log: rewrite default template to use labels (issue2866)
This is a complete rewrite of the default template to use labels. This
seems ultimately useless to me in most cases. The biggest benefit of
this patch to me seems to be a fairly complicated example of the
templating engine. It was a lot of hard work to figure out the precise
acceptable syntax, since it's almost undocumented. Hat tip to Steve
Losh's smartlog template, which helped me figure out a lot of the
syntax. Hopefully later I can use the present default log template
as an example for documenting the templating engine.
A test is attached. My goal was to match the --color=debug output,
which may differ slightly in newlines from the actual ANSI escape
codes output. I consider this an acceptable invisible deviation.
There seems to be a considerable slowdown with this rewrite.
Before:
$ time hg log -T default -r .~100::. > /dev/null
real 0m0.882s
user 0m0.812s
sys 0m0.064s
$ time hg log -T default -r .~100::. > /dev/null
real 0m0.872s
user 0m0.796s
sys 0m0.068s
$ time hg log -T default -r .~100::. > /dev/null
real 0m0.917s
user 0m0.836s
sys 0m0.076s
After:
$ time hg log -T default -r .~100::. > /dev/null
real 0m1.480s
user 0m1.392s
sys 0m0.072s
$ time hg log -T default -r .~100::. > /dev/null
real 0m1.500s
user 0m1.400s
sys 0m0.088s
$ time hg log -T default -r .~100::. > /dev/null
real 0m1.462s
user 0m1.364s
sys 0m0.092s
Following the maxim, "make it work, profile, make it faster, in that
order", I deem this slowdown acceptable for now.
I suspect but have not confirmed that a big slowdown comes from
calling keywords twice in the file templates, once to test the
existence of output and again to actually list the output. If so, a
simple speedup might be to improve the templating engine to cache
keywords when called more than once on the same revision.
TODO: I found a bug while working on this. The following stack traces:
hg log -r . -T '{ifcontains(phase, "secret public", "lol", "omg")}\n'
hide outer repo
$ hg init
Invalid syntax: no value
$ cat > .hg/hgrc << EOF
> novaluekey
> EOF
$ hg showconfig
hg: parse error at $TESTTMP/.hg/hgrc:1: novaluekey
[255]
Invalid syntax: no key
$ cat > .hg/hgrc << EOF
> =nokeyvalue
> EOF
$ hg showconfig
hg: parse error at $TESTTMP/.hg/hgrc:1: =nokeyvalue
[255]
Test hint about invalid syntax from leading white space
$ cat > .hg/hgrc << EOF
> key=value
> EOF
$ hg showconfig
hg: parse error at $TESTTMP/.hg/hgrc:1: key=value
unexpected leading whitespace
[255]
$ cat > .hg/hgrc << EOF
> [section]
> key=value
> EOF
$ hg showconfig
hg: parse error at $TESTTMP/.hg/hgrc:1: [section]
unexpected leading whitespace
[255]
Reset hgrc
$ echo > .hg/hgrc
Test case sensitive configuration
$ echo '[Section]' >> $HGRCPATH
$ echo 'KeY = Case Sensitive' >> $HGRCPATH
$ echo 'key = lower case' >> $HGRCPATH
$ hg showconfig Section
Section.KeY=Case Sensitive
Section.key=lower case
Test "%unset"
$ cat >> $HGRCPATH <<EOF
> [unsettest]
> local-hgrcpath = should be unset (HGRCPATH)
> %unset local-hgrcpath
>
> global = should be unset (HGRCPATH)
>
> both = should be unset (HGRCPATH)
>
> set-after-unset = should be unset (HGRCPATH)
> EOF
$ cat >> .hg/hgrc <<EOF
> [unsettest]
> local-hgrc = should be unset (.hg/hgrc)
> %unset local-hgrc
>
> %unset global
>
> both = should be unset (.hg/hgrc)
> %unset both
>
> set-after-unset = should be unset (.hg/hgrc)
> %unset set-after-unset
> set-after-unset = should be set (.hg/hgrc)
> EOF
$ hg showconfig unsettest
unsettest.set-after-unset=should be set (.hg/hgrc)
Test exit code when no config matches
$ hg config Section.idontexist
[1]