preflate-rs 0.7.0

use bitcode::{Decode, Encode};

#[derive(Encode, Decode, Debug, Copy, Clone, Eq, PartialEq, Default)]
pub enum HashAlgorithm {
    #[default]
    None,
    Zlib {
        hash_mask: u16,
        hash_shift: u32,
    },
    MiniZFast,

    /// Libflate 4 byte hash only
    Libdeflate4Fast,
    /// Libflate 4 byte hash with 3 byte secondary hash
    Libdeflate4,

    ZlibNG,
    RandomVector,
    Crc32cHash,
}

const HASH_ALGORITHM_NONE: u16 = 0;
const HASH_ALGORITHM_ZLIB: u16 = 1;
const HASH_ALGORITHM_MINIZ_FAST: u16 = 2;
const HASH_ALGORITHM_LIBDEFLATE4: u16 = 3;
const HASH_ALGORITHM_LIBDEFLATE4_FAST: u16 = 4;
const HASH_ALGORITHM_ZLIBNG: u16 = 5;
const HASH_ALGORITHM_RANDOMVECTOR: u16 = 6;
const HASH_ALGORITHM_CRC32C: u16 = 7;

impl HashAlgorithm {
    pub fn to_u16(self) -> u16 {
        match self {
            HashAlgorithm::None => HASH_ALGORITHM_NONE,
            HashAlgorithm::Zlib {
                hash_mask,
                hash_shift,
            } => {
                HASH_ALGORITHM_ZLIB
                    | ((hash_mask.trailing_ones() as u16) << 8)
                    | ((hash_shift as u16) << 12)
            }
            HashAlgorithm::MiniZFast => HASH_ALGORITHM_MINIZ_FAST,
            HashAlgorithm::Libdeflate4Fast => HASH_ALGORITHM_LIBDEFLATE4_FAST,
            HashAlgorithm::Libdeflate4 => HASH_ALGORITHM_LIBDEFLATE4,
            HashAlgorithm::ZlibNG => HASH_ALGORITHM_ZLIBNG,
            HashAlgorithm::RandomVector => HASH_ALGORITHM_RANDOMVECTOR,
            HashAlgorithm::Crc32cHash => HASH_ALGORITHM_CRC32C,
        }
    }

    pub fn from_u16(v: u16) -> Option<Self> {
        match v & 0xff {
            HASH_ALGORITHM_NONE => Some(HashAlgorithm::None),
            HASH_ALGORITHM_ZLIB => {
                let hash_mask = (1 << ((v >> 8) & 0xf)) - 1;
                let hash_shift = (v >> 12) & 0xf;
                Some(HashAlgorithm::Zlib {
                    hash_mask,
                    hash_shift: hash_shift.into(),
                })
            }
            HASH_ALGORITHM_MINIZ_FAST => Some(HashAlgorithm::MiniZFast),
            HASH_ALGORITHM_LIBDEFLATE4_FAST => Some(HashAlgorithm::Libdeflate4Fast),
            HASH_ALGORITHM_LIBDEFLATE4 => Some(HashAlgorithm::Libdeflate4),
            HASH_ALGORITHM_ZLIBNG => Some(HashAlgorithm::ZlibNG),
            HASH_ALGORITHM_RANDOMVECTOR => Some(HashAlgorithm::RandomVector),
            HASH_ALGORITHM_CRC32C => Some(HashAlgorithm::Crc32cHash),
            _ => None,
        }
    }
}

#[test]
fn roundtrip_hash_algorithm_to_int() {
    let test_hashes = [
        HashAlgorithm::Zlib {
            hash_mask: 0x7ff,
            hash_shift: 3,
        },
        HashAlgorithm::MiniZFast,
        HashAlgorithm::Libdeflate4Fast,
        HashAlgorithm::Libdeflate4,
        HashAlgorithm::ZlibNG,
        HashAlgorithm::RandomVector,
        HashAlgorithm::Crc32cHash,
    ];

    for &hash in test_hashes.iter() {
        let hash_int = hash.to_u16();
        let hash2 = HashAlgorithm::from_u16(hash_int).unwrap();
        assert_eq!(hash, hash2);
    }
}

pub trait HashImplementation: Default + Copy + Clone {
    const NUM_HASH_BYTES: usize;

