view contrib/check-code.py @ 39506:b66ea3fc3a86

sparse-revlog: set max delta chain length to on thousand

The new snapshot system used in the sparse-revlog case gave us some small size
benefit so far. However its most important property is to gracefully handle
harder limit on delta chainlength.

Long delta chain has a very detrimental impact on read (and write) performance
in revlog. Being able to shorter them provide a great boost. However, shorting
delta used to result significantly lower compression ratio. The intermediate
snapshots effectively suppress most of this effect (even all in some case).

# Effect on the test repository

The repository we use for test is not "realistic" but can still show this in
action using an unreasonably low chain limit. Limiting the chain length show a
sizeable increase but stay under control: +6% for limit=15; +15% for limit=10.
Without the snapshot system the increase is significantly bigger: +45% for
limit=15; +80% for limit=10. Even slightly larger than without delta chain
limit, the resulting size is still smaller than before we started doing
snapshots.

Here is a table for comparison. *Since the repository is not branchy, the
initial sparse-revlog version does not bring much benefit compare to the
non-sparse one):

       chain length limit |     none   |   limit=15  |   limit=10  |
    without sparse-revlog | 62 818 987 | 112 664 615 | 131 222 574 |
    without snapshot      | 74 365 490 | 108 211 410 | 133 857 764 |
    with    snapshot      | 59 230 936 |  63 002 924 |  68 415 329 |


# Effect On Real Life Repositories

The series provides significant benefits on all kind of repositories.

Using `hg debugupgraderepo -o redeltaparent --run`, we recomputed delta chain
for various repositories with different settings:
  - delta chain length: unlimited or 1000 limit
  - sparse-revlog:      enabled or disabled
  - this series:        applied or not applied

We can observe multiple types of effect:

 - On very branchy repositories:
   * The delta chain limit as low impact on the repo size.
   * Intermediate snapshot greatly reduces manifest size:
     - pypy:     -80%
     - netbeans: -95%
   * The delta chain limit is effective, without a size impact:
     - netbeans average:      613 -> 282
     - private #1 average:  1 068 -> 307

 - On more linear repository:
   * Intermediate snapshot limit the impact of delta chain limit:
     - mozilla:
         without the series: +360%
         with the series:     +25%
   * The delta chain limit provides large improvement:
     - mozilla's average chain length:
        unlimited: 15 338
        limited:      469
   * Despite the chain length limit, the manifest size is reduced:
     - mercurial: -25%
     - mozilla:   -30%

It is clear that the use of chains of intermediate snapshots provide large
benefits both in storage size and delta chains quality. We should now switch our
effort toward making sure the write performance are acceptable. Then,
`sparse-revlog` will be a suitable format for all new repository.

# Raw Statistic

  * no-sparse:   general delta repository not using sparse-revlog
  * no-snapshot: sparse-revlog repository not using this series
  * snapshot:    sparse-revlog repository using this series

mercurial

    Manifest Size:
        limit       | none        |        1000
        ------------|-------------|------------
        no-sparse   |   8 021 373 |  8 199 366
        no-snapshot |   8 103 561 |  8 259 719
        snapshot    |   6 137 116 |  6 126 433

    Manifest Chain length data
        limit       ||       none        ||       1000        ||
        value       || average |   max   || average |   max   ||
        ------------||---------|---------||---------|---------||
        no-sparse   ||     307 |    1456 ||     279 |    1000 ||
        no-snapshot ||     312 |    1456 ||     283 |    1000 ||
        snapshot    ||     248 |    1208 ||     241 |    1000 ||

    Full Store Size
        limit       | none        |        1000
        ------------|-------------|------------
        no-sparse   |  51 013 198 | 51 201 574
        no-snapshot |  50 930 795 | 51 141 006
        snapshot    |  48 072 037 | 48 093 572

pypy

    Manifest Size:
        limit       | none        |        1000
        ------------|-------------|------------
        no-sparse   | 193 987 784 | 193 987 784
        no-snapshot | 163 171 745 | 163 312 229
        snapshot    |  34 605 900 |  34 600 750

    Manifest Chain length data
        limit       ||       none        ||       1000        ||
        value       || average |   max   || average |   max   ||
        ------------||---------|---------||---------|---------||
        no-sparse   ||     101 |     692 ||     101 |     692 ||
        no-snapshot ||     151 |    1307 ||     148 |    1000 ||
        snapshot    ||     128 |    1309 ||     125 |    1000 ||

    Full Store Size
        limit       | none        |        1000
        ------------|-------------|------------
        no-sparse   | 495 931 473 | 495 931 473
        no-snapshot | 465 441 017 | 465 581 501
        snapshot    | 355 467 301 | 355 472 451

Mozilla

    Manifest Size:
        limit       | none           |        1000
        ------------|----------------|---------------
        no-sparse   |    416 757 148 |  1 869 009 668
        no-snapshot |    401 592 370 |  1 843 493 795
        snapshot    |    224 359 521 |    284 615 500

