Convert watch page to flask framework

1 files changed, 933 insertions, 0 deletions

diff --git a/python/werkzeug/contrib/cache.py b/python/werkzeug/contrib/cache.py
new file mode 100644
index 0000000..79c749b
--- /dev/null
+++ b/python/werkzeug/contrib/cache.py
@@ -0,0 +1,933 @@
+# -*- coding: utf-8 -*-
+"""
+    werkzeug.contrib.cache
+    ~~~~~~~~~~~~~~~~~~~~~~
+
+    The main problem with dynamic Web sites is, well, they're dynamic.  Each
+    time a user requests a page, the webserver executes a lot of code, queries
+    the database, renders templates until the visitor gets the page he sees.
+
+    This is a lot more expensive than just loading a file from the file system
+    and sending it to the visitor.
+
+    For most Web applications, this overhead isn't a big deal but once it
+    becomes, you will be glad to have a cache system in place.
+
+    How Caching Works
+    =================
+
+    Caching is pretty simple.  Basically you have a cache object lurking around
+    somewhere that is connected to a remote cache or the file system or
+    something else.  When the request comes in you check if the current page
+    is already in the cache and if so, you're returning it from the cache.
+    Otherwise you generate the page and put it into the cache. (Or a fragment
+    of the page, you don't have to cache the full thing)
+
+    Here is a simple example of how to cache a sidebar for 5 minutes::
+
+        def get_sidebar(user):
+            identifier = 'sidebar_for/user%d' % user.id
+            value = cache.get(identifier)
+            if value is not None:
+                return value
+            value = generate_sidebar_for(user=user)
+            cache.set(identifier, value, timeout=60 * 5)
+            return value
+
+    Creating a Cache Object
+    =======================
+
+    To create a cache object you just import the cache system of your choice
+    from the cache module and instantiate it.  Then you can start working
+    with that object:
+
+    >>> from werkzeug.contrib.cache import SimpleCache
+    >>> c = SimpleCache()
+    >>> c.set("foo", "value")
+    >>> c.get("foo")
+    'value'
+    >>> c.get("missing") is None
+    True
+
+    Please keep in mind that you have to create the cache and put it somewhere
+    you have access to it (either as a module global you can import or you just
+    put it into your WSGI application).
+
+    :copyright: 2007 Pallets
+    :license: BSD-3-Clause
+"""
+import errno
+import os
+import platform
+import re
+import tempfile
+import warnings
+from hashlib import md5
+from time import time
+
+from .._compat import integer_types
+from .._compat import iteritems
+from .._compat import string_types
+from .._compat import text_type
+from .._compat import to_native
+from ..posixemulation import rename
+
+try:
+    import cPickle as pickle
+except ImportError:  # pragma: no cover
+    import pickle
+
+warnings.warn(
+    "'werkzeug.contrib.cache' is deprecated as of version 0.15 and will"
+    " be removed in version 1.0. It has moved to https://github.com"
+    "/pallets/cachelib.",
+    DeprecationWarning,
+    stacklevel=2,
+)
+
+
+def _items(mappingorseq):
+    """Wrapper for efficient iteration over mappings represented by dicts
+    or sequences::
+
+        >>> for k, v in _items((i, i*i) for i in xrange(5)):
+        ...    assert k*k == v
+
+        >>> for k, v in _items(dict((i, i*i) for i in xrange(5))):
+        ...    assert k*k == v
+
+    """
+    if hasattr(mappingorseq, "items"):
+        return iteritems(mappingorseq)
+    return mappingorseq
+
+
+class BaseCache(object):
+    """Baseclass for the cache systems.  All the cache systems implement this
+    API or a superset of it.
+
+    :param default_timeout: the default timeout (in seconds) that is used if
+                            no timeout is specified on :meth:`set`. A timeout
+                            of 0 indicates that the cache never expires.
+    """
+
+    def __init__(self, default_timeout=300):
+        self.default_timeout = default_timeout
+
+    def _normalize_timeout(self, timeout):
+        if timeout is None:
+            timeout = self.default_timeout
+        return timeout
+
+    def get(self, key):
+        """Look up key in the cache and return the value for it.
+
+        :param key: the key to be looked up.
+        :returns: The value if it exists and is readable, else ``None``.
