util: lower water mark when removing nodes after cost limit reached
See the inline comment for the reasoning here. This is a pretty
common strategy for garbage collectors, other cache-like primtives.
The performance impact is substantial:
$ hg perflrucachedict --size 4 --gets 1000000 --sets 1000000 --mixed 1000000 --costlimit 100
! inserts w/ cost limit
! wall 1.659181 comb 1.650000 user 1.650000 sys 0.000000 (best of 7)
! wall 1.722122 comb 1.720000 user 1.720000 sys 0.000000 (best of 6)
! mixed w/ cost limit
! wall 1.139955 comb 1.140000 user 1.140000 sys 0.000000 (best of 9)
! wall 1.182513 comb 1.180000 user 1.180000 sys 0.000000 (best of 9)
$ hg perflrucachedict --size 1000 --gets 1000000 --sets 1000000 --mixed 1000000 --costlimit 10000
! inserts
! wall 0.679546 comb 0.680000 user 0.680000 sys 0.000000 (best of 15)
! sets
! wall 0.825147 comb 0.830000 user 0.830000 sys 0.000000 (best of 13)
! inserts w/ cost limit
! wall 25.105273 comb 25.080000 user 25.080000 sys 0.000000 (best of 3)
! wall 1.724397 comb 1.720000 user 1.720000 sys 0.000000 (best of 6)
! mixed
! wall 0.807096 comb 0.810000 user 0.810000 sys 0.000000 (best of 13)
! mixed w/ cost limit
! wall 12.104470 comb 12.070000 user 12.070000 sys 0.000000 (best of 3)
! wall 1.190563 comb 1.190000 user 1.190000 sys 0.000000 (best of 9)
$ hg perflrucachedict --size 1000 --gets 1000000 --sets 1000000 --mixed 1000000 --costlimit 10000 --mixedgetfreq 90
! inserts
! wall 0.711177 comb 0.710000 user 0.710000 sys 0.000000 (best of 14)
! sets
! wall 0.846992 comb 0.850000 user 0.850000 sys 0.000000 (best of 12)
! inserts w/ cost limit
! wall 25.963028 comb 25.960000 user 25.960000 sys 0.000000 (best of 3)
! wall 2.184311 comb 2.180000 user 2.180000 sys 0.000000 (best of 5)
! mixed
! wall 0.728256 comb 0.730000 user 0.730000 sys 0.000000 (best of 14)
! mixed w/ cost limit
! wall 3.174256 comb 3.170000 user 3.170000 sys 0.000000 (best of 4)
! wall 0.773186 comb 0.770000 user 0.770000 sys 0.000000 (best of 13)
$ hg perflrucachedict --size 100000 --gets 1000000 --sets 1000000 --mixed 1000000 --mixedgetfreq 90 --costlimit 5000000
! gets
! wall 1.191368 comb 1.190000 user 1.190000 sys 0.000000 (best of 9)
! wall 1.195304 comb 1.190000 user 1.190000 sys 0.000000 (best of 9)
! inserts
! wall 0.950995 comb 0.950000 user 0.950000 sys 0.000000 (best of 11)
! inserts w/ cost limit
! wall 1.589732 comb 1.590000 user 1.590000 sys 0.000000 (best of 7)
! sets
! wall 1.094941 comb 1.100000 user 1.090000 sys 0.010000 (best of 9)
! mixed
! wall 0.936420 comb 0.940000 user 0.930000 sys 0.010000 (best of 10)
! mixed w/ cost limit
! wall 0.882780 comb 0.870000 user 0.870000 sys 0.000000 (best of 11)
This puts us ~2x slower than caches without cost accounting. And for
read-heavy workloads (the prime use cases for caches), performance is
nearly identical.
In the worst case (pure write workloads with cost accounting enabled),
we're looking at ~1.5us per insert on large caches. That seems "fast
enough."
