The current behaviour of FcSortWalk() is to create a new FcCharSet on
each iteration that is the union of the previous iteration with the next
FcCharSet in the font set. This causes the existing FcCharSet to be
reproduced in its entirety and then allocates fresh leaves for the new
FcCharSet. In essence the number of allocations is quadratic wrt the
number of fonts required.
By introducing a new method for merging a new FcCharSet with an existing
one we can change the behaviour to be effectively linear with the number
of fonts - allocating no more leaves than necessary to cover all the
fonts in the set.
For example, profiling 'gedit UTF-8-demo.txt'
Allocator nAllocs nBytes
Before:
FcCharSetFindLeafCreate 62886 2012352
FcCharSetPutLeaf 9361 11441108
After:
FcCharSetFindLeafCreate 1940 62080
FcCharSetPutLeaf 281 190336
The savings are even more significant for applications like firefox-3.0b5
which need to switch between large number of fonts.
Before:
FcCharSetFindLeafCreate 4461192 142758144
FcCharSetPutLeaf 1124536 451574172
After:
FcCharSetFindLeafCreate 80359 2571488
FcCharSetPutLeaf 18940 9720522
Out of interest, the next most frequent allocations are
FcPatternObjectAddWithBinding 526029 10520580
tt_face_load_eblc 42103 2529892
Note that this also fixes a bug with FcFontList() where previously
it was NOT checking whether the config is up-to-date. May want to
keep the old behavior and document that ScanInterval is essentially
unused internally (FcFontSetList uses it, but we can remove that
too).
Added -h instead of -?. And upon -h and --help, write usave to stdout
instead of stdin, and return 0 instead of 1.
-? still works like before as that's what getopt returns upon unknown
arguments.
A private FcObjectGetSet() is implemented that provides an
FcObjectSet of all registered elements. FcFontSetList() is
then modified to use the object set from FcObjectGetSet() if
provided object-set is NULL.
Alternatively FcObjectGetSet() can be made public. In that
case fc-list can use that as a base if --verbose is included,
and also add any elements provided by the user (though that has
no effect, as all elements from the cache are already registered).
Currently fc-list ignores user-provided elements if --verbose
is specified.
The fact that we now drop final slashes from all filenames without
checking that the file name represents a directory may surprise some,
but it doesn't bother me really.
At OLPC, we came across a bug where the Browse activity (based on xulrunner)
took 100% CPU after an upgrade/. It turns out the Mozilla uses
FcConfigUptoDate() to check if new fonts have been added to the system, and
this function was always returning FcFalse since we have the mtimes of some
font directories set in the future. The attached patch makes
FcConfigUptoDate() print a warning and return FcTrue if mtime of directories
are in the future.
Behdad Esfahbod
Harshula Jayasuriya
Alexey Khoroshilov
Rahul Bhalerao
Harald Fernengel
Chris Wilson
Benjamin Close
Peter
Keith Packard
Sayamindu Dasgupta