extensions/renderer/resources/entry_id_manager.js

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 var fileSystemNatives = requireNative('file_system_natives');
   6
   7 var nameToIds = {};
   8 var idsToEntries = {};
   9
  10 function computeName(entry) {
  11   return entry.filesystem.name + ':' + entry.fullPath;
  12 }
  13
  14 function computeId(entry) {
  15   var fileSystemId = fileSystemNatives.CrackIsolatedFileSystemName(
  16       entry.filesystem.name);
  17   if (!fileSystemId)
  18     return null;
  19   // Strip the leading '/' from the path.
  20   return fileSystemId + ':' + $String.slice(entry.fullPath, 1);
  21 }
  22
  23 function registerEntry(id, entry) {
  24   var name = computeName(entry);
  25   nameToIds[name] = id;
  26   idsToEntries[id] = entry;
  27 }
  28
  29 function getEntryId(entry) {
  30   var name = null;
  31   try {
  32     name = computeName(entry);
  33   } catch(e) {
  34     return null;
  35   }
  36   var id = nameToIds[name];
  37   if (id != null)
  38     return id;
  39
  40   // If an entry has not been registered, compute its id and register it.
  41   id = computeId(entry);
  42   registerEntry(id, entry);
  43   return id;
  44 }
  45
  46 function getEntryById(id) {
  47   return idsToEntries[id];
  48 }
  49
  50 exports.registerEntry = registerEntry;
  51 exports.getEntryId = getEntryId;
  52 exports.getEntryById = getEntryById;