git ssb

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var broadcast = require('broadcast-stream')
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var ref = require('ssb-ref')
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// local plugin
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// broadcasts the address:port:pubkey triple of the ssb server
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// on the LAN, using multicast UDP
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function isFunction (f) {
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  return 'function' === typeof f
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}
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function isEmpty (o) {
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  for(var k in o)
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    return false
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  return true
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}
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/*
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  idea: instead of broadcasting constantly,
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  broadcast at startup, or when ip address changes (change networks)
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  or when you receive a boardcast.
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  this should use network more efficiently.
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*/
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module.exports = {
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  name: 'local',
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  version: '2.0.0',
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  init: function init (ssbServer, config) {
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    if(config.gossip && config.gossip.local === false)
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      return {
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        init: function () {
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          delete this.init
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          init(ssbServer, config)
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        }
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      }
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    var local = broadcast(config.port)
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    var addrs = {}
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    var lastSeen = {}
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    // cleanup old local peers
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    setInterval(function () {
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      Object.keys(lastSeen).forEach((key) => {
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        if (Date.now() - lastSeen[key] > 10e3) {
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          ssbServer.gossip.remove(addrs[key])
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          delete lastSeen[key]
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        }
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      })
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    }, 5e3)
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    // discover new local peers
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    local.on('data', function (buf) {
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      if (buf.loopback) return
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      var data = buf.toString()
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      var peer = ref.parseAddress(data)
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      if (peer && peer.key !== ssbServer.id) {
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        addrs[peer.key] = peer
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        lastSeen[peer.key] = Date.now()
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        //note: add the raw data, not the parsed data.
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        //so we still have the whole address, including protocol (eg, websockets)
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        ssbServer.gossip.add(data, 'local')
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      }
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    })
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    ssbServer.status.hook(function (fn) {
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      var _status = fn()
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      if(!isEmpty(addrs)) {
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        _status.local = {}
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        for(var k in addrs)
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          _status.local[k] = {address: addrs[k], seen: lastSeen[k]}
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      }
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      return _status
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    })
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    setImmediate(function () {
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      // broadcast self
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      var int = setInterval(function () {
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        if(config.gossip && config.gossip.local === false)
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          return
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        // TODO: sign beacons, so that receipient can be confidant
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        // that is really your id.
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        // (which means they can update their peer table)
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        // Oh if this includes your local address,
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        // then it becomes unforgeable.
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        var addr = ssbServer.getAddress('private') || ssbServer.getAddress('local')
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        if(addr) local.write(addr)
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      }, 1000)
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      if(int.unref) int.unref()
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    })
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  }
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}
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