    Manifest Chain length data
        limit       ||       none        ||       1000        ||
        value       || average |   max   || average |   max   ||
        ------------||---------|---------||---------|---------||
        no-sparse   ||  15 333 |  58 980 ||     468 |   1 000 ||
        no-snapshot ||  15 336 |  58 980 ||     469 |   1 000 ||
        snapshot    ||  15 338 |  58 983 ||     469 |   1 000 ||

    Full Store Size
        limit       | none           |        1000
        ------------|----------------|---------------
        no-sparse   |  2 712 477 887 | 4 164 995 451
        no-snapshot |  2 698 887 835 | 4 141 054 304
        snapshot    |  2 518 130 385 | 2 578 587 596

Netbeans

    Manifest Size:
        limit       | none           |        1000
        ------------|----------------|---------------
        no-sparse   |  4 766 794 101 |  4 870 642 687
        no-snapshot |  4 334 806 082 |  4 428 681 309
        snapshot    |    232 659 666 |    240 330 665

    Manifest Chain length data
        limit       ||       none        ||       1000        ||
        value       || average |   max   || average |   max   ||
        ------------||---------|---------||---------|---------||
        no-sparse   ||     597 |   6802  ||     254 |   1 000 ||
        no-snapshot ||     648 |   6 802 ||     305 |   1 000 ||
        snapshot    ||     613 |   6 804 ||     282 |   1 000 ||

    Full Store Size
        limit       | none           |        1000
        ------------|----------------|---------------
        no-sparse   |  5 807 347 998 |  5 911 196 584
        no-snapshot |  5 375 398 602 |  5 469 273 829
        snapshot    |  1 282 519 928 |  1 290 190 927

Private repo #1

    Manifest Size:
        limit       | none            |        1000
        ------------|-----------------|---------------
        no-sparse   | 41 389 010 840  | 41 398 162 091
        no-snapshot |  9 737 319 435  | 10 223 773 150
        snapshot    |    744 215 807  |    747 961 822

    Manifest Chain length data
        limit       ||       none        ||       1000        ||
        value       || average |   max   || average |   max   ||
        ------------||---------|---------||---------|---------||
        no-sparse   ||     245 |   8 885 ||     81  |   1 000 ||
        no-snapshot ||   1 225 |   8 885 ||    336  |   1 000 ||
        snapshot    ||   1 068 |   7 909 ||    307  |   1 000 ||

    Full Store Size
        limit       | none           |        1000
        ------------|----------------|---------------
        no-sparse   | 49 646 065 126 | 49 655 216 377
        no-snapshot | 17 924 862 856 | 18 411 316 571
        snapshot    |  9 009 024 710 |  9 012 770 725

Private repo #2

  We currently have less data available for that repository.
    * Before is a sparse-revlog repository without this series
    * After is a sparse-revlog repository with this series + 1000 chain limit


  Manifest Size:
    Before: 1 531 485 040 bytes
    After:  1 091 422 451 bytes
  Manifest Chain:
    Before: 2 218 avg; 6 575 Max
    After:    442 avg; 1 000 Max

  Full Store Size
    Before: 15 203 955 615
    after:   8 207 180 693

#!/usr/bin/env python
#
# check-code - a style and portability checker for Mercurial
#
# Copyright 2010 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

"""style and portability checker for Mercurial

when a rule triggers wrong, do one of the following (prefer one from top):
 * do the work-around the rule suggests
 * doublecheck that it is a false match
 * improve the rule pattern
 * add an ignore pattern to the rule (3rd arg) which matches your good line
   (you can append a short comment and match this, like: #re-raises)
 * change the pattern to a warning and list the exception in test-check-code-hg
 * ONLY use no--check-code for skipping entire files from external sources
"""

from __future__ import absolute_import, print_function
import glob
import keyword
import optparse
import os
import re
import sys
if sys.version_info[0] < 3:
    opentext = open
else:
    def opentext(f):
        return open(f, encoding='latin1')
try:
    xrange
except NameError:
    xrange = range
try:
    import re2
except ImportError:
    re2 = None

def compilere(pat, multiline=False):
    if multiline:
        pat = '(?m)' + pat
    if re2:
        try:
            return re2.compile(pat)
        except re2.error:
            pass
    return re.compile(pat)

# check "rules depending on implementation of repquote()" in each
# patterns (especially pypats), before changing around repquote()
_repquotefixedmap = {' ': ' ', '\n': '\n', '.': 'p', ':': 'q',
                     '%': '%', '\\': 'b', '*': 'A', '+': 'P', '-': 'M'}
def _repquoteencodechr(i):
    if i > 255:
        return 'u'
    c = chr(i)
    if c in _repquotefixedmap:
        return _repquotefixedmap[c]
    if c.isalpha():
        return 'x'
    if c.isdigit():
        return 'n'
    return 'o'
_repquotett = ''.join(_repquoteencodechr(i) for i in xrange(256))

def repquote(m):
    t = m.group('text')
    t = t.translate(_repquotett)
    return m.group('quote') + t + m.group('quote')

def reppython(m):
    comment = m.group('comment')
    if comment:
        l = len(comment.rstrip())
        return "#" * l + comment[l:]
    return repquote(m)

def repcomment(m):
    return m.group(1) + "#" * len(m.group(2))

