/* * Copyright 2013 Jive Software * * 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 q = require('q'); var jive = require('../../api'); var ArrayStream = require('stream-array'); /** * An in-memory implementation of persistence. * @module memoryPersistence * @constructor */ module.exports = function() { jive.logger.warn("******************************"); jive.logger.warn("Memory persistence is configured."); jive.logger.warn("Please note that this should"); jive.logger.warn("not be used for production!"); jive.logger.warn("******************************"); ///////////////////////////////////////////////////////////////////////////////////////////////////////////////// // Private /** * In-memory data structure to use as a database * @type {{}} */ var db = {}; /** * Fetches a named collection from the db if collection exists; otherwise lazily create the collection. * @param collectionID * @return {*} */ var getCollection = function( collectionID ) { var collection = db[collectionID]; if ( collection ) { return collection; } else { collection = {}; db[collectionID] = collection; return collection; } }; ///////////////////////////////////////////////////////////////////////////////////////////////////////////////// // Public /** * @inner * @type {{save: Function, remove: Function, find: Function, findByID: Function, close: Function}} */ var memoryPersistence = { /** * Save the provided data in a named collection * @memberof memoryPersistence * @param {String} collectionID * @param {String} key * @param {Object} data * @returns {Object} promise */ save: function( collectionID, key, data) { return q.fcall( function () { var collection = getCollection(collectionID); collection[key] = data; return data; }); }, /** * Remove a piece of data from a name collection, based to the provided key and return a promise * that returns removed items when done. * @memberof memoryPersistence * @param {String} collectionID * @param {String} key * @returns {Object} promise */ remove: function( collectionID, key ) { return q.fcall( function () { var collection = getCollection(collectionID ); var removed = collection[key]; delete collection[key]; return removed; }); }, /** * Retrieve a piece of data from a named collection, based on the criteria, and returns a promise * that contains found items when done. * @memberof memoryPersistence * @param {String} collectionID * @param {Object} keyValues * @param {Boolean} cursor If true, returns an iterable cursor. * @returns {Object} promise */ find: function( collectionID, keyValues, cursor ) { var p = q.defer(); var collectionItems = []; var collection = getCollection(collectionID ); var findKeys = keyValues ? Object.keys( keyValues ) : undefined; for (var colKey in collection) { if (collection.hasOwnProperty(colKey)) { var entryToInspect = collection[colKey]; var match = true; if ( findKeys ) { for ( var i in findKeys ) { var findKey = findKeys[i]; var keyParts = findKey.split('.'); var entryObj = entryToInspect; for ( var k = 0; k < keyParts.length; k++ ) { var keyPart = keyParts[k]; if ( typeof entryObj == 'object' ) { entryObj = entryObj[keyPart]; } } var keyValue = keyValues[ findKey ]; if ( typeof keyValue == 'object' ) { if ( keyValue['$gt'] ) { if ( entryObj <= keyValue['$gt'] ) { match = false; break; } } if ( keyValue['$gte'] ) { if ( entryObj < keyValue['$gte'] ) { match = false; break; } } if ( keyValue['$lt'] ) { if ( entryObj >= keyValue['$lt'] ) { match = false; break; } } if ( keyValue['$lte'] ) { if ( entryObj > keyValue['$lte'] ) { match = false; break; } } if ( keyValue['$in'] ) { if ( keyValue['$in'].indexOf(entryObj) < 0 ) { match = false; break; } } } else { if ( entryObj !== keyValue ) { match = false; break; } } } } if ( match ) { collectionItems.push( collection[colKey] ); } } } if ( !cursor ) { p.resolve( collectionItems ); } else { var stream = ArrayStream(collectionItems); // graft next method stream.nextCtr = 0; stream.fullCollection = collectionItems; stream.next = function(processorFunction) { if ( !processorFunction ) { return null; } this.nextCtr++; if ( this.nextCtr > this.fullCollection.length - 1 ) { processorFunction(null, null); } else { processorFunction(null, this.fullCollection[this.nextCtr]); } }; p.resolve(stream ); } return p.promise; }, /** * Retrieve a piece of data from a named collection whose key is the one provided. * @memberof memoryPersistence * @param collectionID * @param key * @returns {Object} promise */ findByID: function( collectionID, key ) { return q.fcall( function() { var collection = getCollection(collectionID ); return collection[key]; }); }, /** * Close it down * @memberof memoryPersistence * @returns {Object} promise */ close: function() { return q.resolve(); } }; return memoryPersistence; };