    fn get_hash(&self, b: &[u8]) -> u16;
    fn algorithm(&self) -> HashAlgorithm;
}

#[derive(Default, Debug, Copy, Clone, Eq, PartialEq)]
pub struct ZlibRotatingHashFixed<const HASH_SHIFT: u32, const HASH_MASK: u32> {}

impl<const HASH_SHIFT: u32, const HASH_MASK: u32> HashImplementation
    for ZlibRotatingHashFixed<HASH_SHIFT, HASH_MASK>
{
    const NUM_HASH_BYTES: usize = 3;

    fn get_hash(&self, b: &[u8]) -> u16 {
        assert!(b.len() >= 3);

        let c = u32::from(b[0]);
        let c = (c << HASH_SHIFT) ^ u32::from(b[1]);
        let c = (c << HASH_SHIFT) ^ u32::from(b[2]);
        (c & HASH_MASK) as u16
    }

    fn algorithm(&self) -> HashAlgorithm {
        HashAlgorithm::Zlib {
            hash_mask: HASH_MASK as u16,
            hash_shift: HASH_SHIFT,
        }
    }
}

#[derive(Default, Debug, Copy, Clone, Eq, PartialEq)]
pub struct ZlibRotatingHash {
    pub hash_mask: u16,
    pub hash_shift: u32,
}

impl HashImplementation for ZlibRotatingHash {
    const NUM_HASH_BYTES: usize = 3;

    fn get_hash(&self, b: &[u8]) -> u16 {
        assert!(b.len() >= 3);

        let c = u16::from(b[0]);
        let c = (c << self.hash_shift) ^ u16::from(b[1]);
        let c = (c << self.hash_shift) ^ u16::from(b[2]);
        c & self.hash_mask
    }

    fn algorithm(&self) -> HashAlgorithm {
        HashAlgorithm::Zlib {
            hash_mask: self.hash_mask,
            hash_shift: self.hash_shift,
        }
    }
}

#[derive(Default, Copy, Clone)]
pub struct MiniZHash {}

/// Size of hash chain for fast compression mode.
pub const MINIZ_LEVEL1_HASH_SIZE_MASK: u16 = 4095;

impl HashImplementation for MiniZHash {
    const NUM_HASH_BYTES: usize = 3;

    fn get_hash(&self, b: &[u8]) -> u16 {
        assert!(b.len() >= 3);

        let hash = u32::from(b[0]) | (u32::from(b[1]) << 8) | (u32::from(b[2]) << 16);

        ((hash ^ (hash >> 17)) & u32::from(MINIZ_LEVEL1_HASH_SIZE_MASK)) as u16
    }

    fn algorithm(&self) -> HashAlgorithm {
        HashAlgorithm::MiniZFast
    }
}

/// Fast version of Libflate hash that doesn't use a secondary 3
/// byte hash. This is used by level 1 compression.
#[derive(Default, Copy, Clone)]
pub struct LibdeflateHash4Fast {}

impl HashImplementation for LibdeflateHash4Fast {
    const NUM_HASH_BYTES: usize = 4;

    fn get_hash(&self, b: &[u8]) -> u16 {
        let hash = u32::from_le_bytes(b[..4].try_into().unwrap());

        (hash.wrapping_mul(0x1E35A7BD) >> 16) as u16
    }

    fn algorithm(&self) -> HashAlgorithm {
        HashAlgorithm::Libdeflate4Fast
    }
}

#[derive(Default, Copy, Clone)]
pub struct LibdeflateHash4 {}

impl HashImplementation for LibdeflateHash4 {
    const NUM_HASH_BYTES: usize = 4;

    fn get_hash(&self, b: &[u8]) -> u16 {
        let hash = u32::from_le_bytes(b[..4].try_into().unwrap());

        (hash.wrapping_mul(0x1E35A7BD) >> 16) as u16
    }

    fn algorithm(&self) -> HashAlgorithm {
        HashAlgorithm::Libdeflate4
    }
}

/// This is the 3 byte version of the libdeflate hash algorithm, which is used
/// as a secondary hash value to find 3 byte matches within the first 4096K if
/// we fail to find any four byte matches with the primary hash.
#[derive(Default, Copy, Clone)]
pub struct LibdeflateHash3Secondary {}

impl HashImplementation for LibdeflateHash3Secondary {
    const NUM_HASH_BYTES: usize = 3;

    fn get_hash(&self, b: &[u8]) -> u16 {
        assert!(b.len() >= 3);

        let hash = u32::from(b[0]) | (u32::from(b[1]) << 8) | (u32::from(b[2]) << 16);

