constructor() {
        this._h0 = 0x67452301;
        this._h1 = 0xEFCDAB89;
        this._h2 = 0x98BADCFE;
        this._h3 = 0x10325476;
        this._h4 = 0xC3D2E1F0;
        this._buff = new Uint8Array(64 /* SHA1Constant.BLOCK_SIZE */ + 3 /* to fit any utf-8 */);
        this._buffDV = new DataView(this._buff.buffer);
        this._buffLen = 0;
        this._totalLen = 0;
        this._leftoverHighSurrogate = 0;
        this._finished = false;
    }
A SHA1 implementation that works with strings and does not allocate.