wip.py

import hashlib
import os
import pickle


CACHE_DIR = '~/.playlist_length'

if not os.path.exists(CACHE_DIR):
    os.makedirs(CACHE_DIR)

class CacheUtil:
    def __init__(self, path):
        self.dir_path = os.path.abspath(path)
        self.cache = self._get_cached_data()

    @staticmethod
    def get_hash(string):
        return hashlib.md5(string.encode('utf-8')).hexdigest()

    def _get_cached_data(self):
        file_name = self.get_hash(self.dir_path)
        cache_file_path = os.path.join(CACHE_DIR, file_name)
        if not os.path.exists(cache_file_path):
            with open(os.path.join(CACHE_DIR, file_name), 'wb'):
                data = {}
        else:
            with open(cache_file_path, 'rb') as file:
                data = pickle.load(file)
        return data

    def __call__(self, func):
        def wrap(file_path):
            file_hash = self.get_hash(file_path)
            if not file_hash in self.cache:
                result = func(file_path)
                self.cache[file_hash] = result
            return self.cache[file_hash]
        return wrap

    def save(self):
        cache_file_path = os.path.join(CACHE_DIR, file_name)
        with open(cache_file_path, 'wb') as file:
            pickle.dump(self.cache, file, protocol=pickle.HIGHEST_PROTOCOL)