Fixes for PR #799

- Support multiple &xs= params in parallel
- Fail on 'error' 'warning' events

lib/torrent.js

@@ -114,7 +114,7 @@ function Torrent (torrentId, client, opts) {
 
   // for cleanup
   this._servers = []
-  this._xsRequest = null
+  this._xsRequests = []
 
   // TODO: remove this and expose a hook instead
   // optimization: don't recheck every file if it hasn't changed
@@ -271,38 +271,6 @@ Torrent.prototype._onParsedTorrent = function (parsedTorrent) {
       self._onListening()
     })
   }
-
-  if (parsedTorrent.xs && !self.info) {
-    // TODO: Could try multiple in parallel here
-    var src = parsedTorrent.xs instanceof Array ? parsedTorrent.xs[0] : parsedTorrent.xs
-    var isHTTP = src.substring(0, 7) === 'http://' || src.substring(0, 8) === 'https://'
-
-    if (isHTTP) {
-      var opts = {
-        url: src,
-        method: 'GET',
-        headers: {
-          'user-agent': 'WebTorrent (http://webtorrent.io)'
-        }
-      }
-      this._xsRequest = get.concat(opts, function (err, res, torrent) {
-        if (err || res.statusCode !== 200 || !torrent.length) return
-
-        var parsedTorrent
-        try {
-          parsedTorrent = parseTorrent(torrent)
-        } catch (err) {}
-
-        if (parsedTorrent) {
-          if (parsedTorrent.infoHash !== self.infoHash) {
-            return
-          }
-
-          self._onMetadata(parsedTorrent)
-        }
-      })
-    }
-  }
 }
 
 Torrent.prototype._processParsedTorrent = function (parsedTorrent) {
@@ -395,23 +363,96 @@ Torrent.prototype._onListening = function () {
     self.emit('warning', err)
   }
 
-  // if full metadata was included in initial torrent id, use it immediately. Otherwise,
-  // wait for torrent-discovery to find peers and ut_metadata to get the metadata.
-  if (self.info) self._onMetadata(self)
+  if (self.info) {
+    // if full metadata was included in initial torrent id, use it immediately. Otherwise,
+    // wait for torrent-discovery to find peers and ut_metadata to get the metadata.
+    self._onMetadata(self)
+  } else if (self.xs) {
+    self._getMetadataFromServer()
+  }
+}
+
+Torrent.prototype._getMetadataFromServer = function () {
+  var self = this
+  var urls = Array.isArray(self.xs) ? self.xs : [ self.xs ]
+
+  var tasks = urls.map(function (url) {
+    return function (cb) {
+      getMetadataFromURL(url, cb)
+    }
+  })
+  parallel(tasks)
+
+  function getMetadataFromURL (url, cb) {
+    if (url.indexOf('http://') !== 0 && url.indexOf('https://') !== 0) {
+      self._debug('skipping non-http xs param: %s', url)
+      return cb(null)
+    }
+
+    var opts = {
+      url: url,
+      method: 'GET',
+      headers: {
+        'user-agent': 'WebTorrent (https://webtorrent.io)'
+      }
+    }
+    var req
+    try {
+      req = get.concat(opts, onResponse)
+    } catch (err) {
+      self._debug('skipping invalid url xs param: %s', url)
+      return cb(null)
+    }
+
+    self._xsRequests.push(req)
+
+    function onResponse (err, res, torrent) {
+      if (self.destroyed) return cb(null)
+      if (self.metadata) return cb(null)
+
+      if (err) {
+        self._debug('http error from xs param: %s', url)
+        return cb(null)
+      }
+      if (res.statusCode !== 200) {
+        self._debug('non-200 status code from xs param: %s', url)
+        return cb(null)
+      }
+
+      var parsedTorrent
+      try {
+        parsedTorrent = parseTorrent(torrent)
+      } catch (err) {}
+
+      if (!parsedTorrent) {
+        self._debug('got invalid torrent file from xs param: %s', url)
+        return cb(null)
+      }
+
+      if (parsedTorrent.infoHash !== self.infoHash) {
+        self._debug('got torrent file with incorrect info hash from xs param: %s', url)
+        return cb(null)
+      }
+
+      self._onMetadata(parsedTorrent)
+      cb(null)
+    }
+  }
 }
 
