,0xd3,0xee,0x4f,0xbf,0x04,0xe3,0x24,0x7e,0x0d,0x27,0xf2,0x86,0x42,0x3f],
 374         [0x5f,0xe2,0xc1,0xa1,0x72,0xfe,0x93,0xc4,0xb1,0x5c,0xd3,0x7c,0xae,0xf9,0xf5,0x38],
 375         [0x2c,0x97,0x32,0x5c,0xbd,0x06,0xb3,0x6e,0xb2,0x13,0x3d,0xd0,0x8b,0x3a,0x01,0x7c],
 376         [0x92,0xc8,0x14,0x22,0x7a,0x6b,0xca,0x94,0x9f,0xf0,0x65,0x9f,0x00,0x2a,0xd3,0x9e],
 377         [0xdc,0xe8,0x50,0x11,0x0b,0xd8,0x32,0x8c,0xfb,0xd5,0x08,0x41,0xd6,0x91,0x1d,0x87],
 378         [0x67,0xf1,0x49,0x84,0xc7,0xda,0x79,0x12,0x48,0xe3,0x2b,0xb5,0x92,0x25,0x83,0xda],
 379         [0x19,0x38,0xf2,0xcf,0x72,0xd5,0x4e,0xe9,0x7e,0x94,0x16,0x6f,0xa9,0x1d,0x2a,0x36],
 380         [0x74,0x48,0x1e,0x96,0x46,0xed,0x49,0xfe,0x0f,0x62,0x24,0x30,0x16,0x04,0x69,0x8e],
 381         [0x57,0xfc,0xa5,0xde,0x98,0xa9,0xd6,0xd8,0x00,0x64,0x38,0xd0,0x58,0x3d,0x8a,0x1d],
 382         [0x9f,0xec,0xde,0x1c,0xef,0xdc,0x1c,0xbe,0xd4,0x76,0x36,0x74,0xd9,0x57,0x53,0x59],
 383         [0xe3,0x04,0x0c,0x00,0xeb,0x28,0xf1,0x53,0x66,0xca,0x73,0xcb,0xd8,0x72,0xe7,0x40],
 384         [0x76,0x97,0x00,0x9a,0x6a,0x83,0x1d,0xfe,0xcc,0xa9,0x1c,0x59,0x93,0x67,0x0f,0x7a],
 385         [0x58,0x53,0x54,0x23,0x21,0xf5,0x67,0xa0,0x05,0xd5,0x47,0xa4,0xf0,0x47,0x59,0xbd],
 386         [0x51,0x50,0xd1,0x77,0x2f,0x50,0x83,0x4a,0x50,0x3e,0x06,0x9a,0x97,0x3f,0xbd,0x7c],
 387     ];
 388
 389     // Test vector from reference implementation
 390     #[test]
 391     fn test_siphash_2_4_test_vector() {
 392         let k0 = 0x_07_06_05_04_03_02_01_00;
 393         let k1 = 0x_0f_0e_0d_0c_0b_0a_09_08;
 394
 395         let mut input: Vec<u8> = Vec::new();
 396
 397         for i in 0 .. 64 {
 398             let out = hash_with(SipHasher128::new_with_keys(k0, k1),
 399                                 &Bytes(&input[..]));
 400             let expected = (
 401                 ((TEST_VECTOR[i][0] as u64) <<  0) |
 402                 ((TEST_VECTOR[i][1] as u64) <<  8) |
 403                 ((TEST_VECTOR[i][2] as u64) << 16) |
 404                 ((TEST_VECTOR[i][3] as u64) << 24) |
 405                 ((TEST_VECTOR[i][4] as u64) << 32) |
 406                 ((TEST_VECTOR[i][5] as u64) << 40) |
 407                 ((TEST_VECTOR[i][6] as u64) << 48) |
 408                 ((TEST_VECTOR[i][7] as u64) << 56),
 409
 410                 ((TEST_VECTOR[i][8] as u64) <<  0) |
 411                 ((TEST_VECTOR[i][9] as u64) <<  8) |
 412                 ((TEST_VECTOR[i][10] as u64) << 16) |
 413                 ((TEST_VECTOR[i][11] as u64) << 24) |
 414                 ((TEST_VECTOR[i][12] as u64) << 32) |
 415                 ((TEST_VECTOR[i][13] as u64) << 40) |
 416                 ((TEST_VECTOR[i][14] as u64) << 48) |
 417                 ((TEST_VECTOR[i][15] as u64) << 56),
 418             );
 419
 420             assert_eq!(out, expected);
 421             input.push(i as u8);
 422         }
 423     }
 424
 425     #[test] #[cfg(target_arch = "arm")]
 426     fn test_hash_usize() {
 427         let val = 0xdeadbeef_deadbeef_u64;
 428         assert!(hash(&(val as u64)) != hash(&(val as usize)));
 429         assert_eq!(hash(&(val as u32)), hash(&(val as usize)));
 430     }
 431     #[test] #[cfg(target_arch = "x86_64")]
 432     fn test_hash_usize() {
 433         let val = 0xdeadbeef_deadbeef_u64;
