经常需要保存些程序执行的状态,使用redis等服务有点太重了,发现了轻量级的kv数据库lmdb,但是直接使用有点麻烦,简单实现了个包装类。
用法:
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# 写数据
with KVDB() as kvdb:
kvdb.set('abc', 'bingal')
# 读数据
with KVDB() as kvdb:
print(kvdb.get('abc'))
# 游标循环读取所有数据
with KVDB() as kvdb:
for key, value in kvdb.cursor():
print(key, value)
代码如下:
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#!/usr/bin/python
# encoding: utf-8
# author: bingal
# descryption: 更优雅的方式使用lmdb
import lmdb
class KVDB:
def __init__(self, path=None, size=100*1024*1024):
# 默认100MB
self.env = lmdb.open(os.path.join(os.path.split(os.path.realpath(__file__))[0], 'lmdb') if not path else path,
map_size=size)
def __enter__(self):
return self
def __exit__(self, exc_type, exc_val, exc_tb):
return self.close()
def set(self, sid, name):
txn = self.env.begin(write=True)
txn.put(str(sid).encode(), name.encode())
txn.commit()
def delete(self, sid):
txn = self.env.begin(write=True)
txn.delete(str(sid).encode())
txn.commit()
def get(self, sid):
txn = self.env.begin()
name = txn.get(str(sid).encode())
return name.decode() if name else ''
def cursor(self):
txn = self.env.begin()
cur = txn.cursor()
return cur
def close(self):
self.env.close()
if __name__ == '__main__':
with KVDB() as kvdb:
kvdb.set('abc', 'bingal')
with KVDB() as kvdb:
print(kvdb.get('abc'))
with KVDB() as kvdb:
for key, value in kvdb.cursor():
print(key, value)