This document describes the current stable version of Celery (5.3). For development docs, go here.

Source code for celery.backends.couchdb

"""CouchDB result store backend."""
from kombu.utils.encoding import bytes_to_str
from kombu.utils.url import _parse_url

from celery.exceptions import ImproperlyConfigured

from .base import KeyValueStoreBackend

try:
    import pycouchdb
except ImportError:
    pycouchdb = None

__all__ = ('CouchBackend',)

ERR_LIB_MISSING = """\
You need to install the pycouchdb library to use the CouchDB result backend\
"""


[docs]class CouchBackend(KeyValueStoreBackend): """CouchDB backend. Raises: celery.exceptions.ImproperlyConfigured: if module :pypi:`pycouchdb` is not available. """ container = 'default' scheme = 'http' host = 'localhost' port = 5984 username = None password = None def __init__(self, url=None, *args, **kwargs): super().__init__(*args, **kwargs) self.url = url if pycouchdb is None: raise ImproperlyConfigured(ERR_LIB_MISSING) uscheme = uhost = uport = uname = upass = ucontainer = None if url: _, uhost, uport, uname, upass, ucontainer, _ = _parse_url(url) ucontainer = ucontainer.strip('/') if ucontainer else None self.scheme = uscheme or self.scheme self.host = uhost or self.host self.port = int(uport or self.port) self.container = ucontainer or self.container self.username = uname or self.username self.password = upass or self.password self._connection = None def _get_connection(self): """Connect to the CouchDB server.""" if self.username and self.password: conn_string = f'{self.scheme}://{self.username}:{self.password}@{self.host}:{self.port}' server = pycouchdb.Server(conn_string, authmethod='basic') else: conn_string = f'{self.scheme}://{self.host}:{self.port}' server = pycouchdb.Server(conn_string) try: return server.database(self.container) except pycouchdb.exceptions.NotFound: return server.create(self.container) @property def connection(self): if self._connection is None: self._connection = self._get_connection() return self._connection
[docs] def get(self, key): key = bytes_to_str(key) try: return self.connection.get(key)['value'] except pycouchdb.exceptions.NotFound: return None
[docs] def set(self, key, value): key = bytes_to_str(key) data = {'_id': key, 'value': value} try: self.connection.save(data) except pycouchdb.exceptions.Conflict: # document already exists, update it data = self.connection.get(key) data['value'] = value self.connection.save(data)
[docs] def mget(self, keys): return [self.get(key) for key in keys]
[docs] def delete(self, key): self.connection.delete(key)