def repccomment(m):
    t = re.sub(r"((?<=\n) )|\S", "x", m.group(2))
    return m.group(1) + t + "*/"

def repcallspaces(m):
    t = re.sub(r"\n\s+", "\n", m.group(2))
    return m.group(1) + t

def repinclude(m):
    return m.group(1) + "<foo>"

def rephere(m):
    t = re.sub(r"\S", "x", m.group(2))
    return m.group(1) + t


testpats = [
  [
    (r'\b(push|pop)d\b', "don't use 'pushd' or 'popd', use 'cd'"),
    (r'\W\$?\(\([^\)\n]*\)\)', "don't use (()) or $(()), use 'expr'"),
    (r'grep.*-q', "don't use 'grep -q', redirect to /dev/null"),
    (r'(?<!hg )grep.* -a', "don't use 'grep -a', use in-line python"),
    (r'sed.*-i', "don't use 'sed -i', use a temporary file"),
    (r'\becho\b.*\\n', "don't use 'echo \\n', use printf"),
    (r'echo -n', "don't use 'echo -n', use printf"),
    (r'(^|\|\s*)\bwc\b[^|]*$\n(?!.*\(re\))', "filter wc output"),
    (r'head -c', "don't use 'head -c', use 'dd'"),
    (r'tail -n', "don't use the '-n' option to tail, just use '-<num>'"),
    (r'sha1sum', "don't use sha1sum, use $TESTDIR/md5sum.py"),
    (r'\bls\b.*-\w*R', "don't use 'ls -R', use 'find'"),
    (r'printf.*[^\\]\\([1-9]|0\d)', r"don't use 'printf \NNN', use Python"),
    (r'printf.*[^\\]\\x', "don't use printf \\x, use Python"),
    (r'\$\(.*\)', "don't use $(expr), use `expr`"),
    (r'rm -rf \*', "don't use naked rm -rf, target a directory"),
    (r'\[[^\]]+==', '[ foo == bar ] is a bashism, use [ foo = bar ] instead'),
    (r'(^|\|\s*)grep (-\w\s+)*[^|]*[(|]\w',
     "use egrep for extended grep syntax"),
    (r'(^|\|\s*)e?grep .*\\S', "don't use \\S in regular expression"),
    (r'(?<!!)/bin/', "don't use explicit paths for tools"),
    (r'#!.*/bash', "don't use bash in shebang, use sh"),
    (r'[^\n]\Z', "no trailing newline"),
    (r'export .*=', "don't export and assign at once"),
    (r'^source\b', "don't use 'source', use '.'"),
    (r'touch -d', "don't use 'touch -d', use 'touch -t' instead"),
    (r'\bls +[^|\n-]+ +-', "options to 'ls' must come before filenames"),
    (r'[^>\n]>\s*\$HGRCPATH', "don't overwrite $HGRCPATH, append to it"),
    (r'^stop\(\)', "don't use 'stop' as a shell function name"),
    (r'(\[|\btest\b).*-e ', "don't use 'test -e', use 'test -f'"),
    (r'\[\[\s+[^\]]*\]\]', "don't use '[[ ]]', use '[ ]'"),
    (r'^alias\b.*=', "don't use alias, use a function"),
    (r'if\s*!', "don't use '!' to negate exit status"),
    (r'/dev/u?random', "don't use entropy, use /dev/zero"),
    (r'do\s*true;\s*done', "don't use true as loop body, use sleep 0"),
    (r'sed (-e )?\'(\d+|/[^/]*/)i(?!\\\n)',
     "put a backslash-escaped newline after sed 'i' command"),
    (r'^diff *-\w*[uU].*$\n(^  \$ |^$)', "prefix diff -u/-U with cmp"),
    (r'^\s+(if)? diff *-\w*[uU]', "prefix diff -u/-U with cmp"),
    (r'[\s="`\']python\s(?!bindings)', "don't use 'python', use '$PYTHON'"),
    (r'seq ', "don't use 'seq', use $TESTDIR/seq.py"),
    (r'\butil\.Abort\b', "directly use error.Abort"),
    (r'\|&', "don't use |&, use 2>&1"),
    (r'\w =  +\w', "only one space after = allowed"),
    (r'\bsed\b.*[^\\]\\n', "don't use 'sed ... \\n', use a \\ and a newline"),
    (r'env.*-u', "don't use 'env -u VAR', use 'unset VAR'"),
    (r'cp.* -r ', "don't use 'cp -r', use 'cp -R'"),
    (r'grep.* -[ABC]', "don't use grep's context flags"),
    (r'find.*-printf',
     "don't use 'find -printf', it doesn't exist on BSD find(1)"),
    (r'\$RANDOM ', "don't use bash-only $RANDOM to generate random values"),
  ],
  # warnings
  [
    (r'^function', "don't use 'function', use old style"),
    (r'^diff.*-\w*N', "don't use 'diff -N'"),
    (r'\$PWD|\${PWD}', "don't use $PWD, use `pwd`"),
    (r'^([^"\'\n]|("[^"\n]*")|(\'[^\'\n]*\'))*\^', "^ must be quoted"),
    (r'kill (`|\$\()', "don't use kill, use killdaemons.py")
  ]
]

