Introduce VolumeInfoList which holds all VolumeInfo instance.

This CL introduces VolumeInfoList class, which holds all VolumeInfo instances
for each mounted volume with keeping the order.
This will replaces DirectoryModel.rootsList in following CLs.

BUG=268817
TEST=Ran browser_tests --gtest_filter="*FileSystemExtensionApiTest*:*FileManagerBrowserTest*:*FileBrowserPrivateApiTest*" and tested manually.

Review URL: https://chromiumcodereview.appspot.com/23111006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@219783 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 148 insertions, 11 deletions

diff --git a/chrome/browser/resources/file_manager/js/volume_manager.js b/chrome/browser/resources/file_manager/js/volume_manager.js
index f7edcbc..eb5503a 100644
--- a/chrome/browser/resources/file_manager/js/volume_manager.js
+++ b/chrome/browser/resources/file_manager/js/volume_manager.js
@@ -116,6 +116,144 @@ volumeManagerUtil.createVolumeInfo = function(mountPath, error, callback) {
 };
 
 /**
+ * The order of the volume list based on root type.
+ * @type {Array.<string>}
+ * @const
+ * @private
+ */
+volumeManagerUtil.volumeListOrder_ = [
+  RootType.DRIVE, RootType.DOWNLOADS, RootType.ARCHIVE, RootType.REMOVABLE
+];
+
+/**
+ * Compares mount paths to sort the volume list order.
+ * @param {string} mountPath1 The mount path for the first volume.
+ * @param {string} mountPath2 The mount path for the second volume.
+ * @return {number} 0 if mountPath1 and mountPath2 are same, -1 if VolumeInfo
+ *     mounted at mountPath1 should be listed before the one mounted at
+ *     mountPath2, otherwise 1.
+ */
+volumeManagerUtil.compareMountPath = function(mountPath1, mountPath2) {
+  var order1 = volumeManagerUtil.volumeListOrder_.indexOf(
+      PathUtil.getRootType(mountPath1));
+  var order2 = volumeManagerUtil.volumeListOrder_.indexOf(
+      PathUtil.getRootType(mountPath2));
+  if (order1 != order2)
+    return order1 < order2 ? -1 : 1;
+
+  if (mountPath1 != mountPath2)
+    return mountPath1 < mountPath2 ? -1 : 1;
+
+  // The path is same.
+  return 0;
+};
+
+/**
+ * The container of the VolumeInfo for each mounted volume.
+ * @constructor
+ */
+function VolumeInfoList() {
+  /**
+   * Holds VolumeInfo instances.
+   * @type {cr.ui.ArrayDataModel}
+   * @private
+   */
+  this.model_ = new cr.ui.ArrayDataModel([]);
+
+  Object.freeze(this);
+}
+
+VolumeInfoList.prototype = {
+  get length() { return this.model_.length; }
+};
+
+/**
+ * Adds the event listener to listen the change of volume info.
+ * @param {string} type The name of the event.
+ * @param {function(cr.Event)} handler The handler for the event.
+ */
+VolumeInfoList.prototype.addEventListener = function(type, handler) {
+  this.model_.addEventListener(type, handler);
+};
+
+/**
+ * Removes the event listener.
+ * @param {string} type The name of the event.
+ * @param {function(cr.Event)} handler The handler to be removed.
+ */
+VolumeInfoList.prototype.removeEventListener = function(type, handler) {
+  this.model_.removeEventListener(type, handler);
+};
+
+/**
+ * Adds the volumeInfo to the appropriate position. If there already exists,
+ * just replaces it.
+ * @param {VolumeInfo} volumeInfo The information of the new volume.
+ */
+VolumeInfoList.prototype.add = function(volumeInfo) {
+  var index = this.findLowerBoundIndex_(volumeInfo.mountPath);
+  if (index < this.length &&
+      this.item(index).mountPath == volumeInfo.mountPath) {
+    // Replace the VolumeInfo.
+    this.model_.splice(index, 1, volumeInfo);
+  } else {
+    // Insert the VolumeInfo.
+    this.model_.splice(index, 0, volumeInfo);
+  }
+};
+
+/**
+ * Removes the VolumeInfo of the volume mounted at mountPath.
+ * @param {string} mountPath The path to the location where the volume is
+ *     mounted.
+ */
+VolumeInfoList.prototype.remove = function(mountPath) {
+  var index = this.findLowerBoundIndex_(mountPath);
+  if (index < this.length && this.item(index).mountPath == mountPath)
+    this.model_.splice(index, 1);
+};
+
+/**
+ * Searches the information of the volume mounted at mountPath.
+ * @param {string} mountPath The path to the location where the volume is
+ *     mounted.
+ * @return {VolumeInfo} The volume's information, or null if not found.
+ */
+VolumeInfoList.prototype.find = function(mountPath) {
+  var index = this.findLowerBoundIndex_(mountPath);
+  if (index < this.length && this.item(index).mountPath == mountPath)
+    return this.item(index);
+
+  // Not found.
+  return null;
+};
+
+/**
+ * @param {string} mountPath The mount path of searched volume.
+ * @return {number} The index of the volumee if found, or the inserting
+ *     position of the volume.
+ * @private
+ */
+VolumeInfoList.prototype.findLowerBoundIndex_ = function(mountPath) {
+  // Assuming the number of elements in the array data model is very small
+  // in most cases, use simple linear search, here.
+  for (var i = 0; i < this.length; i++) {
+    if (volumeManagerUtil.compareMountPath(
+            this.item(i).mountPath, mountPath) >= 0)
+      return i;
+  }
+  return this.length;
+};
+
+/**
+ * @param {number} index The index of the volume in the list.
+ * @return {VolumeInfo} The VolumeInfo instance.
+ */
+VolumeInfoList.prototype.item = function(index) {
+  return this.model_.item(index);
+};
+
+/**
  * VolumeManager is responsible for tracking list of mounted volumes.
  *
  * @param {Entry} root The root of file system.
@@ -140,11 +278,10 @@ function VolumeManager(root) {
   this.requests_ = {};
 
