view mercurial/version.py @ 2434:a2df85adface

http server: support persistent connections.

only "hg serve" affected yet.  http server running cgi script will not
use persistent connections.  support for fastcgi will help that.

clients that support keepalive can use one tcp connection for all
commands during clone and pull.  this makes latency of binary search
during pull much lower over wan.

if server does not know content-length, it will force connection to
close at end.  right fix is to use chunked transfer-encoding but this is
easier and does not hurt performance. only command that is affected is
"changegroup" which is always last command during a pull.

# Copyright (C) 2005 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 os.path
import re
import time
import util

unknown_version = 'unknown'
remembered_version = False

def get_version():
    """Return version information if available."""
    try:
        from mercurial.__version__ import 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()

def remember_version(version=None):
    """Store version information."""
    global remembered_version
    if not version and os.path.isdir(".hg"):
        f = os.popen("hg identify 2> %s" % util.nulldev)  # 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)