gistfile1.txt

        static int EIO_AfterDrawMap(eio_req *req) {
          HandleScope scope;
          drawmap_request *baton =(drawmap_request *)req->data;
          ev_unref(EV_DEFAULT_UC);
          baton->map->Unref();

          Local<Value> argv[1];
          Buffer * buffer = Buffer::New(baton->data, baton->size, FreeImageBuffer, NULL);
          
          argv[0] = buffer;

          TryCatch try_catch;

          baton->cb->Call(Context::GetCurrent()->Global(), 1, argv);

          if (try_catch.HasCaught()) {
            FatalException(try_catch);
          }

          baton->cb.Dispose();

          delete baton;
          return 0;
        }