match: avoid translating glob to matcher multiple times for large sets
For hgignore with many globs, the resulting regexp might not fit under the 20K
length limit. So the patterns need to be broken up in smaller pieces.
Before this change, the logic was re-starting the full process from scratch
for each smaller pieces, including the translation of globs into regexp.
Effectively doing the work over and over.
If the 20K limit is reached, we are likely in a case where there is many such
glob, so exporting them is especially expensive and we should be careful not
to do that work more than once.
To work around this, we now translate glob to regexp once and for all. Then,
we assemble the resulting individual regexp into valid blocks.
This raises a very significant performance win for large `.hgignore file`:
Before: ! wall 0.153153 comb 0.150000 user 0.150000 sys 0.000000 (median of 66)
After: ! wall 0.059793 comb 0.060000 user 0.060000 sys 0.000000 (median of 100)
$ . "$TESTDIR/helpers-testrepo.sh"
Testing that hghave does not crash when checking features
$ hghave --test-features 2>/dev/null
Testing hghave extensibility for third party tools
$ cat > hghaveaddon.py <<EOF
> import hghave
> @hghave.check("custom", "custom hghave feature")
> def has_custom():
> return True
> EOF
(invocation via run-tests.py)
$ cat > test-hghaveaddon.t <<EOF
> #require custom
> $ echo foo
> foo
> EOF
$ ( \
> testrepohgenv; \
> "$PYTHON" $TESTDIR/run-tests.py -j 1 \
> $HGTEST_RUN_TESTS_PURE test-hghaveaddon.t \
> )
running 1 tests using 1 parallel processes
.
# Ran 1 tests, 0 skipped, 0 failed.
(invocation via command line)
$ unset TESTDIR
$ hghave custom
(terminate with exit code 2 at failure of importing hghaveaddon.py)
$ rm hghaveaddon.*
$ cat > hghaveaddon.py <<NO_CHECK_EOF
> importing this file should cause syntax error
> NO_CHECK_EOF
$ hghave custom
failed to import hghaveaddon.py from '.': invalid syntax (hghaveaddon.py, line 1)
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