ssb-content-stream

Scuttlebutt stream of both messages and off-chain content.

This plugin exposes a method that wraps createHistoryStream and returns all off-chain content referenced by those messages. This gives us the ability to do deletion and feed replication without using the blob system.

Install
Usage
API
Maintainers
Contributing
License

Install

npm install ssb-content-stream

Usage

const server = require('ssb-server')
  .use(require('ssb-master'))
  .use(require('./'))

const config = Object.assign({}, require('ssb-config'), {
  keys: require('ssb-keys').generate() // Random key for testing!
})

const ssb = server(config)

ssb.contentStream.publish({ type: 'test', randomNumber: 42 }, (err, msg) => {
  if (err) throw err
  console.log(msg)
})

{ key: '%hK2+Ed0KJlJ5kR4IbvEs3GZywPJ3GWyyWjsCgsuhtO8=.sha256',
  value:
   { previous: null,
     sequence: 1,
     author: '@MJ+WR+PF/6QPnzN2ef2XyhRNSBIWsx0T45ZAffEcEPk=.ed25519',
     timestamp: 1559086953009,
     hash: 'sha256',
     content:
      { type: 'content',
        href:
         'ssb:content:sha256:rWqRaMb0dfFmss2xan936taWQFfJ_1GGOeckZrFUit8=',
        mediaType: 'text/json' },
     signature:
      'lcCJSMl1cDHr85m8u0WjhZl/DjOENOCzTsH58Jqo2RpQ0AKoGlQVoEC+nwRIStvfz58tbvCIt+ilEOyYxb2rAg==.sig.ed25519' },
  timestamp: 1559086953010 }

API

`createSource(opts)`

Wrapper for createHistoryStream that prepends all off-chain content to the stream. Since createHistoryStream only returns public and unencrypted messages this function will only return public messages and its content.

`createHandler(cb)`

Creates a through-stream that filters content out of the stream, adds them to the content store, and only passes the original metadata message through the stream.

`getContent(msg, cb)`

Takes a full message ({ key, value: { previous, sequence, ... } }) and returns the extracted content from that message in msg.value.content as if it wasn't a message with off-chain content.

`getContent(opts)`

Passes createSource() through createHandler() and getContent().

`publish(content, cb)`

Wraps ssb.publish to publish off-chain messages that can be accessed with content streams. Message schema is:

{
  "href": "ssb:content:sha256:rWqRaMb0dfFmss2xan936taWQFfJ_1GGOeckZrFUit8=",
  "mediaType": "text/json",
  "type": "content"
}