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BREAKING: Use ES class, drop inherits dep
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For: brave/brave-browser#5490
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@feross
feross committed Aug 6, 2019
1 parent e2bad03 commit 167446e
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Showing 2 changed files with 125 additions and 139 deletions.
263 changes: 125 additions & 138 deletions index.js
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Original file line number Diff line number Diff line change
@@ -1,5 +1,3 @@
/* jshint camelcase: false */

// TODO: ipv6 support
// TODO: parse and send peer flags (currently unused)
// NOTE: addPeer should take in an optional second argument, flags
Expand All @@ -9,163 +7,152 @@ var EventEmitter = require('events').EventEmitter
var compact2string = require('compact2string')
var string2compact = require('string2compact')
var bencode = require('bencode')
var inherits = require('inherits')

var PEX_INTERVAL = 65000 // just over one minute
var PEX_MAX_PEERS = 50 // max number of peers to advertise per PEX message

module.exports = function () {
inherits(utPex, EventEmitter)

function utPex (wire) {
var self = this
EventEmitter.call(self)

self._wire = wire
self._intervalId = null

self.reset()
}
module.exports = () => {
class utPex extends EventEmitter {
constructor (wire) {
super()

utPex.prototype.name = 'ut_pex'
this._wire = wire
this._intervalId = null

/**
* Start sending regular PEX updates to remote peer.
*/
utPex.prototype.start = function () {
var self = this
clearInterval(self._intervalId)
self._intervalId = setInterval(self._sendMessage.bind(self), PEX_INTERVAL)
if (self._intervalId.unref) self._intervalId.unref()
}
this.reset()
}

/**
* Stop sending PEX updates to the remote peer.
*/
utPex.prototype.stop = function () {
var self = this
clearInterval(self._intervalId)
self._intervalId = null
}
/**
* Start sending regular PEX updates to remote peer.
*/
start () {
clearInterval(this._intervalId)
this._intervalId = setInterval(() => this._sendMessage(), PEX_INTERVAL)
if (this._intervalId.unref) this._intervalId.unref()
}

/**
* Stops sending updates to the remote peer and resets internal state of peers seen.
*/
utPex.prototype.reset = function () {
var self = this
self._remoteAddedPeers = {}
self._remoteDroppedPeers = {}
self._localAddedPeers = {}
self._localDroppedPeers = {}
self.stop()
}
/**
* Stop sending PEX updates to the remote peer.
*/
stop () {
clearInterval(this._intervalId)
this._intervalId = null
}

/**
* Adds a peer to the locally discovered peer list for the next PEX message.
*/
utPex.prototype.addPeer = function (peer) {
var self = this
if (peer.indexOf(':') < 0) return // disregard invalid peers
if (peer in self._remoteAddedPeers) return // never advertise peer the remote wire already sent us
if (peer in self._localDroppedPeers) delete self._localDroppedPeers[peer]
self._localAddedPeers[peer] = true
}
/**
* Stops sending updates to the remote peer and resets internal state of peers seen.
*/
reset () {
this._remoteAddedPeers = {}
this._remoteDroppedPeers = {}
this._localAddedPeers = {}
this._localDroppedPeers = {}
this.stop()
}

/**
* Adds a peer to the locally dropped peer list for the next PEX message.
*/
utPex.prototype.dropPeer = function (peer) {
var self = this
if (peer.indexOf(':') < 0) return // disregard invalid peers
if (peer in self._remoteDroppedPeers) return // never advertise peer the remote wire already sent us
if (peer in self._localAddedPeers) delete self._localAddedPeers[peer]
self._localDroppedPeers[peer] = true
}
/**
* Adds a peer to the locally discovered peer list for the next PEX message.
*/
addPeer (peer) {
if (peer.indexOf(':') < 0) return // disregard invalid peers
if (peer in this._remoteAddedPeers) return // never advertise peer the remote wire already sent us
if (peer in this._localDroppedPeers) delete this._localDroppedPeers[peer]
this._localAddedPeers[peer] = true
}

utPex.prototype.onExtendedHandshake = function (handshake) {
var self = this
if (!handshake.m || !handshake.m.ut_pex) {
return self.emit('warning', new Error('Peer does not support ut_pex'))
/**
* Adds a peer to the locally dropped peer list for the next PEX message.
*/
dropPeer (peer) {
if (peer.indexOf(':') < 0) return // disregard invalid peers
if (peer in this._remoteDroppedPeers) return // never advertise peer the remote wire already sent us
if (peer in this._localAddedPeers) delete this._localAddedPeers[peer]
this._localDroppedPeers[peer] = true
}
}

