hgwebdir: avoid systematic full garbage collection
Forcing a systematic full garbage collection upon each request
can serioulsy harm performance. This is reported as
https://bz.mercurial-scm.org/show_bug.cgi?id=6075
With this change we're performing the full collection according
to a new setting, `experimental.web.full-garbage-collection-rate`.
The default value is 1, which doesn't change the behavior and will
allow us to test on real use cases. If the value is 0, no full garbage
collection occurs.
Regardless of the value of the setting, a partial garbage collection
still occurs upon each request (not attempting to collect objects from
the oldest generation). This should be enough to take care of
reference cycles that have been created by the last request
(assessment of this requires changing the setting, not to be 1).
In my experience chasing memory leaks in Mercurial servers,
the full collection never reclaimed any memory, but this is with
Python 3 and biased towards small repositories.
On the other hand, as explained in the Python developer docs [1],
frequent full collections are very harmful in terms of performance if
lots of objects survive the collection, and hence stay in the
oldest generation. Note that `gc.collect()` is indeed trying to
collect the oldest generation [2]. This happens usually in two cases:
- unwanted lingering objects (i.e., an actual memory leak that
the GC cannot do anything about). Sadly, we have lots of those
these days.
- desireable long-term objects, typically in caches (not inner caches
carried by repositories, which should be collected with them). This
is a subject of interest for the Heptapod project.
In short, the flat rate that this change still permits is
probably a bad idea in most cases, and the default value can
be tweaked later on (or even be set to 0) according to experiments
in the wild.
The test is inspired from test-hgwebdir-paths.py
[1] https://devguide.python.org/garbage_collector/#collecting-the-oldest-generation
[2] https://docs.python.org/3/library/gc.html#gc.collect
Differential Revision: https://phab.mercurial-scm.org/D11204
#testcases dirstate-v1 dirstate-v1-tree dirstate-v2
#if dirstate-v1-tree
#require rust
$ echo '[experimental]' >> $HGRCPATH
$ echo 'dirstate-tree.in-memory=1' >> $HGRCPATH
#endif
#if dirstate-v2
#require rust
$ echo '[format]' >> $HGRCPATH
$ echo 'exp-dirstate-v2=1' >> $HGRCPATH
#endif
$ hg init ignorerepo
$ cd ignorerepo
debugignore with no hgignore should be deterministic:
$ hg debugignore
<nevermatcher>
Issue562: .hgignore requires newline at end:
$ touch foo
$ touch bar
$ touch baz
$ cat > makeignore.py <<EOF
> f = open(".hgignore", "w")
> f.write("ignore\n")
> f.write("foo\n")
> # No EOL here
> f.write("bar")
> f.close()
> EOF
$ "$PYTHON" makeignore.py
Should display baz only:
$ hg status
? baz
$ rm foo bar baz .hgignore makeignore.py
$ touch a.o
$ touch a.c
$ touch syntax
$ mkdir dir
$ touch dir/a.o
$ touch dir/b.o
$ touch dir/c.o
$ hg add dir/a.o
$ hg commit -m 0
$ hg add dir/b.o
$ hg status
A dir/b.o
? a.c
? a.o
? dir/c.o
? syntax
$ echo "*.o" > .hgignore
$ hg status
abort: $TESTTMP/ignorerepo/.hgignore: invalid pattern (relre): *.o (glob)
[255]
Ensure given files are relative to cwd
$ echo "dir/.*\.o" > .hgignore
$ hg status -i
I dir/c.o
$ hg debugignore dir/c.o dir/missing.o
dir/c.o is ignored
(ignore rule in $TESTTMP/ignorerepo/.hgignore, line 1: 'dir/.*\.o') (glob)
dir/missing.o is ignored
(ignore rule in $TESTTMP/ignorerepo/.hgignore, line 1: 'dir/.*\.o') (glob)
$ cd dir
$ hg debugignore c.o missing.o
c.o is ignored
(ignore rule in $TESTTMP/ignorerepo/.hgignore, line 1: 'dir/.*\.o') (glob)
missing.o is ignored
(ignore rule in $TESTTMP/ignorerepo/.hgignore, line 1: 'dir/.*\.o') (glob)
For icasefs, inexact matches also work, except for missing files
#if icasefs
$ hg debugignore c.O missing.O
c.o is ignored
(ignore rule in $TESTTMP/ignorerepo/.hgignore, line 1: 'dir/.*\.o') (glob)
missing.O is not ignored
#endif
$ cd ..
