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LokiJS Overview LokiJS is a document oriented database written in javascript, published under MIT License. Its purpose is to store javascript objects as documents in a nosql fashion and retrieve them with a simila
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Category: JavaScript / Storage
Watchers: 162
Star: 6.6k
Fork: 540
Last update: Dec 5, 2023
Resource links
http://lokijs.org
https://github.com/techfort/LokiJS

LokiJS

Join the chat at https://gitter.im/techfort/LokiJS alt CI-badge npm version alt packagequality

Overview

LokiJS is a document oriented database written in javascript, published under MIT License. Its purpose is to store javascript objects as documents in a nosql fashion and retrieve them with a similar mechanism. Runs in node (including cordova/phonegap and node-webkit), nativescript and the browser. LokiJS is ideal for the following scenarios:

  1. client-side in-memory db is ideal (e.g., a session store)
  2. performance critical applications
  3. cordova/phonegap mobile apps where you can leverage the power of javascript and avoid interacting with native databases
  4. data sets loaded into a browser page and synchronised at the end of the work session
  5. node-webkit desktop apps
  6. nativescript mobile apps that mix the power and ubiquity of javascript with native performance and ui

LokiJS supports indexing and views and achieves high-performance through maintaining unique and binary indexes (indices) for data.

Demo

The following demos are available:

  • Sandbox / Playground
  • a node-webkit small demo in the folder demos/desktop_app. You can launch it by running /path/to/nw demos/desktop_app/

Wiki

Example usage can be found on the wiki

Main Features

  1. Fast performance NoSQL in-memory database, collections with unique index (1.1M ops/s) and binary-index (500k ops/s)
  2. Runs in multiple environments (browser, node, nativescript)
  3. Dynamic Views for fast access of data subsets
  4. Built-in persistence adapters, and the ability to support user-defined ones
  5. Changes API
  6. Joins

Current state

LokiJS is at version 1.3 [Eostre].

As LokiJS is written in JavaScript it can be run on any environment supporting JavaScript such as browsers, node.js/node-webkit, nativescript mobile framework and hybrid mobile apps (such as phonegap/cordova).

Made by @techfort, with the precious help of Dave Easterday.

Leave a tip or give us a star if you find LokiJS useful!

Installation

For browser environments you simply need the lokijs.js file contained in src/

You can use bower to install lokijs with bower install lokijs

For node and nativescript environments you can install through npm install lokijs.

Roadmap

  • exactIndex
  • key-value datastore
  • MRU cache
  • MongoDB API compatibility
  • server standalone (tcp and http servers and clients)
  • replication and horizontal scaling

Contact

For help / enquiries contact [email protected]

Commercial Support

For commercial support contact [email protected]

License

Copyright (c) 2015 TechFort [email protected]

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

27 Open More issues
Closed

Joins

At the moment Loki supports in-memory joins e.g.

var author = authors.insert({name: 'Stephen King'});
var book = books.insert({title: 'Salems Lot', author: author})

But this will not persist correctly as the author will be serialized as an embedded object, not the original author object. There should be a more solid mechanism to operate joins.

opened Mar 19, 2015 by techfort 67
Closed

Bulk Inserts and Collection Constraints

I don't think I'm using indexes correclty.

When merging 10,000+ records from a remote database into a local database, I have to use the id (not the $loki id) to make sure the document is not already there. (if its there I want to merge instead of update). To do this effeciently, I'm trying to use Loki indices:

let loki = new Loki('testdb');
myCollection = loki.addCollection('myCollection', {indices:['id']})

Then on each insert I do

localRecord = myCollection.findOne({id: remoteRecord.id})
if( localRecord ) {
  // Merge code
} else {
  myCollection.insert( remoteRecord );  
}

When I disable the localRecord check and just insert, things are smoking fast! Only slowed by data fetching/paging.

  • http://screencast.com/t/H3wsetchhQ

When I enable the findOne check, things slow down a bit:

  • http://screencast.com/t/gBJQ49yBJwW

When I hack an index to the side that is a big hash of ids mapped to $loki I get really fast again.

  • http://screencast.com/t/V5R0g7hPt

I think there must be something I don't understand about indexes.

Please advise :)

enhancement 
opened Mar 24, 2015 by jrhicks 43
Closed

Documentation for HTTP wrapper

I couldn't see the documentation for the HTTP wrapper although it is mentioned in the features list. Would you mind pointing me in the right direction please?

wontfix 
opened Nov 8, 2015 by dukedougal 38
Closed

db save circular structure issue

Currently I have a problem in the area of loading/saving database. After object update and try to save db the following error occurs:

stream.js:94
      throw er; // Unhandled stream error in pipe.
            ^
TypeError: Converting circular structure to JSON
    at Object.stringify (native)
    at LokiEventEmitter.Loki.serialize (/home/teef/leonardo/WebApplications/Leonardo-CommHub/node_modules/lokijs/src/lokijs.js:385:19)
    at LokiEventEmitter.Loki.saveDatabase (/home/teef/leonardo/WebApplications/Leonardo-CommHub/node_modules/lokijs/src/lokijs.js:744:47)

I am using one collection as well as one dynamic view.

Seems like there are two dynamic views which should not happen.