        (hash.wrapping_mul(0x1E35A7BD) >> 17) as u16
    }

    fn algorithm(&self) -> HashAlgorithm {
        unimplemented!("shoudln't get called on secondary hash");
    }
}

#[derive(Default, Copy, Clone)]
pub struct ZlibNGHash {}

impl HashImplementation for ZlibNGHash {
    const NUM_HASH_BYTES: usize = 4;

    fn get_hash(&self, b: &[u8]) -> u16 {
        let hash = u32::from_le_bytes(b[..4].try_into().unwrap());

        (hash.wrapping_mul(2654435761) >> 16) as u16
    }

    fn algorithm(&self) -> HashAlgorithm {
        HashAlgorithm::ZlibNG
    }
}

#[derive(Default, Copy, Clone)]
pub struct Crc32cHash {}

impl HashImplementation for Crc32cHash {
    const NUM_HASH_BYTES: usize = 4;

    fn get_hash(&self, b: &[u8]) -> u16 {
        assert!(b.len() >= 4);

        let mut crc = CRC32C_TABLE[b[0] as usize];
        crc = (crc >> 8) ^ CRC32C_TABLE[((crc ^ u32::from(b[1])) & 0xFF) as usize];
        crc = (crc >> 8) ^ CRC32C_TABLE[((crc ^ u32::from(b[2])) & 0xFF) as usize];
        crc = (crc >> 8) ^ CRC32C_TABLE[((crc ^ u32::from(b[3])) & 0xFF) as usize];

