843771 - [email] Disable logging for email

Status: RESOLVED WONTFIX

(Firefox OS Graveyard :: Gaia::E-Mail, defect)

Description

[Gregor Wagner [:gwagner]]

We have seen in the past that console logging can be very expensive.
Let's disable it and create the logging strings based on a debug flag.

Comment 1

[Andrew Sutherland [:asuth] (he/him)]

Our logging is actually shunted directly to dump() whenever we have mozTCPSocket around.  See console-hook.js.  Does that have the same level of overhead?

Also, it's worth noting that our console.BLAH calls are our poor man's debugging mechanism.  We have a rather extensive logging infrastructure in place that's accessible via the secret debug menu:
https://wiki.mozilla.org/Gaia/Email/SecretDebugMode

Said secret debug menu currently works but our device storage persistence is broken for some reason, which does not turn out great.  (The bookmarklet means of triggering the UI work when running in Firefox, however.)

Comment 2

[Gregor Wagner [:gwagner]]

Generating the strings has a high overhead. Even if you don't print it to the console. For contacts this was a 2x slowdown for example.
That's why you see all this |if (DEBUG) debug(...)| stuff in contacts, settings....

Comment 3

[Chris Jones [:cjones] inactive; ni?/f?/r? if you need me]

The dump()s go to logcat, which is expensive even if you're not dynamically building the message.

Comment 4

[Andrew Sutherland [:asuth] (he/him)]

(In reply to Chris Jones [:cjones] [:warhammer] from comment #3)
> The dump()s go to logcat, which is expensive even if you're not dynamically
> building the message.

Right, logcat and stdout can be slow because of the sync I/O.  I thought we had turned off the dump pref for non-engineer builds though?

In any event, we can just strip out the console.BLAH stuff from the back-end (stuff in apps/email/js/ext/).  They were just band-aids that grew in popularity because 'adb logcat' was good enough for debugging for a while when we had a lot of dumb bugs.  The fancy logging is much better for us.  Whatever would have been hooked up to set the DEBUG flag can just turn on fancy logging instead and presumably be used to trigger a dump of that (or enable direct streaming to dump()).

For the front-end (stuff not in js/ext/) we're not really that chatty in terms of console.BLAH calls, but it likely would correlate with times we really don't want to hitch because of a synchronous I/O write, so that makes good sense.

Comment 5

[Andrew Sutherland [:asuth] (he/him)]

We've seen no evidence of meaningful slowdowns from our various logging strategies, whereas we've seen massive QA/debugging benefits, so this is WONTFIX until we get smoking gun performance data in the future.