75 lines
2.4 KiB
Python
75 lines
2.4 KiB
Python
# Copyright (c) 2012 Web Notes Technologies Pvt Ltd (http://erpnext.com)
|
|
#
|
|
# MIT License (MIT)
|
|
#
|
|
# Permission is hereby granted, free of charge, to any person obtaining a
|
|
# copy of this software and associated documentation files (the "Software"),
|
|
# to deal in the Software without restriction, including without limitation
|
|
# the rights to use, copy, modify, merge, publish, distribute, sublicense,
|
|
# and/or sell copies of the Software, and to permit persons to whom the
|
|
# Software is furnished to do so, subject to the following conditions:
|
|
#
|
|
# The above copyright notice and this permission notice shall be included in
|
|
# all copies or substantial portions of the Software.
|
|
#
|
|
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
|
|
# INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
|
|
# PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
|
|
# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
|
|
# CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE
|
|
# OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
|
|
#
|
|
|
|
"""
|
|
Simple Caching:
|
|
|
|
Stores key-value pairs in database and enables simple caching
|
|
|
|
CacheItem(key).get() returns the cached value if not expired (else returns null)
|
|
CacheItem(key).set(interval = 60000) sets a value to cache, expiring after x seconds
|
|
CahceItem(key).clear() clears an old value
|
|
setup() sets up cache
|
|
"""
|
|
|
|
import webnotes
|
|
|
|
class CacheItem:
|
|
def __init__(self, key):
|
|
"""create a new cache"""
|
|
self.key = key
|
|
|
|
def get(self):
|
|
"""get value"""
|
|
try:
|
|
return webnotes.conn.sql("select `value` from __CacheItem where `key`=%s and expires_on > NOW()", self.key)[0][0]
|
|
except Exception:
|
|
return None
|
|
|
|
def set(self, value, interval=6000):
|
|
"""set a new value, with interval"""
|
|
try:
|
|
self.clear()
|
|
webnotes.conn.sql("""INSERT INTO
|
|
__CacheItem (`key`, `value`, expires_on)
|
|
VALUES
|
|
(%s, %s, addtime(now(), sec_to_time(%s)))
|
|
""", (self.key, str(value), interval))
|
|
except Exception, e:
|
|
if e.args[0]==1146:
|
|
setup()
|
|
self.set(value, interval)
|
|
else: raise e
|
|
|
|
def clear(self):
|
|
"""clear the item"""
|
|
webnotes.conn.sql("delete from __CacheItem where `key`=%s", self.key)
|
|
|
|
def setup():
|
|
webnotes.conn.commit()
|
|
webnotes.conn.sql("""create table __CacheItem(
|
|
`key` VARCHAR(180) NOT NULL PRIMARY KEY,
|
|
`value` TEXT,
|
|
`expires_on` TIMESTAMP
|
|
)""")
|
|
webnotes.conn.begin()
|
|
|