Split localfilesystem storage plugin into component parts

red/runtime/storage/localfilesystem/sessions.js

@@ -0,0 +1,52 @@
+/**
+ * Copyright JS Foundation and other contributors, http://js.foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ **/
+
+var when = require('when');
+var fs = require('fs-extra');
+var fspath = require("path");
+
+var log = require("../../log");
+var util = require("./util");
+
+var sessionsFile;
+var settings;
+
+module.exports = {
+    init: function(_settings) {
+        settings = _settings;
+        sessionsFile = fspath.join(settings.userDir,".sessions.json");
+    },
+    getSessions: function() {
+        return when.promise(function(resolve,reject) {
+            fs.readFile(sessionsFile,'utf8',function(err,data){
+                if (!err) {
+                    try {
+                        return resolve(util.parseJSON(data));
+                    } catch(err2) {
+                        log.trace("Corrupted sessions file - resetting");
+                    }
+                }
+                resolve({});
+            })
+        });
+    },
+    saveSessions: function(sessions) {
+        if (settings.readOnly) {
+            return when.resolve();
+        }
+        return util.writeFile(sessionsFile,JSON.stringify(sessions));
+    }
+}