testfilters = [
    (r"( *)(#([^!][^\n]*\S)?)", repcomment),
    (r"<<(\S+)((.|\n)*?\n\1)", rephere),
]

uprefix = r"^  \$ "
utestpats = [
  [
    (r'^(\S.*||  [$>] \S.*)[ \t]\n', "trailing whitespace on non-output"),
    (uprefix + r'.*\|\s*sed[^|>\n]*\n',
     "use regex test output patterns instead of sed"),
    (uprefix + r'(true|exit 0)', "explicit zero exit unnecessary"),
    (uprefix + r'.*(?<!\[)\$\?', "explicit exit code checks unnecessary"),
    (uprefix + r'.*\|\| echo.*(fail|error)',
     "explicit exit code checks unnecessary"),
    (uprefix + r'set -e', "don't use set -e"),
    (uprefix + r'(\s|fi\b|done\b)', "use > for continued lines"),
    (uprefix + r'.*:\.\S*/', "x:.y in a path does not work on msys, rewrite "
     "as x://.y, or see `hg log -k msys` for alternatives", r'-\S+:\.|' #-Rxxx
     '# no-msys'), # in test-pull.t which is skipped on windows
    (r'^  [^$>].*27\.0\.0\.1',
     'use $LOCALIP not an explicit loopback address'),
    (r'^  (?![>$] ).*\$LOCALIP.*[^)]$',
     'mark $LOCALIP output lines with (glob) to help tests in BSD jails'),
    (r'^  (cat|find): .*: \$ENOENT\$',
     'use test -f to test for file existence'),
    (r'^  diff -[^ -]*p',
     "don't use (external) diff with -p for portability"),
    (r' readlink ', 'use readlink.py instead of readlink'),
    (r'^  [-+][-+][-+] .* [-+]0000 \(glob\)',
     "glob timezone field in diff output for portability"),
    (r'^  @@ -[0-9]+ [+][0-9]+,[0-9]+ @@',
     "use '@@ -N* +N,n @@ (glob)' style chunk header for portability"),
    (r'^  @@ -[0-9]+,[0-9]+ [+][0-9]+ @@',
     "use '@@ -N,n +N* @@ (glob)' style chunk header for portability"),
    (r'^  @@ -[0-9]+ [+][0-9]+ @@',
     "use '@@ -N* +N* @@ (glob)' style chunk header for portability"),
    (uprefix + r'hg( +-[^ ]+( +[^ ]+)?)* +extdiff'
     r'( +(-[^ po-]+|--(?!program|option)[^ ]+|[^-][^ ]*))*$',
     "use $RUNTESTDIR/pdiff via extdiff (or -o/-p for false-positives)"),
  ],
  # warnings
  [
    (r'^  (?!.*\$LOCALIP)[^*?/\n]* \(glob\)$',
     "glob match with no glob string (?, *, /, and $LOCALIP)"),
  ]
]

# transform plain test rules to unified test's
for i in [0, 1]:
    for tp in testpats[i]:
        p = tp[0]
        m = tp[1]
        if p.startswith(r'^'):
            p = r"^  [$>] (%s)" % p[1:]
        else:
            p = r"^  [$>] .*(%s)" % p
        utestpats[i].append((p, m) + tp[2:])

# don't transform the following rules:
# "  > \t" and "  \t" should be allowed in unified tests
testpats[0].append((r'^( *)\t', "don't use tabs to indent"))
utestpats[0].append((r'^( ?)\t', "don't use tabs to indent"))

utestfilters = [
    (r"<<(\S+)((.|\n)*?\n  > \1)", rephere),
    (r"( +)(#([^!][^\n]*\S)?)", repcomment),
]

