explain cost of WebSocket compression and how to disable it

mojolicious · May 14, 2014 · f917592 · f917592
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diff --git a/lib/Mojo/UserAgent.pm b/lib/Mojo/UserAgent.pm
@@ -877,7 +877,8 @@ L<Mojo::Transaction::HTTP> object.
   Mojo::IOLoop->start unless Mojo::IOLoop->is_running;
 
 You can activate C<permessage-deflate> compression by setting the
-C<Sec-WebSocket-Extensions> header.
+C<Sec-WebSocket-Extensions> header, this can result in much better
+performance, but also increases memory usage by up to 300KB per connection.
 
   my $headers = {'Sec-WebSocket-Extensions' => 'permessage-deflate'};
   $ua->websocket('ws://example.com/foo' => $headers => sub {...});

diff --git a/lib/Mojolicious/Guides/Cookbook.pod b/lib/Mojolicious/Guides/Cookbook.pod
@@ -570,6 +570,15 @@ L<Mojolicious::Controller/"send">.
 The event L<Mojo::Transaction::WebSocket/"finish"> will be emitted right after
 the WebSocket connection has been closed.
 
+  $self->tx->compressed(0);
+  $self->res->headers->remove('Sec-WebSocket-Extensions');
+
+By default C<permessage-deflate> compression will be used if the client
+supports it, this can result in much better performance, but also increases
+memory usage by up to 300KB per connection. It can be disabled with
+L<Mojo::Transaction::WebSocket/"compressed"> and by removing the
+C<Sec-WebSocket-Extensions> header from the WebSocket handshake response.
+
 =head2 Testing WebSocket web services
 
 While the message flow on WebSocket connections can be rather dynamic, it