struct Murmur2_32 [src]

Members

hash (Function)
hashUint32 (Function)
hashUint32WithSeed (Function)
hashUint64 (Function)
hashUint64WithSeed (Function)
hashWithSeed (Function)
Source

  pub const Murmur2_32 = struct {
    const Self = @This();

    pub fn hash(str: []const u8) u32 {
        return @call(.always_inline, Self.hashWithSeed, .{ str, default_seed });
    }

    pub fn hashWithSeed(str: []const u8, seed: u32) u32 {
        const m: u32 = 0x5bd1e995;
        const len: u32 = @truncate(str.len);
        var h1: u32 = seed ^ len;
        for (@as([*]align(1) const u32, @ptrCast(str.ptr))[0..(len >> 2)]) |v| {
            var k1: u32 = v;
            if (native_endian == .big)
                k1 = @byteSwap(k1);
            k1 *%= m;
            k1 ^= k1 >> 24;
            k1 *%= m;
            h1 *%= m;
            h1 ^= k1;
        }
        const offset = len & 0xfffffffc;
        const rest = len & 3;
        if (rest >= 3) {
            h1 ^= @as(u32, @intCast(str[offset + 2])) << 16;
        }
        if (rest >= 2) {
            h1 ^= @as(u32, @intCast(str[offset + 1])) << 8;
        }
        if (rest >= 1) {
            h1 ^= @as(u32, @intCast(str[offset + 0]));
            h1 *%= m;
        }
        h1 ^= h1 >> 13;
        h1 *%= m;
        h1 ^= h1 >> 15;
        return h1;
    }

    pub fn hashUint32(v: u32) u32 {
        return @call(.always_inline, Self.hashUint32WithSeed, .{ v, default_seed });
    }

    pub fn hashUint32WithSeed(v: u32, seed: u32) u32 {
        const m: u32 = 0x5bd1e995;
        const len: u32 = 4;
        var h1: u32 = seed ^ len;
        var k1: u32 = undefined;
        k1 = v *% m;
        k1 ^= k1 >> 24;
        k1 *%= m;
        h1 *%= m;
        h1 ^= k1;
        h1 ^= h1 >> 13;
        h1 *%= m;
        h1 ^= h1 >> 15;
        return h1;
    }

    pub fn hashUint64(v: u64) u32 {
        return @call(.always_inline, Self.hashUint64WithSeed, .{ v, default_seed });
    }

    pub fn hashUint64WithSeed(v: u64, seed: u32) u32 {
        const m: u32 = 0x5bd1e995;
        const len: u32 = 8;
        var h1: u32 = seed ^ len;
        var k1: u32 = undefined;
        k1 = @as(u32, @truncate(v)) *% m;
        k1 ^= k1 >> 24;
        k1 *%= m;
        h1 *%= m;
        h1 ^= k1;
        k1 = @as(u32, @truncate(v >> 32)) *% m;
        k1 ^= k1 >> 24;
        k1 *%= m;
        h1 *%= m;
        h1 ^= k1;
        h1 ^= h1 >> 13;
        h1 *%= m;
        h1 ^= h1 >> 15;
        return h1;
    }
}  