libp2p-crdt-synchronizer

A CRDT synchronizer for Libp2p.

Table of Contents

• Install
• Usage
• API
  • createCRDTSynchronizer
  • CRDTSynchronizer
    • start
    • stop
    • set
    • get
    • sync
    • keys
• Logging
• Building
• Tests
• To-Do

install

npm i @organicdesign/libp2p-crdt-synchronizer

Usage

import { createCRDTSynchronizer } from "@organicdesign/libp2p-crdt-synchronizer";

const synchronizer = createCRDTSynchronizer(options)(libp2p);

synchronizer.start();

// 'crdt' is an instance of a crdt wich follows the 'CRDT' interface.
synchronizer.set("my-crdt", crdt);

// Manually synchronize crdts. (Only needed if autoSync is disabled.)
await synchronizer.sync();

// Output the value,
console.log(synchronizer.get("my-crdt").toValue());

// Stop the synchronizer.
await synchronizer.stop();

Any crdt should work if it follows the CRDT interface from @organicdesign/crdt-interfaces and all instances in your network are using the same CRDT under each name. You can also use one of the CRDT implementations from @organicdesign/crdts.

API

createCRDTSynchronizer

createCRDTSynchronizer([options])(libp2p);

• options <Object> An optional object with the following properties:
  • protocol <string> Specifies the name of the protocol to sync crdts over. Default: "/libp2p-crdt-synchronizer/0.0.1".
  • autoSync <boolean> Enables auto sync. Default: true.
  • interval <integer> Specifies the interval to sync the crdts. Requires autoSync to be enabled. Default: 120000 (2 minutes).
• libp2p <Libp2p> The libp2p instance.
• Returns: <MessageHandler> The message handler instance.

Creates a Libp2p message handler

CRDTSynchronizer

new CRDTSynchronizer(libp2p, [options]);

• options <Object> An optional object with the following properties:
  • protocol <string> Specifies the name of the protocol to sync crdts over. Default: "/libp2p-crdt-synchronizer/0.0.1".
  • autoSync <boolean> Enables auto sync. Default: true.
  • interval <integer> Specifies the interval to sync the crdts. Requires autoSync to be enabled. Default: 120000 (2 minutes).
• libp2p <Libp2p> The libp2p instance.

The CRDTSynchronizer class. It is not recommended to instanciate it directly but rather use the createCRDTSynchronizer function.

start

crdtSynchronizer.start();

• Returns: <Promise>

Start the synchronizer, resolves when it has finished starting.

stop

crdtSynchronizer.stop();

• Returns: <Promise>

Stop the synchronizer, resolves when it has finished stopping.

set

crdtSynchronizer.set(name, crdt);

• name <string> The name to store the CRDT under.
• crdt <CRDT> A CRDT implementing the CRDT interface from @organicdesign/crdt-interfaces.

Add a CRDT to the synchronizer under a name.

get

crdtSynchronizer.get(name);

• name <string> The name to get the CRDT by.
• Returns: <CRDT> | <undefined> The CRDT that was assigned to this name or undefined if the name is not assigned.

Get a CRDT from the synchronizer by name.

sync

crdtSynchronizer.sync();

• Returns: <Promise>

Manually run synchronization with all connected peers. Resolves when completed. It is not necessary to call this if autoSync in the options is enabled but may still be called if synchronization is needed on demand.

keys

crdtSynchronizer.keys();

• Returns: <Iterable<string>> The list names with CRDTs assigned to them.

Get a list of CRDT names.

Logging

The logger has the following namespaces:

• libp2p:crdt-synchronizer - Logs general actions like starting, stopping and sync.
• libp2p:crdt-synchronizer:peers - Logs individual peer sync cycles.
• libp2p:crdt-synchronizer:crdts - Logs individual CRDT sync cycles.

To enable logging in nodejs add the following environment variable (by prefixing the start command):

DEBUG=libp2p:crdt-synchronizer*

Or in the browser:

localStorage.setItem("debug", "libp2p:crdt-synchronizer*");

Building

To build the project files:

npm run build:protos && npm run build

Tests

To run the test suite:

npm run test

To lint the files:

npm run lint

To-Do

• [x] Add tests.
• [x] Add logging.