        crc as u16
    }

    fn algorithm(&self) -> HashAlgorithm {
        HashAlgorithm::Crc32cHash
    }
}

static CRC32C_TABLE: [u32; 256] = [
    0x00000000, 0xF26B8303, 0xE13B70F7, 0x1350F3F4, 0xC79A971F, 0x35F1141C, 0x26A1E7E8, 0xD4CA64EB,
    0x8AD958CF, 0x78B2DBCC, 0x6BE22838, 0x9989AB3B, 0x4D43CFD0, 0xBF284CD3, 0xAC78BF27, 0x5E133C24,
    0x105EC76F, 0xE235446C, 0xF165B798, 0x030E349B, 0xD7C45070, 0x25AFD373, 0x36FF2087, 0xC494A384,
    0x9A879FA0, 0x68EC1CA3, 0x7BBCEF57, 0x89D76C54, 0x5D1D08BF, 0xAF768BBC, 0xBC267848, 0x4E4DFB4B,
    0x20BD8EDE, 0xD2D60DDD, 0xC186FE29, 0x33ED7D2A, 0xE72719C1, 0x154C9AC2, 0x061C6936, 0xF477EA35,
    0xAA64D611, 0x580F5512, 0x4B5FA6E6, 0xB93425E5, 0x6DFE410E, 0x9F95C20D, 0x8CC531F9, 0x7EAEB2FA,
    0x30E349B1, 0xC288CAB2, 0xD1D83946, 0x23B3BA45, 0xF779DEAE, 0x05125DAD, 0x1642AE59, 0xE4292D5A,
    0xBA3A117E, 0x4851927D, 0x5B016189, 0xA96AE28A, 0x7DA08661, 0x8FCB0562, 0x9C9BF696, 0x6EF07595,
    0x417B1DBC, 0xB3109EBF, 0xA0406D4B, 0x522BEE48, 0x86E18AA3, 0x748A09A0, 0x67DAFA54, 0x95B17957,
    0xCBA24573, 0x39C9C670, 0x2A993584, 0xD8F2B687, 0x0C38D26C, 0xFE53516F, 0xED03A29B, 0x1F682198,
    0x5125DAD3, 0xA34E59D0, 0xB01EAA24, 0x42752927, 0x96BF4DCC, 0x64D4CECF, 0x77843D3B, 0x85EFBE38,
    0xDBFC821C, 0x2997011F, 0x3AC7F2EB, 0xC8AC71E8, 0x1C661503, 0xEE0D9600, 0xFD5D65F4, 0x0F36E6F7,
    0x61C69362, 0x93AD1061, 0x80FDE395, 0x72966096, 0xA65C047D, 0x5437877E, 0x4767748A, 0xB50CF789,
    0xEB1FCBAD, 0x197448AE, 0x0A24BB5A, 0xF84F3859, 0x2C855CB2, 0xDEEEDFB1, 0xCDBE2C45, 0x3FD5AF46,
    0x7198540D, 0x83F3D70E, 0x90A324FA, 0x62C8A7F9, 0xB602C312, 0x44694011, 0x5739B3E5, 0xA55230E6,
    0xFB410CC2, 0x092A8FC1, 0x1A7A7C35, 0xE811FF36, 0x3CDB9BDD, 0xCEB018DE, 0xDDE0EB2A, 0x2F8B6829,
    0x82F63B78, 0x709DB87B, 0x63CD4B8F, 0x91A6C88C, 0x456CAC67, 0xB7072F64, 0xA457DC90, 0x563C5F93,
    0x082F63B7, 0xFA44E0B4, 0xE9141340, 0x1B7F9043, 0xCFB5F4A8, 0x3DDE77AB, 0x2E8E845F, 0xDCE5075C,
    0x92A8FC17, 0x60C37F14, 0x73938CE0, 0x81F80FE3, 0x55326B08, 0xA759E80B, 0xB4091BFF, 0x466298FC,
    0x1871A4D8, 0xEA1A27DB, 0xF94AD42F, 0x0B21572C, 0xDFEB33C7, 0x2D80B0C4, 0x3ED04330, 0xCCBBC033,
    0xA24BB5A6, 0x502036A5, 0x4370C551, 0xB11B4652, 0x65D122B9, 0x97BAA1BA, 0x84EA524E, 0x7681D14D,
    0x2892ED69, 0xDAF96E6A, 0xC9A99D9E, 0x3BC21E9D, 0xEF087A76, 0x1D63F975, 0x0E330A81, 0xFC588982,
    0xB21572C9, 0x407EF1CA, 0x532E023E, 0xA145813D, 0x758FE5D6, 0x87E466D5, 0x94B49521, 0x66DF1622,
    0x38CC2A06, 0xCAA7A905, 0xD9F75AF1, 0x2B9CD9F2, 0xFF56BD19, 0x0D3D3E1A, 0x1E6DCDEE, 0xEC064EED,
    0xC38D26C4, 0x31E6A5C7, 0x22B65633, 0xD0DDD530, 0x0417B1DB, 0xF67C32D8, 0xE52CC12C, 0x1747422F,
    0x49547E0B, 0xBB3FFD08, 0xA86F0EFC, 0x5A048DFF, 0x8ECEE914, 0x7CA56A17, 0x6FF599E3, 0x9D9E1AE0,
    0xD3D3E1AB, 0x21B862A8, 0x32E8915C, 0xC083125F, 0x144976B4, 0xE622F5B7, 0xF5720643, 0x07198540,
    0x590AB964, 0xAB613A67, 0xB831C993, 0x4A5A4A90, 0x9E902E7B, 0x6CFBAD78, 0x7FAB5E8C, 0x8DC0DD8F,
    0xE330A81A, 0x115B2B19, 0x020BD8ED, 0xF0605BEE, 0x24AA3F05, 0xD6C1BC06, 0xC5914FF2, 0x37FACCF1,
    0x69E9F0D5, 0x9B8273D6, 0x88D28022, 0x7AB90321, 0xAE7367CA, 0x5C18E4C9, 0x4F48173D, 0xBD23943E,
    0xF36E6F75, 0x0105EC76, 0x12551F82, 0xE03E9C81, 0x34F4F86A, 0xC69F7B69, 0xD5CF889D, 0x27A40B9E,
    0x79B737BA, 0x8BDCB4B9, 0x988C474D, 0x6AE7C44E, 0xBE2DA0A5, 0x4C4623A6, 0x5F16D052, 0xAD7D5351,
];

/// This vector uses a lookup into a table for random values
#[derive(Debug, Default, Copy, Clone, Eq, PartialEq)]
pub struct RandomVectorHash {}

