Decompose getArrayOfHoles.

index.js

@@ -31,6 +31,23 @@ function encode(value) {
  return JSON.stringify(toTable(value));
 }
 
+// This array will grow as needed so that we can slice arrays filled with
+// ARRAY_HOLE_INDEX from it.
+var HOLY_ARRAY = [];
+
+// Returns an array of the given length filled with ARRAY_HOLE_INDEX.
+function getArrayOfHoles(length) {
+ var holyLen = HOLY_ARRAY.length;
+ if (length > holyLen) {
+ HOLY_ARRAY.length = length;
+ for (var i = holyLen; i < length; ++i) {
+ HOLY_ARRAY[i] = ARRAY_HOLE_INDEX;
+ }
+ }
+
+ return HOLY_ARRAY.slice(0, length);
+}
+
 function toTable(value) {
  var values = [];
  var getIndex = makeGetIndexFunction(values);
@@ -45,15 +62,7 @@ function toTable(value) {
  result = {};
 
  } else if (Array.isArray(value)) {
- result = Array(value.length);
- var len = value.length;
- if (len > keys.length) {
- // The array has holes, so make sure we fill them with the
- // ARRAY_HOLE_INDEX constant.
- for (var i = 0; i < len; ++i) {
- result[i] = ARRAY_HOLE_INDEX;
- }
- }
+ result = getArrayOfHoles(value.length);
 
  } else {
  for (var typeName in customTypes) {