Examples
========

example.ini
***********

.. literalinclude:: ../example.ini
  :language: ini

Caching
*******

.. code-block::

    class GitViewCache(Cache):
        """
        File-based cache that stores content using ``pickle``.

        File paths inside the cache directory are based on a SHA-256 hash
        of the original URL path.

        Args:
            hostname (str): Hostname that this cache belongs to.
            file_root (str): Directory where the cached content is stored.
                A large number of hash-prefix subdirectories are created.
        """
        def __init__(self, hostname, file_root):
            super().__init__()
            self.hostname = hostname
            self.file_root = file_root
            os.makedirs(file_root, exist_ok=True)
            self.ptn_static_path = \
                re.compile('.*/(tags|commits|patch|cdiff|pcdiff)/[0-9a-f]+')

        def storage_path(self, path):
            digest = hashlib.sha256(path.encode('utf-8')).hexdigest()
            return digest[0:2] + '/' + digest[2:]

        def max_age(self, path):
            if self.ptn_static_path.match(path):
                return 60 * 24 * 3600  # two months
            return 3600 # one hour for dynamic content

        def try_load(self, path):
            if not path.startswith(self.hostname + '/'):
                return None, None
            storage_path = pjoin(self.file_root, self.storage_path(path))
            if not os.path.exists(storage_path):
                return None, None
            now_time = time.time()
            storage_time = os.path.getmtime(storage_path)
            if now_time - storage_time > self.max_age(path):
                return None, None
            return pickle.load(open(storage_path, 'rb'))

        def save(self, path, media_type, content):
            if not path.startswith(self.hostname + '/'):
                return False
            storage_path = pjoin(self.file_root, self.storage_path(path))
            os.makedirs(os.path.dirname(storage_path), exist_ok=True)
            pickle.dump((media_type, content), open(storage_path, 'wb'))
            return True