$ echo ".*\.o" > .hgignore
$ hg status
A dir/b.o
? .hgignore
? a.c
? syntax
Ensure that comments work:
$ touch 'foo#bar' 'quux#' 'quu0#'
#if no-windows
$ touch 'baz\' 'baz\wat' 'ba0\#wat' 'ba1\\' 'ba1\\wat' 'quu0\'
#endif
$ cat <<'EOF' >> .hgignore
> # full-line comment
> # whitespace-only comment line
> syntax# pattern, no whitespace, then comment
> a.c # pattern, then whitespace, then comment
> baz\\# # (escaped) backslash, then comment
> ba0\\\#w # (escaped) backslash, escaped comment character, then comment
> ba1\\\\# # (escaped) backslashes, then comment
> foo\#b # escaped comment character
> quux\## escaped comment character at end of name
> EOF
$ hg status
A dir/b.o
? .hgignore
? quu0#
? quu0\ (no-windows !)
$ cat <<'EOF' > .hgignore
> .*\.o
> syntax: glob
> syntax# pattern, no whitespace, then comment
> a.c # pattern, then whitespace, then comment
> baz\\#* # (escaped) backslash, then comment
> ba0\\\#w* # (escaped) backslash, escaped comment character, then comment
> ba1\\\\#* # (escaped) backslashes, then comment
> foo\#b* # escaped comment character
> quux\## escaped comment character at end of name
> quu0[\#]# escaped comment character inside [...]
> EOF
$ hg status
A dir/b.o
? .hgignore
? ba1\\wat (no-windows !)
? baz\wat (no-windows !)
? quu0\ (no-windows !)
$ rm 'foo#bar' 'quux#' 'quu0#'
#if no-windows
$ rm 'baz\' 'baz\wat' 'ba0\#wat' 'ba1\\' 'ba1\\wat' 'quu0\'
#endif
Check that '^\.' does not ignore the root directory:
$ echo "^\." > .hgignore
$ hg status
A dir/b.o
? a.c
? a.o
? dir/c.o
? syntax
Test that patterns from ui.ignore options are read:
$ echo > .hgignore
$ cat >> $HGRCPATH << EOF
> [ui]
> ignore.other = $TESTTMP/ignorerepo/.hg/testhgignore
> EOF
$ echo "glob:**.o" > .hg/testhgignore
$ hg status
A dir/b.o
? .hgignore
? a.c
? syntax
empty out testhgignore
$ echo > .hg/testhgignore
Test relative ignore path (issue4473):
$ cat >> $HGRCPATH << EOF
> [ui]
> ignore.relative = .hg/testhgignorerel
> EOF
$ echo "glob:*.o" > .hg/testhgignorerel
$ cd dir
$ hg status
A dir/b.o
? .hgignore
? a.c
? syntax
$ hg debugignore
<includematcher includes='.*\\.o(?:/|$)'>
$ cd ..
$ echo > .hg/testhgignorerel
$ echo "syntax: glob" > .hgignore
$ echo "re:.*\.o" >> .hgignore
$ hg status
A dir/b.o
? .hgignore
? a.c
? syntax
$ echo "syntax: invalid" > .hgignore
$ hg status
$TESTTMP/ignorerepo/.hgignore: ignoring invalid syntax 'invalid'
A dir/b.o
? .hgignore
? a.c
? a.o
? dir/c.o
? syntax
$ echo "syntax: glob" > .hgignore
$ echo "*.o" >> .hgignore
$ hg status
A dir/b.o
? .hgignore
? a.c
? syntax
$ echo "relglob:syntax*" > .hgignore
$ hg status
A dir/b.o
? .hgignore
? a.c
? a.o
? dir/c.o
$ echo "relglob:*" > .hgignore
$ hg status
A dir/b.o
$ cd dir
$ hg status .
A b.o
$ hg debugignore
<includematcher includes='.*(?:/|$)'>
$ hg debugignore b.o
b.o is ignored
(ignore rule in $TESTTMP/ignorerepo/.hgignore, line 1: '*') (glob)
$ cd ..
Check patterns that match only the directory
"(fsmonitor !)" below assumes that fsmonitor is enabled with
"walk_on_invalidate = false" (default), which doesn't involve
re-walking whole repository at detection of .hgignore change.
$ echo "^dir\$" > .hgignore
$ hg status
A dir/b.o
? .hgignore
? a.c
? a.o
? dir/c.o (fsmonitor !)
