Refactoring file manager: moving volume mounting related code to a separate class.

chrome/browser/resources/file_manager/js/volume_manager.js

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/**
+ * VolumeManager is responsible for tracking list of mounted volumes.
+ *
+ * @constructor
+ * @extends {cr.EventTarget}
+ */
+function VolumeManager() {
+  /**
+   * The list of archives requested to mount. We will show contents once
+   * archive is mounted, but only for mounts from within this filebrowser tab.
+   * @type {Object.<string, Object>}
+   * @private
+   */
+  this.requests_ = {};
+
+  /**
+   * @type {Object.<string, Object>}
+   * @private
+   */
+  this.mountedVolumes_ = {};
+
+  this.initMountPoints_();
+  chrome.fileBrowserPrivate.onMountCompleted.addListener(
+        this.onMountCompleted_.bind(this));
+  this.gDataStatus_ = VolumeManager.GDataStatus.UNMOUNTED;
+}
+
+/**
+ * VolumeManager extends cr.EventTarget.
+ */
+VolumeManager.prototype.__proto__ = cr.EventTarget.prototype;
+
+/**
+ * @enum
+ */
+VolumeManager.Error = {
+  /* Internal errors */
+  NOT_MOUNTED: 'not_mounted',
+  TIMEOUT: 'timeout',
+
+  /* System events */
+  UNKNOWN: 'error_unknown',
+  INTERNAL: 'error_internal',
+  UNKNOWN_FILESYSTEM: 'error_unknown_filesystem',
+  UNSUPPORTED_FILESYSTEM: 'error_unsuported_filesystem',
+  INVALID_ARCHIVE: 'error_invalid_archive',
+  LIBCROS_MISSING: 'error_libcros_missing',
+  AUTHENTICATION: 'error_authentication',
+  PATH_UNMOUNTED: 'error_path_unmounted'
+};
+
+/**
+ * @enum
+ */
+VolumeManager.GDataStatus = {
+  UNMOUNTED: 'unmounted',
+  MOUNTING: 'mounting',
+  ERROR: 'error',
+  MOUNTED: 'mounted'
+};
+
+/**
+ * Time in milliseconds that we wait a respone for. If no response on
+ * mount/unmount received the request supposed failed.
+ */
+VolumeManager.TIMEOUT = 15 * 60 * 1000;
+
+/**
+ * Delay in milliseconds GDATA changes its state from |UNMOUNTED| to
+ * |MOUNTING|. Used to display progress in the UI.
+ */
+VolumeManager.MOUNTING_DELAY = 500;
+
+/**
+ * @return {VolumeManager} Singleton instance.
+ */
+VolumeManager.getInstance = function() {
+  return VolumeManager.instance_ = VolumeManager.instance_ ||
+                                   new VolumeManager();
+};
+
+/**
+ * @param {VolumeManager.GDataStatus} newStatus New GDATA status.
+ * @private
+ */
+VolumeManager.prototype.setGDataStatus_ = function(newStatus) {
+  if (this.gDataStatus_ != newStatus) {
+    this.gDataStatus_ = newStatus;
+    cr.dispatchSimpleEvent(this, 'gdata-status-changed');
+  }
+};
+
+/**
+ * @return {VolumeManager.GDataStatus} Current GDATA status.
+ */
+VolumeManager.prototype.getGDataStatus = function() {
+  return this.gDataStatus_;
+};
+
+/**
+ * @param {string} mountPath Volume root path.
+ * @return {boolean} True if mounted.
+ */
+VolumeManager.prototype.isMounted = function(mountPath) {
+  this.validateMountPath_(mountPath);
+  return mountPath in this.mountedVolumes_;
+};
+
+/**
+ * Initialized mount points.