+        """
+        return None
+
+    def delete(self, key):
+        """Delete `key` from the cache.
+
+        :param key: the key to delete.
+        :returns: Whether the key existed and has been deleted.
+        :rtype: boolean
+        """
+        return True
+
+    def get_many(self, *keys):
+        """Returns a list of values for the given keys.
+        For each key an item in the list is created::
+
+            foo, bar = cache.get_many("foo", "bar")
+
+        Has the same error handling as :meth:`get`.
+
+        :param keys: The function accepts multiple keys as positional
+                     arguments.
+        """
+        return [self.get(k) for k in keys]
+
+    def get_dict(self, *keys):
+        """Like :meth:`get_many` but return a dict::
+
+            d = cache.get_dict("foo", "bar")
+            foo = d["foo"]
+            bar = d["bar"]
+
+        :param keys: The function accepts multiple keys as positional
+                     arguments.
+        """
+        return dict(zip(keys, self.get_many(*keys)))
+
+    def set(self, key, value, timeout=None):
+        """Add a new key/value to the cache (overwrites value, if key already
+        exists in the cache).
+
+        :param key: the key to set
+        :param value: the value for the key
+        :param timeout: the cache timeout for the key in seconds (if not
+                        specified, it uses the default timeout). A timeout of
+                        0 idicates that the cache never expires.
+        :returns: ``True`` if key has been updated, ``False`` for backend
+                  errors. Pickling errors, however, will raise a subclass of
+                  ``pickle.PickleError``.
+        :rtype: boolean
+        """
+        return True
+
+    def add(self, key, value, timeout=None):
+        """Works like :meth:`set` but does not overwrite the values of already
+        existing keys.
+
+        :param key: the key to set
+        :param value: the value for the key
+        :param timeout: the cache timeout for the key in seconds (if not
+                        specified, it uses the default timeout). A timeout of
+                        0 idicates that the cache never expires.
+        :returns: Same as :meth:`set`, but also ``False`` for already
+                  existing keys.
+        :rtype: boolean
+        """
+        return True
+
+    def set_many(self, mapping, timeout=None):
+        """Sets multiple keys and values from a mapping.
+
+        :param mapping: a mapping with the keys/values to set.
+        :param timeout: the cache timeout for the key in seconds (if not
+                        specified, it uses the default timeout). A timeout of
+                        0 idicates that the cache never expires.
+        :returns: Whether all given keys have been set.
+        :rtype: boolean
+        """
+        rv = True
+        for key, value in _items(mapping):
+            if not self.set(key, value, timeout):
+                rv = False
+        return rv
+
+    def delete_many(self, *keys):
+        """Deletes multiple keys at once.
+
+        :param keys: The function accepts multiple keys as positional
+                     arguments.
+        :returns: Whether all given keys have been deleted.
+        :rtype: boolean
+        """
+        return all(self.delete(key) for key in keys)
+
+    def has(self, key):
+        """Checks if a key exists in the cache without returning it. This is a
+        cheap operation that bypasses loading the actual data on the backend.
+
+        This method is optional and may not be implemented on all caches.
+
+        :param key: the key to check
+        """
+        raise NotImplementedError(
+            "%s doesn't have an efficient implementation of `has`. That "
+            "means it is impossible to check whether a key exists without "
+            "fully loading the key's data. Consider using `self.get` "
+            "explicitly if you don't care about performance."
+        )
+
+    def clear(self):
+        """Clears the cache.  Keep in mind that not all caches support
+        completely clearing the cache.
+
+        :returns: Whether the cache has been cleared.
+        :rtype: boolean
+        """
+        return True
+
+    def inc(self, key, delta=1):
+        """Increments the value of a key by `delta`.  If the key does
+        not yet exist it is initialized with `delta`.
+
+        For supporting caches this is an atomic operation.
+
+        :param key: the key to increment.
+        :param delta: the delta to add.
+        :returns: The new value or ``None`` for backend errors.
+        """
+        value = (self.get(key) or 0) + delta
+        return value if self.set(key, value) else None
+
+    def dec(self, key, delta=1):
+        """Decrements the value of a key by `delta`.  If the key does
+        not yet exist it is initialized with `-delta`.
+
+        For supporting caches this is an atomic operation.
