crossfilter/src/array.js

Fast multidimensional filtering for coordinated views.

var crossfilter_array8 = crossfilter_arrayUntyped,
    crossfilter_array16 = crossfilter_arrayUntyped,
    crossfilter_array32 = crossfilter_arrayUntyped,
    crossfilter_arrayLengthen = crossfilter_arrayLengthenUntyped,
    crossfilter_arrayWiden = crossfilter_arrayWidenUntyped;

if (typeof Uint8Array !== "undefined") {
  crossfilter_array8 = function(n) { return new Uint8Array(n); };
  crossfilter_array16 = function(n) { return new Uint16Array(n); };
  crossfilter_array32 = function(n) { return new Uint32Array(n); };

  crossfilter_arrayLengthen = function(array, length) {
    if (array.length >= length) return array;
    var copy = new array.constructor(length);
    copy.set(array);
    return copy;
  };

  crossfilter_arrayWiden = function(array, width) {
    var copy;
    switch (width) {
      case 16: copy = crossfilter_array16(array.length); break;
      case 32: copy = crossfilter_array32(array.length); break;
      default: throw new Error("invalid array width!");
    }
    copy.set(array);
    return copy;
  };
}

function crossfilter_arrayUntyped(n) {
  var array = new Array(n), i = -1;
  while (++i < n) array[i] = 0;
  return array;
}

function crossfilter_arrayLengthenUntyped(array, length) {
  var n = array.length;
  while (n < length) array[n++] = 0;
  return array;
}

function crossfilter_arrayWidenUntyped(array, width) {
  if (width > 32) throw new Error("invalid array width!");
  return array;
}