view mercurial/version.py @ 6369:53912d30ac40

Avoid calling heads() twice on every hg commit.

In an extreme case (merging two revisions with very low revision numbers)
this could be slower than the previous code, but it should be much faster
in the usual cases (parents are near the tip).  It also avoids some races
in some uninteresting cases (e.g. two concurrent hg commits).

# Copyright (C) 2005, 2006, 2008 by Intevation GmbH
# Author(s):
# Thomas Arendsen Hein <[e-mail]>
#
# This program is free software under the GNU GPL (>=v2)
# Read the file COPYING coming with the software for details.

"""
Mercurial version
"""

import os
import re
import time

unknown_version = 'unknown'
remembered_version = False

def get_version(doreload=False):
    """Return version information if available."""
    try:
        import mercurial.__version__
        if doreload:
            reload(mercurial.__version__)
        version = mercurial.__version__.version
    except ImportError:
        version = unknown_version
    return version

def write_version(version):
    """Overwrite version file."""
    if version == get_version():
        return
    directory = os.path.dirname(__file__)
    for suffix in ['py', 'pyc', 'pyo']:
        try:
            os.unlink(os.path.join(directory, '__version__.%s' % suffix))
        except OSError:
            pass
    f = open(os.path.join(directory, '__version__.py'), 'w')
    f.write("# This file is auto-generated.\n")
    f.write("version = %r\n" % version)
    f.close()
    # reload the file we've just written
    get_version(True)

def remember_version(version=None):
    """Store version information."""
    global remembered_version
    if not version and os.path.isdir(".hg"):
        f = os.popen("hg identify")  # use real hg installation
        ident = f.read()[:-1]
        if not f.close() and ident:
            ids = ident.split(' ', 1)
            version = ids.pop(0)
            if version[-1] == '+':
                version = version[:-1]
                modified = True
            else:
                modified = False
            if version.isalnum() and ids:
                for tag in ids[0].split('/'):
                    # is a tag is suitable as a version number?
                    if re.match(r'^(\d+\.)+[\w.-]+$', tag):
                        version = tag
                        break
            if modified:
                version += time.strftime('+%Y%m%d')
    if version:
        remembered_version = True
        write_version(version)

def forget_version():
    """Remove version information."""
    if remembered_version:
        write_version(unknown_version)