419744 - load font cmap info via a background task on windows

Status: RESOLVED FIXED

(Core :: Graphics, defect, P2)

Description

[John Daggett (:jtd)]

Follow-on bug from bug 416946 which implements deferred cmap loading on the mac.  Windows current loads all cmaps at startup in InitFontList.  Moving this out of the startup process would improve startup time.

Comment 1

[John Daggett (:jtd)]

With Stuart's lazy cmap loading work in 424018, doing cmap loading in an idle proc is now more important on Windows.  Bumping to a P2 blocker.

Comment 2

[John Daggett (:jtd)]

Attachment: work in progress patch, untested

This includes the contents of patch v.0.4 for 416946.  Untested, buyer beware!

Comment 3

[John Daggett (:jtd)]

Attachment: work in progress, v.0.2, simplify timer handling code

The underlying timer code exhibits weird behavior when re-init'ed as a recurring timer rather than a one shot, the callback gets called twice in succession.  So I just simplified the code to adjust the interval after the initial delay, this reduces the housekeeping code.

Timer parameters same as on mac, 10sec initial delay then loads occur in 150ms intervals.  Using perf timers it looks like the loads average about 20ms each.

Note: like the last patch, this also includes the mac loading code from bug 416946, patch v.0.4

Comment 4

[John Daggett (:jtd)]

Attachment: patch, v.0.3, eliminate extra helper classes, both mac and windows

With this patch, gfxWindowsPlatform and gfxQuartzFontCache both subclass gfxFontInfoLoader.  Because of this, changed the virtual methods to be xxxLoader (e.g. Run ==> RunLoader) to avoid method name collisions.  This simplifies things a bit, removes the need to have an extra object that just hangs around.

Stuart, let me know what you think and I'll set up a patch that removes all the debugging stuff.

Comment 5

[John Daggett (:jtd)]

Attachment: patch, v.0.4, clean out debugging stuff, both mac and windows

Comment 6

[John Daggett (:jtd)]

Running on my system, measuring the size of the gfxSparseBitSet structures used to store the cmaps per face:

With size += sizeof(nsAutoPtr<Block>) in gfxSparseBitSet::GetSize:
  561 faces, 1100288 bytes (1074KB)
  
Without:
  561 faces, 448864 bytes (438KB)
  
So just the nsAutoPtr's in the set are taking up 636KB.  That's probably why bumping up the block size affects the overall memory usage.

Comment 7

[John Daggett (:jtd)]

Attachment: patch, v.0.5, use private inheritance

Switch to private gfxFontInfoLoader inheritance, adjust gfxSparseBitSet size calculation.

Comment 8

[John Daggett (:jtd)]

checked in.