| // Note: adler32 takes 12% for level 0 and 2% for level 6. | |
| // It doesn't worth to make additional optimizationa as in original. | |
| // Small size is preferable. | |
| function adler32(adler, buf, len, pos) { | |
| var s1 = (adler & 0xffff) |0, | |
| s2 = ((adler >>> 16) & 0xffff) |0, | |
| n = 0; | |
| while (len !== 0) { | |
| // Set limit ~ twice less than 5552, to keep | |
| // s2 in 31-bits, because we force signed ints. | |
| // in other case %= will fail. | |
| n = len > 2000 ? 2000 : len; | |
| len -= n; | |
| do { | |
| s1 = (s1 + buf[pos++]) |0; | |
| s2 = (s2 + s1) |0; | |
| } while (--n); | |
| s1 %= 65521; | |
| s2 %= 65521; | |
| } | |
| return (s1 | (s2 << 16)) |0; | |
| } | |
| export default adler32; | |