static RANDOM_VECTOR: [u16; 768] = [
    0x499d, 0x3dc2, 0x2d07, 0x705b, 0x7a76, 0x3469, 0x59db, 0x0c58, 0x2b72, 0x412d, 0x1246, 0x2095,
    0x1c1c, 0x4726, 0x5f45, 0x2c4e, 0x7b1b, 0x1e70, 0x2743, 0x554f, 0x1334, 0x5328, 0x78c1, 0x41cc,
    0x4b2c, 0x62a5, 0x1d93, 0x4aa4, 0x64c8, 0x65f0, 0x194d, 0x1ac0, 0x3f96, 0x41df, 0x4389, 0x065b,
    0x4b74, 0x15e2, 0x0389, 0x0b7e, 0x5778, 0x5d95, 0x7ffc, 0x1e6f, 0x5465, 0x23d3, 0x01ab, 0x567e,
    0x0b3b, 0x6c2f, 0x5e4d, 0x2641, 0x03a4, 0x1214, 0x4b01, 0x48f3, 0x7ba9, 0x7009, 0x1270, 0x0e67,
    0x40e8, 0x710d, 0x6b7f, 0x1418, 0x45f6, 0x2785, 0x4725, 0x7904, 0x14a2, 0x71b8, 0x3189, 0x6ccc,
    0x4d66, 0x701e, 0x4148, 0x6c05, 0x01a8, 0x5ff1, 0x4fbb, 0x0a2a, 0x541d, 0x4378, 0x3f15, 0x3677,
    0x0d82, 0x578b, 0x345d, 0x6052, 0x0beb, 0x553d, 0x4d89, 0x1315, 0x311c, 0x3f33, 0x226d, 0x3223,
    0x478b, 0x487b, 0x5326, 0x160e, 0x05b3, 0x486d, 0x0f2f, 0x1ecc, 0x04b7, 0x01a0, 0x6f70, 0x425c,
    0x3d3f, 0x1610, 0x4211, 0x68d3, 0x3041, 0x7ddf, 0x5967, 0x36f3, 0x31a5, 0x2137, 0x4692, 0x56de,
    0x53d8, 0x4466, 0x5720, 0x6d64, 0x3421, 0x6979, 0x3151, 0x5ee6, 0x0e2f, 0x35d8, 0x30ff, 0x3070,
    0x19b1, 0x4651, 0x6b4f, 0x4cea, 0x7991, 0x4e0b, 0x2d3f, 0x3d1e, 0x09a0, 0x4bac, 0x0571, 0x079a,
    0x4380, 0x411a, 0x4012, 0x57f5, 0x0f7a, 0x5ae9, 0x1b6d, 0x6f3c, 0x3b37, 0x0b66, 0x60af, 0x17b9,
    0x77df, 0x286f, 0x14c9, 0x2274, 0x1d96, 0x67dc, 0x7801, 0x68d9, 0x0942, 0x1c06, 0x4922, 0x7a4b,
    0x1732, 0x6c5d, 0x4928, 0x3c70, 0x64fa, 0x6ce8, 0x2979, 0x163b, 0x4379, 0x64ee, 0x37d3, 0x5bf2,
    0x1725, 0x5749, 0x26aa, 0x13e7, 0x1e82, 0x2226, 0x723c, 0x4677, 0x4a6f, 0x0e39, 0x6431, 0x50f7,
    0x7ff9, 0x7b82, 0x2307, 0x7254, 0x1c17, 0x1d2c, 0x580d, 0x3b5f, 0x3e99, 0x46ee, 0x3105, 0x5d19,
    0x38bb, 0x4134, 0x21bc, 0x068a, 0x0e6b, 0x5aa7, 0x68ef, 0x2bd2, 0x71b5, 0x0db8, 0x28c5, 0x5a48,
    0x14ad, 0x1ec0, 0x2c71, 0x690c, 0x1559, 0x5638, 0x73b2, 0x26c6, 0x301b, 0x2aad, 0x256f, 0x15fd,
    0x7e60, 0x5a5a, 0x70a8, 0x70a2, 0x3c76, 0x5a00, 0x49b3, 0x0f1d, 0x7a43, 0x18d8, 0x56e1, 0x6101,
    0x3f86, 0x4ad9, 0x26b4, 0x0305, 0x388c, 0x13e2, 0x36e9, 0x35e4, 0x587c, 0x2e31, 0x5ecb, 0x2ed3,
    0x4493, 0x40a6, 0x0d5c, 0x57de, 0x5b6b, 0x656c, 0x1ca2, 0x167c, 0x65a5, 0x7597, 0x1f4f, 0x47dd,