+
+        :param key: the key to increment.
+        :param delta: the delta to subtract.
+        :returns: The new value or `None` for backend errors.
+        """
+        value = (self.get(key) or 0) - delta
+        return value if self.set(key, value) else None
+
+
+class NullCache(BaseCache):
+    """A cache that doesn't cache.  This can be useful for unit testing.
+
+    :param default_timeout: a dummy parameter that is ignored but exists
+                            for API compatibility with other caches.
+    """
+
+    def has(self, key):
+        return False
+
+
+class SimpleCache(BaseCache):
+    """Simple memory cache for single process environments.  This class exists
+    mainly for the development server and is not 100% thread safe.  It tries
+    to use as many atomic operations as possible and no locks for simplicity
+    but it could happen under heavy load that keys are added multiple times.
+
+    :param threshold: the maximum number of items the cache stores before
+                      it starts deleting some.
+    :param default_timeout: the default timeout that is used if no timeout is
+                            specified on :meth:`~BaseCache.set`. A timeout of
+                            0 indicates that the cache never expires.
+    """
+
+    def __init__(self, threshold=500, default_timeout=300):
+        BaseCache.__init__(self, default_timeout)
+        self._cache = {}
+        self.clear = self._cache.clear
+        self._threshold = threshold
+
+    def _prune(self):
+        if len(self._cache) > self._threshold:
+            now = time()
+            toremove = []
+            for idx, (key, (expires, _)) in enumerate(self._cache.items()):
+                if (expires != 0 and expires <= now) or idx % 3 == 0:
+                    toremove.append(key)
+            for key in toremove:
+                self._cache.pop(key, None)
+
+    def _normalize_timeout(self, timeout):
+        timeout = BaseCache._normalize_timeout(self, timeout)
+        if timeout > 0:
+            timeout = time() + timeout
+        return timeout
+
+    def get(self, key):
+        try:
+            expires, value = self._cache[key]
+            if expires == 0 or expires > time():
+                return pickle.loads(value)
+        except (KeyError, pickle.PickleError):
+            return None
+
+    def set(self, key, value, timeout=None):
+        expires = self._normalize_timeout(timeout)
+        self._prune()
+        self._cache[key] = (expires, pickle.dumps(value, pickle.HIGHEST_PROTOCOL))
+        return True
+
+    def add(self, key, value, timeout=None):
+        expires = self._normalize_timeout(timeout)
+        self._prune()
+        item = (expires, pickle.dumps(value, pickle.HIGHEST_PROTOCOL))
+        if key in self._cache:
+            return False
+        self._cache.setdefault(key, item)
+        return True
+
+    def delete(self, key):
+        return self._cache.pop(key, None) is not None
+
+    def has(self, key):
+        try:
+            expires, value = self._cache[key]
+            return expires == 0 or expires > time()
+        except KeyError:
+            return False
+
+
+_test_memcached_key = re.compile(r"[^\x00-\x21\xff]{1,250}$").match
+
+
+class MemcachedCache(BaseCache):
+    """A cache that uses memcached as backend.
+
+    The first argument can either be an object that resembles the API of a
+    :class:`memcache.Client` or a tuple/list of server addresses. In the
+    event that a tuple/list is passed, Werkzeug tries to import the best
+    available memcache library.
+
+    This cache looks into the following packages/modules to find bindings for
+    memcached:
+
+        - ``pylibmc``
+        - ``google.appengine.api.memcached``
+        - ``memcached``
+        - ``libmc``
+
+    Implementation notes:  This cache backend works around some limitations in
+    memcached to simplify the interface.  For example unicode keys are encoded
+    to utf-8 on the fly.  Methods such as :meth:`~BaseCache.get_dict` return
+    the keys in the same format as passed.  Furthermore all get methods
+    silently ignore key errors to not cause problems when untrusted user data
+    is passed to the get methods which is often the case in web applications.
+
+    :param servers: a list or tuple of server addresses or alternatively
+                    a :class:`memcache.Client` or a compatible client.
+    :param default_timeout: the default timeout that is used if no timeout is
+                            specified on :meth:`~BaseCache.set`. A timeout of
+                            0 indicates that the cache never expires.
