wifi_state_machine.js

// Copyright 2016 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
'use strict';

/**
 * @fileoverview WiFiStateMachine class to represent and hold state for each
 * instance of an Android WiFiStateMachine for a given log being processed.
 */

/**
 * @constructor
 *
 * @param {String} id Identifier for new WifiStateMachine instance.
 * @param {long} ms WifiStateMachine start time in ms.
 */
function WifiStateMachine(id, ms) {
  this.id = id;
  this.startTime = ms;
  this.scans = 0;
  this.scanDetails = [];
  this.networkDetailedStates = [];
  this.endTime = -1;
  this.supplicantStates = [];
}

/**
 * This method adds supplicant state transitions.
 *
 * @param {Update} update Object holding previous state, new state and time.
 */
WifiStateMachine.prototype.addSupplicantState = function(update) {
  if (update.time == null) {
    this.supplicantStates.push({'x': 0, 'y': update.newState});
    return;
  }

  var updateElapsedTime = Date.parse(update.time) - this.startTime;
  if (update.oldState == update.newState) {
    // not a new state transition...  still check if we have anything stored
    if (this.supplicantStates.length > 0) {
      // not a new transition...  return
      return;
    }
    this.supplicantStates.push({'x': updateElapsedTime, 'y': update.oldState});
    return;
  }
  // now we know the states are different, we need to process this update
  if (this.supplicantStates.length > 0) {
    // should check states to make sure they match
    var lastUpdate = this.supplicantStates[this.supplicantStates.length - 1];
    if (lastUpdate.y != update.oldState) {
      this.supplicantStates.push({'x': updateElapsedTime,
                                  'y': lastUpdate.y});
      this.supplicantStates.push({'x': updateElapsedTime,
                                  'y': update.oldState});

    }
  } else {
    // need to enter previous state - use update time since we do not have the
    // start time.
    this.supplicantStates.push({'x': updateElapsedTime, 'y': update.oldState});
  }
  this.supplicantStates.push({'x': updateElapsedTime,
                              'y': update.oldState});
  this.supplicantStates.push({'x': updateElapsedTime,
                              'y': update.newState});
};