pypats = [
  [
    (r'^\s*def\s*\w+\s*\(.*,\s*\(',
     "tuple parameter unpacking not available in Python 3+"),
    (r'lambda\s*\(.*,.*\)',
     "tuple parameter unpacking not available in Python 3+"),
    (r'(?<!def)\s+(cmp)\(', "cmp is not available in Python 3+"),
    (r'(?<!\.)\breduce\s*\(.*', "reduce is not available in Python 3+"),
    (r'\bdict\(.*=', 'dict() is different in Py2 and 3 and is slower than {}',
     'dict-from-generator'),
    (r'\.has_key\b', "dict.has_key is not available in Python 3+"),
    (r'\s<>\s', '<> operator is not available in Python 3+, use !='),
    (r'^\s*\t', "don't use tabs"),
    (r'\S;\s*\n', "semicolon"),
    (r'[^_]_\([ \t\n]*(?:"[^"]+"[ \t\n+]*)+%', "don't use % inside _()"),
    (r"[^_]_\([ \t\n]*(?:'[^']+'[ \t\n+]*)+%", "don't use % inside _()"),
    (r'(\w|\)),\w', "missing whitespace after ,"),
    (r'(\w|\))[+/*\-<>]\w', "missing whitespace in expression"),
    (r'^\s+(\w|\.)+=\w[^,()\n]*$', "missing whitespace in assignment"),
    (r'\w\s=\s\s+\w', "gratuitous whitespace after ="),
    ((
        # a line ending with a colon, potentially with trailing comments
        r':([ \t]*#[^\n]*)?\n'
        # one that is not a pass and not only a comment
        r'(?P<indent>[ \t]+)[^#][^\n]+\n'
        # more lines at the same indent level
        r'((?P=indent)[^\n]+\n)*'
        # a pass at the same indent level, which is bogus
        r'(?P=indent)pass[ \t\n#]'
      ), 'omit superfluous pass'),
    (r'.{81}', "line too long"),
    (r'[^\n]\Z', "no trailing newline"),
    (r'(\S[ \t]+|^[ \t]+)\n', "trailing whitespace"),
#    (r'^\s+[^_ \n][^_. \n]+_[^_\n]+\s*=',
#     "don't use underbars in identifiers"),
    (r'^\s+(self\.)?[A-Za-z][a-z0-9]+[A-Z]\w* = ',
     "don't use camelcase in identifiers", r'#.*camelcase-required'),
    (r'^\s*(if|while|def|class|except|try)\s[^[\n]*:\s*[^\\n]#\s]+',
     "linebreak after :"),
    (r'class\s[^( \n]+:', "old-style class, use class foo(object)",
     r'#.*old-style'),
    (r'class\s[^( \n]+\(\):',
     "class foo() creates old style object, use class foo(object)",
     r'#.*old-style'),
    (r'\b(%s)\(' % '|'.join(k for k in keyword.kwlist
                            if k not in ('print', 'exec')),
     "Python keyword is not a function"),
    (r',]', "unneeded trailing ',' in list"),
#    (r'class\s[A-Z][^\(]*\((?!Exception)',
#     "don't capitalize non-exception classes"),
#    (r'in range\(', "use xrange"),
#    (r'^\s*print\s+', "avoid using print in core and extensions"),
    (r'[\x80-\xff]', "non-ASCII character literal"),
    (r'("\')\.format\(', "str.format() has no bytes counterpart, use %"),
    (r'^\s*(%s)\s\s' % '|'.join(keyword.kwlist),
     "gratuitous whitespace after Python keyword"),
    (r'([\(\[][ \t]\S)|(\S[ \t][\)\]])', "gratuitous whitespace in () or []"),
#    (r'\s\s=', "gratuitous whitespace before ="),
    (r'[^>< ](\+=|-=|!=|<>|<=|>=|<<=|>>=|%=)\S',
     "missing whitespace around operator"),
    (r'[^>< ](\+=|-=|!=|<>|<=|>=|<<=|>>=|%=)\s',
     "missing whitespace around operator"),
    (r'\s(\+=|-=|!=|<>|<=|>=|<<=|>>=|%=)\S',
     "missing whitespace around operator"),
    (r'[^^+=*/!<>&| %-](\s=|=\s)[^= ]',
     "wrong whitespace around ="),
    (r'\([^()]*( =[^=]|[^<>!=]= )',
     "no whitespace around = for named parameters"),
    (r'raise Exception', "don't raise generic exceptions"),
    (r'raise [^,(]+, (\([^\)]+\)|[^,\(\)]+)$',
     "don't use old-style two-argument raise, use Exception(message)"),
    (r' is\s+(not\s+)?["\'0-9-]', "object comparison with literal"),
    (r' [=!]=\s+(True|False|None)',
     "comparison with singleton, use 'is' or 'is not' instead"),
    (r'^\s*(while|if) [01]:',
     "use True/False for constant Boolean expression"),
    (r'^\s*if False(:| +and)', 'Remove code instead of using `if False`'),
    (r'(?:(?<!def)\s+|\()hasattr\(',
     'hasattr(foo, bar) is broken on py2, use util.safehasattr(foo, bar) '
     'instead', r'#.*hasattr-py3-only'),
    (r'opener\([^)]*\).read\(',
     "use opener.read() instead"),
    (r'opener\([^)]*\).write\(',
     "use opener.write() instead"),
    (r'[\s\(](open|file)\([^)]*\)\.read\(',
     "use util.readfile() instead"),
    (r'[\s\(](open|file)\([^)]*\)\.write\(',
     "use util.writefile() instead"),
    (r'^[\s\(]*(open(er)?|file)\([^)]*\)(?!\.close\(\))',
     "always assign an opened file to a variable, and close it afterwards"),
    (r'[\s\(](open|file)\([^)]*\)\.(?!close\(\))',
     "always assign an opened file to a variable, and close it afterwards"),
    (r'(?i)descend[e]nt', "the proper spelling is descendAnt"),
    (r'\.debug\(\_', "don't mark debug messages for translation"),
    (r'\.strip\(\)\.split\(\)', "no need to strip before splitting"),
    (r'^\s*except\s*:', "naked except clause", r'#.*re-raises'),
    (r'^\s*except\s([^\(,]+|\([^\)]+\))\s*,',
     'legacy exception syntax; use "as" instead of ","'),
    (r':\n(    )*( ){1,3}[^ ]', "must indent 4 spaces"),
    (r'release\(.*wlock, .*lock\)', "wrong lock release order"),
    (r'\bdef\s+__bool__\b', "__bool__ should be __nonzero__ in Python 2"),
    (r'os\.path\.join\(.*, *(""|\'\')\)',
     "use pathutil.normasprefix(path) instead of os.path.join(path, '')"),
    (r'\s0[0-7]+\b', 'legacy octal syntax; use "0o" prefix instead of "0"'),
    # XXX only catch mutable arguments on the first line of the definition
    (r'def.*[( ]\w+=\{\}', "don't use mutable default arguments"),
    (r'\butil\.Abort\b', "directly use error.Abort"),
    (r'^@(\w*\.)?cachefunc', "module-level @cachefunc is risky, please avoid"),
    (r'^import atexit', "don't use atexit, use ui.atexit"),
    (r'^import Queue', "don't use Queue, use pycompat.queue.Queue + "
                       "pycompat.queue.Empty"),
    (r'^import cStringIO', "don't use cStringIO.StringIO, use util.stringio"),
    (r'^import urllib', "don't use urllib, use util.urlreq/util.urlerr"),
    (r'^import SocketServer', "don't use SockerServer, use util.socketserver"),
    (r'^import urlparse', "don't use urlparse, use util.urlreq"),
    (r'^import xmlrpclib', "don't use xmlrpclib, use util.xmlrpclib"),
    (r'^import cPickle', "don't use cPickle, use util.pickle"),
    (r'^import pickle', "don't use pickle, use util.pickle"),
    (r'^import httplib', "don't use httplib, use util.httplib"),
    (r'^import BaseHTTPServer', "use util.httpserver instead"),
    (r'^(from|import) mercurial\.(cext|pure|cffi)',
     "use mercurial.policy.importmod instead"),
    (r'\.next\(\)', "don't use .next(), use next(...)"),
    (r'([a-z]*).revision\(\1\.node\(',
     "don't convert rev to node before passing to revision(nodeorrev)"),
    (r'platform\.system\(\)', "don't use platform.system(), use pycompat"),

