This document describes the current stable version of Kombu (5.0). For development docs, go here.
Source code for kombu.pools
"""Public resource pools."""
import os
from itertools import chain
from .connection import Resource
from .messaging import Producer
from .utils.collections import EqualityDict
from .utils.compat import register_after_fork
from .utils.functional import lazy
__all__ = ('ProducerPool', 'PoolGroup', 'register_group',
'connections', 'producers', 'get_limit', 'set_limit', 'reset')
_limit = [10]
_groups = []
use_global_limit = object()
disable_limit_protection = os.environ.get('KOMBU_DISABLE_LIMIT_PROTECTION')
def _after_fork_cleanup_group(group):
group.clear()
[docs]class ProducerPool(Resource):
"""Pool of :class:`kombu.Producer` instances."""
Producer = Producer
close_after_fork = True
def __init__(self, connections, *args, **kwargs):
self.connections = connections
self.Producer = kwargs.pop('Producer', None) or self.Producer
super().__init__(*args, **kwargs)
def _acquire_connection(self):
return self.connections.acquire(block=True)
[docs] def create_producer(self):
conn = self._acquire_connection()
try:
return self.Producer(conn)
except BaseException:
conn.release()
raise
[docs] def setup(self):
if self.limit:
for _ in range(self.limit):
self._resource.put_nowait(self.new())
[docs] def prepare(self, p):
if callable(p):
p = p()
if p._channel is None:
conn = self._acquire_connection()
try:
p.revive(conn)
except BaseException:
conn.release()
raise
return p
[docs] def release(self, resource):
if resource.__connection__:
resource.__connection__.release()
resource.channel = None
super().release(resource)
[docs]class PoolGroup(EqualityDict):
"""Collection of resource pools."""
def __init__(self, limit=None, close_after_fork=True):
self.limit = limit
self.close_after_fork = close_after_fork
if self.close_after_fork and register_after_fork is not None:
register_after_fork(self, _after_fork_cleanup_group)
[docs] def create(self, resource, limit):
raise NotImplementedError('PoolGroups must define ``create``')
def __missing__(self, resource):
limit = self.limit
if limit is use_global_limit:
limit = get_limit()
k = self[resource] = self.create(resource, limit)
return k
[docs]def register_group(group):
"""Register group (can be used as decorator)."""
_groups.append(group)
return group
class Connections(PoolGroup):
"""Collection of connection pools."""
def create(self, connection, limit):
return connection.Pool(limit=limit)
connections = register_group(Connections(limit=use_global_limit)) # noqa: E305
class Producers(PoolGroup):
"""Collection of producer pools."""
def create(self, connection, limit):
return ProducerPool(connections[connection], limit=limit)
producers = register_group(Producers(limit=use_global_limit)) # noqa: E305
def _all_pools():
return chain(*[(g.values() if g else iter([])) for g in _groups])
[docs]def set_limit(limit, force=False, reset_after=False, ignore_errors=False):
"""Set new connection pool limit."""
limit = limit or 0
glimit = _limit[0] or 0
if limit != glimit:
_limit[0] = limit
for pool in _all_pools():
pool.resize(limit)
return limit
[docs]def reset(*args, **kwargs):
"""Reset all pools by closing open resources."""
for pool in _all_pools():
try:
pool.force_close_all()
except Exception:
pass
for group in _groups:
group.clear()