Source code for swiftly.client.localmemcache
"""
Provides a local in-memory memcache client lookalike for use with
Swift Proxy Server code.
See swift.common.memcached.MemcacheRing for what this is acting as.
"""
"""
Copyright 2011-2013 Gregory Holt
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
"""
class _Node(object):
def __init__(self, key, val, prv, nxt):
self.key = key
self.val = val
self.prv = prv
self.nxt = nxt
[docs]class LocalMemcache(object):
def __init__(self):
self.cache = {}
self.first = None
self.last = None
self.count = 0
self.max_count = 1000
[docs] def set(self, key, value, serialize=True, timeout=0, time=0):
self.delete(key)
self.last = node = _Node(key, value, self.last, None)
if node.prv:
node.prv.nxt = node
elif not self.first:
self.first = node
self.cache[key] = node
self.count += 1
if self.count > self.max_count:
self.delete(self.first.key)
[docs] def get(self, key):
node = self.cache.get(key)
return node.val if node else None
[docs] def incr(self, key, delta=1, timeout=0, time=0):
result = (self.get(key) or 0) + delta
self.set(key, result)
return result
[docs] def decr(self, key, delta=1, timeout=0, time=0):
return self.incr(key, delta=-delta, timeout=timeout, time=time)
[docs] def delete(self, key):
node = self.cache.get(key)
if node:
del self.cache[key]
if node.prv:
node.prv.nxt = node.nxt
if node.nxt:
node.nxt.prv = node.prv
if self.first == node:
self.first = node.nxt
if self.last == node:
self.last = node.prv
self.count -= 1
[docs] def set_multi(self, mapping, server_key, serialize=True, timeout=0,
time=0):
for key, value in mapping.iteritems():
self.set(key, value)
[docs] def get_multi(self, keys, server_key):
return [self.get(k) for k in keys]