filectx: use ctx.size comparisons to speed up ctx.cmp
Comparing sizes is cheaper than comparing file contents, as it does not
involve reading the file on disk or from the filelog.
It is however not always possible: some extensions, or encode filters,
change data when extracting it to the working directory.
$ echo "[extensions]" >> $HGRCPATH
$ echo "bookmarks=" >> $HGRCPATH
$ echo "[bookmarks]" >> $HGRCPATH
$ echo "track.current = True" >> $HGRCPATH
$ hg init
no bookmarks
$ hg bookmarks
no bookmarks set
set bookmark X
$ hg bookmark X
list bookmarks
$ hg bookmark
* X -1:000000000000
list bookmarks with color
$ hg --config extensions.color= --config color.mode=ansi \
> bookmark --color=always
[0;32m * X -1:000000000000[0m
update to bookmark X
$ hg update X
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
list bookmarks
$ hg bookmarks
* X -1:000000000000
rename
$ hg bookmark -m X Z
list bookmarks
$ hg bookmarks
* Z -1:000000000000
new bookmark Y
$ hg bookmark Y
list bookmarks
$ hg bookmark
* Y -1:000000000000
Z -1:000000000000
commit
$ echo 'b' > b
$ hg add b
$ hg commit -m'test'
list bookmarks
$ hg bookmark
* Y 0:719295282060
Z -1:000000000000
delete bookmarks
$ hg bookmark -d Y
$ hg bookmark -d Z
list bookmarks
$ hg bookmark
no bookmarks set
update to tip
$ hg update tip
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
set bookmark Y using -r .
$ hg bookmark -r . Y
list bookmarks
$ hg bookmark
* Y 0:719295282060