/**
* PEX messages are bencoded dictionaries with the following keys:
* 'added' : array of peers met since last PEX message
* 'added.f' : array of flags per peer
* '0x01' : peer prefers encryption
* '0x02' : peer is seeder
* 'dropped' : array of peers locally dropped from swarm since last PEX message
* 'added6' : ipv6 version of 'added'
* 'added6.f' : ipv6 version of 'added.f'
* 'dropped.f' : ipv6 version of 'dropped'
*
* @param {Buffer} buf bencoded PEX dictionary
*/
utPex.prototype.onMessage = function (buf) {
var self = this
var message

try {
message = bencode.decode(buf)
} catch (err) {
// drop invalid messages
return
onExtendedHandshake (handshake) {
if (!handshake.m || !handshake.m.ut_pex) {
return this.emit('warning', new Error('Peer does not support ut_pex'))
}
}

if (message.added) {
compact2string.multi(message.added).forEach(function (peer) {
delete self._remoteDroppedPeers[peer]
if (!(peer in self._remoteAddedPeers)) {
self._remoteAddedPeers[peer] = true
self.emit('peer', peer)
}
})
/**
* PEX messages are bencoded dictionaries with the following keys:
* 'added' : array of peers met since last PEX message
* 'added.f' : array of flags per peer
* '0x01' : peer prefers encryption
* '0x02' : peer is seeder
* 'dropped' : array of peers locally dropped from swarm since last PEX message
* 'added6' : ipv6 version of 'added'
* 'added6.f' : ipv6 version of 'added.f'
* 'dropped.f' : ipv6 version of 'dropped'
*
* @param {Buffer} buf bencoded PEX dictionary
*/
onMessage (buf) {
var message

try {
message = bencode.decode(buf)
} catch (err) {
// drop invalid messages
return
}

if (message.added) {
compact2string.multi(message.added).forEach(peer => {
delete this._remoteDroppedPeers[peer]
if (!(peer in this._remoteAddedPeers)) {
this._remoteAddedPeers[peer] = true
this.emit('peer', peer)
}
})
}

if (message.dropped) {
compact2string.multi(message.dropped).forEach(peer => {
delete this._remoteAddedPeers[peer]
if (!(peer in this._remoteDroppedPeers)) {
this._remoteDroppedPeers[peer] = true
this.emit('dropped', peer)
}
})
}
}

if (message.dropped) {
compact2string.multi(message.dropped).forEach(function (peer) {
delete self._remoteAddedPeers[peer]
if (!(peer in self._remoteDroppedPeers)) {
self._remoteDroppedPeers[peer] = true
self.emit('dropped', peer)
}
/**
* Sends a PEX message to the remote peer including information about any locally
* added / dropped peers.
*/
_sendMessage () {
var localAdded = Object.keys(this._localAddedPeers).slice(0, PEX_MAX_PEERS)
var localDropped = Object.keys(this._localDroppedPeers).slice(0, PEX_MAX_PEERS)

var added = Buffer.concat(localAdded.map(string2compact))
var dropped = Buffer.concat(localDropped.map(string2compact))

var addedFlags = Buffer.concat(localAdded.map(() => {
// TODO: support flags
return Buffer.from([0])
}))

// update local deltas
localAdded.forEach(peer => delete this._localAddedPeers[peer])
localDropped.forEach(peer => delete this._localDroppedPeers[peer])

// send PEX message
this._wire.extended('ut_pex', {
added: added,
'added.f': addedFlags,
dropped: dropped,
added6: Buffer.alloc(0),
'added6.f': Buffer.alloc(0),
dropped6: Buffer.alloc(0)
})
}
}

/**
* Sends a PEX message to the remote peer including information about any locally
* added / dropped peers.
*/
utPex.prototype._sendMessage = function () {
var self = this

var localAdded = Object.keys(self._localAddedPeers).slice(0, PEX_MAX_PEERS)
var localDropped = Object.keys(self._localDroppedPeers).slice(0, PEX_MAX_PEERS)

var added = Buffer.concat(localAdded.map(string2compact))
var dropped = Buffer.concat(localDropped.map(string2compact))

var addedFlags = Buffer.concat(localAdded.map(function () {
// TODO: support flags
return Buffer.from([0])
}))

// update local deltas
localAdded.forEach(function (peer) { delete self._localAddedPeers[peer] })
localDropped.forEach(function (peer) { delete self._localDroppedPeers[peer] })

// send PEX message
self._wire.extended('ut_pex', {
added: added,
'added.f': addedFlags,
dropped: dropped,
added6: Buffer.alloc(0),
'added6.f': Buffer.alloc(0),
dropped6: Buffer.alloc(0)
})
}
utPex.prototype.name = 'ut_pex'

return utPex
}
1 change: 0 additions & 1 deletion package.json
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Original file line number Diff line number Diff line change
Expand Up @@ -13,7 +13,6 @@
"dependencies": {
"bencode": "^2.0.0",
"compact2string": "^1.2.0",
"inherits": "^2.0.1",
"string2compact": "^1.2.5"
},
"devDependencies": {
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