view mercurial/server.py @ 35963:efbd04238029

cmdutil: convert _revertprefetch() to a generic stored file hook (API)

This will be used by LFS to fetch required files in a group for multiple
commands, prior to being accessed.  That avoids the one-at-a-time fetch when the
filelog wrapper goes to access it, and it is missing locally (which costs two
round trips to the server.)  The core command list that needs this is probably
at least:

  - annotate
  - archive (which is also used by extdiff)
  - cat
  - diff
  - export
  - grep
  - verify (sadly)
  - anything that has the '{data}' template

There are no core users of the revert prefetch hook, and never have been since
it was introduced in 45e02cfad4bd for remotefilelog.  Thanks to Yuya for
figuring out a way to reliably trigger the deprecated warning.  Unfortunately,
it wanted to blame the caller of revert.  Passing along an adjusted stack level
seemed the least bad choice (although it still blames a core function).

One thing to note is that the store lock isn't being held when this is called.
I'm not at all familiar with remotefilelog or its locking requirements, so this
may not be a big deal.  Currently, LFS doesn't hold a lock when downloading
files.  Even though largefiles doesn't either, I'm starting to think it should,
and maybe the .hg/store/lock isn't good enough to cover the globally shared
cache.

.. api::

   The cmdutil._revertprefetch() hook point for prefetching stored files has
   been replaced by the command agnostic cmdutil._prefetchfiles().  The new
   function takes a list of files, instead of a list of lists of files.

# server.py - utility and factory of server
#
# Copyright 2005-2007 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.

from __future__ import absolute_import

import os
import tempfile

from .i18n import _

from . import (
    chgserver,
    cmdutil,
    commandserver,
    error,
    hgweb,
    pycompat,
    util,
)

def runservice(opts, parentfn=None, initfn=None, runfn=None, logfile=None,
               runargs=None, appendpid=False):
    '''Run a command as a service.'''

    def writepid(pid):
        if opts['pid_file']:
            if appendpid:
                mode = 'ab'
            else:
                mode = 'wb'
            fp = open(opts['pid_file'], mode)
            fp.write('%d\n' % pid)
            fp.close()

    if opts['daemon'] and not opts['daemon_postexec']:
        # Signal child process startup with file removal
        lockfd, lockpath = tempfile.mkstemp(prefix='hg-service-')
        os.close(lockfd)
        try:
            if not runargs:
                runargs = util.hgcmd() + pycompat.sysargv[1:]
            runargs.append('--daemon-postexec=unlink:%s' % lockpath)
            # Don't pass --cwd to the child process, because we've already
            # changed directory.
            for i in xrange(1, len(runargs)):
                if runargs[i].startswith('--cwd='):
                    del runargs[i]
                    break
                elif runargs[i].startswith('--cwd'):
                    del runargs[i:i + 2]
                    break
            def condfn():
                return not os.path.exists(lockpath)
            pid = util.rundetached(runargs, condfn)
            if pid < 0:
                raise error.Abort(_('child process failed to start'))
            writepid(pid)
        finally:
            util.tryunlink(lockpath)
        if parentfn:
            return parentfn(pid)
        else:
            return

    if initfn:
        initfn()

    if not opts['daemon']:
        writepid(util.getpid())

    if opts['daemon_postexec']:
        try:
            os.setsid()
        except AttributeError:
            pass
        for inst in opts['daemon_postexec']:
            if inst.startswith('unlink:'):
                lockpath = inst[7:]
                os.unlink(lockpath)
            elif inst.startswith('chdir:'):
                os.chdir(inst[6:])
            elif inst != 'none':
                raise error.Abort(_('invalid value for --daemon-postexec: %s')
                                  % inst)
        util.hidewindow()
        util.stdout.flush()
        util.stderr.flush()

        nullfd = os.open(os.devnull, os.O_RDWR)
        logfilefd = nullfd
        if logfile:
            logfilefd = os.open(logfile, os.O_RDWR | os.O_CREAT | os.O_APPEND,
                                0o666)
        os.dup2(nullfd, 0)
        os.dup2(logfilefd, 1)
        os.dup2(logfilefd, 2)
        if nullfd not in (0, 1, 2):
            os.close(nullfd)
        if logfile and logfilefd not in (0, 1, 2):
            os.close(logfilefd)

    if runfn:
        return runfn()

_cmdservicemap = {
    'chgunix': chgserver.chgunixservice,
    'pipe': commandserver.pipeservice,
    'unix': commandserver.unixforkingservice,
}

def _createcmdservice(ui, repo, opts):
    mode = opts['cmdserver']
    try:
        return _cmdservicemap[mode](ui, repo, opts)
    except KeyError:
        raise error.Abort(_('unknown mode %s') % mode)

def _createhgwebservice(ui, repo, opts):
    # this way we can check if something was given in the command-line
    if opts.get('port'):
        opts['port'] = util.getport(opts.get('port'))

    alluis = {ui}
    if repo:
        baseui = repo.baseui
        alluis.update([repo.baseui, repo.ui])
    else:
        baseui = ui
    webconf = opts.get('web_conf') or opts.get('webdir_conf')
    if webconf:
        if opts.get('subrepos'):
            raise error.Abort(_('--web-conf cannot be used with --subrepos'))

        # load server settings (e.g. web.port) to "copied" ui, which allows
        # hgwebdir to reload webconf cleanly
        servui = ui.copy()
        servui.readconfig(webconf, sections=['web'])
        alluis.add(servui)
    elif opts.get('subrepos'):
        servui = ui

        # If repo is None, hgweb.createapp() already raises a proper abort
        # message as long as webconf is None.
        if repo:
            webconf = dict()
            cmdutil.addwebdirpath(repo, "", webconf)
    else:
        servui = ui

    optlist = ("name templates style address port prefix ipv6"
               " accesslog errorlog certificate encoding")
    for o in optlist.split():
        val = opts.get(o, '')
        if val in (None, ''): # should check against default options instead
            continue
        for u in alluis:
            u.setconfig("web", o, val, 'serve')

    app = hgweb.createapp(baseui, repo, webconf)
    return hgweb.httpservice(servui, app, opts)

def createservice(ui, repo, opts):
    if opts["cmdserver"]:
        return _createcmdservice(ui, repo, opts)
    else:
        return _createhgwebservice(ui, repo, opts)