Annotate zerver/lib/queue.py.

This commit is contained in:
Conrad Dean
2016-07-03 19:28:27 +05:30
committed by Eklavya Sharma
parent 192663edcf
commit 9812e676f0

View File

@@ -2,6 +2,8 @@ from __future__ import absolute_import
from django.conf import settings
import pika
from pika.adapters.blocking_connection import BlockingChannel
from pika.spec import Basic
import logging
import ujson
import random
@@ -11,7 +13,9 @@ import atexit
from collections import defaultdict
from zerver.lib.utils import statsd
from typing import Any, Callable
from typing import Any, Callable, Dict, Mapping, Optional, Set, Union
Consumer = Callable[[BlockingChannel, Basic.Deliver, pika.BasicProperties, str], None]
# This simple queuing library doesn't expose much of the power of
# rabbitmq/pika's queuing system; its purpose is to just provide an
@@ -19,27 +23,31 @@ from typing import Any, Callable
# out from bots without having to import pika code all over our codebase.
class SimpleQueueClient(object):
def __init__(self):
# type: () -> None
self.log = logging.getLogger('zulip.queue')
self.queues = set() # type: Set[str]
self.channel = None # type: Any
self.consumers = defaultdict(set) # type: Dict[str, Set[Any]]
self.channel = None # type: Optional[BlockingChannel]
self.consumers = defaultdict(set) # type: Dict[str, Set[Consumer]]
# Disable RabbitMQ heartbeats since BlockingConnection can't process them
self.rabbitmq_heartbeat = 0
self._connect()
def _connect(self):
# type: () -> None
start = time.time()
self.connection = pika.BlockingConnection(self._get_parameters())
self.channel = self.connection.channel()
self.log.info('SimpleQueueClient connected (connecting took %.3fs)' % (time.time() - start,))
def _reconnect(self):
# type: () -> None
self.connection = None
self.channel = None
self.queues = set()
self._connect()
def _get_parameters(self):
# type: () -> pika.ConnectionParameters
# We explicitly disable the RabbitMQ heartbeat feature, since
# it doesn't make sense with BlockingConnection
credentials = pika.PlainCredentials(settings.RABBITMQ_USERNAME,
@@ -49,27 +57,33 @@ class SimpleQueueClient(object):
credentials=credentials)
def _generate_ctag(self, queue_name):
# type: (str) -> str
return "%s_%s" % (queue_name, str(random.getrandbits(16)))
def _reconnect_consumer_callback(self, queue, consumer):
# type: (str, Consumer) -> None
self.log.info("Queue reconnecting saved consumer %s to queue %s" % (consumer, queue))
self.ensure_queue(queue, lambda: self.channel.basic_consume(consumer,
queue=queue,
consumer_tag=self._generate_ctag(queue)))
def _reconnect_consumer_callbacks(self):
# type: () -> None
for queue, consumers in self.consumers.items():
for consumer in consumers:
self._reconnect_consumer_callback(queue, consumer)
def close(self):
# type: () -> None
if self.connection:
self.connection.close()
def ready(self):
# type: () -> bool
return self.channel is not None
def ensure_queue(self, queue_name, callback):
# type: (str, Callable[[], None]) -> None
'''Ensure that a given queue has been declared, and then call
the callback with no arguments.'''
if not self.connection.is_open:
@@ -81,7 +95,9 @@ class SimpleQueueClient(object):
callback()
def publish(self, queue_name, body):
# type: (str, str) -> None
def do_publish():
# type: () -> None
self.channel.basic_publish(
exchange='',
routing_key=queue_name,
@@ -93,6 +109,8 @@ class SimpleQueueClient(object):
self.ensure_queue(queue_name, do_publish)
def json_publish(self, queue_name, body):
# type: (str, Union[Mapping[str, Any], str]) -> None
# Union because of zerver.middleware.write_log_line uses a str
try:
self.publish(queue_name, ujson.dumps(body))
except (AttributeError, pika.exceptions.AMQPConnectionError):
@@ -102,7 +120,9 @@ class SimpleQueueClient(object):
self.publish(queue_name, ujson.dumps(body))
def register_consumer(self, queue_name, consumer):
# type: (str, Consumer) -> None
def wrapped_consumer(ch, method, properties, body):
# type: (BlockingChannel, Basic.Deliver, pika.BasicProperties, str) -> None
try:
consumer(ch, method, properties, body)
ch.basic_ack(delivery_tag=method.delivery_tag)
@@ -116,14 +136,18 @@ class SimpleQueueClient(object):
consumer_tag=self._generate_ctag(queue_name)))
def register_json_consumer(self, queue_name, callback):
# type: (str, Callable[[Mapping[str, Any]], None]) -> None
def wrapped_callback(ch, method, properties, body):
return callback(ujson.loads(body))
return self.register_consumer(queue_name, wrapped_callback)
