Issue 4580 - Removed ext.storage

lib/io.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present 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/>.
  */
 
 "use strict";
 
 const keyPrefix = "file:";
 
 function fileToKey(fileName)
 {
   return keyPrefix + fileName;
 }
 
 function loadFile(fileName)
 {
-  return new Promise((resolve, reject) =>
+  let key = fileToKey(fileName);
+  return browser.storage.local.get(key).then(items =>
   {
-    let key = fileToKey(fileName);
-
-    ext.storage.get(key, items =>
-    {
-      let entry = items[key];
-
-      if (entry)
-        resolve(entry);
-      else
-        reject({type: "NoSuchFile"});
-    });
+    let entry = items[key];
+    if (entry)
+      return entry;
+    throw {type: "NoSuchFile"};

[kzar, 2018/04/24 20:38:56]

Don't we normally throw an Error instance? (I get the feeling you know what
you're doing here, so I'm not saying this is wrong. Just kinda curious, since
I've not seen throw used like this before.)

[Sebastian Noack, 2018/04/24 21:12:55]

Yeah, I had a similar WTF moment when I converted this code, but didn't feel
like doing an unrelated change here.

FWIW you can throw any kind of value (or reject a promise with any kind of
value). It will just be passed through to any catch statement (or error callback
attached to the promise). There is nothing special about Error objects in
JavaScript (other than that they have a traceback attached).

Its of course good practice to use Error objects to indicate an error, but then
I have to also change the code that detects non existing files, and adding a
custom property to the error object might not be much better. If we want to do
that properly we would just resolve the promise with null if the file does not
exist, but then I have to change even more. 

[kzar, 2018/04/25 10:33:39]

Acknowledged.

   });
 }
 
 function saveFile(fileName, data)
 {
-  return new Promise((resolve, reject) =>
-  {
-    ext.storage.set(
-      fileToKey(fileName),
-      {
-        content: Array.from(data),
-        lastModified: Date.now()
-      },
-      resolve
-    );
+  return browser.storage.local.set({
+    [fileToKey(fileName)]: {
+      content: Array.from(data),
+      lastModified: Date.now()
+    }
   });
 }
 
-function removeFile(fileName)
-{
-  return new Promise((resolve, reject) =>
-  {
-    ext.storage.remove(fileToKey(fileName), () =>
-    {
-      if (browser.runtime.lastError)
-        reject(browser.runtime.lastError.message);
-      else
-        resolve();
-    });
-  });
-}
-
 exports.IO =
 {
   /**
    * Reads text lines from a file.
    * @param {string} fileName
    *    Name of the file to be read
    * @param {TextSink} listener
    *    Function that will be called for each line in the file
    * @return {Promise}
    *    Promise to be resolved or rejected once the operation is completed
@@ skipping 40 matching lines @@
    * Renames a file.
    * @param {string} fromFile
    *    Name of the file to be renamed
    * @param {string} newName
    *    New file name, will be overwritten if exists
    * @return {Promise}
    *    Promise to be resolved or rejected once the operation is completed
    */
   renameFile(fromFile, newName)
   {
-    return loadFile(fromFile).then(entry =>
-    {
-      return new Promise((resolve, reject) =>
-      {
-        ext.storage.set(fileToKey(newName), entry, () =>
-        {
-          if (browser.runtime.lastError)
-            reject(browser.runtime.lastError.message);
-          else
-            resolve();
-        });
-      });
-    }).then(() => removeFile(fromFile));
+    return loadFile(fromFile)
+      .then(entry => browser.storage.local.set({[fileToKey(newName)]: entry}))
+      .then(() => this.removeFile(fromFile));
   },
 
   /**
    * Removes a file.
    * @param {string} fileName
    *    Name of the file to be removed
    * @return {Promise}
    *    Promise to be resolved or rejected once the operation is completed
    */
   removeFile(fileName)
   {
-    return removeFile(fileName);
+    return browser.storage.local.remove(fileToKey(fileName));
   },
 
   /**
    * Retrieves file metadata.
    * @param {string} fileName
    *    Name of the file to be looked up
    * @return {Promise.<StatData>}
    *    Promise to be resolved with file metadata once the operation is
    *    completed
    */
   statFile(fileName)
   {
     return loadFile(fileName).then(entry =>
     {
       return {
         exists: true,
         lastModified: entry.lastModified
       };
     }).catch(error =>
     {
       if (error.type == "NoSuchFile")
         return {exists: false};
       throw error;
     });
   }
 };