   /**
-   * TODO(hidehiko): Replace Object with cr.ui.ArrayDataModel.
-   * @type {Object.<string, VolumeInfo>}
-   * @private
+   * The list of VolumeInfo instances for each mounted volume.
+   * @type {VolumeInfoList}
    */
-  this.mountedVolumes_ = {};
+  this.volumeInfoList = new VolumeInfoList();
 
   /**
    * True, if mount points have been initialized.
@@ -348,7 +485,7 @@ VolumeManager.prototype.getDriveStatus = function() {
  */
 VolumeManager.prototype.isMounted = function(mountPath) {
   volumeManagerUtil.validateMountPath(mountPath);
-  return mountPath in this.mountedVolumes_;
+  return !!this.volumeInfoList.find(mountPath);
 };
 
 /**
@@ -386,7 +523,7 @@ VolumeManager.prototype.initMountPoints_ = function() {
         volumeManagerUtil.createVolumeInfo(
             '/' + mountPoint.mountPath, error,
             function(volumeInfo) {
-              this.mountedVolumes_[volumeInfo.mountPath] = volumeInfo;
+              this.volumeInfoList.add(volumeInfo);
               callback();
             }.bind(this));
       }.bind(this, mountPoint, error));
@@ -429,7 +566,7 @@ VolumeManager.prototype.onMountCompleted_ = function(event) {
       var error = event.status == 'success' ? '' : event.status;
       volumeManagerUtil.createVolumeInfo(
           event.mountPath, error, function(volume) {
-            this.mountedVolumes_[volume.mountPath] = volume;
+            this.volumeInfoList.add(volume);
             this.finishRequest_(requestKey, event.status, event.mountPath);
             cr.dispatchSimpleEvent(this, 'change');
           }.bind(this));
@@ -448,7 +585,7 @@ VolumeManager.prototype.onMountCompleted_ = function(event) {
     var requestKey = this.makeRequestKey_('unmount', '', event.mountPath);
     var requested = requestKey in this.requests_;
     if (event.status == 'success' && !requested &&
-        mountPath in this.mountedVolumes_) {
+        this.volumeInfoList.find(mountPath)) {
       console.warn('Mounted volume without a request: ', mountPath);
       var e = new cr.Event('externally-unmounted');
       e.mountPath = mountPath;
@@ -457,7 +594,7 @@ VolumeManager.prototype.onMountCompleted_ = function(event) {
     this.finishRequest_(requestKey, status);
 
     if (event.status == 'success') {
-      delete this.mountedVolumes_[mountPath];
+      this.volumeInfoList.remove(mountPath);
       cr.dispatchSimpleEvent(this, 'change');
     }
   }
@@ -584,7 +721,7 @@ VolumeManager.prototype.unmount = function(mountPath,
     return;
   }
 
-  var volumeInfo = this.mountedVolumes_[mountPath];
+  var volumeInfo = this.volumeInfoList.find(mountPath);
   if (!volumeInfo) {
     errorCallback(VolumeManager.Error.NOT_MOUNTED);
     return;
@@ -601,7 +738,7 @@ VolumeManager.prototype.unmount = function(mountPath,
  */
 VolumeManager.prototype.getVolumeInfo = function(mountPath) {
   volumeManagerUtil.validateMountPath(mountPath);
-  return this.mountedVolumes_[mountPath];
+  return this.volumeInfoList.find(mountPath);
 };
 
 /**