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.

Table of Contents

• 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"
}

Maintainers

@fraction

Contributing

PRs accepted.

License

ISC © 2019 Fraction LLC