def _init(self, server, params):
super(CacheClass, self).__init__(params)
self._server = server
self._params = params
unix_socket_path = None
if ':' in self.server:
host, port = self.server.rsplit(':', 1)
try:
port = int(port)
except (ValueError, TypeError):
raise Exception("port value must be an integer")
else:
host, port = None, None
unix_socket_path = self.server
kwargs = {
'db': self.db,
'password': self.password,
'host': host,
'port': port,
'unix_socket_path': unix_socket_path,
}
connection_pool = pool.get_connection_pool(
parser_class=self.parser_class,
**kwargs
)
self._client = Redis(
connection_pool=connection_pool,
**kwargs
)
def from_url(url, db=None, **kwargs):
"""Returns an active Redis client generated from the given database URL.
Will attempt to extract the database id from the path url fragment, if
none is provided.
"""
return Redis.from_url(url, db, **kwargs)
class CacheClass(BaseCache):
def __init__(self, server, params):
"""
Connect to Redis, and set up cache backend.
"""
self._init(server, params)
def _init(self, server, params):
super(CacheClass, self).__init__(params)
self._server = server
self._params = params
unix_socket_path = None
if ':' in self.server:
host, port = self.server.rsplit(':', 1)
try:
port = int(port)
except (ValueError, TypeError):
raise Exception("port value must be an integer")
else:
host, port = None, None
unix_socket_path = self.server
kwargs = {
'db': self.db,
'password': self.password,
'host': host,
'port': port,
'unix_socket_path': unix_socket_path,
}
connection_pool = pool.get_connection_pool(
parser_class=self.parser_class,
**kwargs
)
self._client = Redis(
connection_pool=connection_pool,
**kwargs
)
@property
def server(self):
return self._server or "127.0.0.1:6379"
@property
def params(self):
return self._params or {}
@property
def options(self):
return self.params.get('OPTIONS', {})
@property
def db(self):
_db = self.params.get('db', self.options.get('DB', 1))
try:
_db = int(_db)
except (ValueError, TypeError):
raise Exception("db value must be an integer")
return _db
@property
def password(self):
return self.params.get('password', self.options.get('PASSWORD', None))
@property
def parser_class(self):
cls = self.options.get('PARSER_CLASS', None)
if cls is None:
return DefaultParser
mod_path, cls_name = cls.rsplit('.', 1)
try:
mod = import_module(mod_path)
parser_class = getattr(mod, cls_name)
except (AttributeError, ImportError):
raise Exception("Could not find parser class '%s'" % parser_class)
return parser_class
def __getstate__(self):
return {'params': self._params, 'server': self._server}
def __setstate__(self, state):
self._init(**state)
def make_key(self, key, version=None):
"""
Returns the utf-8 encoded bytestring of the given key as a CacheKey
instance to be able to check if it was "made" before.
"""
if not isinstance(key, CacheKey):
key = CacheKey(key)
return key
def add(self, key, value, timeout=None, version=None):
"""
Add a value to the cache, failing if the key already exists.
Returns ``True`` if the object was added, ``False`` if not.
"""
return self.set(key, value, timeout, _add_only=True)
def get(self, key, default=None, version=None):
"""
Retrieve a value from the cache.
Returns unpickled value if key is found, the default if not.
"""
key = self.make_key(key, version=version)
value = self._client.get(key)
if value is None:
return default
try:
result = int(value)
except (ValueError, TypeError):
result = self.unpickle(value)
return result
def _set(self, key, value, timeout, client, _add_only=False):
if timeout == 0:
if _add_only:
return client.setnx(key, value)
return client.set(key, value)
elif timeout > 0:
if _add_only:
added = client.setnx(key, value)
if added:
client.expire(key, timeout)
return added
return client.setex(key, value, timeout)
else:
return False
def set(self, key, value, timeout=None, version=None, client=None, _add_only=False):
"""
Persist a value to the cache, and set an optional expiration time.
"""
if not client:
client = self._client
key = self.make_key(key, version=version)
if timeout is None:
timeout = self.default_timeout
try:
value = float(value)
# If you lose precision from the typecast to str, then pickle value
if int(value) != value:
raise TypeError
except (ValueError, TypeError):
result = self._set(key, pickle.dumps(value), int(timeout), client, _add_only)
else:
result = self._set(key, int(value), int(timeout), client, _add_only)
# result is a boolean
return result
def delete(self, key, version=None):
"""
Remove a key from the cache.
"""
self._client.delete(self.make_key(key, version=version))
def delete_many(self, keys, version=None):
"""
Remove multiple keys at once.
"""
if keys:
keys = map(lambda key: self.make_key(key, version=version), keys)
self._client.delete(*keys)
def clear(self):
"""
Flush all cache keys.
"""
# TODO : potential data loss here, should we only delete keys based on the correct version ?
self._client.flushdb()
def unpickle(self, value):
"""
Unpickles the given value.
"""
value = smart_str(value)
return pickle.loads(value)
def get_many(self, keys, version=None):
"""
Retrieve many keys.
"""
if not keys:
return {}
recovered_data = dict()
new_keys = map(lambda key: self.make_key(key, version=version), keys)
map_keys = dict(zip(new_keys, keys))
results = self._client.mget(new_keys)
for key, value in zip(new_keys, results):
if value is None:
continue
try:
value = int(value)
except (ValueError, TypeError):
value = self.unpickle(value)
if isinstance(value, basestring):
value = smart_unicode(value)
recovered_data[map_keys[key]] = value
return recovered_data
def set_many(self, data, timeout=None, version=None):
"""
Set a bunch of values in the cache at once from a dict of key/value
pairs. This is much more efficient than calling set() multiple times.
If timeout is given, that timeout will be used for the key; otherwise
the default cache timeout will be used.
"""
pipeline = self._client.pipeline()
for key, value in data.iteritems():
self.set(key, value, timeout, version=version, client=pipeline)
pipeline.execute()
def set_json(self, key, json, **kwargs):
return self._client.hmset(key, json)
def get_json(self, key):
return self._client.hgetall(key)
def exists(self, key):
return self._client.exists(key)
def expire(self, key, ttl):
return self._client.expire(key, ttl)
def incr(self, key, delta=1, version=None):
"""
Add delta to value in the cache. If the key does not exist, raise a
ValueError exception.
"""
key = self.make_key(key, version=version)
exists = self._client.exists(key)
if not exists:
raise ValueError("Key '%s' not found" % key)
try:
value = self._client.incr(key, delta)
except ResponseError:
value = self.get(key) + 1
self.set(key, value)
return value
