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This is an example of documentation generated by ZigDoc, an alternative to Zig's built-in Auto Doc feature. See also examples in other modes/formats. The project being documented here (as the example) is the Zig standard library. Public Function

permute

Public Function
std.hash.Adler32.permute
pub fn permute(state: u32, input: []const u8) u32

Params

  • state: u32
  • input: []const u8

File

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pub fn permute(state: u32, input: []const u8) u32 {
    const base = 65521;
    const nmax = 5552;

    var s1 = state & 0xffff;
    var s2 = (state >> 16) & 0xffff;

    if (input.len == 1) {
        s1 +%= input[0];
        if (s1 >= base) {
            s1 -= base;
        }
        s2 +%= s1;
        if (s2 >= base) {
            s2 -= base;
        }
    } else if (input.len < 16) {
        for (input) |b| {
            s1 +%= b;
            s2 +%= s1;
        }
        if (s1 >= base) {
            s1 -= base;
        }

        s2 %= base;
    } else {
        const n = nmax / 16; // note: 16 | nmax

        var i: usize = 0;

        while (i + nmax <= input.len) {
            var rounds: usize = 0;
            while (rounds < n) : (rounds += 1) {
                comptime var j: usize = 0;
                inline while (j < 16) : (j += 1) {
                    s1 +%= input[i + j];
                    s2 +%= s1;
                }
                i += 16;
            }

            s1 %= base;
            s2 %= base;
        }

        if (i < input.len) {
            while (i + 16 <= input.len) : (i += 16) {
                comptime var j: usize = 0;
                inline while (j < 16) : (j += 1) {
                    s1 +%= input[i + j];
                    s2 +%= s1;
                }
            }
            while (i < input.len) : (i += 1) {
                s1 +%= input[i];
                s2 +%= s1;
            }

            s1 %= base;
            s2 %= base;
        }
    }

    return s1 | (s2 << 16);
}