ipfs-observed-remove
Version:
[](https://circleci.com/gh/wehriam/ipfs-observed-remove) [](http://badge.fury.io/js/ipfs-observed-remove) [](https://circleci.com/gh/wehriam/ipfs-observed-remove) [](http://badge.fury.io/js/ipfs-observed-remove) [](https://codecov.io/gh/wehriam/ipfs-observed-remove)
Eventually-consistent, conflict-free replicated data types (CRDT) [implemented](https://github.com/wehriam/ipfs-observed-remove/blob/master/src/index.js) using IPFS and native `Map` and `Set` objects.
This module and the IPFS PubSub system are experimental. If you encounter an issue, fork the repository, [write tests demonstrating](https://github.com/wehriam/ipfs-observed-remove/tree/master/tests) the issue, and create a [pull request](https://github.com/wehriam/ipfs-observed-remove).
```js
const ipfsAPI = require('ipfs-http-client');
const { IpfsObservedRemoveSet } = require('ipfs-observed-remove');
// IPFS nodes with PubSub enabled
const ipfs1 = ipfsAPI('/ip4/127.0.0.1/tcp/5001');
const ipfs2 = ipfsAPI('/ip4/127.0.0.1/tcp/5002');
const topic = "CRDT_SET";
const alice = new IpfsObservedRemoveSet(ipfs1, topic);
const bob = new IpfsObservedRemoveSet(ipfs2, topic);
alice.on('add', (value) => {
console.log(value); // logs foo, bar
});
alice.add('foo');
bob.add('bar');
// Later
alice.has('bar'); // true
bob.has('foo'); // true
```
```js
const ipfsAPI = require('ipfs-http-client');
const { IpfsObservedRemoveMap } = require('ipfs-observed-remove');
// IPFS nodes with PubSub enabled
const ipfs1 = ipfsAPI('/ip4/127.0.0.1/tcp/5001');
const ipfs2 = ipfsAPI('/ip4/127.0.0.1/tcp/5002');
const topic = "CRDT_MAP";
const alice = new IpfsObservedRemoveMap(ipfs1, topic);
const bob = new IpfsObservedRemoveMap(ipfs2, topic);
alice.on('set', (key, value) => {
console.log(key, value); // logs [a, 1], [b, 2]
});
alice.set('a', 1);
bob.add('b', 2);
// Later
alice.get('b'); // 2
bob.get('a'); // 1
```
## Install
`yarn add ipfs-observed-remove`
## Set API
<!-- Generated by documentation.js. Update this documentation by updating the source code. -->
#### Table of Contents
* [constructor](#constructor)
* [Parameters](#parameters)
* [ipfsSync](#ipfssync)
* [dump](#dump)
* [getIpfsHash](#getipfshash)
* [ipfsPeerCount](#ipfspeercount)
* [shutdown](#shutdown)
* [IpfsObservedRemoveSet#readyPromise](#ipfsobservedremovesetreadypromise)
### constructor
Create an observed-remove CRDT.
#### Parameters
* `ipfs` **[Object](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object)?** Object implementing the [core IPFS API](https://github.com/ipfs/interface-ipfs-core#api), most likely a [js-ipfs](https://github.com/ipfs/js-ipfs) or [ipfs-http-client](https://github.com/ipfs/js-ipfs-http-client) object.
* `topic` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)?** IPFS pubub topic to use in synchronizing the CRDT.
* `entries` **Iterable\<V>** Iterable of initial values (optional, default `[]`)
* `options` **[Object](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object)** (optional, default `{}`)
* `options.maxAge` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)** Max age of insertion/deletion identifiers (optional, default `5000`)
* `options.bufferPublishing` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)** Interval by which to buffer 'publish' events (optional, default `20`)
### ipfsSync
Publish an IPFS hash of an array containing all of the object's insertions and deletions.
Returns **[Array](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array)<[Array](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array)\<any>>**
### dump
Return a sorted array containing all of the set's insertions and deletions.
### getIpfsHash
Stores and returns an IPFS hash of the current insertions and deletions
Returns **[Promise](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Promise)<[string](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)>**
### ipfsPeerCount
Current number of IPFS pubsub peers.
Returns **[number](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number)**
### shutdown
Gracefully shutdown
Returns **void**
### IpfsObservedRemoveSet#readyPromise
Resolves when IPFS topic subscriptions are confirmed.
Type: [Promise](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Promise)\<void>
## Map API
<!-- Generated by documentation.js. Update this documentation by updating the source code. -->
#### Table of Contents
* [constructor](#constructor)
* [Parameters](#parameters)
* [ipfsSync](#ipfssync)
* [dump](#dump)
* [getIpfsHash](#getipfshash)
* [ipfsPeerCount](#ipfspeercount)
* [shutdown](#shutdown)
* [IpfsObservedRemoveSet#readyPromise](#ipfsobservedremovesetreadypromise)
### constructor
Create an observed-remove CRDT.
#### Parameters
* `ipfs` **[Object](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object)?** Object implementing the [core IPFS API](https://github.com/ipfs/interface-ipfs-core#api), most likely a [js-ipfs](https://github.com/ipfs/js-ipfs) or [ipfs-http-client](https://github.com/ipfs/js-ipfs-http-client) object.
* `topic` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)?** IPFS pubub topic to use in synchronizing the CRDT.
* `entries` **Iterable\<V>** Iterable of initial values (optional, default `[]`)
* `options` **[Object](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object)** (optional, default `{}`)
* `options.maxAge` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)** Max age of insertion/deletion identifiers (optional, default `5000`)
* `options.bufferPublishing` **[String](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)** Interval by which to buffer 'publish' events (optional, default `20`)
* `options.chunkPubSub` **[boolean](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Boolean)** Chunk pubsub messages for values greater than 1 MB (optional, default `false`)
### ipfsSync
Publish an IPFS hash of an array containing all of the object's insertions and deletions.
Returns **[Array](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array)<[Array](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Array)\<any>>**
### dump
Return a sorted array containing all of the set's insertions and deletions.
### getIpfsHash
Stores and returns an IPFS hash of the current insertions and deletions
Returns **[Promise](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Promise)<[string](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)>**
### ipfsPeerCount
Current number of IPFS pubsub peers.
Returns **[number](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Number)**
### shutdown
Gracefully shutdown
Returns **void**
### IpfsObservedRemoveSet#readyPromise
Resolves when IPFS topic subscriptions are confirmed.
Type: [Promise](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Promise)\<void>