 /**
  * Called when the full torrent metadata is received.
  */
 Torrent.prototype._onMetadata = function (metadata) {
   var self = this
-  if (self._xsRequest) {
-    self._xsRequest.abort()
-    self._xsRequest = null
-  }
   if (self.metadata || self.destroyed) return
   self._debug('got metadata')
 
+  self._xsRequests.forEach(function (req) {
+    req.abort()
+  })
+  self._xsRequests = []
+
   var parsedTorrent
   if (metadata && metadata.infoHash) {
     // `metadata` is a parsed torrent (from parse-torrent module)
@@ -591,13 +632,14 @@ Torrent.prototype._destroy = function (err, cb) {
   self.destroyed = true
   self._debug('destroy')
 
-  if (self._xsRequest) {
-    self._xsRequest.abort()
-  }
   self.client._remove(self)
 
   clearInterval(self._rechokeIntervalId)
 
+  self._xsRequests.forEach(function (req) {
+    req.abort()
+  })
+
   if (self._rarityMap) {
     self._rarityMap.destroy()
   }
@@ -653,7 +695,7 @@ Torrent.prototype._destroy = function (err, cb) {
   self._rarityMap = null
   self._peers = null
   self._servers = null
-  self._xsRequest = null
+  self._xsRequests = null
 }
 
 Torrent.prototype.addPeer = function (peer) {

test/node/download-metadata.js

@@ -25,9 +25,12 @@ test('Download metadata for magnet URI with xs parameter', function (t) {
 
   var client = new WebTorrent({ dht: false, tracker: false })
 
+  client.on('error', function (err) { t.fail(err) })
+  client.on('warning', function (err) { t.fail(err) })
+
   createServer(fixtures.leaves.torrent, function (url, next) {
     client.add(fixtures.leaves.magnetURI + '&xs=' + encodeURIComponent(url), function (torrent) {
-      t.equal(torrent.name, 'Leaves of Grass by Walt Whitman.epub')
+      t.equal(torrent.files[0].name, 'Leaves of Grass by Walt Whitman.epub')
 
       client.destroy(function (err) { t.error(err, 'client destroyed') })
       next()
@@ -40,12 +43,15 @@ test('Download metadata for magnet URI with xs parameter', function (t) {
 
   var client = new WebTorrent({ dht: false, tracker: false })
 
+  client.on('error', function (err) { t.fail(err) })
+  client.on('warning', function (err) { t.fail(err) })
+
   createServer(fixtures.leaves.torrent, function (url, next) {
     var encoded = encodeURIComponent(url)
     var uri = fixtures.leaves.magnetURI + '&xs=' + encoded + '&xs=' + encoded + '2'
 
     client.add(uri, function (torrent) {
-      t.equal(torrent.name, 'Leaves of Grass by Walt Whitman.epub')
+      t.equal(torrent.files[0].name, 'Leaves of Grass by Walt Whitman.epub')
 
       client.destroy(function (err) { t.error(err, 'client destroyed') })
       next()
@@ -54,12 +60,17 @@ test('Download metadata for magnet URI with xs parameter', function (t) {
 })
 
 test('Download metadata magnet URI with unsupported protocol in xs parameter', function (t) {
-  t.plan(2)
+  t.plan(1)
 
   var client = new WebTorrent({ dht: false, tracker: false })
+
+  client.on('error', function (err) { t.fail(err) })
+  client.on('warning', function (err) { t.fail(err) })
+
   client.add(fixtures.leaves.magnetURI + '&xs=' + encodeURIComponent('invalidurl:example'))
+
   setTimeout(function () {
-    t.ok(true, 'no crash')
+    // no crash by now
     client.destroy(function (err) { t.error(err, 'client destroyed') })
   }, 100)
 })