+ * @private
+ */
+VolumeManager.prototype.initMountPoints_ = function() {
+  var mountedVolumes = [];
+  var self = this;
+  var index = 0;
+  function step(mountPoints) {
+    if (index < mountPoints.length) {
+      var info = mountPoints[index];
+      if (info.mountType == 'gdata')
+        console.error('GData is not expected initially mounted');
+      var error = info.mountCondition ? 'error_' + info.mountCondition : '';
+      function onVolumeInfo(volume) {
+        mountedVolumes.push(volume);
+        index++;
+        step(mountPoints);
+      }
+      self.makeVolumeInfo_('/' + info.mountPath, error, onVolumeInfo);
+    } else {
+      for (var i = 0; i < mountedVolumes.length; i++) {
+        var volume = mountedVolumes[i];
+        self.mountedVolumes_[volume.mountPath] = volume;
+      }
+      if (mountedVolumes.length > 0)
+        cr.dispatchSimpleEvent(self, 'change');
+    }
+  }
+
+  chrome.fileBrowserPrivate.getMountPoints(step);
+};
+
+/**
+ * Event handler called when some volume was mounted or unmouted.
+ * @param {MountCompletedEvent} event Received event.
+ * @private
+ */
+VolumeManager.prototype.onMountCompleted_ = function(event) {
+  if (event.eventType == 'mount') {
+    if (event.mountPath) {
+      var requestKey = this.makeRequestKey_(
+          'mount', event.mountType, event.sourcePath);
+      var error = event.status == 'success' ? '' : event.status;
+      this.makeVolumeInfo_(event.mountPath, error, function(volume) {
+        this.mountedVolumes_[volume.mountPath] = volume;
+        this.finishRequest_(requestKey, event.status, event.mountPath);
+        cr.dispatchSimpleEvent(this, 'change');
+      }.bind(this));
+    } else {
+      console.log('No mount path');
+      this.finishRequest_(requestKey, event.status);
+    }
+  } else if (event.eventType == 'unmount') {
+    var mountPath = event.mountPath;
+    this.validateMountPath_(mountPath);
+    var status = event.status;
+    if (status == VolumeManager.Error.PATH_UNMOUNTED) {
+      console.log('Volume already unmounted: ', mountPath);
+      status = 'success';
+    }
+    var requestKey = this.makeRequestKey_('unmount', '', event.mountPath);
+    var requested = requestKey in this.requests_;
+    if (event.status == 'success' && !requested &&
+        mountPath in this.mountedVolumes_) {
+      console.log('Mounted volume without a request: ', mountPath);
+      var e = new cr.Event('externally-unmounted');
+      e.mountPath = mountPath;
+      this.dispatchEvent(e);
+    }
+    this.finishRequest_(requestKey, status);
+
+    if (event.status == 'success') {
+      delete this.mountedVolumes_[mountPath];
+      cr.dispatchSimpleEvent(this, 'change');
+    }
+  }
+
+  if (event.mountType == 'gdata') {
+    if (event.status == 'success') {
+      if (event.eventType == 'mount')
+        this.setGDataStatus_(VolumeManager.GDataStatus.MOUNTED);
+      else if (event.eventType == 'unmount')
+        this.setGDataStatus_(VolumeManager.GDataStatus.UMOUNTED);
+    }
+  }
+};
+
+/**
+ * @param {string} mountPath Path to the volume.
+ * @param {VolumeManager?} error Mounting error if any.
+ * @param {function(Object)} callback Result acceptor.
+ * @private
+ */
+VolumeManager.prototype.makeVolumeInfo_ = function(
+    mountPath, error, callback) {
+  if (error)
+    this.validateError_(error);
+  this.validateMountPath_(mountPath);
+  function onVolumeMetadata(metadata) {
+   callback({
+     mountPath: mountPath,
+     error: error,
+     readonly: !!metadata && metadata.isReadOnly
+   });
+  }
+  chrome.fileBrowserPrivate.getVolumeMetadata(
+      util.makeFilesystemUrl(mountPath), onVolumeMetadata);
+};
+
+/**
+ * Creates string to match mount events with requests.
+ * @param {string} requestType 'mount' | 'unmount'.
+ * @param {string} mountType 'device' | 'file' | 'network' | 'gdata'.
+ * @param {string} mountOrSourcePath Source path provided by API after
+ *     resolving mount request or mountPath for unmount request.
+ * @return {string} Key for |this.requests_|.
