Issue 2021 - Replaced FileSystem API with chrome.storage.local

lib/io.js

Index: lib/io.js
===================================================================
new file mode 100644
--- /dev/null
+++ b/lib/io.js
@@ -0,0 +1,158 @@
+/*
+ * This file is part of Adblock Plus <https://adblockplus.org/>,
+ * Copyright (C) 2006-2015 Eyeo GmbH
+ *
+ * Adblock Plus is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * Adblock Plus is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+const keyPrefix = "file:";
+
+function fileToKey(file)
+{
+  return keyPrefix + (file instanceof FakeFile ? file.path : file.spec);
+}
+
+function loadFile(file, successCallback, errorCallback)
+{
+  let key = fileToKey(file);
+
+  ext.storage.get([key], function(items)
+  {
+    let entry = items[key];
+
+    if (entry)
+      successCallback(entry);
+    else
+      errorCallback(new Error("File doesn't exist"));
+  });
+}
+
+function saveFile(file, data, callback)
+{
+  ext.storage.set(
+    fileToKey(file),
+    {
+      content: data,
+      lastModified: Date.now()
+    },
+    callback
+  );
+}
+
+exports.IO =
+{
+  resolveFilePath: function(path)
+  {
+    return new FakeFile(path);
+  },
+
+  readFromFile: function(file, listener, callback)
+  {
+    runWhenMigrated(function()
+    {
+      function onLoaded(entry)
+      {
+        for (let line of entry.content)
+          listener.process(line);
+
+        listener.process(null);
+        callback(null);
+      }
+
+      loadFile(file, onLoaded, callback);
+    });
+  },
+
+  writeToFile: function(file, data, callback)
+  {
+    runWhenMigrated(function()
+    {
+      saveFile(file, data, callback);
+    });
+  },
+
+  copyFile: function(fromFile, toFile, callback)
+  {
+    runWhenMigrated(function()
+    {
+      function onLoaded(entry)
+      {
+        saveFile(toFile, entry.content, callback);
+      }
+
+      loadFile(fromFile, onLoaded, callback);
+    });
+  },
+
+  renameFile: function(fromFile, newName, callback)
+  {
+    runWhenMigrated(function()
+    {
+      function onLoaded()
+      {
+        ext.storage.remove(fileToKey(fromFile), function()
+        {
+          ext.storage.set(keyPrefix + newName, entry, callback);
+        });
+      }
+
+      loadFile(fromFile, onLoaded, callback);
+    });
+  },
+
+  removeFile: function(file, callback)
+  {
+    runWhenMigrated(function()
+    {
+      ext.storage.remove(fileToKey(file), callback);
+    });
+  },
+
+  statFile: function(file, callback)
+  {
+    runWhenMigrated(function()
+    {
+      function onLoaded(entry)
+      {
+        callback(null, {
+          exists: true,
+          lastModified: entry.lastModified
+        });
+      }
+
+      loadFile(file, onLoaded, callback);
+    });
+  }
+};
+
+// Migrate files for users updating from old versions.
+// Defer IO operations until migration is complete.
+// TODO: Remove the migration code after a few releases.
+let migrated = false;
+let deferred = [];
+
+function runWhenMigrated(callback)
+{
+  if (migrated)
+    callback();
+  else
+    deferred.push(callback);
+}
+
+ext.storage.migrateFiles(function()
+{
+  migrated = true;
+
+  while (deferred.length > 0)
+    deferred.shift()();
+});