    # rules depending on implementation of repquote()
    (r' x+[xpqo%APM][\'"]\n\s+[\'"]x',
     'string join across lines with no space'),
    (r'''(?x)ui\.(status|progress|write|note|warn)\(
         [ \t\n#]*
         (?# any strings/comments might precede a string, which
           # contains translatable message)
         ((['"]|\'\'\'|""")[ \npq%bAPMxno]*(['"]|\'\'\'|""")[ \t\n#]+)*
         (?# sequence consisting of below might precede translatable message
           # - formatting string: "% 10s", "%05d", "% -3.2f", "%*s", "%%" ...
           # - escaped character: "\\", "\n", "\0" ...
           # - character other than '%', 'b' as '\', and 'x' as alphabet)
         (['"]|\'\'\'|""")
         ((%([ n]?[PM]?([np]+|A))?x)|%%|b[bnx]|[ \nnpqAPMo])*x
         (?# this regexp can't use [^...] style,
           # because _preparepats forcibly adds "\n" into [^...],
           # even though this regexp wants match it against "\n")''',
     "missing _() in ui message (use () to hide false-positives)"),
  ],
  # warnings
  [
    # rules depending on implementation of repquote()
    (r'(^| )pp +xxxxqq[ \n][^\n]', "add two newlines after '.. note::'"),
  ]
]

pyfilters = [
    (r"""(?msx)(?P<comment>\#.*?$)|
         ((?P<quote>('''|\"\"\"|(?<!')'(?!')|(?<!")"(?!")))
          (?P<text>(([^\\]|\\.)*?))
          (?P=quote))""", reppython),
]

# non-filter patterns
pynfpats = [
    [
    (r'pycompat\.osname\s*[=!]=\s*[\'"]nt[\'"]', "use pycompat.iswindows"),
    (r'pycompat\.osname\s*[=!]=\s*[\'"]posix[\'"]', "use pycompat.isposix"),
    (r'pycompat\.sysplatform\s*[!=]=\s*[\'"]darwin[\'"]',
     "use pycompat.isdarwin"),
    ],
    # warnings
    [],
]

# extension non-filter patterns
pyextnfpats = [
    [(r'^"""\n?[A-Z]', "don't capitalize docstring title")],
    # warnings
    [],
]

txtfilters = []

txtpats = [
  [
    ('\s$', 'trailing whitespace'),
    ('.. note::[ \n][^\n]', 'add two newlines after note::')
  ],
  []
]

cpats = [
  [
    (r'//', "don't use //-style comments"),
    (r'\S\t', "don't use tabs except for indent"),
    (r'(\S[ \t]+|^[ \t]+)\n', "trailing whitespace"),
    (r'.{81}', "line too long"),
    (r'(while|if|do|for)\(', "use space after while/if/do/for"),
    (r'return\(', "return is not a function"),
    (r' ;', "no space before ;"),
    (r'[^;] \)', "no space before )"),
    (r'[)][{]', "space between ) and {"),
    (r'\w+\* \w+', "use int *foo, not int* foo"),
    (r'\W\([^\)]+\) \w+', "use (int)foo, not (int) foo"),
    (r'\w+ (\+\+|--)', "use foo++, not foo ++"),
    (r'\w,\w', "missing whitespace after ,"),
    (r'^[^#]\w[+/*]\w', "missing whitespace in expression"),
    (r'\w\s=\s\s+\w', "gratuitous whitespace after ="),
    (r'^#\s+\w', "use #foo, not # foo"),
    (r'[^\n]\Z', "no trailing newline"),
    (r'^\s*#import\b', "use only #include in standard C code"),
    (r'strcpy\(', "don't use strcpy, use strlcpy or memcpy"),
    (r'strcat\(', "don't use strcat"),