    0x602c, 0x2169, 0x7ccb, 0x7719, 0x07a3, 0x735b, 0x1afd, 0x6315, 0x1fba, 0x36fe, 0x5961, 0x4c63,
    0x79af, 0x1126, 0x269a, 0x312f, 0x3d20, 0x1783, 0x334b, 0x44a8, 0x6580, 0x2f6b, 0x5174, 0x5daf,
    0x01b4, 0x15b8, 0x33c1, 0x5c4b, 0x302f, 0x73bf, 0x59ce, 0x0b13, 0x1c9b, 0x2e1b, 0x27f7, 0x00a7,
    0x7c7e, 0x6763, 0x202e, 0x7a6d, 0x4a1c, 0x20dd, 0x591d, 0x7edb, 0x7c3b, 0x7532, 0x1909, 0x1dd6,
    0x466a, 0x72d0, 0x2c9a, 0x79d7, 0x0fda, 0x6dc0, 0x4907, 0x0a6c, 0x3f75, 0x34cc, 0x6e42, 0x35e4,
    0x6dbb, 0x51f0, 0x2af5, 0x441f, 0x6907, 0x27d9, 0x540b, 0x7095, 0x6723, 0x66b3, 0x1f85, 0x6213,
    0x405b, 0x06ed, 0x1d8b, 0x6550, 0x2585, 0x002e, 0x3c07, 0x5208, 0x7933, 0x3897, 0x777d, 0x03db,
    0x4d9f, 0x50cc, 0x31f1, 0x3213, 0x4a70, 0x6e2f, 0x78c4, 0x5c1e, 0x391e, 0x0e49, 0x007b, 0x7c8f,
    0x55d8, 0x51b7, 0x4477, 0x61ac, 0x7eb2, 0x330e, 0x1882, 0x4d04, 0x4b59, 0x3188, 0x74f5, 0x3ebe,
    0x2a7f, 0x6b8e, 0x705b, 0x6688, 0x1cfc, 0x084d, 0x60ed, 0x1cd9, 0x5799, 0x1f59, 0x0beb, 0x6732,
    0x6640, 0x782b, 0x455f, 0x5910, 0x7066, 0x26b0, 0x26d2, 0x7e26, 0x22bd, 0x15b3, 0x634e, 0x24f0,
    0x4649, 0x282b, 0x5631, 0x4539, 0x1b49, 0x4023, 0x48b1, 0x115b, 0x6ca6, 0x5bde, 0x4f40, 0x288f,
    0x4106, 0x6f41, 0x62fe, 0x09b1, 0x7929, 0x71e0, 0x2a80, 0x2164, 0x66be, 0x3fa8, 0x094b, 0x4a09,
    0x1177, 0x355f, 0x645a, 0x2940, 0x5a2a, 0x5369, 0x7ade, 0x0a66, 0x74e8, 0x6502, 0x6cbb, 0x1971,
    0x2ba3, 0x0ab5, 0x2f4f, 0x4539, 0x150e, 0x1dc4, 0x3262, 0x04ed, 0x5df0, 0x35af, 0x5c4a, 0x4fb4,
    0x5fcd, 0x0dc7, 0x6fef, 0x266e, 0x0be6, 0x69d9, 0x5e02, 0x4650, 0x561f, 0x03e8, 0x26e5, 0x4778,
    0x6be3, 0x4375, 0x1559, 0x7786, 0x0653, 0x2a4a, 0x4825, 0x70f0, 0x56f2, 0x596f, 0x4f6b, 0x0937,
    0x4e89, 0x5390, 0x5bf9, 0x03ea, 0x1eb7, 0x1296, 0x1966, 0x77bc, 0x6d2a, 0x3cf1, 0x43a7, 0x01a3,
    0x2e0f, 0x696e, 0x5654, 0x4ba6, 0x66be, 0x6b16, 0x2c6c, 0x3db4, 0x7b52, 0x2d5f, 0x0b3c, 0x7391,
    0x25f7, 0x45bf, 0x44c7, 0x7052, 0x3da7, 0x117c, 0x0797, 0x20b9, 0x6b35, 0x61bc, 0x511a, 0x2168,
    0x7693, 0x6de2, 0x4c7c, 0x04e1, 0x234a, 0x1e36, 0x16c7, 0x2b67, 0x5c40, 0x1dd8, 0x7164, 0x77cc,
    0x0c10, 0x6789, 0x1a4b, 0x42dd, 0x5ea5, 0x545a, 0x2c55, 0x0eb7, 0x6126, 0x48b6, 0x1a5b, 0x093d,
    0x77ee, 0x75d6, 0x5e4c, 0x0153, 0x2b53, 0x5587, 0x4e6d, 0x4cff, 0x2afb, 0x37e1, 0x4f61, 0x6ff2,
