23491 - [PERF] Need to hook at imap urls to the memory cache

Status: VERIFIED FIXED

(MailNews Core :: Networking, defect, P3)

Description

[Scott MacGregor]

This came out of our performance meeting the other day. We really need to get at
least imap message urls hooked up into the disk cache. And if we have time
before beta, news and even mailbox urls could go in there.


This will be a big win for message display for messages that contain lots of
images or parts that need re-fecthed in order to display. I've noticed us
downloading the message multiple times in these cases. Once to feed to the mime
parser, then it generates urls referring to the images which cause layout to
load the url again to download the image.

for msgs with lots of parts this gets expensive very fast!!!

Comment 1

[Scott MacGregor]

I wanted to do something different late last night so I sat down and got my
hands dirty with the memory cache.

The good news is that I now have the memory cache working for imap. What a
difference it makes! Especially when viewing messages with many embedded images.
Because for each embedded image, we would try to download the message again! Now
that it's in the memory cache, we only download it once and the urls that get
run again for each image result in hits in the memory cache.

Assuming I get a code review, I'll check this in today. Then I'll work with
Suresh to get some performance numbers.

This also speeds up the time it takes to reply to a message because the quoting
is done from the message which is in the memory cache instead of hitting the
network and downloading the message again.

Phil, do you think we should hook up the memory cache for news before beta or
should I make that a separate post beta bug?

Comment 2

[Scott MacGregor]

I landed my changes for imap and the memory cache tonight. I'm going to mark
this as fixed and then file another bug for getting news into the memory cache
as well.

See my post in n.p.m.mail-news for info about the performance implications of
this checkin.

They include but are not limited to improving:
*displaying a message already in the memory cache
*displaying a message with one or more inlined attachments should be
dramatically improved as we went from n+1 times downloading the message to 1
time where n = # of inlined attachments.
* time to reply to a message.

Comment 3

[[e-mail] (gone - use [e-mail] instead)]

Scott did this again when the new cache landed.  marking verified fixed.