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
71
72
73
74
75
76
|
# sAsync:
# An enhancement to the SQLAlchemy package that provides persistent
# dictionaries, text indexing and searching, and an access broker for
# conveniently managing database access, table setup, and
# transactions. Everything is run in an asynchronous fashion using the Twisted
# framework and its deferred processing capabilities.
#
# Copyright (C) 2006-2007 by Edwin A. Suominen, http://www.eepatents.com
#
# 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 2 of the License, or (at your option) 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 file COPYING 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
"""
Misc stuff, including an object for keeping track of deferreds
"""
from twisted.internet import defer
class DeferredTracker(object):
"""
I allow you to track and wait for deferreds without actually having
received a reference to them.
"""
def __init__(self):
self.list = []
def put(self, d):
"""
Put another deferred in the tracker.
"""
if not isinstance(d, defer.Deferred):
raise TypeError("Object '%s' is not a deferred" % d)
self.list.append(d)
def deferToAll(self):
"""
Return a deferred that tracks all active deferreds that aren't yet
being tracked. When the tracked deferreds fire, the returned deferred
fires, too.
"""
if self.list:
d = defer.DeferredList(self.list)
self.list = []
elif hasattr(self, 'd_WFA') and not self.d_WFA.called():
d = defer.Deferred()
self.d_WFA.chainDeferred(d)
else:
d = defer.succeed(None)
return d
def deferToLast(self):
"""
Return a deferred that tracks the deferred that was most recently put
in the tracker. When the tracked deferred fires, the returned deferred
fires, too.
"""
if self.list:
d = defer.Deferred()
self.list.pop().chainDeferred(d)
elif hasattr(self, 'd_WFL') and not self.d_WFL.called():
d = defer.Deferred()
self.d_WFL.chainDeferred(d)
else:
d = defer.succeed(None)
return d
|
