cleanup torrent.torrentFileURL blob on destroy

For #322

1 files changed, 7 insertions, 1 deletions

diff --git a/lib/torrent.js b/lib/torrent.js
index e34041f..3bb44a0 100644
--- a/lib/torrent.js
+++ b/lib/torrent.js
@@ -75,6 +75,7 @@ function Torrent (torrentId, opts) {
   self._selections = []
   self._critical = []
   self._storageImpl = opts.storage || Storage
+  this._torrentFileURL = null
 
   var parsedTorrent
   try {
@@ -213,9 +214,12 @@ Object.defineProperty(Torrent.prototype, 'torrentFile', {
 
 Object.defineProperty(Torrent.prototype, 'torrentFileURL', {
   get: function () {
-    return window.URL.createObjectURL(
+    if (typeof window === 'undefined') throw new Error('browser-only property')
+    if (this._torrentFileURL) return this._torrentFileURL
+    this._torrentFileURL = window.URL.createObjectURL(
       new window.Blob([ this.torrentFile ], { type: 'application/x-bittorrent' })
     )
+    return this._torrentFileURL
   }
 })
 
@@ -361,6 +365,8 @@ Torrent.prototype.destroy = function (cb) {
     self._rechokeIntervalId = null
   }
 
+  if (self._torrentFileURL) window.URL.revokeObjectURL(self._torrentFileURL)
+
   var tasks = []
   if (self.swarm) tasks.push(function (cb) { self.swarm.destroy(cb) })
   if (self.discovery) tasks.push(function (cb) { self.discovery.stop(cb) })