struct DecoderWithIgnore [src]

A decoder that ignores certain characters. The decoder will skip any characters that are in the ignore list.

Fields

ignored_chars: StaticBitSet(256) = undefinedThe characters to ignore.

Members

decode (Function)
decodedLenForSlice (Function)
decodedLenUpperBound (Function)

Source

  pub const DecoderWithIgnore = struct {
    /// The characters to ignore.
    ignored_chars: StaticBitSet(256) = undefined,

    /// Decodes a hexadecimal string into a binary buffer.
    /// The output buffer must be half the size of the input buffer.
    pub fn decode(
        self: DecoderWithIgnore,
        bin: []u8,
        encoded: []const u8,
    ) error{ NoSpaceLeft, InvalidCharacter, InvalidPadding }![]const u8 {
        return decodeAny(bin, encoded, self.ignored_chars);
    }

    /// Returns the decoded length of a hexadecimal string, ignoring any characters in the ignore list.
    /// This operation does not run in constant time, but it aims to avoid leaking information about the underlying hexadecimal string.
    pub fn decodedLenForSlice(decoder: DecoderWithIgnore, encoded: []const u8) !usize {
        var hex_len = encoded.len;
        for (encoded) |c| {
            if (decoder.ignored_chars.isSet(c)) hex_len -= 1;
        }
        if (hex_len % 2 != 0) {
            return error.InvalidPadding;
        }
        return hex_len / 2;
    }

    /// Returns the maximum possible decoded size for a given input length after skipping ignored characters.
    pub fn decodedLenUpperBound(hex_len: usize) usize {
        return hex_len / 2;
    }
}  