hypercore-archiver

Easily archive multiple hypercores or hyperdrives

Usage

var archiver = require('hypercore-archiver')
var hypercore = require('hypercore')

var ar = archiver('./my-archiver') // also supports passing in a storage provider
var feed = hypercore('./my-feed')

feed.on('ready', function () {
  ar.add(feed.key, function (err) {
    console.log('will now archive the feed')
  })
})

ar.on('sync', function (feed) {
  console.log('feed is synced', feed.key)
})

// setup replication
var stream = ar.replicate()
stream.pipe(feed.replicate({live: true})).pipe(stream)

feed.append(['hello', 'world'])

API

var ar = archiver(storage, [key], [options])

Create a new archvier. storage can be a file system path or a storage provider like random-access-memory.

If this archiver is a clone of another archiver pass the changes feed key as the 2nd argument.

Options include

{
  sparse: false // set to true to only archive blocks you request
}

Sparse File Storage

The sparse option uses sparse file mode, only availalbe on some file systems. It will appear as a full size file but only take up the space actually used on disk.

• Use ls -alsh to view the actual size (first column)
• sparse file mode (APFS) is not available on Mac OSX.

ar.add(key, [callback])

Add a new hypercore or hyperdrive key to be archived.

ar.remove(key, [callback])

Remove a key.

ar.list(callback)

List all hypercores and hyperdrives being archived.

ar.get(key, callback)

Retrieve the feed being archived. If the key points to a hyperdrive the callback is called with (err, metadataFeed, contentFeed)

ar.changes

A changes feed containing the archiver state. Pass the changes feed key to another hypercore archiver to replicate the archiver and all feeds

var stream = ar.replicate([options])

Create a replication stream. Per defaults the archiver will replicate any feed the remote asks for. To have the archiver ask to replicate one pass in {key: feedKey} as an option.

ar.on('add', feed)

Emitted when a feed is being added

ar.on('remove', feed)

Emitted when a feed is being removed

ar.on('sync', feed)

Emitted when a feed has been fully synced

ar.on('download', feed, index, data, peer)

Emitted when the archiver downloads a block of data

ar.on('upload', feed, index, data, peer)

Emitted when the archiver uploads a block of data

ar.on('ready')

Emitted when all internal state has been loaded (the changes feed will be set). You do not have to wait for this event before calling any async function.

Network Swarm

The archiver comes with a network swarm as well. This will make the archiver replicate over the internet and local network. To use it do:

var swarm = require('hypercore-archiver/swarm')
swarm(archiver)

License

MIT