1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125

use key::Key;
use portable::PortableHash;
use traits::HighwayHash;
use std::default::Default;

#[cfg(target_arch = "x86_64")]
use avx::AvxHash;
#[cfg(target_arch = "x86_64")]
use sse::SseHash;

#[derive(Debug, Clone)]
enum HighwayChoices {
    Portable(PortableHash),
    #[cfg(target_arch = "x86_64")]
    Sse(SseHash),
    #[cfg(target_arch = "x86_64")]
    Avx(AvxHash),
}

/// Main HighwayHash implementation that delegates to one of the other implementations depending on
/// the target compiled for and a runtime CPU check.
///
/// In order of preference:
///
///  - AvxHash
///  - SseHash
///  - PortableHash
#[derive(Debug, Clone)]
pub struct HighwayBuilder(HighwayChoices);

impl HighwayHash for HighwayBuilder {
    fn hash64(self, data: &[u8]) -> u64 {
        match self.0 {
            HighwayChoices::Portable(x) => x.hash64(data),
            #[cfg(target_arch = "x86_64")]
            HighwayChoices::Avx(x) => x.hash64(data),
            #[cfg(target_arch = "x86_64")]
            HighwayChoices::Sse(x) => x.hash64(data),
        }
    }

    fn hash128(self, data: &[u8]) -> [u64; 2] {
        match self.0 {
            HighwayChoices::Portable(x) => x.hash128(data),
            #[cfg(target_arch = "x86_64")]
            HighwayChoices::Avx(x) => x.hash128(data),
            #[cfg(target_arch = "x86_64")]
            HighwayChoices::Sse(x) => x.hash128(data),
        }
    }

    fn hash256(self, data: &[u8]) -> [u64; 4] {
        match self.0 {
            HighwayChoices::Portable(x) => x.hash256(data),
            #[cfg(target_arch = "x86_64")]
            HighwayChoices::Avx(x) => x.hash256(data),
            #[cfg(target_arch = "x86_64")]
            HighwayChoices::Sse(x) => x.hash256(data),
        }
    }

    fn append(&mut self, data: &[u8]) {
        match &mut self.0 {
            HighwayChoices::Portable(x) => x.append(data),
            #[cfg(target_arch = "x86_64")]
            HighwayChoices::Avx(x) => x.append(data),
            #[cfg(target_arch = "x86_64")]
            HighwayChoices::Sse(x) => x.append(data),
        }
    }

    fn finalize64(self) -> u64 {
        match self.0 {
            HighwayChoices::Portable(x) => x.finalize64(),
            #[cfg(target_arch = "x86_64")]
            HighwayChoices::Avx(x) => x.finalize64(),
            #[cfg(target_arch = "x86_64")]
            HighwayChoices::Sse(x) => x.finalize64(),
        }
    }

    fn finalize128(self) -> [u64; 2] {
        match self.0 {
            HighwayChoices::Portable(x) => x.finalize128(),
            #[cfg(target_arch = "x86_64")]
            HighwayChoices::Avx(x) => x.finalize128(),
            #[cfg(target_arch = "x86_64")]
            HighwayChoices::Sse(x) => x.finalize128(),
        }
    }

    fn finalize256(self) -> [u64; 4] {
        match self.0 {
            HighwayChoices::Portable(x) => x.finalize256(),
            #[cfg(target_arch = "x86_64")]
            HighwayChoices::Avx(x) => x.finalize256(),
            #[cfg(target_arch = "x86_64")]
            HighwayChoices::Sse(x) => x.finalize256(),
        }
    }
}

impl HighwayBuilder {
    /// Creates a new hasher based on compilation and runtime capabilities
    pub fn new(key: &Key) -> Self {
        #[cfg(target_arch = "x86_64")]
        {
            if let Some(h) = AvxHash::new(key) {
                return HighwayBuilder(HighwayChoices::Avx(h));
            }

            if let Some(h) = SseHash::new(key) {
                return HighwayBuilder(HighwayChoices::Sse(h));
            }
        }

        HighwayBuilder(HighwayChoices::Portable(PortableHash::new(key)))
    }
}

impl Default for HighwayBuilder {
    fn default() -> Self {
        HighwayBuilder::new(&Key::default())
    }
}