tests/test-contrib-check-code.t

nodemap: introduce an option to use mmap to read the nodemap mapping

The performance and memory benefit is much greater if we don't have to copy all
the data in memory for each information. So we introduce an option (on by
default) to read the data using mmap.

This changeset is the last one definition the API for index support nodemap
data. (they have to be able to use the mmaping).

Below are some benchmark comparing the best we currently have in 5.3 with the
final step of this series (using the persistent nodemap implementation in
Rust). The benchmark run `hg perfindex` with various revset and the following
variants:

Before:

 * do not use the persistent nodemap
 * use the CPython implementation of the index for nodemap
 * use mmapping of the changelog index

After:

 * use the MixedIndex Rust code, with the NodeTree object for nodemap access
   (still in review)
 * use the persistent nodemap data from disk
 * access the persistent nodemap data through mmap
 * use mmapping of the changelog index

The persistent nodemap greatly speed up  most operation on very large
repositories. Some of the previously very fast lookup end up a bit slower because
the persistent nodemap has to be setup. However the absolute slowdown is very
small and won't matters in the big picture.

Here are some numbers (in seconds) for the reference copy of mozilla-try:

Revset            Before   After     abs-change speedup

-10000:           0.004622 0.005532   0.000910  ×   0.83
-10:              0.000050 0.000132   0.000082  ×   0.37
tip               0.000052 0.000085   0.000033  ×   0.61
0 + (-10000:)     0.028222 0.005337  -0.022885  ×   5.29
0                 0.023521 0.000084  -0.023437  × 280.01
(-10000:) + 0     0.235539 0.005308  -0.230231  ×  44.37
(-10:) + :9       0.232883 0.000180  -0.232703  ×1293.79
(-10000:) + (:99) 0.238735 0.005358  -0.233377  ×  44.55
:99 + (-10000:)   0.317942 0.005593  -0.312349  ×  56.84
:9 + (-10:)       0.313372 0.000179  -0.313193  ×1750.68
:9                0.316450 0.000143  -0.316307  ×2212.93


On smaller repositories, the cost of nodemap related operation is not as big, so
the win is much more modest. Yet it helps shaving a handful of millisecond here
and there.

Here are some numbers (in seconds) for the reference copy of mercurial:

Revset            Before   After     abs-change speedup
-10:              0.000065 0.000097   0.000032  × 0.67
tip               0.000063 0.000078   0.000015  × 0.80
0                 0.000561 0.000079  -0.000482  × 7.10
-10000:           0.004609 0.003648  -0.000961  × 1.26
0 + (-10000:)     0.005023 0.003715  -0.001307  × 1.35
(-10:) + :9       0.002187 0.000108  -0.002079  ×20.25
(-10000:) + 0     0.006252 0.003716  -0.002536  × 1.68
(-10000:) + (:99) 0.006367 0.003707  -0.002660  × 1.71
:9 + (-10:)       0.003846 0.000110  -0.003736  ×34.96
:9                0.003854 0.000099  -0.003755  ×38.92
:99 + (-10000:)   0.007644 0.003778  -0.003866  × 2.02

Differential Revision: https://phab.mercurial-scm.org/D7894

  $ cat > correct.py <<NO_CHECK_EOF
  > def toto(arg1, arg2):
  >     del arg2
  >     return (5 + 6, 9)
  > NO_CHECK_EOF
  $ cat > wrong.py <<NO_CHECK_EOF
  > def toto( arg1, arg2):
  >     del(arg2)
  >     return ( 5+6, 9)
  > def badwrap():
  >     return 1 + \\
  >        2
  > NO_CHECK_EOF
  $ cat > quote.py <<NO_CHECK_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"
  > NO_CHECK_EOF
  $ cat > classstyle.py <<NO_CHECK_EOF
  > class newstyle_class(object):
  >     pass
  > 
  > class oldstyle_class:
  >     pass
  > 
  > class empty():
  >     pass
  > 
  > no_class = 1:
  >     pass
  > NO_CHECK_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
  ./wrong.py:5:
   >     return 1 + \
   Use () to wrap long lines in Python, not \
  ./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 << NO_CHECK_EOF
  > foo <> bar
  > reduce(lambda a, b: a + b, [1, 2, 3, 4])
  > dict(key=value)
  > NO_CHECK_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 <<NO_CHECK_EOF
  > void narf() {
  > 	strcpy(foo, bar);
  > 	// strcpy_s is okay, but this comment is not
  > 	strcpy_s(foo, bar);
  > }
  > NO_CHECK_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 <<NO_CHECK_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
  > NO_CHECK_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 <<NO_CHECK_EOF
  > except:
  > NO_CHECK_EOF
  $ "$check_code" for-nolineno.py --nolineno
  for-nolineno.py:0:
   > except:
   naked except clause
  [1]