    0x1758, 0x74b2, 0x0b70, 0x4146, 0x51b8, 0x51fe, 0x6fae, 0x696b, 0x0a58, 0x43d0, 0x623e, 0x57c4,
    0x07f8, 0x712c, 0x1221, 0x7378, 0x7c69, 0x7bd0, 0x00f4, 0x35de, 0x6cd7, 0x4947, 0x6344, 0x1575,
    0x67ed, 0x1bd0, 0x45f3, 0x3d2d, 0x0bd1, 0x66c8, 0x7c11, 0x47b0, 0x19bb, 0x6695, 0x6509, 0x5eed,
    0x4e6a, 0x19ac, 0x3234, 0x5dab, 0x3a2b, 0x7a79, 0x5c58, 0x2347, 0x434b, 0x32a7, 0x3eb5, 0x1a2a,
    0x02ec, 0x1f61, 0x62a7, 0x70c0, 0x228e, 0x445d, 0x5ab6, 0x401c, 0x5404, 0x41cd, 0x46a9, 0x3358,
    0x1cb1, 0x67d6, 0x3106, 0x7ae3, 0x1ea6, 0x2ad7, 0x07d5, 0x7aa5, 0x750a, 0x6601, 0x595b, 0x4867,
    0x7b8c, 0x0c0c, 0x3f99, 0x7843, 0x27ac, 0x7a3c, 0x7928, 0x20d9, 0x024f, 0x6c8f, 0x1b90, 0x1142,
    0x75c0, 0x0227, 0x1cb7, 0x4863, 0x7705, 0x553f, 0x7d44, 0x6dff, 0x5f8c, 0x3dae, 0x1984, 0x2410,
    0x757d, 0x6403, 0x567c, 0x4bda, 0x49de, 0x10e9, 0x6a0a, 0x2054, 0x5cb1, 0x534e, 0x0206, 0x7a42,
    0x66b3, 0x18f0, 0x604f, 0x1b4f, 0x2b97, 0x1a34, 0x0284, 0x5d71, 0x0642, 0x6390, 0x6d85, 0x2e2a,
    0x17d9, 0x3d3f, 0x35d6, 0x4118, 0x5700, 0x3e89, 0x6ddb, 0x0dc2, 0x6750, 0x232e, 0x566b, 0x77b6,
    0x607f, 0x31cc, 0x0c29, 0x602b, 0x50f6, 0x6ac0, 0x305c, 0x181a, 0x4c16, 0x701b, 0x7b3d, 0x20c5,
    0x3359, 0x7034, 0x1837, 0x090a, 0x5f2d, 0x5837, 0x53dd, 0x6827, 0x0afb, 0x2968, 0x5983, 0x3a36,
    0x6a3b, 0x0b8e, 0x04e4, 0x3bf7, 0x3bba, 0x2c2b, 0x084e, 0x5ad4, 0x0da4, 0x6828, 0x7332, 0x15f4,
    0x034d, 0x1c30, 0x6907, 0x6c5f, 0x07c3, 0x0154, 0x69d0, 0x6779, 0x30bc, 0x7bf6, 0x702e, 0x614c,
    0x2696, 0x76ff, 0x0463, 0x56f7, 0x5cfa, 0x6bf7, 0x6cbc, 0x57d9, 0x4d25, 0x10fb, 0x4e57, 0x3668,
    0x091c, 0x63a8, 0x1a6d, 0x60b1, 0x5675, 0x62ca, 0x5a16, 0x550e, 0x3b66, 0x1479, 0x6827, 0x1511,
    0x64e9, 0x7ee7, 0x7b8d, 0x4137, 0x1c46, 0x44e9, 0x6d7c, 0x1709, 0x646e, 0x620a, 0x497a, 0x2971,
    0x23df, 0x1451, 0x558d, 0x693c, 0x52d6, 0x27e1, 0x487d, 0x404e, 0x092b, 0x1f57, 0x33b7, 0x3748,
];

impl HashImplementation for RandomVectorHash {
    const NUM_HASH_BYTES: usize = 3;

    fn get_hash(&self, b: &[u8]) -> u16 {
        assert!(b.len() >= 3);

        RANDOM_VECTOR[b[0] as usize]
            ^ RANDOM_VECTOR[b[1] as usize + 256]
            ^ RANDOM_VECTOR[b[2] as usize + 512]
    }

    fn algorithm(&self) -> HashAlgorithm {
        HashAlgorithm::RandomVector
    }
}