[dev] I/O hammering (was: imp folder prefix)

[Chuck Hagenbuch]

Quoting Egan <egan@sevenkings.net>:

> Anytime we need information for building a list of messages, maximum
> performance will be obtained by making a single call to a single
> function which accepts a sequence.  Just making that one design change
> will eliminate at least 90% of the server communication overhead we
> have now for building the message list; that would make it as fast as
> it could possibly be.

Right. The modified mailbox.php that I sent you uses imap_fetch_overview to 
build the message list. But looking that that function, it wasn't _entirely_ 
clear that it'd do better, which is why I wanted you to trace it again.

> So it seems to me, an enhanced imap_fetch_overview is what we need.

I already patched it to return To: information, which is everything that we 
need for building the message list except for whether or not the message has 
any attachments. There doesn't seem to be an efficient way to get that out of c-
client.

> If you agree in principle, I will start looking at what's needed to
> accomplish that in php_imap.c.

If you've got ideas for php_imap.c, I'm happy to hear them - I'm nominally the 
maintainer of the IMAP extension.

-chuck

--
Charles Hagenbuch, <chuck@horde.org>
Black and white and grey, all the shades of truth.