把一些常用的字符串hash算法做了一下封裝

[js]代碼：

// hash.js

exports.additive = function (key, prime) {

key = key instanceof Buffer ? key : new Buffer(key);

prime = prime == undefined ? 0xffffffff : prime;

for (var hash = key.length, i = 0; i < key.length; i++) {

hash += key[i];

}

return (hash % prime);

}

exports.rotating = function(key) {

key = key instanceof Buffer ? key : new Buffer(key);

for (var hash = key.length, i = 0; i> 28) ^ key[i];

}

return hash;

}

exports.bernstein = function(key, prime) {

key = key instanceof Buffer ? key : new Buffer(key);

prime = prime == undefined ? 0xffffffff : prime;

var hash = 0;

for (i=0; i> 7;

hash += hash << 3;

hash ^= hash >> 17;

hash += hash << 5;

return hash;

}

exports.fnv1a = function (key){

key = key instanceof Buffer ? key : new Buffer(key);

var p = 16777619, hash = 0x811C9DC5;

for(var i=0; i< key.length; i++) {

hash = (hash ^ key[i]) * p;

}

hash += hash << 13;

hash ^= hash >> 7;

hash += hash << 3;

hash ^= hash >> 17;

hash += hash << 5;

return hash;

}

更多信息請查看IT技術專欄