? syntax
Check recursive glob pattern matches no directories (dir/**/c.o matches dir/c.o)
$ echo "syntax: glob" > .hgignore
$ echo "dir/**/c.o" >> .hgignore
$ touch dir/c.o
$ mkdir dir/subdir
$ touch dir/subdir/c.o
$ hg status
A dir/b.o
? .hgignore
? a.c
? a.o
? syntax
$ hg debugignore a.c
a.c is not ignored
$ hg debugignore dir/c.o
dir/c.o is ignored
(ignore rule in $TESTTMP/ignorerepo/.hgignore, line 2: 'dir/**/c.o') (glob)
Check rooted globs
$ hg purge --all --config extensions.purge=
$ echo "syntax: rootglob" > .hgignore
$ echo "a/*.ext" >> .hgignore
$ for p in a b/a aa; do mkdir -p $p; touch $p/b.ext; done
$ hg status -A 'set:**.ext'
? aa/b.ext
? b/a/b.ext
I a/b.ext
Check using 'include:' in ignore file
$ hg purge --all --config extensions.purge=
$ touch foo.included
$ echo ".*.included" > otherignore
$ hg status -I "include:otherignore"
? foo.included
$ echo "include:otherignore" >> .hgignore
$ hg status
A dir/b.o
? .hgignore
? otherignore
Check recursive uses of 'include:'
$ echo "include:nested/ignore" >> otherignore
$ mkdir nested nested/more
$ echo "glob:*ignore" > nested/ignore
$ echo "rootglob:a" >> nested/ignore
$ touch a nested/a nested/more/a
$ hg status
A dir/b.o
? nested/a
? nested/more/a
$ rm a nested/a nested/more/a
$ cp otherignore goodignore
$ echo "include:badignore" >> otherignore
$ hg status
skipping unreadable pattern file 'badignore': $ENOENT$
A dir/b.o
$ mv goodignore otherignore
Check using 'include:' while in a non-root directory
$ cd ..
$ hg -R ignorerepo status
A dir/b.o
$ cd ignorerepo
Check including subincludes
$ hg revert -q --all
$ hg purge --all --config extensions.purge=
$ echo ".hgignore" > .hgignore
$ mkdir dir1 dir2
$ touch dir1/file1 dir1/file2 dir2/file1 dir2/file2
$ echo "subinclude:dir2/.hgignore" >> .hgignore
$ echo "glob:file*2" > dir2/.hgignore
$ hg status
? dir1/file1
? dir1/file2
? dir2/file1
Check including subincludes with other patterns
$ echo "subinclude:dir1/.hgignore" >> .hgignore
$ mkdir dir1/subdir
$ touch dir1/subdir/file1
$ echo "rootglob:f?le1" > dir1/.hgignore
$ hg status
? dir1/file2
? dir1/subdir/file1
? dir2/file1
$ rm dir1/subdir/file1
$ echo "regexp:f.le1" > dir1/.hgignore
$ hg status
? dir1/file2
? dir2/file1
Check multiple levels of sub-ignores
$ touch dir1/subdir/subfile1 dir1/subdir/subfile3 dir1/subdir/subfile4
$ echo "subinclude:subdir/.hgignore" >> dir1/.hgignore
$ echo "glob:subfil*3" >> dir1/subdir/.hgignore
$ hg status
? dir1/file2
? dir1/subdir/subfile4
? dir2/file1
Check include subignore at the same level
$ mv dir1/subdir/.hgignore dir1/.hgignoretwo
$ echo "regexp:f.le1" > dir1/.hgignore
$ echo "subinclude:.hgignoretwo" >> dir1/.hgignore
$ echo "glob:file*2" > dir1/.hgignoretwo
$ hg status | grep file2
[1]
$ hg debugignore dir1/file2
dir1/file2 is ignored
(ignore rule in dir2/.hgignore, line 1: 'file*2')
#if windows
Windows paths are accepted on input
$ rm dir1/.hgignore
$ echo "dir1/file*" >> .hgignore
$ hg debugignore "dir1\file2"
dir1/file2 is ignored
(ignore rule in $TESTTMP\ignorerepo\.hgignore, line 4: 'dir1/file*')
$ hg up -qC .
#endif
#if dirstate-v2
Check the hash of ignore patterns written in the dirstate
$ hg status > /dev/null
$ cat .hg/testhgignore .hg/testhgignorerel .hgignore dir2/.hgignore dir1/.hgignore dir1/.hgignoretwo | $TESTDIR/f --sha1
sha1=6e315b60f15fb5dfa02be00f3e2c8f923051f5ff
$ hg debugdirstateignorepatternshash
6e315b60f15fb5dfa02be00f3e2c8f923051f5ff
$ echo rel > .hg/testhgignorerel
$ hg status > /dev/null
$ cat .hg/testhgignore .hg/testhgignorerel .hgignore dir2/.hgignore dir1/.hgignore dir1/.hgignoretwo | $TESTDIR/f --sha1
sha1=dea19cc7119213f24b6b582a4bae7b0cb063e34e
$ hg debugdirstateignorepatternshash
dea19cc7119213f24b6b582a4bae7b0cb063e34e
#endif