DynamicViews: 
   [ { collection: [Circular],
       name: 'aciveDevices',
       persistent: false,
       resultset: [Object],
       resultdata: [],
       resultsdirty: true,
       cachedresultset: null,
       filterPipeline: [],
       sortFunction: null,
       sortCriteria: null,
       sortDirty: false,
       events: [Object] },
     { collection: [Circular],
       name: 'aciveDevices',
       persistent: false,
       resultset: [Object],
       resultdata: [],
       resultsdirty: false,
       cachedresultset: null,
       filterPipeline: [Object],
       sortFunction: null,
       sortCriteria: null,
       sortDirty: false,
       events: [Object] } ],

Database: https://gist.github.com/teef/c3f8f2139a1e13188e09

opened Jan 13, 2015 by teef 35
Closed

Querying empty collection with binary index throws error

If a collection has a binary index set, and the collection is empty, querying it will result in an error. The error happens in the calculateRange function on the following lines:

var minVal = rcd[index[min]][prop]; var maxVal = rcd[index[max]][prop];

If the collection is empty, then rcd[index[min/max]] will be undefined. We may want to set default min and max values here, but also, maybe shortcut the find() function to return an empty result set if the data is empty to save some work.

opened Dec 13, 2014 by assafweinberg 32
Closed

lokiFSAdaptor

Not an issue as such so sorry but I was wondering if there was an example anywhere of using loki with window.requestFileSystem/window.webkitRequestFileSystem...? My aim is for my DB to persists in a Cordova app by saving it to the FileSystem... I'm developing on Chrome so I could save it to PERSISTENT storage on the browser as well. I've looked all over and it seems as though I'll need to write my own adapter but I was wondering if anyone had already done so so I could cast my eye over their solution?

opened May 12, 2015 by annoyingmouse 31
Open

'Leave a tip" link is broken

I'd like to give to show my appreciation for and support of this invaluable piece of software, but the Leave a tip link in the readme is broken.

opened Nov 22, 2023 by adueck 0
Open

Feature Request: IPFS Adapter

I am willing to create a PR which adds IPFS adapter, thereby enabling users to push their db file to IPFS and load whenever needed.

opened Jun 30, 2023 by amandesai01 1
Open

Update lokijs.js to allow objects keys to contain dots

Sometimes objects keys contain dots, for example, obj={ a='one', 'b.c'='two'} with a simple split('.') we can not do a proper Xpath search. I have added a function called split path that takes care of this issue. So if we need to do a query with a key that contains dots, to work we just need to put the key inside <> search({ $and: [{'metadata.labels.<app.kubernetes.io/instance>': 'gq-drupal'}]})

opened Jun 22, 2023 by guiqui 0
Open

[Question] Reload database / cancel changes

I'm using lokijs with auto save off, and saving the database using db.saveDatabase() after certain actions.

Suppose I make a few changes and want to discard them. I don't call saveDatabase(), but the data stays in-memory, for the duration of the work session, I believe.

Instead of manually undoing the changes, is there a way to revert the database to the previously saved state? Or clear the in-memory changes?

Thank you so much!

opened Apr 23, 2023 by HanimHank 2
Open

Use https in description

use https not http

opened Apr 16, 2023 by K-Rawson 0
Open

Update eqJoin

If we change the eqJoin like this then it is possible to join an array of keys instead of one key

opened Apr 13, 2023 by JeffreySyrinx 0

Contents

    Restream Embeddable, in-memory, document-oriented database with a high-level Query builder interface.
    DynamoRIO Memory Debugger for Windows, Linux, Mac, and Android
    Akaion A Windows virtual memory editing library with support for pattern scanning.
    emluque Embeddable in memory key/value store for strings in golang
    wolkykim Embeddable Event-based Asynchronous Message/HTTP Server library for C/C++
    RudjiGames MTuner is a C/C++ memory profiler and memory leak finder for Windows, PlayStation 4 and 3, Android and other platforms
    deroproject Graviton Database: ZFS for key-value stores.
    canonical Embeddable, replicated and fault tolerant SQL engine.
    ccxvii An embeddable Javascript interpreter in C.
    FriendsOfREDAXO YCOM Impersonate. Login as selected YCOM user 🧙‍♂️in frontend.
    hashicorp Golang in-memory database built on immutable radix trees
    small-tech A transparent, in-memory, streaming write-on-update JavaScript database for Small Web applications that persists to a JavaScript transaction log.
    hse-project Heterogeneous-memory storage engine (HSE)
    svaarala Duktape - embeddable Javascript engine with a focus on portability and compact footprint
    lithdew Go bindings to QuickJS: a fast, small, and embeddable ES2020 JavaScript interpreter.
    tidwall BuntDB is an embeddable, in-memory key/value database for Go with custom indexing and geospatial support
    AqibMukhtar A lightweight JavaScript package for generating and validating OTP (One Time Password) maintaining high performance using in-memory database.
    pbnjay A go function to report total system memory
    ufrisk The Memory Process File System
    koute memory-profiler — A memory profiler for Linux
    OrenLeung AWS Tags As A Database (AWS TaaDb)🚀 is a Python 🐍 library using AWS Tags as a Key-Value database. This database is completely free* 💸
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