+ * @private
+ */
+VolumeManager.prototype.makeRequestKey_ = function(requestType,
+                                                   mountType,
+                                                   mountOrSourcePath) {
+  return requestType + ':' + mountType + ':' + mountOrSourcePath;
+};
+
+
+/**
+ * @param {Function} successCallback Success callback.
+ * @param {Function} errorCallback Error callback.
+ */
+VolumeManager.prototype.mountGData = function(successCallback, errorCallback) {
+  if (this.getGDataStatus() == VolumeManager.GDataStatus.ERROR) {
+    this.setGDataStatus_(VolumeManager.GDataStatus.UNMOUNTED);
+  }
+  var self = this;
+  var timeout = setTimeout(function() {
+    if (self.getGDataStatus() == VolumeManager.GDataStatus.UNMOUNTED)
+      self.setGDataStatus_(VolumeManager.GDataStatus.MOUNTING);
+    timeout = null;
+  }, VolumeManager.MOUNTING_DELAY);
+  this.mount_('', 'gdata', function(mountPath) {
+    if (timeout !== null)
+      clearTimeout(timeout);
+    successCallback(mountPath);
+  }, function(error) {
+    if (self.getGDataStatus() != VolumeManager.GDataStatus.MOUNTED)
+      self.setGDataStatus_(VolumeManager.GDataStatus.ERROR);
+    if (timeout != null)
+      clearTimeout(timeout);
+    errorCallback(error);
+  });
+};
+
+/**
+ * @param {string} fullPath Path to the archive file.
+ * @param {Function} successCallback Success callback.
+ * @param {Function} errorCallback Error callback.
+ */
+VolumeManager.prototype.mountArchive = function(fullPath, successCallback,
+                                                errorCallback) {
+  this.mount_(util.makeFilesystemUrl(fullPath),
+      'file', successCallback, errorCallback);
+};
+
+/**
+ * Unmounts volume.
+ * @param {string} mountPath Volume mounted path.
+ * @param {Function} successCallback Success callback.
+ * @param {Function} errorCallback Error callback.
+ */
+VolumeManager.prototype.unmount = function(mountPath,
+                                           successCallback,
+                                           errorCallback) {
+  this.validateMountPath_(mountPath);
+  var volumeInfo = this.mountedVolumes_[mountPath];
+  if (!volumeInfo) {
+    errorCallback(VolumeManager.Error.NOT_MOUNTED);
+    return;
+  }
+
+  chrome.fileBrowserPrivate.removeMount(util.makeFilesystemUrl(mountPath));
+  var requestKey = this.makeRequestKey_('unmount', '', volumeInfo.mountPath);
+  this.startRequest_(requestKey, successCallback, errorCallback);
+};
+
+/**
+ * @param {string} mountPath Volume mounted path.
+ * @return {VolumeManager.Error?} Returns mount error code
+ *                                or undefined if no error.
+ */
+VolumeManager.prototype.getMountError = function(mountPath) {
+  return this.getVolumeInfo_(mountPath).error;
+};
+
+/**
+ * @param {string} mountPath Volume mounted path.
+ * @return {boolean} True if volume at |mountedPath| is mounted but not usable.
+ */
+VolumeManager.prototype.isUnreadable = function(mountPath) {
+  var error = this.getMountError(mountPath);
+  return error == VolumeManager.Error.UNKNOWN_FILESYSTEM ||
+         error == VolumeManager.Error.UNSUPPORTED_FILESYSTEM;
+};
+
+/**
+ * @param {string} mountPath Volume mounted path.
+ * @return {boolean} True if volume at |mountedPath| is read only.
+ */
+VolumeManager.prototype.isReadOnly = function(mountPath) {
+  return !!this.getVolumeInfo_(mountPath).readonly;
+};
+
+/**
+ * Helper method.
+ * @param {string} mountPath Volume mounted path.
+ * @return {Object} Structure created in |startRequest_|.
+ * @private
+ */
+VolumeManager.prototype.getVolumeInfo_ = function(mountPath) {
+  this.validateMountPath_(mountPath);
+  return this.mountedVolumes_[mountPath] || {};
+};
+
+/**
+ * @param {string} url URL for for |fileBrowserPrivate.addMount|.