 434         assert_eq!(hash(&(val as u64)), hash(&(val as usize)));
 435         assert!(hash(&(val as u32)) != hash(&(val as usize)));
 436     }
 437     #[test] #[cfg(target_arch = "x86")]
 438     fn test_hash_usize() {
 439         let val = 0xdeadbeef_deadbeef_u64;
 440         assert!(hash(&(val as u64)) != hash(&(val as usize)));
 441         assert_eq!(hash(&(val as u32)), hash(&(val as usize)));
 442     }
 443
 444     #[test]
 445     fn test_hash_idempotent() {
 446         let val64 = 0xdeadbeef_deadbeef_u64;
 447         assert_eq!(hash(&val64), hash(&val64));
 448         let val32 = 0xdeadbeef_u32;
 449         assert_eq!(hash(&val32), hash(&val32));
 450     }
 451
 452     #[test]
 453     fn test_hash_no_bytes_dropped_64() {
 454         let val = 0xdeadbeef_deadbeef_u64;
 455
 456         assert!(hash(&val) != hash(&zero_byte(val, 0)));
 457         assert!(hash(&val) != hash(&zero_byte(val, 1)));
 458         assert!(hash(&val) != hash(&zero_byte(val, 2)));
 459         assert!(hash(&val) != hash(&zero_byte(val, 3)));
 460         assert!(hash(&val) != hash(&zero_byte(val, 4)));
 461         assert!(hash(&val) != hash(&zero_byte(val, 5)));
 462         assert!(hash(&val) != hash(&zero_byte(val, 6)));
 463         assert!(hash(&val) != hash(&zero_byte(val, 7)));
 464
 465         fn zero_byte(val: u64, byte: usize) -> u64 {
 466             assert!(byte < 8);
 467             val & !(0xff << (byte * 8))
 468         }
 469     }
 470
 471     #[test]
 472     fn test_hash_no_bytes_dropped_32() {
 473         let val = 0xdeadbeef_u32;
 474
 475         assert!(hash(&val) != hash(&zero_byte(val, 0)));
 476         assert!(hash(&val) != hash(&zero_byte(val, 1)));
 477         assert!(hash(&val) != hash(&zero_byte(val, 2)));
 478         assert!(hash(&val) != hash(&zero_byte(val, 3)));
 479
 480         fn zero_byte(val: u32, byte: usize) -> u32 {
 481             assert!(byte < 4);
 482             val & !(0xff << (byte * 8))
 483         }
 484     }
 485
 486     #[test]
 487     fn test_hash_no_concat_alias() {
 488         let s = ("aa", "bb");
 489         let t = ("aabb", "");
 490         let u = ("a", "abb");
 491
 492         assert!(s != t && t != u);
 493         assert!(hash(&s) != hash(&t) && hash(&s) != hash(&u));
 494
 495         let u = [1, 0, 0, 0];
 496         let v = (&u[..1], &u[1..3], &u[3..]);
 497         let w = (&u[..], &u[4..4], &u[4..4]);
 498
 499         assert!(v != w);
 500         assert!(hash(&v) != hash(&w));
 501     }
 502
 503     #[test]
 504     fn test_write_short_works() {
 505         let test_usize = 0xd0c0b0a0usize;
 506         let mut h1 = SipHasher128::new_with_keys(0, 0);
 507         h1.write_usize(test_usize);
 508         h1.write(b"bytes");
 509         h1.write(b"string");
 510         h1.write_u8(0xFFu8);
 511         h1.write_u8(0x01u8);
 512         let mut h2 = SipHasher128::new_with_keys(0, 0);
 513         h2.write(unsafe {
 514             slice::from_raw_parts(&test_usize as *const _ as *const u8,
 515                                   mem::size_of::<usize>())
 516         });
 517         h2.write(b"bytes");
 518         h2.write(b"string");
 519         h2.write(&[0xFFu8, 0x01u8]);
 520         assert_eq!(h1.finish128(), h2.finish128());
 521     }
 522
 523 }