|
1
|
|
|
# Licensed to the StackStorm, Inc ('StackStorm') under one or more |
|
2
|
|
|
# contributor license agreements. See the NOTICE file distributed with |
|
3
|
|
|
# this work for additional information regarding copyright ownership. |
|
4
|
|
|
# The ASF licenses this file to You under the Apache License, Version 2.0 |
|
5
|
|
|
# (the "License"); you may not use this file except in compliance with |
|
6
|
|
|
# the License. You may obtain a copy of the License at |
|
7
|
|
|
# |
|
8
|
|
|
# http://www.apache.org/licenses/LICENSE-2.0 |
|
9
|
|
|
# |
|
10
|
|
|
# Unless required by applicable law or agreed to in writing, software |
|
11
|
|
|
# distributed under the License is distributed on an "AS IS" BASIS, |
|
12
|
|
|
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
|
13
|
|
|
# See the License for the specific language governing permissions and |
|
14
|
|
|
# limitations under the License. |
|
15
|
|
|
|
|
16
|
|
|
import abc |
|
17
|
|
|
import eventlet |
|
18
|
|
|
import six |
|
19
|
|
|
|
|
20
|
|
|
from kombu.mixins import ConsumerMixin |
|
21
|
|
|
|
|
22
|
|
|
from st2common import log as logging |
|
23
|
|
|
from st2common.util.greenpooldispatch import BufferedDispatcher |
|
24
|
|
|
|
|
25
|
|
|
|
|
26
|
|
|
LOG = logging.getLogger(__name__) |
|
27
|
|
|
|
|
28
|
|
|
|
|
29
|
|
|
class QueueConsumer(ConsumerMixin): |
|
30
|
|
|
def __init__(self, connection, queues, handler): |
|
31
|
|
|
self.connection = connection |
|
32
|
|
|
self._dispatcher = BufferedDispatcher() |
|
33
|
|
|
self._queues = queues |
|
34
|
|
|
self._handler = handler |
|
35
|
|
|
|
|
36
|
|
|
def shutdown(self): |
|
37
|
|
|
self._dispatcher.shutdown() |
|
38
|
|
|
|
|
39
|
|
|
def get_consumers(self, Consumer, channel): |
|
40
|
|
|
consumer = Consumer(queues=self._queues, accept=['pickle'], callbacks=[self.process]) |
|
41
|
|
|
|
|
42
|
|
|
# use prefetch_count=1 for fair dispatch. This way workers that finish an item get the next |
|
43
|
|
|
# task and the work does not get queued behind any single large item. |
|
44
|
|
|
consumer.qos(prefetch_count=1) |
|
45
|
|
|
|
|
46
|
|
|
return [consumer] |
|
47
|
|
|
|
|
48
|
|
|
def process(self, body, message): |
|
49
|
|
|
try: |
|
50
|
|
|
if not isinstance(body, self._handler.message_type): |
|
51
|
|
|
raise TypeError('Received an unexpected type "%s" for payload.' % type(body)) |
|
52
|
|
|
|
|
53
|
|
|
self._dispatcher.dispatch(self._process_message, body) |
|
54
|
|
|
except: |
|
55
|
|
|
LOG.exception('%s failed to process message: %s', self.__class__.__name__, body) |
|
56
|
|
|
|
|
57
|
|
|
message.ack() |
|
58
|
|
|
|
|
59
|
|
|
def _process_message(self, body): |
|
60
|
|
|
try: |
|
61
|
|
|
self._handler.process(body) |
|
62
|
|
|
except: |
|
63
|
|
|
LOG.exception('%s failed to process message: %s', self.__class__.__name__, body) |
|
64
|
|
|
|
|
65
|
|
|
|
|
66
|
|
|
class StagedQueueConsumer(QueueConsumer): |
|
67
|
|
|
|
|
68
|
|
|
def process(self, body, message): |
|
69
|
|
|
try: |
|
70
|
|
|
if not isinstance(body, self._handler.message_type): |
|
71
|
|
|
raise TypeError('Received an unexpected type "%s" for payload.' % type(body)) |
|
72
|
|
|
processed_body = self._handler.pre_ack_process(body) |
|
73
|
|
|
self._dispatcher.dispatch(self._process_message, processed_body) |
|
74
|
|
|
except: |
|
75
|
|
|
LOG.exception('%s failed to process message: %s', self.__class__.__name__, body) |
|
76
|
|
|
# At this point we will always ack a specific message. |
|
77
|
|
|
message.ack() |
|
78
|
|
|
|
|
79
|
|
|
|
|
80
|
|
|
@six.add_metaclass(abc.ABCMeta) |
|
81
|
|
|
class MessageHandler(object): |
|
82
|
|
|
message_type = None |
|
83
|
|
|
|
|
84
|
|
|
def __init__(self, connection, queues): |
|
85
|
|
|
self._queue_consumer = self._get_queue_consumer(connection, queues) |
|
86
|
|
|
self._consumer_thread = None |
|
87
|
|
|
|
|
88
|
|
|
def start(self, wait=False): |
|
89
|
|
|
LOG.info('Starting %s...', self.__class__.__name__) |
|
90
|
|
|
self._consumer_thread = eventlet.spawn(self._queue_consumer.run) |
|
91
|
|
|
|
|
92
|
|
|
if wait: |
|
93
|
|
|
self.wait() |
|
94
|
|
|
|
|
95
|
|
|
def wait(self): |
|
96
|
|
|
self._consumer_thread.wait() |
|
97
|
|
|
|
|
98
|
|
|
def shutdown(self): |
|
99
|
|
|
LOG.info('Shutting down %s...', self.__class__.__name__) |
|
100
|
|
|
self._queue_consumer.shutdown() |
|
101
|
|
|
|
|
102
|
|
|
@abc.abstractmethod |
|
103
|
|
|
def process(self, message): |
|
104
|
|
|
pass |
|
105
|
|
|
|
|
106
|
|
|
def _get_queue_consumer(self, connection, queues): |
|
107
|
|
|
return QueueConsumer(connection, queues, self) |
|
108
|
|
|
|
|
109
|
|
|
|
|
110
|
|
|
@six.add_metaclass(abc.ABCMeta) |
|
111
|
|
|
class StagedMessageHandler(MessageHandler): |
|
112
|
|
|
|
|
113
|
|
|
@abc.abstractmethod |
|
114
|
|
|
def pre_ack_process(self, message): |
|
115
|
|
|
pass |
|
116
|
|
|
|
|
117
|
|
|
def _get_queue_consumer(self, connection, queues): |
|
118
|
|
|
return StagedQueueConsumer(connection, queues, self) |
|
119
|
|
|
|
StackStorm /
st2