+ * @param {'gdata'|'file'} mountType Mount type for
+ *     |fileBrowserPrivate.addMount|.
+ * @param {Function} successCallback Success callback.
+ * @param {Function} errorCallback Error callback.
+ * @private
+ */
+VolumeManager.prototype.mount_ = function(url, mountType,
+                                          successCallback, errorCallback) {
+  chrome.fileBrowserPrivate.addMount(url, mountType, {},
+                                     function(sourcePath) {
+    console.log('Mount request: url=' + url + '; mountType=' + mountType +
+                '; sourceUrl=' + sourcePath);
+    var requestKey = this.makeRequestKey_('mount', mountType, sourcePath);
+    this.startRequest_(requestKey, successCallback, errorCallback);
+  }.bind(this));
+};
+
+/**
+ * @param {sting} key Key produced by |makeRequestKey_|.
+ * @param {Function} successCallback To be called when request finishes
+ *                                   successfully.
+ * @param {Function} errorCallback To be called when request fails.
+ * @private
+ */
+VolumeManager.prototype.startRequest_ = function(key,
+    successCallback, errorCallback) {
+  if (key in this.requests_) {
+    var request = this.requests_[key];
+    request.successCallbacks.push(successCallback);
+    request.errorCallbacks.push(errorCallback);
+  } else {
+    this.requests_[key] = {
+      successCallbacks: [successCallback],
+      errorCallbacks: [errorCallback],
+
+      timeout: setTimeout(this.onTimeout_.bind(this, key),
+                          VolumeManager.TIMEOUT)
+    };
+  }
+};
+
+/**
+ * Called if no response received in |TIMEOUT|.
+ * @param {sting} key Key produced by |makeRequestKey_|.
+ * @private
+ */
+VolumeManager.prototype.onTimeout_ = function(key) {
+  this.invokeRequestCallbacks_(this.requests_[key],
+                               VolumeManager.Error.TIMEOUT);
+  delete this.requests_[key];
+};
+
+/**
+ * @param {sting} key Key produced by |makeRequestKey_|.
+ * @param {VolumeManager.Error|'success'} status Status received from the API.
+ * @param {string} opt_mountPath Mount path.
+ * @private
+ */
+VolumeManager.prototype.finishRequest_ = function(key, status, opt_mountPath) {
+  var request = this.requests_[key];
+  if (!request)
+    return;
+
+  clearTimeout(request.timeout);
+  this.invokeRequestCallbacks_(request, status, opt_mountPath);
+  delete this.requests_[key];
+};
+
+/**
+ * @param {object} request Structure created in |startRequest_|.
+ * @param {VolumeManager.Error|string} status If status == 'success'
+ *     success callbacks are called.
+ * @param {string} opt_mountPath Mount path. Required if success.
+ * @private
+ */
+VolumeManager.prototype.invokeRequestCallbacks_ = function(request, status,
+                                                           opt_mountPath) {
+  function callEach(callbacks, self, args) {
+    for (var i = 0; i < callbacks.length; i++) {
+      callbacks[i].apply(self, args);
+    }
+  }
+  if (status == 'success') {
+    callEach(request.successCallbacks, this, [opt_mountPath]);
+  } else {
+    this.validateError_(status);
+    callEach(request.errorCallbacks, this, [status]);
+  }
+};
+
+/**
+ * @param {VolumeManager.Error} error Status string iusually received from API.
+ * @private
+ */
+VolumeManager.prototype.validateError_ = function(error) {
+  for (var i in VolumeManager.Error) {
+    if (error == VolumeManager.Error[i])
+      return;
+  }
+  throw new Error('Invalid mount error: ', error);
+};
+
+/**
+ * @param {string} mountPath Mount path.
+ * @private
+ */
+VolumeManager.prototype.validateMountPath_ = function(mountPath) {
+  if (!/^\/(((archive|removable)\/[^\/]+)|drive|Downloads)$/.test(mountPath))
+    throw new Error('Invalid mount path: ', mountPath);
+};