    # rules depending on implementation of repquote()
  ],
  # warnings
  [
    # rules depending on implementation of repquote()
  ]
]

cfilters = [
    (r'(/\*)(((\*(?!/))|[^*])*)\*/', repccomment),
    (r'''(?P<quote>(?<!")")(?P<text>([^"]|\\")+)"(?!")''', repquote),
    (r'''(#\s*include\s+<)([^>]+)>''', repinclude),
    (r'(\()([^)]+\))', repcallspaces),
]

inutilpats = [
  [
    (r'\bui\.', "don't use ui in util"),
  ],
  # warnings
  []
]

inrevlogpats = [
  [
    (r'\brepo\.', "don't use repo in revlog"),
  ],
  # warnings
  []
]

webtemplatefilters = []

webtemplatepats = [
  [],
  [
    (r'{desc(\|(?!websub|firstline)[^\|]*)+}',
     'follow desc keyword with either firstline or websub'),
  ]
]

allfilesfilters = []

allfilespats = [
  [
    (r'(http|https)://[a-zA-Z0-9./]*selenic.com/',
     'use mercurial-scm.org domain URL'),
    (r'mercurial@selenic\.com',
     'use mercurial-scm.org domain for mercurial ML address'),
    (r'mercurial-devel@selenic\.com',
     'use mercurial-scm.org domain for mercurial-devel ML address'),
  ],
  # warnings
  [],
]

py3pats = [
  [
    (r'os\.environ', "use encoding.environ instead (py3)", r'#.*re-exports'),
    (r'os\.name', "use pycompat.osname instead (py3)"),
    (r'os\.getcwd', "use pycompat.getcwd instead (py3)"),
    (r'os\.sep', "use pycompat.ossep instead (py3)"),
    (r'os\.pathsep', "use pycompat.ospathsep instead (py3)"),
    (r'os\.altsep', "use pycompat.osaltsep instead (py3)"),
    (r'sys\.platform', "use pycompat.sysplatform instead (py3)"),
    (r'getopt\.getopt', "use pycompat.getoptb instead (py3)"),
    (r'os\.getenv', "use encoding.environ.get instead"),
    (r'os\.setenv', "modifying the environ dict is not preferred"),
    (r'(?<!pycompat\.)xrange', "use pycompat.xrange instead (py3)"),
  ],
  # warnings
  [],
]

checks = [
    ('python', r'.*\.(py|cgi)$', r'^#!.*python', pyfilters, pypats),
    ('python', r'.*\.(py|cgi)$', r'^#!.*python', [], pynfpats),
    ('python', r'.*hgext.*\.py$', '', [], pyextnfpats),
    ('python 3', r'.*(hgext|mercurial)/(?!demandimport|policy|pycompat).*\.py',
     '', pyfilters, py3pats),
    ('test script', r'(.*/)?test-[^.~]*$', '', testfilters, testpats),
    ('c', r'.*\.[ch]$', '', cfilters, cpats),
    ('unified test', r'.*\.t$', '', utestfilters, utestpats),
    ('layering violation repo in revlog', r'mercurial/revlog\.py', '',
     pyfilters, inrevlogpats),
    ('layering violation ui in util', r'mercurial/util\.py', '', pyfilters,
     inutilpats),
    ('txt', r'.*\.txt$', '', txtfilters, txtpats),
    ('web template', r'mercurial/templates/.*\.tmpl', '',
     webtemplatefilters, webtemplatepats),
    ('all except for .po', r'.*(?<!\.po)$', '',
     allfilesfilters, allfilespats),
]

def _preparepats():
    for c in checks:
        failandwarn = c[-1]
        for pats in failandwarn:
            for i, pseq in enumerate(pats):
                # fix-up regexes for multi-line searches
                p = pseq[0]
                # \s doesn't match \n (done in two steps)
                # first, we replace \s that appears in a set already
                p = re.sub(r'\[\\s', r'[ \\t', p)
                # now we replace other \s instances.
                p = re.sub(r'(?<!(\\|\[))\\s', r'[ \\t]', p)
                # [^...] doesn't match newline
                p = re.sub(r'(?<!\\)\[\^', r'[^\\n', p)

                pats[i] = (re.compile(p, re.MULTILINE),) + pseq[1:]
        filters = c[3]
        for i, flt in enumerate(filters):
            filters[i] = re.compile(flt[0]), flt[1]

class norepeatlogger(object):
    def __init__(self):
        self._lastseen = None

    def log(self, fname, lineno, line, msg, blame):
        """print error related a to given line of a given file.

