tingodb

Embedded Node.js database upward compatible with MongoDB

TingoDB

TingoDB is an embedded JavaScript in-process filesystem or in-memory database upwards compatible with MongoDB at the API level.

Upwards compatible means that if you build an app that uses functionality implemented by TingoDB you can switch to MongoDB almost without code changes. This greatly reduces implementation risks and give you freedom to switch to a mature solution at any moment.

As a proof for upward compatibility, all tests designed to run against both MongoDB and TingoDB. Moreover, significant parts of tests contributed from MongoDB nodejs driver projects and are used as is without modifications.

For those folks who familiar with the Mongoose.js ODM, we suggest to look at Tungus, an experimental driver that allows using the famous ODM tool with our database.

TingoDB can be dropin replacement for existing apps and frameworks that are based on MongoDB. Please some of 3rd party integrations

For more details please visit http://www.tingodb.com

Goal of our project is to fully mimics MongoDB functionality. Which means that we will consider bug as bug only when you find something that is working with MongoDB but didn't work with TingoDB. It would be very helful to get bugs in that case as pull requests to /test/misc-test.js file (or new file) which will contain code that reproduce issue.

To run test with MongoDB: ./test.sh --quick --single=misc-test --db=mongodb.

To run test with TingoDB: ./test.sh --quick --single=misc-test --db=tingodb

Usage

npm install tingodb

As stated, the API is fully compatible with MongoDB. The only differences are the initialization and getting the Db object. Consider this MongoDB code:

var Db = require('mongodb').Db,
    Server = require('mongodb').Server,
    assert = require('assert');
 
var db = new Db('test', new Server('localhost', 27017));
var collection = db.collection("batch_document_insert_collection_safe");
collection.insert([{hello:'world_safe1'}
  , {hello:'world_safe2'}], {w:1}, function(errresult) {
  assert.equal(null, err);
 
  collection.findOne({hello:'world_safe2'}, function(erritem) {
    assert.equal(null, err);
    assert.equal('world_safe2', item.hello);
  })
});

The same example using TingoDB will be as follows:

var Db = require('tingodb')().Db,
    assert = require('assert');
 
var db = new Db('/some/local/path', {});
// Fetch a collection to insert document into 
var collection = db.collection("batch_document_insert_collection_safe");
// Insert a single document 
collection.insert([{hello:'world_safe1'}
  , {hello:'world_safe2'}], {w:1}, function(errresult) {
  assert.equal(null, err);
 
  // Fetch the document 
  collection.findOne({hello:'world_safe2'}, function(erritem) {
    assert.equal(null, err);
    assert.equal('world_safe2', item.hello);
  })
});

As you can see, the difference is in the require call and database object initialization.

In contrast to MongoDB, the module require call will not return a usable module. It will return a function that accepts configuration options. This function will return something similar to the MongoDB module. THe extra step allows for passing some options that will control database behavior.

Enable in memory (no file access) mode. Can be useful for unit tests. File path will be used as db identity.

Doing some experimentation we found that using integer keys we can get the database to work faster and save some space. Additionally, for in-process databases there are almost no drawbacks versus globally unique keys. However, at the same time, it is relatively hard to keep unique integer keys outside of the database engine, so we made it part of the database engine code. Generated keys will be unique in the collection scope.

When required, it is possible to switch to BSON ObjectID using the configuration option.

Maximum number of cached objects per collection.

Maximum size of objects that can be placed in the cache.

Globally enables support of search in nested arrays. MongoDB supports this unconditionally. For TingoDB, search in arrays when there are no arrays incurs a performance penalty. That's why this is switched off by default. Additionally, and this might be better a approach, nested arrays support can be enabled for individual indexes or search queries.

To enable nested arrays in individual indexed, use "_tiarr:true" option.

self._cash_transactions.ensureIndex("splits.accountId",{_tiarr:true},cb);

To enable nested arrays in individual queries for fields that do not use indexes, use "_tiarr." to prefix field names.

coll.find({'arr.num':10},{"_tiar.arr.num":0})

The only required parameter is the database path. It should be a valid path to an empty folder or a folder that already contains collection files.

Dual usage

It is possible to build applications that will transparently support both MongoDB and TingoDB. Here are some hints on how to do that:

  • Wrap the module require call into a helper module or make it part of the core object. This way you can control which engine is loaded in one place.
  • Use only native JavaScript types. BSON types can be slow in JavaScript and will need special attention when passed to or from client JavaScript.
  • Treat ObjectID just as a unique value that can be converted to and from String regardless its actual meaning.