Differential Revision: https://phab.mercurial-scm.org/D4505
$ cat > correct.py <<EOF
> def toto(arg1, arg2):
> del arg2
> return (5 + 6, 9)
> EOF
$ cat > wrong.py <<EOF
> def toto( arg1, arg2):
> del(arg2)
> return ( 5+6, 9)
> EOF
$ cat > quote.py <<EOF
> # let's use quote in comments
> (''' ( 4x5 )
> but """\\''' and finally''',
> """let's fool checkpatch""", '1+2',
> '"""', 42+1, """and
> ( 4-1 ) """, "( 1+1 )\" and ")
> a, '\\\\\\\\', "\\\\\\" x-2", "c-1"
> EOF
$ cat > classstyle.py <<EOF
> class newstyle_class(object):
> pass
>
> class oldstyle_class:
> pass
>
> class empty():
> pass
>
> no_class = 1:
> pass
> EOF
$ check_code="$TESTDIR"/../contrib/check-code.py
$ "$check_code" ./wrong.py ./correct.py ./quote.py ./classstyle.py
./wrong.py:1:
> def toto( arg1, arg2):
gratuitous whitespace in () or []
./wrong.py:2:
> del(arg2)
Python keyword is not a function
./wrong.py:3:
> return ( 5+6, 9)
gratuitous whitespace in () or []
missing whitespace in expression
./quote.py:5:
> '"""', 42+1, """and
missing whitespace in expression
./classstyle.py:4:
> class oldstyle_class:
old-style class, use class foo(object)
./classstyle.py:7:
> class empty():
class foo() creates old style object, use class foo(object)
[1]
$ cat > python3-compat.py << EOF
> foo <> bar
> reduce(lambda a, b: a + b, [1, 2, 3, 4])
> dict(key=value)
> EOF
$ "$check_code" python3-compat.py
python3-compat.py:1:
> foo <> bar
<> operator is not available in Python 3+, use !=
python3-compat.py:2:
> reduce(lambda a, b: a + b, [1, 2, 3, 4])
reduce is not available in Python 3+
python3-compat.py:3:
> dict(key=value)
dict() is different in Py2 and 3 and is slower than {}
[1]
$ cat > foo.c <<EOF
> void narf() {
> strcpy(foo, bar);
> // strcpy_s is okay, but this comment is not
> strcpy_s(foo, bar);
> }
> EOF
$ "$check_code" ./foo.c
./foo.c:2:
> strcpy(foo, bar);
don't use strcpy, use strlcpy or memcpy
./foo.c:3:
> // strcpy_s is okay, but this comment is not
don't use //-style comments
[1]
$ cat > is-op.py <<EOF
> # is-operator comparing number or string literal
> x = None
> y = x is 'foo'
> y = x is "foo"
> y = x is 5346
> y = x is -6
> y = x is not 'foo'
> y = x is not "foo"
> y = x is not 5346
> y = x is not -6
> EOF
$ "$check_code" ./is-op.py
./is-op.py:3:
> y = x is 'foo'
object comparison with literal
./is-op.py:4:
> y = x is "foo"
object comparison with literal
./is-op.py:5:
> y = x is 5346
object comparison with literal
./is-op.py:6:
> y = x is -6
object comparison with literal
./is-op.py:7:
> y = x is not 'foo'
object comparison with literal
./is-op.py:8:
> y = x is not "foo"
object comparison with literal
./is-op.py:9:
> y = x is not 5346
object comparison with literal
./is-op.py:10:
> y = x is not -6
object comparison with literal
[1]
$ cat > for-nolineno.py <<EOF
> except:
> EOF
$ "$check_code" for-nolineno.py --nolineno
for-nolineno.py:0:
> except:
naked except clause
[1]
$ cat > warning.t <<EOF
> $ function warnonly {
> > }
> $ diff -N aaa
> $ function onwarn {}
> EOF
$ "$check_code" warning.t
$ "$check_code" --warn warning.t
warning.t:1:
> $ function warnonly {
warning: don't use 'function', use old style
warning.t:3:
> $ diff -N aaa
warning: don't use 'diff -N'
warning.t:4:
> $ function onwarn {}
warning: don't use 'function', use old style
[1]
$ cat > error.t <<EOF
> $ [ foo == bar ]
> EOF
$ "$check_code" error.t
error.t:1:
> $ [ foo == bar ]
[ foo == bar ] is a bashism, use [ foo = bar ] instead
[1]
$ rm error.t
$ cat > raise-format.py <<EOF
> raise SomeException, message
> # this next line is okay
> raise SomeException(arg1, arg2)
> EOF
$ "$check_code" not-existing.py raise-format.py
Skipping*not-existing.py* (glob)
raise-format.py:1:
> raise SomeException, message
don't use old-style two-argument raise, use Exception(message)
[1]
$ cat <<EOF > tab.t
> indent
> > heredoc
