change db.set/get to use data field instead of value

src/database/mongo/main.js

@@ -66,7 +66,7 @@ module.exports = function (db, module) {
 		if (!key) {
 			return callback();
 		}
-		module.getObjectField(key, 'value', callback);
+		module.getObjectField(key, 'data', callback);
 	};
 
 	module.set = function (key, value, callback) {
@@ -74,7 +74,7 @@ module.exports = function (db, module) {
 		if (!key) {
 			return callback();
 		}
-		var data = { value: value };
+		var data = { data: value };
 		module.setObject(key, data, callback);
 	};
 
@@ -115,7 +115,7 @@ module.exports = function (db, module) {
 				return callback(null, 'set');
 			} else if (keys.length === 3 && data.hasOwnProperty('_key') && data.hasOwnProperty('array')) {
 				return callback(null, 'list');
-			} else if (keys.length === 3 && data.hasOwnProperty('_key') && data.hasOwnProperty('value')) {
+			} else if (keys.length === 3 && data.hasOwnProperty('_key') && data.hasOwnProperty('data')) {
 				return callback(null, 'string');
 			}
 			callback(null, 'hash');

src/upgrades/1.7.3/key_value_schema_change.js

@@ -0,0 +1,67 @@
+'use strict';
+
+var async = require('async');
+
+var db = require('../../database');
+
+module.exports = {
+	name: 'Change the schema of simple keys so they don\'t use value field (mongodb only)',
+	timestamp: Date.UTC(2017, 11, 18),
+	method: function (callback) {
+		var configJSON = require('../../../config.json');
+		var isMongo = configJSON.hasOwnProperty('mongo') && configJSON.database === 'mongo';
+		var progress = this.progress;
+		if (!isMongo) {
+			return callback();
+		}
+		var client = db.client;
+		var cursor;
+		async.waterfall([
+			function (next) {
+				client.collection('objects').count({
+					_key: { $exists: true },
+					value: { $exists: true },
+					score: { $exists: false },
+				}, next);
+			},
+			function (count, next) {
+				progress.total = count;
+				cursor = client.collection('objects').find({
+					_key: { $exists: true },
+					value: { $exists: true },
+					score: { $exists: false },
+				}).batchSize(1000);
+
+				var done = false;
+				async.whilst(
+					function () {
+						return !done;
+					},
+					function (next) {
+						async.waterfall([
+							function (next) {
+								cursor.next(next);
+							},
+							function (item, next) {
+								progress.incr();
+								if (item === null) {
+									done = true;
+									return next();
+								}
+
+								if (Object.keys(item).length === 3 && item.hasOwnProperty('_key') && item.hasOwnProperty('value')) {
+									client.collection('objects').update({ _key: item._key }, { $rename: { value: 'data' } }, next);
+								} else {
+									next();
+								}
+							},
+						], function (err) {
+							next(err);
+						});
+					},
+					next
+				);
+			},
+		], callback);
+	},
+};