# type: (BlockingChannel, Basic.Deliver, pika.BasicProperties, str) -> None
callback(ujson.loads(body))
self.register_consumer(queue_name, wrapped_callback)
def drain_queue(self, queue_name, json=False):
# type: (str, bool) -> List[Dict[str, Any]]
"Returns all messages in the desired queue"
messages = []
def opened():
# type: () -> None
while True:
(meta, _, message) = self.channel.basic_get(queue_name)
@@ -139,9 +163,11 @@ class SimpleQueueClient(object):
return messages
def start_consuming(self):
# type: () -> None
self.channel.start_consuming()
def stop_consuming(self):
# type: () -> None
self.channel.stop_consuming()
# Patch pika.adapters.TornadoConnection so that a socket error doesn't
@@ -149,6 +175,7 @@ class SimpleQueueClient(object):
# queue. Instead, just re-connect as usual
class ExceptionFreeTornadoConnection(pika.adapters.TornadoConnection):
def _adapter_disconnect(self):
# type: () -> None
try:
super(ExceptionFreeTornadoConnection, self)._adapter_disconnect()
except (pika.exceptions.ProbableAuthenticationError,
@@ -162,14 +189,16 @@ class TornadoQueueClient(SimpleQueueClient):
# Based on:
# https://pika.readthedocs.io/en/0.9.8/examples/asynchronous_consumer_example.html
def __init__(self):
# type: () -> None
super(TornadoQueueClient, self).__init__()
# Enable rabbitmq heartbeat since TornadoConection can process them
self.rabbitmq_heartbeat = None
self._on_open_cbs = [] # type: List[Callable[[], None]]
def _connect(self, on_open_cb = None):
# type: (Optional[Callable[[], None]]) -> None
self.log.info("Beginning TornadoQueueClient connection")
if on_open_cb:
if on_open_cb is not None:
self._on_open_cbs.append(on_open_cb)
self.connection = ExceptionFreeTornadoConnection(
self._get_parameters(),
@@ -178,16 +207,19 @@ class TornadoQueueClient(SimpleQueueClient):
self.connection.add_on_close_callback(self._on_connection_closed)
def _reconnect(self):
# type: () -> None
self.connection = None
self.channel = None
self.queues = set()
self._connect()
def _on_open(self, connection):
# type: (pika.Connection) -> None
self.connection.channel(
on_open_callback = self._on_channel_open)
def _on_channel_open(self, channel):
# type: (BlockingChannel) -> None
self.channel = channel
for callback in self._on_open_cbs:
callback()
@@ -195,12 +227,14 @@ class TornadoQueueClient(SimpleQueueClient):
self.log.info('TornadoQueueClient connected')
def _on_connection_closed(self, connection, reply_code, reply_text):
# type: (pika.Connection, int, str) -> None
self.log.warning("TornadoQueueClient lost connection to RabbitMQ, reconnecting...")
from tornado import ioloop
# Try to reconnect in two seconds
retry_seconds = 2
def on_timeout():
# type: () -> None
try:
self._reconnect()
except pika.exceptions.AMQPConnectionError:
@@ -210,7 +244,9 @@ class TornadoQueueClient(SimpleQueueClient):
ioloop.IOLoop.instance().add_timeout(time.time() + retry_seconds, on_timeout)
def ensure_queue(self, queue_name, callback):
# type: (str, Callable[[], None]) -> None
def finish(frame):
# type: (Any) -> None
self.queues.add(queue_name)
callback()
@@ -226,7 +262,9 @@ class TornadoQueueClient(SimpleQueueClient):
callback()
def register_consumer(self, queue_name, consumer):
# type: (str, Consumer) -> None
def wrapped_consumer(ch, method, properties, body):
# type: (BlockingChannel, Basic.Deliver, pika.BasicProperties, str) -> None
consumer(ch, method, properties, body)
ch.basic_ack(delivery_tag=method.delivery_tag)
@@ -239,8 +277,9 @@ class TornadoQueueClient(SimpleQueueClient):
lambda: self.channel.basic_consume(wrapped_consumer, queue=queue_name,
consumer_tag=self._generate_ctag(queue_name)))
queue_client = None # type: SimpleQueueClient
queue_client = None # type: Optional[SimpleQueueClient]
def get_queue_client():
# type: () -> SimpleQueueClient
global queue_client
if queue_client is None:
if settings.RUNNING_INSIDE_TORNADO and settings.USING_RABBITMQ:
@@ -251,6 +290,7 @@ def get_queue_client():
return queue_client
def setup_tornado_rabbitmq():
# type: () -> None
# When tornado is shut down, disconnect cleanly from rabbitmq
if settings.USING_RABBITMQ:
atexit.register(lambda: queue_client.close())
@@ -263,9 +303,10 @@ def setup_tornado_rabbitmq():
queue_lock = threading.RLock()
def queue_json_publish(queue_name, event, processor):
# type: (str, Union[Mapping[str, Any], str], Callable[[Any], None]) -> None
# most events are dicts, but zerver.middleware.write_log_line uses a str
with queue_lock:
if settings.USING_RABBITMQ:
get_queue_client().json_publish(queue_name, event)
else:
processor(event)