RE: [jira] Commented: (DIRMINA-121) Per-port filter chain

[Jose Alberto Fernandez]

From: Trustin Lee [mailto:[EMAIL PROTECTED] Sent: 17 November 2005 05:33 To: Apache Directory Developers List Subject: Re: [jira] Commented: (DIRMINA-121) Per-port filter chain   2005/11/17, Trustin Lee <[EMAIL PROTECTED]>: This is a great example that makes us reconsider chain copying.  To resolve this we must have only one chain per session, and per-acceptor chain and per-port chain should be added to the per-session chain just before sessionCreated is invoked.  It's a little bit overhead, but I think it is fine if we implement it very effectively.  Perhaps per-port and per-acceptor chains could be implemented as an array list and used only as a configuration.  WDYT? This approach will give a performance penalt if we're going to add a filter to multiple sessions.  The question is if we can afford it. The alternative today is to create the entire chain on each session, which is even more expensive. This is why I have proposed some sort of lazy copying of the chain, which means that you only pay the price if you need to (if you actually modify your chain on a session). Per-acceptor (if we still keep it) and per-port can be added together during port binding (as this is a one time of operation).   The only issue left is that NextFilters are not safe anymore to remember for the entire lifecycle of the Filter. I see two possible solutions here:   1)   Tell people it is not safe to remember and if you do it is at your own risk. You can always obtain the NextFilter from the session. 2)   Add a IoFilter.chainRelocated(NextFilter old, NextFilter new) method to be called in the filter in the case of a copy. So any filter that caches will be notified of the change and do whatever is necessary.   I do not like (2) as I do not think we should encourage caching, but it may solve the problem easily.   Jose Alberto