lib: move duplicate spliceOne into internal/util

lib/url.js and lib/events.js are using the same spliceOne function. This change is to move it into the internal/util for avoiding duplicate code.

Author: starkwang

lib/events.js

@@ -22,6 +22,7 @@
 'use strict';
 
 var domain;
+var spliceOne;
 
 function EventEmitter() {
  EventEmitter.init.call(this);
@@ -416,8 +417,11 @@ EventEmitter.prototype.removeListener =
 
  if (position === 0)
  list.shift();
- else
+ else {
+ if (spliceOne === undefined)
+ spliceOne = require('internal/util').spliceOne;
  spliceOne(list, position);
+ }
 
  if (list.length === 1)
  events[type] = list[0];
@@ -529,13 +533,6 @@ EventEmitter.prototype.eventNames = function eventNames() {
  return this._eventsCount > 0 ? Reflect.ownKeys(this._events) : [];
 };
 
-// About 1.5x faster than the two-arg version of Array#splice().
-function spliceOne(list, index) {
- for (var i = index, k = i + 1, n = list.length; k < n; i += 1, k += 1)
- list[i] = list[k];
- list.pop();
-}
-
 function arrayClone(arr, n) {
  var copy = new Array(n);
  for (var i = 0; i < n; ++i)

lib/internal/util.js

@@ -271,6 +271,13 @@ function join(output, separator) {
  return str;
 }
 
+// About 1.5x faster than the two-arg version of Array#splice().
+function spliceOne(list, index) {
+ for (var i = index, k = i + 1, n = list.length; k < n; i += 1, k += 1)
+ list[i] = list[k];
+ list.pop();
+}
+
 module.exports = {
  assertCrypto,
  cachedResult,
@@ -281,10 +288,11 @@ module.exports = {
  filterDuplicateStrings,
  getConstructorOf,
  isError,
+ join,
  normalizeEncoding,
  objectToString,
  promisify,
- join,
+ spliceOne,
 
  // Symbol used to customize promisify conversion
  customPromisifyArgs: kCustomPromisifyArgsSymbol,

lib/url.js

@@ -28,6 +28,8 @@ const { hexTable } = require('internal/querystring');
 
 const errors = require('internal/errors');
 
+const { spliceOne } = require('internal/util');
+
 // WHATWG URL implementation provided by internal/url
 const {
  URL,
@@ -952,13 +954,6 @@ Url.prototype.parseHost = function parseHost() {
  if (host) this.hostname = host;
 };
 
-// About 1.5x faster than the two-arg version of Array#splice().
-function spliceOne(list, index) {
- for (var i = index, k = i + 1, n = list.length; k < n; i += 1, k += 1)
- list[i] = list[k];
- list.pop();
-}
-
 // These characters do not need escaping:
 // ! - . _ ~
 // ' ( ) * :