/* charCodeAt is the best approach for binary strings */ var use_buffer = typeof Buffer !== 'undefined'; function crc32_bstr(bstr) { if(bstr.length > 32768) if(use_buffer) return crc32_buf(Buffer(bstr)); var crc = -1, L = bstr.length - 1; for(var i = 0; i < L;) { crc = table[(crc ^ bstr.charCodeAt(i++)) & 0xFF] ^ (crc >>> 8); crc = table[(crc ^ bstr.charCodeAt(i++)) & 0xFF] ^ (crc >>> 8); } if(i === L) crc = (crc >>> 8) ^ table[(crc ^ bstr.charCodeAt(i)) & 0xFF]; return crc ^ -1; } function crc32_buf(buf) { for(var crc = -1, i = 0, L=buf.length-3; i < L;) { crc = (crc >>> 8) ^ table[(crc^buf[i++])&0xFF]; crc = (crc >>> 8) ^ table[(crc^buf[i++])&0xFF]; crc = (crc >>> 8) ^ table[(crc^buf[i++])&0xFF]; crc = (crc >>> 8) ^ table[(crc^buf[i++])&0xFF]; } if(i < L+3) { crc = (crc >>> 8) ^ table[(crc^buf[i++])&0xFF]; if(i < L+3) { crc = (crc >>> 8) ^ table[(crc^buf[i++])&0xFF]; if(i < L+3) { crc = (crc >>> 8) ^ table[(crc^buf[i++])&0xFF]; }}} return crc ^ -1; } /* much much faster to intertwine utf8 and crc */ function crc32_str(str) { for(var crc = -1, i = 0, L=str.length, c, d; i < L;) { c = str.charCodeAt(i++); if(c < 0x80) { crc = (crc >>> 8) ^ table[(crc ^ c) & 0xFF]; } else if(c < 0x800) { crc = (crc >>> 8) ^ table[(crc ^ (192|((c>>6)&31))) & 0xFF]; crc = (crc >>> 8) ^ table[(crc ^ (128|(c&63))) & 0xFF]; } else if(c >= 0xD800 && c < 0xE000) { c = (c&1023)+64; d = str.charCodeAt(i++) & 1023; crc = (crc >>> 8) ^ table[(crc ^ (240|((c>>8)&7))) & 0xFF]; crc = (crc >>> 8) ^ table[(crc ^ (128|((c>>2)&63))) & 0xFF]; crc = (crc >>> 8) ^ table[(crc ^ (128|((d>>6)&15)|(c&3))) & 0xFF]; crc = (crc >>> 8) ^ table[(crc ^ (128|(d&63))) & 0xFF]; } else { crc = (crc >>> 8) ^ table[(crc ^ (224|((c>>12)&15))) & 0xFF]; crc = (crc >>> 8) ^ table[(crc ^ (128|((c>>6)&63))) & 0xFF]; crc = (crc >>> 8) ^ table[(crc ^ (128|(c&63))) & 0xFF]; } } return crc ^ -1; }