more cleanup

src/database/level/hash.js

@@ -82,16 +82,7 @@ module.exports = function(db, module) {
 	};
 
 	module.getObjectsFields = function(keys, fields, callback) {
-		var arr = [];
-
-		async.each(keys, function(key, next) {
-			module.getObjectFields(key, fields, function(err, obj) {
-				arr.push(obj);
-				next();
-			});
-		}, function(err) {
-			callback(err, arr);
-		});
+		module.iterator('getObjectFields', keys, fields, callback);
 	};
 
 	module.getObjectKeys = function(key, callback) {

src/database/level/main.js

@@ -1,6 +1,7 @@
 "use strict";
 
-var nconf = require('nconf');
+var nconf = require('nconf'),
+	async = require('async');
 
 module.exports = function(db, module) {
 	module.close = function(callback) {
@@ -32,8 +33,6 @@ module.exports = function(db, module) {
 		//  v v
 	};
 
-	// key
-
 	module.exists = function(key, callback) {
 		db.get(key, function(err, value) {
 			callback(null, !!value);
@@ -79,5 +78,18 @@ module.exports = function(db, module) {
 		// <__<
 	};
 
+	module.iterator = function(fn, keys, value, callback) {
+		var results = [];
+
+		async.each(keys, function(key, next) {
+			module.isSetMember(key, value, function(err, result) {
+				results.push(result);
+				next();
+			});
+		}, function(err) {
+			callback(err, results);
+		});
+	};
+
 	return module;
 };

src/database/level/sets.js

@@ -40,17 +40,7 @@ module.exports = function(db, module) {
 	};
 
 	module.isMemberOfSets = function(sets, value, callback) {
-		// can be improved
-		var members = [];
-
-		async.each(sets, function(set, next) {
-			module.isSetMember(set, value, function(err, isMember) {
-				members.push(value);
-				next();
-			});
-		}, function(err) {
-			callback(err, members);
-		});
+		module.iterator('isSetMember', sets, value, callback);
 	};
 
 	module.getSetMembers = function(key, callback) {