First commit

node_modules/ldapjs/lib/client/message-tracker/ge-window.js

@@ -0,0 +1,25 @@
+'use strict'
+
+const { MAX_MSGID } = require('../constants')
+
+/**
+ * Compare a reference id with another id to determine "greater than or equal"
+ * between the two values according to a sliding window.
+ *
+ * @param {integer} ref
+ * @param {integer} comp
+ *
+ * @returns {boolean} `true` if the `comp` value is >= to the `ref` value
+ * within the computed window, otherwise `false`.
+ */
+module.exports = function geWindow (ref, comp) {
+  let max = ref + Math.floor(MAX_MSGID / 2)
+  const min = ref
+  if (max >= MAX_MSGID) {
+    // Handle roll-over
+    max = max - MAX_MSGID - 1
+    return ((comp <= max) || (comp >= min))
+  } else {
+    return ((comp <= max) && (comp >= min))
+  }
+}

node_modules/ldapjs/lib/client/message-tracker/id-generator.js

@@ -0,0 +1,23 @@
+'use strict'
+
+const { MAX_MSGID } = require('../constants')
+
+/**
+ * Returns a function that generates message identifiers. According to RFC 4511
+ * the identifers should be `(0, MAX_MSGID)`. The returned function handles
+ * this and wraps around when the maximum has been reached.
+ *
+ * @param {integer} [start=0] Starting number in the identifier sequence.
+ *
+ * @returns {function} This function accepts no parameters and returns an
+ * increasing sequence identifier each invocation until it reaches the maximum
+ * identifier. At this point the sequence starts over.
+ */
+module.exports = function idGeneratorFactory (start = 0) {
+  let currentID = start
+  return function nextID () {
+    const id = currentID + 1
+    currentID = (id >= MAX_MSGID) ? 1 : id
+    return currentID
+  }
+}

