pouchdb-adapter-react-native-sqlite

PouchDB adapter using ReactNative SQLite as its backing store.

Why?

SQLite storage performs much faster than AsyncStorage, especially with secondary index. Here is benchmark results:

1) allDocs speed	min	max	mean
AsyncStorage	72ms	94ms	77ms
SQLite	27ms	39ms	28ms

2) query speed	min	max	mean
AsyncStorage	1,075ms	1,117ms	1,092ms
SQLite	33ms	39ms	35ms

• Device: iPhone 6s
• Documents: 434
• Update seq: 453
• Iterations: 100
• Used options: { include_docs: true }

On Simulator

• Device: iPad Pro 9.7" (Simulator) - iOS 10.3.2
• Documents: 5000

3) bulkDocs speed	total	mean
AsyncStorage	25.821ms	5.16ms
SQLite	22.213ms	4.44ms

4) allDocs speed	total	mean
AsyncStorage	189,379ms	37.87ms
SQLite	30,527ms	6.10ms

• allDocs options: { include_docs: true, attachments: true }
• Using this test script

How to use it

Read this blogpost for the complete description. Here is a working demo app.

Install deps

Install PouchDB core packages:

npm i pouchdb-adapter-http pouchdb-mapreduce

And install hacked packages for React Native:

npm i @craftzdog/pouchdb-core-react-native @craftzdog/pouchdb-replication-react-native 

Next, install SQLite3 engine modules:

npm i pouchdb-adapter-react-native-sqlite react-native-sqlite-2
react-native link react-native-sqlite-2

Then, install some packages to polyfill functions that PouchDB needs:

npm i base-64 events

Create polyfills

Make a js file to polyfill some functions that PouchDB needs:

import {decode, encode} from 'base-64'

if (!global.btoa) {
    global.btoa = encode;
}

if (!global.atob) {
    global.atob = decode;
}

// Avoid using node dependent modules
process.browser = true

Import it at the first line of your index.js.

Load PouchDB

Make pouchdb.js like so:

import PouchDB from '@craftzdog/pouchdb-core-react-native'
import HttpPouch from 'pouchdb-adapter-http'
import replication from '@craftzdog/pouchdb-replication-react-native'
import mapreduce from 'pouchdb-mapreduce'

import SQLite from 'react-native-sqlite-2'
import SQLiteAdapterFactory from 'pouchdb-adapter-react-native-sqlite'

const SQLiteAdapter = SQLiteAdapterFactory(SQLite)

export default PouchDB
  .plugin(HttpPouch)
  .plugin(replication)
  .plugin(mapreduce)
  .plugin(SQLiteAdapter)

If you need other plugins like pouchdb-find, just add them to it.

Use PouchDB

Then, use it as usual:

import PouchDB from './pouchdb'

function loadDB () {
  return new PouchDB('mydb.db', { adapter: 'react-native-sqlite' })
}

Changelog

• 2.0.0
  • Upgrade pouchdb-adapter-websql-core to 7.0.0
• 1.0.3
  • Remove pouchdb-utils dependency
• 1.0.2
  • Upgrade pouchdb-util & pouchdb-adapter-websql-core to 6.2.0
  • Update benchmark result
• 1.0.1
  • Remove unnecessary console output
• 1.0.0
  • Initial release