avahiserve / aserve / avahiserve.py

##   avahiserve - Mercurial serve command with avahi publishing

##   Copyright (C) 2008  Alessio Caiazza

##   

##   This program is free software: you can redistribute it and/or modify

##   it under the terms of the GNU General Public License as published by

##   the Free Software Foundation, either version 3 of the License, or

##   any later version.

##   

##   This program is distributed in the hope that it will be useful,

##   but WITHOUT ANY WARRANTY; without even the implied warranty of

##   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

##   GNU General Public License for more details.

##   

##   You should have received a copy of the GNU General Public License

##   along with this program.  If not, see <http://www.gnu.org/licenses/>.

from mercurial import commands

import dbus

import gobject

import avahi

from dbus.mainloop.glib import DBusGMainLoop

VERSION='0.1.0'

class AvahiReg:

	def __init__(self, name, port):

		self.verbose = False

		self.serviceName = "Mercurial"

		if name != '':

			self.serviceName += ": " + name

		self.serviceType = "_http._tcp" # See http://www.dns-sd.org/ServiceTypes.html

		self.servicePort = port

		self.serviceTXT = ["extension's author=Alessio Caiazza"] #TXT record for the service

		self.domain = "" # Domain to publish on, default to .local

		self.host = "" # Host to publish records for, default to localhost

		self.group = None #our entry group

		self.rename_count = 12 # Counter so we only rename after collisions a sensible number of times

	def add_service(self):

		if self.group is None:

			self.group = dbus.Interface(

				self.bus.get_object( avahi.DBUS_NAME, self.server.EntryGroupNew()),

				avahi.DBUS_INTERFACE_ENTRY_GROUP)

			self.group.connect_to_signal('StateChanged', self.entry_group_state_changed)

		if self.verbose:

			print "Adding service '%s' of type '%s' ..." % (self.serviceName, self.serviceType)

		self.group.AddService(

			avahi.IF_UNSPEC,    #interface

			avahi.PROTO_UNSPEC, #protocol

			0,                  #flags

			self.serviceName, self.serviceType,

			self.domain, self.host,

			dbus.UInt16(self.servicePort),

			avahi.string_array_to_txt_array(self.serviceTXT))

		self.group.Commit()

	def remove_service(self):

		if not group is None:

			group.Reset()

	def server_state_changed(self, state):

		if state == avahi.SERVER_COLLISION:

			if self.verbose:

				print "WARNING: Server name collision"

			remove_service()

		elif state == avahi.SERVER_RUNNING:

			self.add_service()

	def entry_group_state_changed(self,state, error):

		if self.verbose:

			print "state change: %i" % state

		if state == avahi.ENTRY_GROUP_ESTABLISHED:

			print "Service established."

		elif state == avahi.ENTRY_GROUP_COLLISION:

			rename_count = rename_count - 1

			if rename_count > 0:

				name = server.GetAlternativeServiceName(name)

				if self.verbose:

					print "WARNING: Service name collision, changing name to '%s' ..." % name

				remove_service()

				add_service()

			else:

				if self.verbose:

					print "ERROR: No suitable service name found after %i retries, exiting." % n_rename

				main_loop.quit()

		elif state == avahi.ENTRY_GROUP_FAILURE:

			if self.verbose:

				print "Error in group state changed", error

			main_loop.quit()

			return

	def start(self):

		if self.verbose:

			print "Starting avahiserve version " + VERSION

		DBusGMainLoop( set_as_default=True )

		self.bus = dbus.SystemBus()

		self.server = dbus.Interface(

			self.bus.get_object( avahi.DBUS_NAME, avahi.DBUS_PATH_SERVER ),

			avahi.DBUS_INTERFACE_SERVER )

		self.server.connect_to_signal( "StateChanged", self.server_state_changed )

		self.server_state_changed( self.server.GetState() )

	def stop(self):

		if self.verbose:

			print "Stopping avahi-publish-service"

		if not self.group is None:

			self.group.Free()

# every command must take a ui and and repo as arguments.

# opts is a dict where you can find other command line flags

#

# Other parameters are taken in order from items on the command line that

# don't start with a dash.  If no default value is given in the parameter list,

# they are required.

def avahi_serve(ui, repo, **opts):

	# The doc string below will show up in hg help

	"""Serve and publish on avahi zeroconf"""

	#print opts

	if opts['port'] != 0:

		port = int(opts['port'])

	else:

		port = 8000

	a = AvahiReg(opts['name'], port)

	if ui.cdata.has_option('web', 'description'):

		a.serviceTXT += ["description=" + ui.cdata.get('web','description')]

	if ui.cdata.has_option('ui', 'username'):

		#remove < and > cose make problems on Avahi Discovery

		a.serviceTXT += ["owner=" + 

				ui.cdata.get('ui','username')

				.replace('<','')

				.replace('>','')]

	a.verbose = ui.verbose

	a.start()

	try:

		commands.serve(ui,repo, **opts)

	except KeyboardInterrupt:

		pass

	a.stop()