node_modules/ldapjs/lib/client/message-tracker/index.js

@@ -0,0 +1,161 @@
+'use strict'
+
+const idGeneratorFactory = require('./id-generator')
+const purgeAbandoned = require('./purge-abandoned')
+
+/**
+ * Returns a message tracker object that keeps track of which message
+ * identifiers correspond to which message handlers. Also handles keeping track
+ * of abandoned messages.
+ *
+ * @param {object} options
+ * @param {string} options.id An identifier for the tracker.
+ * @param {object} options.parser An object that will be used to parse messages.
+ *
+ * @returns {MessageTracker}
+ */
+module.exports = function messageTrackerFactory (options) {
+  if (Object.prototype.toString.call(options) !== '[object Object]') {
+    throw Error('options object is required')
+  }
+  if (!options.id || typeof options.id !== 'string') {
+    throw Error('options.id string is required')
+  }
+  if (!options.parser || Object.prototype.toString.call(options.parser) !== '[object Object]') {
+    throw Error('options.parser object is required')
+  }
+
+  let currentID = 0
+  const nextID = idGeneratorFactory()
+  const messages = new Map()
+  const abandoned = new Map()
+
+  /**
+   * @typedef {object} MessageTracker
+   * @property {string} id The identifier of the tracker as supplied via the options.
+   * @property {object} parser The parser object given by the the options.
+   */
+  const tracker = {
+    id: options.id,
+    parser: options.parser
+  }
+
+  /**
+   * Count of messages awaiting response.
+   *
+   * @alias pending
+   * @memberof! MessageTracker#
+   */
+  Object.defineProperty(tracker, 'pending', {
+    get () {
+      return messages.size
+    }
+  })
+
+  /**
+   * Move a specific message to the abanded track.
+   *
+   * @param {integer} msgID The identifier for the message to move.
+   *
+   * @memberof MessageTracker
+   * @method abandon
+   */
+  tracker.abandon = function abandonMessage (msgID) {
+    if (messages.has(msgID) === false) return false
+    const toAbandon = messages.get(msgID)
+    abandoned.set(msgID, {
+      age: currentID,
+      message: toAbandon.message,
+      cb: toAbandon.callback
+    })
+    return messages.delete(msgID)
+  }
+
+  /**
+   * @typedef {object} Tracked
+   * @property {object} message The tracked message. Usually the outgoing
+   * request object.
+   * @property {Function} callback The handler to use when receiving a
+   * response to the tracked message.
+   */
+
+  /**
+   * Retrieves the message handler for a message. Removes abandoned messages
+   * that have been given time to be resolved.
+   *
+   * @param {integer} msgID The identifier for the message to get the handler for.
+   *
+   * @memberof MessageTracker
+   * @method fetch
+   */
+  tracker.fetch = function fetchMessage (msgID) {
+    const tracked = messages.get(msgID)
+    if (tracked) {
+      purgeAbandoned(msgID, abandoned)
+      return tracked
+    }
+
+    // We sent an abandon request but the server either wasn't able to process
+    // it or has not received it yet. Therefore, we received a response for the
+    // abandoned message. So we must return the abandoned message's callback
+    // to be processed normally.
+    const abandonedMsg = abandoned.get(msgID)
+    if (abandonedMsg) {
+      return { message: abandonedMsg, callback: abandonedMsg.cb }
+    }
+
+    return null
+  }
+
+  /**
+   * Removes all message tracks, cleans up the abandoned track, and invokes
+   * a callback for each message purged.
+   *
+   * @param {function} cb A function with the signature `(msgID, handler)`.
+   *
+   * @memberof MessageTracker
+   * @method purge
+   */
+  tracker.purge = function purgeMessages (cb) {
+    messages.forEach((val, key) => {
+      purgeAbandoned(key, abandoned)
+      tracker.remove(key)
+      cb(key, val.callback)
+    })
+  }
+
+  /**
+   * Removes a message from all tracking.
+   *
+   * @param {integer} msgID The identifier for the message to remove from tracking.
+   *
+   * @memberof MessageTracker
+   * @method remove
+   */
+  tracker.remove = function removeMessage (msgID) {
+    if (messages.delete(msgID) === false) {
+      abandoned.delete(msgID)
+    }
+  }
+
+  /**
+   * Add a message handler to be tracked.
+   *
+   * @param {object} message The message object to be tracked. This object will
+   * have a new property added to it: `messageId`.
+   * @param {function} callback The handler for the message.
+   *
+   * @memberof MessageTracker
+   * @method track
+   */
+  tracker.track = function trackMessage (message, callback) {
+    currentID = nextID()
+    // This side effect is not ideal but the client doesn't attach the tracker
+    // to itself until after the `.connect` method has fired. If this can be
+    // refactored later, then we can possibly get rid of this side effect.
+    message.messageId = currentID
+    messages.set(currentID, { callback, message })
+  }
+
+  return tracker
+}

node_modules/ldapjs/lib/client/message-tracker/purge-abandoned.js

@@ -0,0 +1,34 @@
+'use strict'
+
+const { AbandonedError } = require('../../errors')
+const geWindow = require('./ge-window')
+
+/**
+ * Given a `msgID` and a set of `abandoned` messages, remove any abandoned
+ * messages that existed _prior_ to the specified `msgID`. For example, let's
+ * assume the server has sent 3 messages:
+ *
+ * 1. A search message.
+ * 2. An abandon message for the search message.
+ * 3. A new search message.
+ *
+ * When the response for message #1 comes in, if it does, it will be processed
+ * normally due to the specification. Message #2 will not receive a response, or
+ * if the server does send one since the spec sort of allows it, we won't do
+ * anything with it because we just discard that listener. Now the response
+ * for message #3 comes in. At this point, we will issue a purge of responses
+ * by passing in `msgID = 3`. This result is that we will remove the tracking
+ * for message #1.
+ *
+ * @param {integer} msgID An upper bound for the messages to be purged.
+ * @param {Map} abandoned A set of abandoned messages. Each message is an object
+ * `{ age: <id>, cb: <func> }` where `age` was the current message id when the
+ * abandon message was sent.
+ */
+module.exports = function purgeAbandoned (msgID, abandoned) {
+  abandoned.forEach((val, key) => {
+    if (geWindow(val.age, msgID) === false) return
+    val.cb(new AbandonedError('client request abandoned'))
+    abandoned.delete(key)
+  })
+}