        The faulty line will also be printed but only once in the case
        of multiple errors.

        :fname: filename
        :lineno: line number
        :line: actual content of the line
        :msg: error message
        """
        msgid = fname, lineno, line
        if msgid != self._lastseen:
            if blame:
                print("%s:%d (%s):" % (fname, lineno, blame))
            else:
                print("%s:%d:" % (fname, lineno))
            print(" > %s" % line)
            self._lastseen = msgid
        print(" " + msg)

_defaultlogger = norepeatlogger()

def getblame(f):
    lines = []
    for l in os.popen('hg annotate -un %s' % f):
        start, line = l.split(':', 1)
        user, rev = start.split()
        lines.append((line[1:-1], user, rev))
    return lines

def checkfile(f, logfunc=_defaultlogger.log, maxerr=None, warnings=False,
              blame=False, debug=False, lineno=True):
    """checks style and portability of a given file

    :f: filepath
    :logfunc: function used to report error
              logfunc(filename, linenumber, linecontent, errormessage)
    :maxerr: number of error to display before aborting.
             Set to false (default) to report all errors

    return True if no error is found, False otherwise.
    """
    blamecache = None
    result = True

    try:
        with opentext(f) as fp:
            try:
                pre = post = fp.read()
            except UnicodeDecodeError as e:
                print("%s while reading %s" % (e, f))
                return result
    except IOError as e:
        print("Skipping %s, %s" % (f, str(e).split(':', 1)[0]))
        return result

    for name, match, magic, filters, pats in checks:
        post = pre # discard filtering result of previous check
        if debug:
            print(name, f)
        fc = 0
        if not (re.match(match, f) or (magic and re.search(magic, pre))):
            if debug:
                print("Skipping %s for %s it doesn't match %s" % (
                       name, match, f))
            continue
        if "no-" "check-code" in pre:
            # If you're looking at this line, it's because a file has:
            # no- check- code
            # but the reason to output skipping is to make life for
            # tests easier. So, instead of writing it with a normal
            # spelling, we write it with the expected spelling from
            # tests/test-check-code.t
            print("Skipping %s it has no-che?k-code (glob)" % f)
            return "Skip" # skip checking this file
        for p, r in filters:
            post = re.sub(p, r, post)
        nerrs = len(pats[0]) # nerr elements are errors
        if warnings:
            pats = pats[0] + pats[1]
        else:
            pats = pats[0]
        # print post # uncomment to show filtered version

        if debug:
            print("Checking %s for %s" % (name, f))

        prelines = None
        errors = []
        for i, pat in enumerate(pats):
            if len(pat) == 3:
                p, msg, ignore = pat
            else:
                p, msg = pat
                ignore = None
            if i >= nerrs:
                msg = "warning: " + msg

            pos = 0
            n = 0
            for m in p.finditer(post):
                if prelines is None:
                    prelines = pre.splitlines()
                    postlines = post.splitlines(True)

                start = m.start()
                while n < len(postlines):
                    step = len(postlines[n])
                    if pos + step > start:
                        break
                    pos += step
                    n += 1
                l = prelines[n]

                if ignore and re.search(ignore, l, re.MULTILINE):
                    if debug:
                        print("Skipping %s for %s:%s (ignore pattern)" % (
                            name, f, n))
                    continue
                bd = ""
                if blame:
                    bd = 'working directory'
                    if not blamecache:
                        blamecache = getblame(f)
                    if n < len(blamecache):
                        bl, bu, br = blamecache[n]
                        if bl == l:
                            bd = '%s@%s' % (bu, br)

                errors.append((f, lineno and n + 1, l, msg, bd))
                result = False

        errors.sort()
        for e in errors:
            logfunc(*e)
            fc += 1
            if maxerr and fc >= maxerr:
                print(" (too many errors, giving up)")
                break

    return result

def main():
    parser = optparse.OptionParser("%prog [options] [files | -]")
    parser.add_option("-w", "--warnings", action="store_true",
                      help="include warning-level checks")
    parser.add_option("-p", "--per-file", type="int",
                      help="max warnings per file")
    parser.add_option("-b", "--blame", action="store_true",
                      help="use annotate to generate blame info")
    parser.add_option("", "--debug", action="store_true",
                      help="show debug information")
    parser.add_option("", "--nolineno", action="store_false",
                      dest='lineno', help="don't show line numbers")

    parser.set_defaults(per_file=15, warnings=False, blame=False, debug=False,
                        lineno=True)
    (options, args) = parser.parse_args()

    if len(args) == 0:
        check = glob.glob("*")
    elif args == ['-']:
        # read file list from stdin
        check = sys.stdin.read().splitlines()
    else:
        check = args

    _preparepats()

    ret = 0
    for f in check:
        if not checkfile(f, maxerr=options.per_file, warnings=options.warnings,
                         blame=options.blame, debug=options.debug,
                         lineno=options.lineno):
            ret = 1
    return ret

if __name__ == "__main__":
    sys.exit(main())