### CACHE ############################################################################################

# Code for caching XML-queries, HTML, images in subfolders in /cache.

# The filenames are unique MD5-hases.

# Authors: Frederik De Bleser, Tom De Smedt.

# Copyright (c) 2007 Tom De Smedt.

# See LICENSE.txt for details.

import os

import md5

import datetime

import sys

from glob import glob

# For Mac OS X, the cache is stored inside the web library folder.

# For Linux, it is stored in $HOME/.nodebox-web-cache/

if sys.platform.startswith("darwin") \

or sys.platform.startswith("win"):

CACHE_PATH = os.path.join(os.path.dirname(__file__), "cache", "")

else:

CACHE_PATH = os.path.join(os.environ['HOME'], ".nodebox-web-cache", "")

class Cache:

def __init__(self, name, type=".xml"):

""" The cache can be used to store data downloads.

All of the data is stored in subfolders of the CACHE_PATH.

Each filename is hashed to a unique md5 string.

"""

self.path = CACHE_PATH+name

self.type = type

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

os.makedirs(self.path)

def hash(self, id):

""" Creates a unique filename in the cache for the id.

"""

h = md5.new(id).hexdigest()

return os.path.join(self.path, h+self.type)

def write(self, id, data):

f = open(self.hash(id), "w")

f.write(data)

f.close()

def read(self, id):

path = self.hash(id)

if os.path.exists(path):

f = open(path)

data = f.read()

f.close()

return data

else:

return None

def exists(self, id):

return os.path.exists(self.hash(id))

def age(self, id):

""" Returns the age of the cache entry, in days.

"""

path = self.hash(id)

if os.path.exists(path):

modified = datetime.datetime.fromtimestamp(os.stat(path)[8])

age = datetime.datetime.today() - modified

return age.days

else:

return 0

def remove(self, id):

path = self.hash(id)

if os.path.exists(path):

os.unlink(path)

def clear(self):

for path in glob(os.path.join(self.path,"*")):

os.unlink(path)

#c = Cache("kuler")

#print c.age("http://kuler.adobe.com/kuler/services/theme/getList.cfm?listType=popular")