> EOF
$ "$check_code" tab.t
tab.t:1:
> indent
don't use tabs to indent
[1]
$ rm tab.t
$ cat > rst.py <<EOF
> """problematic rst text
>
> .. note::
> wrong
> """
>
> '''
>
> .. note::
>
> valid
>
> new text
>
> .. note::
>
> also valid
> '''
>
> """mixed
>
> .. note::
>
> good
>
> .. note::
> plus bad
> """
> EOF
$ $check_code -w rst.py
rst.py:3:
> .. note::
warning: add two newlines after '.. note::'
rst.py:26:
> .. note::
warning: add two newlines after '.. note::'
[1]
$ cat > ./map-inside-gettext.py <<EOF
> print(_("map inside gettext %s" % v))
>
> print(_("concatenating " " by " " space %s" % v))
> print(_("concatenating " + " by " + " '+' %s" % v))
>
> print(_("mapping operation in different line %s"
> % v))
>
> print(_(
> "leading spaces inside of '(' %s" % v))
> EOF
$ "$check_code" ./map-inside-gettext.py
./map-inside-gettext.py:1:
> print(_("map inside gettext %s" % v))
don't use % inside _()
./map-inside-gettext.py:3:
> print(_("concatenating " " by " " space %s" % v))
don't use % inside _()
./map-inside-gettext.py:4:
> print(_("concatenating " + " by " + " '+' %s" % v))
don't use % inside _()
./map-inside-gettext.py:6:
> print(_("mapping operation in different line %s"
don't use % inside _()
./map-inside-gettext.py:9:
> print(_(
don't use % inside _()
[1]
web templates
$ mkdir -p mercurial/templates
$ cat > mercurial/templates/example.tmpl <<EOF
> {desc}
> {desc|escape}
> {desc|firstline}
> {desc|websub}
> EOF
$ "$check_code" --warnings mercurial/templates/example.tmpl
mercurial/templates/example.tmpl:2:
> {desc|escape}
warning: follow desc keyword with either firstline or websub
[1]
'string join across lines with no space' detection
$ cat > stringjoin.py <<EOF
> foo = (' foo'
> 'bar foo.'
> 'bar foo:'
> 'bar foo@'
> 'bar foo%'
> 'bar foo*'
> 'bar foo+'
> 'bar foo-'
> 'bar')
> EOF
'missing _() in ui message' detection
$ cat > uigettext.py <<EOF
> ui.status("% 10s %05d % -3.2f %*s %%"
> # this use '\\\\' instead of '\\', because the latter in
> # heredoc on shell becomes just '\'
> '\\\\ \n \t \0'
> """12345
> """
> '''.:*+-=
> ''' "%-6d \n 123456 .:*+-= foobar")
> EOF
superfluous pass
$ cat > superfluous_pass.py <<EOF
> # correct examples
> if foo:
> pass
> else:
> # comment-only line means still need pass
> pass
> def nothing():
> pass
> class empty(object):
> pass
> if whatever:
> passvalue(value)
> # bad examples
> if foo:
> "foo"
> pass
> else: # trailing comment doesn't fool checker
> wat()
> pass
> def nothing():
> "docstring means no pass"
> pass
> class empty(object):
> """multiline
> docstring also
> means no pass"""
> pass
> EOF
(Checking multiple invalid files at once examines whether caching
translation table for repquote() works as expected or not. All files
should break rules depending on result of repquote(), in this case)
$ "$check_code" stringjoin.py uigettext.py superfluous_pass.py
stringjoin.py:1:
> foo = (' foo'
string join across lines with no space
stringjoin.py:2:
> 'bar foo.'
string join across lines with no space
stringjoin.py:3:
> 'bar foo:'
string join across lines with no space
stringjoin.py:4:
> 'bar foo@'
string join across lines with no space
stringjoin.py:5:
> 'bar foo%'
string join across lines with no space
stringjoin.py:6:
> 'bar foo*'
string join across lines with no space
stringjoin.py:7:
> 'bar foo+'
string join across lines with no space
stringjoin.py:8:
> 'bar foo-'
string join across lines with no space
uigettext.py:1:
> ui.status("% 10s %05d % -3.2f %*s %%"
missing _() in ui message (use () to hide false-positives)
superfluous_pass.py:14:
> if foo:
omit superfluous pass
superfluous_pass.py:17:
> else: # trailing comment doesn't fool checker
omit superfluous pass
superfluous_pass.py:20:
> def nothing():
omit superfluous pass
superfluous_pass.py:23:
> class empty(object):
omit superfluous pass
[1]