zeronet-protocol/src/lp2p/index.js

ZeroNet protocol

'use strict'

const ppb = require('pull-protocol-buffers').pull
const pull = require('pull-stream')
const empty = require('protons')('message PeerCmd {required bool empty = 1;}').PeerCmd.encode({
  empty: true
})
const once = require('once')

const debug = require('debug')
const plog = debug('zeronet:protocol:lp2p:client')
plog.enabled = Boolean(process.env.DEBUG_PACKETS)
const clone = require('clone')

function thingInspect (d) {
  if (Buffer.isBuffer(d)) return '<Buffer length=' + d.length + '>'
  return JSON.stringify(d)
}

function objectInspect (data) {
  if (!plog.enabled) return '-'
  let d = clone(data)
  let r = []
  for (var p in d) {
    r.push(p + '=' + thingInspect(d[p], p))
  }
  return r.join(', ')
}

module.exports = function LProtocol (opt, lp2p) {
  const self = this
  const swarm = lp2p.libp2p
  const protos = self.protos = {}

  if (!opt) opt = {}

  self.handle = (name, proto) => {
    protos[name] = proto
    swarm.handle('/zn/' + name + '/2.0.0', (protocol, conn) => {
      pull(
        conn.source,
        ppb.decode(proto.in.proto.msg),
        pull.take(1),
        pull.asyncMap((data, cb) => {
          plog('got   request', name, objectInspect(data))
          proto.peerRequest.handleRequest((err, res) => {
            if (err) {
              res = {
                error: err.toString().split('\n').shift()
              }
              err = null
            }
            plog('sent response', name, objectInspect(res))
            cb(err, res)
          }, data, proto.handler)
        }),
        ppb.encode(proto.out.proto.msg),
        conn.sink
      )
    })
  }

  lp2p.cmd = (peer, cmd, data, _cb) => {
    const cb = once(_cb)
    if (!protos[cmd]) return cb(new Error('CMD Unsupported'))
    const proto = protos[cmd]
    lp2p.dial(peer, '/zn/' + cmd + '/2.0.0', (err, conn) => {
      if (err) return cb(err)
      plog('sent  request', cmd, objectInspect(data))
      proto.peerRequest.sendRequest((data, cb) => {
        pull(
          pull.values([data]),
          ppb.encode(proto.in.proto.msg),
          pull.collect((err, data) => {
            if (err) return cb(err)
            if (!data.length || !data[0].length) data = [empty]
            pull(
              pull.values(data),
              conn,
              ppb.decode(proto.out.proto.msg),
              pull.collect((err, data) => {
                if (err) return cb(err)
                else {
                  if (data.length !== 1 || !data[0]) cb(new Error('Decoding failed! data.len != 1'))
                  const res = data[0]
                  plog('got  response', cmd, objectInspect(res))
                  if (res.error) return cb(new Error(res.error))
                  return cb(null, res)
                }
              })
            )
          })
        )
      }, data, cb)
    })
  }
}