/** * JS Implementation of MurmurHash3 (r136) (as of May 20, 2011) * * @author Gary Court * @see http://github.com/garycourt/murmurhash-js * @author Austin Appleby * @see http://sites.google.com/site/murmurhash/ * * @param {string} key ASCII only * @param {number} seed Positive integer only * @return {number} 32-bit positive integer hash */ function murmurhash3_32_gc(key, seed) { var remainder, bytes, h1, h1b, c1, c1b, c2, c2b, k1, i; remainder = key.length & 3; // key.length % 4 bytes = key.length - remainder; h1 = seed; c1 = 0xcc9e2d51; c2 = 0x1b873593; i = 0; while (i < bytes) { k1 = ((key.charCodeAt(i) & 0xff)) | ((key.charCodeAt(++i) & 0xff) << 8) | ((key.charCodeAt(++i) & 0xff) << 16) | ((key.charCodeAt(++i) & 0xff) << 24); ++i; k1 = ((((k1 & 0xffff) * c1) + ((((k1 >>> 16) * c1) & 0xffff) << 16))) & 0xffffffff; k1 = (k1 << 15) | (k1 >>> 17); k1 = ((((k1 & 0xffff) * c2) + ((((k1 >>> 16) * c2) & 0xffff) << 16))) & 0xffffffff; h1 ^= k1; h1 = (h1 << 13) | (h1 >>> 19); h1b = ((((h1 & 0xffff) * 5) + ((((h1 >>> 16) * 5) & 0xffff) << 16))) & 0xffffffff; h1 = (((h1b & 0xffff) + 0x6b64) + ((((h1b >>> 16) + 0xe654) & 0xffff) << 16)); } k1 = 0; switch (remainder) { case 3: k1 ^= (key.charCodeAt(i + 2) & 0xff) << 16; case 2: k1 ^= (key.charCodeAt(i + 1) & 0xff) << 8; case 1: k1 ^= (key.charCodeAt(i) & 0xff); k1 = (((k1 & 0xffff) * c1) + ((((k1 >>> 16) * c1) & 0xffff) << 16)) & 0xffffffff; k1 = (k1 << 15) | (k1 >>> 17); k1 = (((k1 & 0xffff) * c2) + ((((k1 >>> 16) * c2) & 0xffff) << 16)) & 0xffffffff; h1 ^= k1; } h1 ^= key.length; h1 ^= h1 >>> 16; h1 = (((h1 & 0xffff) * 0x85ebca6b) + ((((h1 >>> 16) * 0x85ebca6b) & 0xffff) << 16)) & 0xffffffff; h1 ^= h1 >>> 13; h1 = ((((h1 & 0xffff) * 0xc2b2ae35) + ((((h1 >>> 16) * 0xc2b2ae35) & 0xffff) << 16))) & 0xffffffff; h1 ^= h1 >>> 16; return h1 >>> 0; }