Example below (please see the three files).

var fs = require('fs'),db,engine;
 
// load config 
var cfg = JSON.parse(fs.readFileSync("./config.json"));
 
// load requestd engine and define engine-agnostic getDB function 
if (cfg.app.engine=="mongodb") {
    engine = require("mongodb");
    module.exports.getDB = function () {
        if (!db) db = new engine.Db(cfg.mongo.db,
            new engine.Server(cfg.mongo.host, cfg.mongo.port, cfg.mongo.opts),
                {native_parser: false, safe:true});
        return db;
    }
} else {
    engine = require("tingodb")({});
    module.exports.getDB = function () {
        if (!db) db = new engine.Db(cfg.tingo.path, {});
        return db;
    }
}
// Depending on engine, this can be a different class 
module.exports.ObjectID = engine.ObjectID;
var engine = require('./engine');
var db = engine.getDB();
 
console.time("sample")
db.open(function(err,db) {
    db.collection("homes", function (errhomes) {
        // it's fine to create ObjectID in advance 
        // NOTE!!! we get class through engine because its type 
        // can depends on database type 
        var homeId = new engine.ObjectID();
        // but with TingoDB.ObjectID righ here it will be negative 
        // which means temporary. However it's unique and can be used for 
        // comparisons 
        console.log(homeId);
        homes.insert({_id:homeId, name:"test"}, function (errhome) {
            var home = home[0];
            // here, homeID will change its value and will be in sync 
            // with the database 
            console.log(homeId,home);
            db.collection("rooms", function (errrooms) {
                for (var i=0; i<5; i++) {
                    // it's ok also to not provide id, then it will be generated 
                    rooms.insert({name:"room_"+i,_idHome:homeId}, function (errroom) {
                        console.log(room[0]);
                        i--;
                        if (i==0) {
                            // now lets assume we serving request like 
                            // /rooms?homeid=_some_string_ 
                            var query = "/rooms?homeid="+homeId.toString();
                            // dirty code to get simulated GET variable 
                            var getId = query.match("homeid=(.*)")[1];
                            console.log(query, getId)
                            // typical code to get id from external world 
                            // and use it for queries 
                            rooms.find({_idHome:new engine.ObjectID(getId)})
                                .count(function (errcount) {
                                    console.log(count);
                                    console.timeEnd("sample");
                            })
                        }
                    })
                }
            })
        })
    })
})
{
    "app":{
        "engine":"tingodb"
    },
    "mongo":{
        "host":"127.0.0.1",
        "port":27017,
        "db":"data",
        "opts":{
            "auto_reconnect": true,
            "safe": true
        }
    },
    "tingo":{
        "path":"./data"
    }
}
-2
13 { _id: 13, name: 'test' }
{ name: 'room_0', _idHome: 13, _id: 57 }
{ name: 'room_1', _idHome: 13, _id: 58 }
{ name: 'room_2', _idHome: 13, _id: 59 }
{ name: 'room_3', _idHome: 13, _id: 60 }
{ name: 'room_4', _idHome: 13, _id: 61 }
/rooms?homeid=13 13
5
sample: 27ms
51b43a05f092a1c544000001
51b43a05f092a1c544000001 { _id: 51b43a05f092a1c544000001, name: 'test' }
{ name: 'room_3',
  _idHome: 51b43a05f092a1c544000001,
  _id: 51b43a05f092a1c544000005 }
{ name: 'room_2',
  _idHome: 51b43a05f092a1c544000001,
  _id: 51b43a05f092a1c544000004 }
{ name: 'room_1',
  _idHome: 51b43a05f092a1c544000001,
  _id: 51b43a05f092a1c544000003 }
{ name: 'room_0',
  _idHome: 51b43a05f092a1c544000001,
  _id: 51b43a05f092a1c544000002 }
{ name: 'room_4',
  _idHome: 51b43a05f092a1c544000001,
  _id: 51b43a05f092a1c544000006 }
/rooms?homeid=51b43a05f092a1c544000001 51b43a05f092a1c544000001
5
sample: 22ms

Compatibility

We maintain full API and functionality compatibility with MongoDB BUT only for what we implemented support. I.e. if we support something it will work exactly the same way, but some features are not yet supported or support is limited.

  • Search, almost all clauses. Indexes are used to increase search speed and sorting.
  • Map reduce, almost all
  • Grouping, almost all
  • Collection, almost all methods
  • Cursor, almost all methods
  • GridFS, no support
  • Feature X, might be :)

3rd Party Integrations

We are open for contributions for this section. If you found or implemented some integration please open pull request :).

Sails.js

TingoDB adapter for Sails.js: http://github.com/andyhu/sails-tingo Sails.js is a RoR like Node.js framework. It has a powerful ORM system called waterline, it supports all major databases (and web services) and provides an easy to use, unified interface for querying all different kind of databases. It also supports cross database (or different database engines) joins.

KeystoneJS

Running KeystoneJS with TingoDB: http://ifrederik.com/blog/2014/11/cms-without-db-running-keystonejs-without-mongodb/

Realistic app with dual database support

Web based GnuCash clone: https://github.com/sergeyksv/skilap

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