  $ cat > warning.t <<NO_CHECK_EOF
  >   $ function warnonly {
  >   > }
  >   $ diff -N aaa
  >   $ function onwarn {}
  > NO_CHECK_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 <<NO_CHECK_EOF
  >   $ [ foo == bar ]
  > NO_CHECK_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 <<NO_CHECK_EOF
  > raise SomeException, message
  > # this next line is okay
  > raise SomeException(arg1, arg2)
  > NO_CHECK_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 <<NO_CHECK_EOF > tab.t
  > 	indent
  >   > 	heredoc
  > NO_CHECK_EOF
  $ "$check_code" tab.t
  tab.t:1:
   > 	indent
   don't use tabs to indent
  [1]
  $ rm tab.t

  $ cat > rst.py <<NO_CHECK_EOF
  > """problematic rst text
  > 
  > .. note::
  >     wrong
  > """
  > 
  > '''
  > 
  > .. note::
  > 
  >     valid
  > 
  > new text
  > 
  >     .. note::
  > 
  >         also valid
  > '''
  > 
  > """mixed
  > 
  > .. note::
  > 
  >   good
  > 
  >     .. note::
  >         plus bad
  > """
  > NO_CHECK_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 <<NO_CHECK_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))
  > NO_CHECK_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 <<NO_CHECK_EOF
  > {desc}
  > {desc|escape}
  > {desc|firstline}
  > {desc|websub}
  > NO_CHECK_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 <<NO_CHECK_EOF
  > foo = (' foo'
  >        'bar foo.'
  >        'bar foo:'
  >        'bar foo@'
  >        'bar foo%'
  >        'bar foo*'
  >        'bar foo+'
  >        'bar foo-'
  >        'bar')
  > NO_CHECK_EOF

'missing _() in ui message' detection

  $ cat > uigettext.py <<NO_CHECK_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")
  > NO_CHECK_EOF

superfluous pass

  $ cat > superfluous_pass.py <<NO_CHECK_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
  > NO_CHECK_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]

Check code fragments embedded in test script

  $ cat > embedded-code.t <<NO_CHECK_EOF
  > code fragment in doctest style
  >   >>> x = (1,2)
  >   ... 
  >   ... x = (1,2)
  > 
  > code fragment in heredoc style
  >   $ python <<EOF
  >   > x = (1,2)
  >   > EOF
  > 
  > code fragment in file heredoc style
  >   $ python > file.py <<EOF
  >   > x = (1,2)
  >   > EOF
  > NO_CHECK_EOF
  $ "$check_code" embedded-code.t
  embedded-code.t:2:
   > x = (1,2)
   missing whitespace after ,
  embedded-code.t:4:
   > x = (1,2)
   missing whitespace after ,
  embedded-code.t:8:
   > x = (1,2)
   missing whitespace after ,
  embedded-code.t:13:
   > x = (1,2)
   missing whitespace after ,
  [1]

"max warnings per file" is shared by all embedded code fragments

  $ "$check_code" --per-file=3 embedded-code.t
  embedded-code.t:2:
   > x = (1,2)
   missing whitespace after ,
  embedded-code.t:4:
   > x = (1,2)
   missing whitespace after ,
  embedded-code.t:8:
   > x = (1,2)
   missing whitespace after ,
   (too many errors, giving up)
  [1]