wrapcache

A python Function / Method OUTPUT cache system base on function Decorators. Supports to cache into redis or LRU memory. 中文README.md

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What's wrapcache?

wrapcache is a decorator that enables caching of return values for functions.

The cache keys are dependent completely on the arguments passed to the function. very simple to use.

Also has some API to Programmatic get cache or remove cache. Support python 2.6 ~ python3.5.

Here's an example of how you might use wrapcache:

import wrapcache

from time import sleep
import random

@wrapcache.wrapcache(timeout = 3)
def need_cache_function(input, t = 2, o = 3):
    sleep(2)
    return random.randint(1, 100)

if __name__ == "__main__":
    for i in range(10):
        sleep(1)
        print(need_cache_function(1, t = 2, o = 3))

    #get cache Programmatic
    key_func = wrapcache.keyof(need_cache_function, 1, o = 3, t = 2)
    print(wrapcache.get(key_func))
    #remove cache Programmatic
    print(wrapcache.remove(wrapcache.keyof(need_cache_function, 1, o = 3, t = 2)))

Some config:

@wrapcache.wrapcache(timeout = timeout, adapter = adapter)

• timeout: how much seconds the cache exist. Default is -1, not cached.
• adapter: cache where, now can be RedisAdapter and MemoryAdapter. Default is MemoryAdapter.

When use RedisAdapter, you need to set redis instance before use. e.g.

REDIS_POOL = redis.ConnectionPool(host = '10.246.13.1', port = 6379, password = 'redis_pwd', db = 1)
REDIS_INST = redis.Redis(connection_pool = REDIS_POOL, charset = 'utf8')
RedisAdapter.db = REDIS_INST

When use MemoryAdapter, you can set Memory Storage Policy before use, that is choose where to store. Default is store in {}, also it provide LUR(Supported by jlhutch/pylru, add dynamic size.) algorithm. e.g.

from wrapcache.database import LruCacheDB
lruDB = MemoryAdapter.db = LruCacheDB(size = 100)
RedisAdapter.db = lruDB

How to Install and Use?

Install

Three ways to install wrapcache:

1. Use tool install

• pip install wrapcache

2. Download to install

• Download from https://pypi.python.org/pypi/wrapcache/, and run python setup.py install.

3. Manual installation

• Manual installation: Put wrapcache folder into current directory or site-packages, then import wrapcache to use.

Usage

Decorators

import wrapcache
@wrapcache.wrapcache(timeout = 3)
def need_cache_function():
    return 'hello wrapcache'

API

1. wrapcache.keyof(func, *args, **kws): get the key of function output cache.
2. wrapcache.get(key, adapter = MemoryAdapter): get the value of cache.
3. wrapcache.set(key, value, timeout = -1, adapter = MemoryAdapter): set cache use code.
4. wrapcache.remove(key, adapter = MemoryAdapter): remove a cache.
5. wrapcache.flush(adapter = MemoryAdapter): clear all the cache.

The API 2~5, need to input a adapter to set which db to operate.

TODO

• usage wiki.