pysolcache

Welcome to pysol

Copyright (C) 2013/2017 Laurent Labatut / Laurent Champagnac

pysolcache is a set of python caches : in-memory and/or redis.

Usefull to handle L1 (memory) and L2 (redis) cache for python daemons.

In all cases, serialization/deserialization of stored datas have to be done at client side (ie, serialize as u wish, ujson or equivalent)

All caches are instrumented by Meters (pysolmeters).

MemoryCache:

• A pure python memory cache storing string/binary keys to string/binary values
• Max bytes capped
• Max items count capped
• Items TTLs
• LRU evictions
• Watchdog evictions

RedisCache:

• A redis backed cache, storing string/binary keys to string/binary values

HighCache:

• A high level cache, coupling MemoryCache adn RedisCache, which handle respectively L1 cache (in memory) and L2 cache (inside redis)

HighCacheEx:

• A high level cache, storing internal data as tuple (ms_added, ttl_ms, string/binary data)
• Provided same level of functionality as HighCache but is able to perform an automatic L1 put in case of L2 hit and L1 miss

It is gevent (co-routines) based.

Usage

MemoryCache

c = MemoryCache()

# Put, ttl 60000 ms
c.put("keyA", "valA", 60000)

# Get
v = c.get("keyA")

# Remove
v = c.remove("keyA")

# Stop
c.stop_cache()

RedisCache

c = RedisCache()

# Put, ttl 60000 ms
c.put("keyA", "valA", 60000)

# Get
v = c.get("keyA")

# Remove
v = c.remove("keyA")

# Stop
c.stop_cache()

HighCache / HighCacheEx

mc = MemoryCache()
rc = RedisCache()
hc = HighCache(mc, rc)

# Put, ttl 60000 ms, in L1 and L2
hc.put("keyA", "valA", 60000, l1=True, l2=True)

# Get from L1 only
v = c.get("keyA", l1=True, l2=False)

# Get from L2 only
v = c.get("keyA", l1=False, l2=True)

# Try get from L1, if miss, try from L2
v = c.get("keyA", l1=True, l2=True)

# Remove from L1
v = c.remove("keyA", l1=True, l2=False)

# Stop
hc.stop_cache()

Source code

• We are pep8 compliant (as far as we can, with some exemptions)
• We use a right margin of 360 characters (please don't talk me about 80 chars)
• All unittest files must begin with test_ or Test, should implement setUp and tearDown methods
• All tests must adapt to any running directory
• The whole project is backed by gevent (http://www.gevent.org/)
• We use docstring (:return, :rtype, :param, :type etc), they are mandatory
• We use PyCharm "noinspection", feel free to use them

Requirements

• Debian 10 or greater, x64, Python 3.7

Unittests

To run unittests, you will need:

• redis-server installed and serving 6379 without creds.

License

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA