chaoran

function fib(n, callback) {
  if (n < 2) return process.nextTick(function() {
    callback(1);
  });

  var results = [];

  function done(ret) {
    results.push(ret);
    if (results.length === 2)

chaoran

var bounds = [0]
var hashs = [inital_number_of_box]

function map(user_id) {
  for (var i = bounds.length-1; i >= 0; --i) {
    if (user_id > bounds[i]) {
      var shard_id = user_id % hashs[i]
      return shard_id
    }
  }