diff mercurial/server.py @ 30506:d9d8d78e6bc9

server: move cmdutil.service() to new module (API)

And call it runservice() because I'll soon add createservice().

The main reason I'm going to introduce the 'server' module is to solve
future dependency cycle between chgserver.py and commandserver.py.

The 'server' module sits at the same layer as the cmdutil. I believe it's
generally good to get rid of things from the big cmdutil module.

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mercurial/server.py	Sat Oct 15 13:47:43 2016 +0900
@@ -0,0 +1,107 @@
+# 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 errno
+import os
+import sys
+import tempfile
+
+from .i18n import _
+
+from . import (
+    error,
+    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 = 'a'
+            else:
+                mode = 'w'
+            fp = open(opts['pid_file'], mode)
+            fp.write(str(pid) + '\n')
+            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() + sys.argv[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:
+            try:
+                os.unlink(lockpath)
+            except OSError as e:
+                if e.errno != errno.ENOENT:
+                    raise
+        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)
+        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()