Refactor the commiter json saving code into its own reusable module

committers.js

@@ -1,8 +1,8 @@
-var fs = require("fs");
-
 var kDatabase = 'committers.json';
+var config = require("./jsondb")(kDatabase);
+
+var committers = config.db;
 
-var committers = JSON.parse(fs.readFileSync(kDatabase, 'utf8'));
 exports.lookup = function lookup(email, certain, guess)
 {
   if (committers.hasOwnProperty(email)) {
@@ -15,30 +15,7 @@ exports.lookup = function lookup(email, certain, guess)
   return guess(undefined);
 };
 
-var saveInProgress = false;
-var dbDirty = false;
-
-function saveDatabase() {
-  saveInProgress = true;
-  var count = Object.keys(committers).length;
-  fs.writeFile(kDatabase, JSON.stringify(committers), 'utf8', function (err) {
-    if (err) {
-      console.error("Got error trying to save committer database: " + e);
-    } else {
-      console.log("Saved new version of committers database with " + count + " entries");
-    }
-    saveInProgress = false;
-    if (dbDirty) {
-      saveDatabase();
-    }
-  });
-  dbDirty = false;
-}
-
 exports.add = function add(email, nick) {
   committers[email] = nick;
-  dbDirty = true;
-  if (saveInProgress)
-    return;
-  saveDatabase();
+  config.markDirty();
 };

jsondb.js

@@ -0,0 +1,38 @@
+var fs = require("fs");
+
+function Config(path)
+{
+  this.path = path;
+  this.db = JSON.parse(fs.readFileSync(path, 'utf8'));
+}
+
+Config.prototype = {
+  isDirty: false,
+  saveInProgress: false,
+  markDirty: function () {
+    this.isDirty = true;
+    if (!this.saveInProgress)
+      this.save();
+  },
+  save: function () {
+    this.saveInProgress = true;
+    var count = Object.keys(this.db).length;
+    fs.writeFile(this.path, JSON.stringify(this.db), 'utf8', this._saveComplete.bind(this, count));
+    this.isDirty = false;
+  },
+  _saveComplete: function (count, err) {
+    if (err) {
+      console.error("Got error trying to save database to " + this.path + ": " + e);
+    } else {
+      console.log("Saved new version of database to " + this.path + " with " + count + " entries");
+    }
+    this.saveInProgress = false;
+    if (this.isDirty) {
+      this.save();
+    }
+  }
+};
+
+module.exports = function (path) {
+  return new Config(path);
+}