Split MemoryStore in a separate module + avoid memory leaks

README.md

@@ -35,9 +35,8 @@ and writes cookies on `req`/`res`. Using `cookie-parser` may result in issues
 if the `secret` is not the same between this module and `cookie-parser`.
 
 **Warning** The default server-side session storage, `MemoryStore`, is _purposely_
-not designed for a production environment. It will leak memory under most
-conditions, does not scale past a single process, and is meant for debugging and
-developing.
+not designed for a production environment. It does not scale past a single
+process, and is meant for debugging and developing.
 
 For a list of stores, see [compatible session stores](#compatible-session-stores).
 
@@ -633,7 +632,7 @@ and other multi-core embedded devices).
 [express-nedb-session-url]: https://www.npmjs.com/package/express-nedb-session
 [express-nedb-session-image]: https://img.shields.io/github/stars/louischatriot/express-nedb-session.svg?label=%E2%98%85
 
-[![★][express-session-cache-manager-image] express-session-cache-manager][express-session-cache-manager-url] 
+[![★][express-session-cache-manager-image] express-session-cache-manager][express-session-cache-manager-url]
 A store that implements [cache-manager](https://www.npmjs.com/package/cache-manager), which supports
 a [variety of storage types](https://www.npmjs.com/package/cache-manager#store-engines).
 

package.json

@@ -15,6 +15,7 @@
     "crc": "3.4.4",
     "debug": "2.6.8",
     "depd": "~1.1.0",
+    "memorystore": "1.5.0",
     "on-headers": "~1.0.1",
     "parseurl": "~1.3.1",
     "uid-safe": "~2.1.4",

session/memory.js

@@ -15,171 +15,10 @@
 
 var Store = require('./store')
 var util = require('util')
-
-/**
- * Shim setImmediate for node.js < 0.10
- * @private
- */
-
-/* istanbul ignore next */
-var defer = typeof setImmediate === 'function'
-  ? setImmediate
-  : function(fn){ process.nextTick(fn.bind.apply(fn, arguments)) }
+var MemoryStore = require('memorystore')
 
 /**
  * Module exports.
  */
 
-module.exports = MemoryStore
-
-/**
- * A session store in memory.
- * @public
- */
-
-function MemoryStore() {
-  Store.call(this)
-  this.sessions = Object.create(null)
-}
-
-/**
- * Inherit from Store.
- */
-
-util.inherits(MemoryStore, Store)
-
-/**
- * Get all active sessions.
- *
- * @param {function} callback
- * @public
- */
-
-MemoryStore.prototype.all = function all(callback) {
-  var sessionIds = Object.keys(this.sessions)
-  var sessions = Object.create(null)
-
-  for (var i = 0; i < sessionIds.length; i++) {
-    var sessionId = sessionIds[i]
-    var session = getSession.call(this, sessionId)
-
-    if (session) {
-      sessions[sessionId] = session;
-    }
-  }
-
-  callback && defer(callback, null, sessions)
-}
-
-/**
- * Clear all sessions.
- *
- * @param {function} callback
- * @public
- */
-
-MemoryStore.prototype.clear = function clear(callback) {
-  this.sessions = Object.create(null)
-  callback && defer(callback)
-}
-
-/**
- * Destroy the session associated with the given session ID.
- *
- * @param {string} sessionId
- * @public
- */
-
-MemoryStore.prototype.destroy = function destroy(sessionId, callback) {
-  delete this.sessions[sessionId]
-  callback && defer(callback)
-}
-
-/**
- * Fetch session by the given session ID.
- *
- * @param {string} sessionId
- * @param {function} callback
- * @public
- */
-
-MemoryStore.prototype.get = function get(sessionId, callback) {
-  defer(callback, null, getSession.call(this, sessionId))
-}
-
-/**
- * Commit the given session associated with the given sessionId to the store.
- *
- * @param {string} sessionId
- * @param {object} session
- * @param {function} callback
- * @public
- */
-
-MemoryStore.prototype.set = function set(sessionId, session, callback) {
-  this.sessions[sessionId] = JSON.stringify(session)
-  callback && defer(callback)
-}
-
-/**
- * Get number of active sessions.
- *
- * @param {function} callback
- * @public
- */
-
-MemoryStore.prototype.length = function length(callback) {
-  this.all(function (err, sessions) {
-    if (err) return callback(err)
-    callback(null, Object.keys(sessions).length)
-  })
-}
-
-/**
- * Touch the given session object associated with the given session ID.
- *
- * @param {string} sessionId
- * @param {object} session
- * @param {function} callback
- * @public
- */
-
-MemoryStore.prototype.touch = function touch(sessionId, session, callback) {
-  var currentSession = getSession.call(this, sessionId)
-
-  if (currentSession) {
-    // update expiration
-    currentSession.cookie = session.cookie
-    this.sessions[sessionId] = JSON.stringify(currentSession)
-  }
-
-  callback && defer(callback)
-}
-
-/**
- * Get session from the store.
- * @private
- */
-
-function getSession(sessionId) {
-  var sess = this.sessions[sessionId]
-
-  if (!sess) {
-    return
-  }
-
-  // parse
-  sess = JSON.parse(sess)
-
-  var expires = typeof sess.cookie.expires === 'string'
-    ? new Date(sess.cookie.expires)
-    : sess.cookie.expires
-
-  // destroy expired session
-  if (expires && expires <= Date.now()) {
-    delete this.sessions[sessionId]
-    return
-  }
-
-  return sess
-}
+module.exports = new MemoryStore({Store: Store})