fix(stor): pause connection to avoid memory build up

src/commands/registration/stor.js

@@ -13,26 +13,33 @@ module.exports = {
     .tap(() => this.commandSocket.pause())
     .then(() => when.try(this.fs.write.bind(this.fs), fileName, {append, start: this.restByteCount}))
     .then(stream => {
-      this.restByteCount = 0;
+      const destroyConnection = (connection, reject) => err => connection && connection.destroy(err) && reject(err);
 
       const streamPromise = when.promise((resolve, reject) => {
-        stream.once('error', err => reject(err));
+        stream.once('error', destroyConnection(this.connector.socket, reject));
         stream.once('finish', () => resolve());
       });
 
       const socketPromise = when.promise((resolve, reject) => {
-        this.connector.socket.on('data', data => stream.write(data, this.transferType));
+        this.connector.socket.on('data', data => {
+          if (this.connector.socket) this.connector.socket.pause();
+          if (stream) {
+            stream.write(data, this.transferType, () => this.connector.socket && this.connector.socket.resume());
+          }
+        });
         this.connector.socket.once('end', () => {
           if (stream.listenerCount('close')) stream.emit('close');
           else stream.end();
           resolve();
         });
-        this.connector.socket.once('error', err => reject(err));
+        this.connector.socket.once('error', destroyConnection(stream, reject));
       });
 
+      this.restByteCount = 0;
+
       return this.reply(150).then(() => this.connector.socket.resume())
       .then(() => when.join(streamPromise, socketPromise))
-      .finally(() => stream.destroy ? stream.destroy() : null);
+      .finally(() => stream.destroy && stream.destroy());
     })
     .then(() => this.reply(226, fileName))
     .catch(when.TimeoutError, err => {