from __future__ import absolute_import

import json

import logging

import os

class BlessCache(object):

CACHEMODE_DISABLED = 'disabled'

CACHEMODE_RECACHE = 'recache'

CACHEMODE_ENABLED = 'enabled'

def __init__(self, filepath, filename, cachemode=CACHEMODE_ENABLED):

self.filepath = filepath

self.filename = filename

self.mode = cachemode

self.cache = None

self.dirty = False

def get(self, key):

if self.mode != self.CACHEMODE_ENABLED:

logging.debug("Cache get disabled")

return None

value = None

if self.cache is None:

self.loadCache()

if key in self.cache.keys():

value = self.cache[key]

return value

def set(self, key, value):

if self.cache is None:

self.loadCache()

self.dirty = True

self.cache[key] = value

def save(self):

if self.dirty and self.mode != self.CACHEMODE_DISABLED:

self.saveCache()

def loadCache(self):

self.cache = {}

cache_file_path = os.path.join(self.filepath, self.filename)

if os.path.isfile(cache_file_path):

with open(cache_file_path, 'r') as cache:

try:

self.cache = json.load(cache)

except Exception:

logging.error("Corrupted cache, using empty cache")

logging.debug("Cache loaded: {}".format(self.cache))

def saveCache(self):

if not os.path.exists(self.filepath):

os.makedirs(self.filepath)

cache_file_path = os.path.join(self.filepath, self.filename)

with open(cache_file_path, 'w') as cache:

json.dump(self.cache, cache)

logging.debug("Cache saved")