1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

# This file is part of Buildbot.  Buildbot 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, version 2. 

# 

# 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, write to the Free Software Foundation, Inc., 51 

# Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 

# 

# Copyright Buildbot Team Members 

 

from zope.interface import implements 

from twisted.application import service 

from twisted.internet import defer, task, reactor 

from twisted.python import log 

 

from buildbot.interfaces import IChangeSource 

from buildbot import util 

 

class ChangeSource(service.Service, util.ComparableMixin): 

    implements(IChangeSource) 

 

    master = None 

    "if C{self.running} is true, then C{cs.master} points to the buildmaster." 

 

    def describe(self): 

        pass 

 

class PollingChangeSource(ChangeSource): 

    """ 

    Utility subclass for ChangeSources that use some kind of periodic polling 

    operation.  Subclasses should define C{poll} and set C{self.pollInterval}. 

    The rest is taken care of. 

    """ 

 

    pollInterval = 60 

    "time (in seconds) between calls to C{poll}" 

 

    _loop = None 

 

    def poll(self): 

        """ 

        Perform the polling operation, and return a deferred that will fire 

        when the operation is complete.  Failures will be logged, but the 

        method will be called again after C{pollInterval} seconds. 

        """ 

 

    def startService(self): 

        ChangeSource.startService(self) 

        def do_poll(): 

            d = defer.maybeDeferred(self.poll) 

            d.addErrback(log.err, 'while polling for changes') 

            return d 

 

        # delay starting the loop until the reactor is running, and do not 

        # run it immediately - if services are still starting up, they may 

        # miss an initial flood of changes 

        def start_loop(): 

            self._loop = task.LoopingCall(do_poll) 

            self._loop.start(self.pollInterval, now=False) 

        reactor.callWhenRunning(start_loop) 

 

    def stopService(self): 

        if self._loop and self._loop.running: 

            self._loop.stop() 

        return ChangeSource.stopService(self)