scientific-programming-exercises/exam/ex01/cache.py

import os
import sqlite3

from proxy import fetch_proxies

def get_cache(directory, name):
	cache_file = os.path.join(directory, "{}.sqlite".format(name))
	if(not os.path.exists(cache_file)):
		with open(cache_file, "w") as fin:
			pass
		db = sqlite3.connect(cache_file)

		cursor = db.cursor()

		cursor.execute("CREATE TABLE proxies(proxy TEXT, lasttime_could_not_be_used DECIMAL)")
		cursor.execute("CREATE TABLE links(source TEXT, destination TEXT)")
		cursor.execute("CREATE TABLE dijkstra_helper(name TEXT UNIQUE, value INT)")
		cursor.execute("CREATE TABLE failed_to_fetch(title TEXT, depth INT)")

		db.commit()
	db = sqlite3.connect(cache_file)
	fetch_proxies(db)
	return db

def clear_cache_data(connection):
	cursor = connection.cursor()
	cursor.execute("DELETE FROM links")
	cursor.execute("DELETE FROM dijkstra_helper")
	connection.commit()