view contrib/check-commit @ 27430:e240e914d226 stable

revlog: seek to end of file before writing (issue4943)

Revlogs were recently refactored to open file handles in "a+" and use a
persistent file handle for reading and writing. This drastically
reduced the number of file handles being opened.

Unfortunately, it appears that some versions of Solaris lose the file
offset when performing a write after the handle has been seeked.

The simplest workaround is to seek to EOF on files opened in a+ mode
before writing to them, which is what this patch does.

Ideally, this code would exist in the vfs layer. However, this would
require creating a proxy class for file objects in order to provide a
custom implementation of write(). This would add overhead. Since
revlogs are the only files we open in a+ mode, the one-off workaround
in revlog.py should be sufficient.

This patch appears to have little to no impact on performance on my
Linux machine.

#!/usr/bin/env python
#
# Copyright 2014 Matt Mackall <[e-mail]>
#
# A tool/hook to run basic sanity checks on commits/patches for
# submission to Mercurial. Install by adding the following to your
# .hg/hgrc:
#
# [hooks]
# pretxncommit = contrib/check-commit
#
# The hook can be temporarily bypassed with:
#
# $ BYPASS= hg commit
#
# See also: https://mercurial-scm.org/wiki/ContributingChanges

import re, sys, os

errors = [
    (r"[(]bc[)]", "(BC) needs to be uppercase"),
    (r"[(]issue \d\d\d", "no space allowed between issue and number"),
    (r"[(]bug(\d|\s)", "use (issueDDDD) instead of bug"),
    (r"^# User [^@\n]+$", "username is not an email address"),
    (r"^# .*\n(?!merge with )[^#]\S+[^:] ",
     "summary line doesn't start with 'topic: '"),
    (r"^# .*\n[A-Z][a-z]\S+", "don't capitalize summary lines"),
    (r"^# .*\n[^\n]*: *[A-Z][a-z]\S+", "don't capitalize summary lines"),
    (r"^# .*\n.*\.\s+$", "don't add trailing period on summary line"),
    (r"^# .*\n.{78,}", "summary line too long (limit is 78)"),
    (r"^\+\n \n", "adds double empty line"),
    (r"^ \n\+\n", "adds double empty line"),
    (r"^\+[ \t]+def [a-z]+_[a-z]", "adds a function with foo_bar naming"),
]

node = os.environ.get("HG_NODE")

if node:
    commit = os.popen("hg export %s" % node).read()
else:
    commit = sys.stdin.read()

exitcode = 0
for exp, msg in errors:
    m = re.search(exp, commit, re.MULTILINE)
    if m:
        pos = 0
        for n, l in enumerate(commit.splitlines(True)):
            pos += len(l)
            if pos >= m.end():
                print "%d: %s" % (n, msg)
                print " %s" % l[:-1]
                if "BYPASS" not in os.environ:
                    exitcode = 1
                break

sys.exit(exitcode)