+    :param key_prefix: a prefix that is added before all keys.  This makes it
+                       possible to use the same memcached server for different
+                       applications.  Keep in mind that
+                       :meth:`~BaseCache.clear` will also clear keys with a
+                       different prefix.
+    """
+
+    def __init__(self, servers=None, default_timeout=300, key_prefix=None):
+        BaseCache.__init__(self, default_timeout)
+        if servers is None or isinstance(servers, (list, tuple)):
+            if servers is None:
+                servers = ["127.0.0.1:11211"]
+            self._client = self.import_preferred_memcache_lib(servers)
+            if self._client is None:
+                raise RuntimeError("no memcache module found")
+        else:
+            # NOTE: servers is actually an already initialized memcache
+            # client.
+            self._client = servers
+
+        self.key_prefix = to_native(key_prefix)
+
+    def _normalize_key(self, key):
+        key = to_native(key, "utf-8")
+        if self.key_prefix:
+            key = self.key_prefix + key
+        return key
+
+    def _normalize_timeout(self, timeout):
+        timeout = BaseCache._normalize_timeout(self, timeout)
+        if timeout > 0:
+            timeout = int(time()) + timeout
+        return timeout
+
+    def get(self, key):
+        key = self._normalize_key(key)
+        # memcached doesn't support keys longer than that.  Because often
+        # checks for so long keys can occur because it's tested from user
+        # submitted data etc we fail silently for getting.
+        if _test_memcached_key(key):
+            return self._client.get(key)
+
+    def get_dict(self, *keys):
+        key_mapping = {}
+        have_encoded_keys = False
+        for key in keys:
+            encoded_key = self._normalize_key(key)
+            if not isinstance(key, str):
+                have_encoded_keys = True
+            if _test_memcached_key(key):
+                key_mapping[encoded_key] = key
+        _keys = list(key_mapping)
+        d = rv = self._client.get_multi(_keys)
+        if have_encoded_keys or self.key_prefix:
+            rv = {}
+            for key, value in iteritems(d):
+                rv[key_mapping[key]] = value
+        if len(rv) < len(keys):
+            for key in keys:
+                if key not in rv:
+                    rv[key] = None
+        return rv
+
+    def add(self, key, value, timeout=None):
+        key = self._normalize_key(key)
+        timeout = self._normalize_timeout(timeout)
+        return self._client.add(key, value, timeout)
+
+    def set(self, key, value, timeout=None):
+        key = self._normalize_key(key)
+        timeout = self._normalize_timeout(timeout)
+        return self._client.set(key, value, timeout)
+
+    def get_many(self, *keys):
+        d = self.get_dict(*keys)
+        return [d[key] for key in keys]
+
+    def set_many(self, mapping, timeout=None):
+        new_mapping = {}
+        for key, value in _items(mapping):
+            key = self._normalize_key(key)
+            new_mapping[key] = value
+
+        timeout = self._normalize_timeout(timeout)
+        failed_keys = self._client.set_multi(new_mapping, timeout)
+        return not failed_keys
+
+    def delete(self, key):
+        key = self._normalize_key(key)
+        if _test_memcached_key(key):
+            return self._client.delete(key)
+
+    def delete_many(self, *keys):
+        new_keys = []
+        for key in keys:
+            key = self._normalize_key(key)
+            if _test_memcached_key(key):
+                new_keys.append(key)
+        return self._client.delete_multi(new_keys)
+
+    def has(self, key):
+        key = self._normalize_key(key)
+        if _test_memcached_key(key):
+            return self._client.append(key, "")
+        return False
+
+    def clear(self):
+        return self._client.flush_all()
+
+    def inc(self, key, delta=1):
+        key = self._normalize_key(key)
+        return self._client.incr(key, delta)
+
+    def dec(self, key, delta=1):
+        key = self._normalize_key(key)
+        return self._client.decr(key, delta)
+
+    def import_preferred_memcache_lib(self, servers):
+        """Returns an initialized memcache client.  Used by the constructor."""
+        try:
+            import pylibmc
+        except ImportError:
+            pass
+        else:
+            return pylibmc.Client(servers)
+
+        try:
+            from google.appengine.api import memcache
+        except ImportError:
+            pass
+        else:
+            return memcache.Client()
+
+        try:
+            import memcache
+        except ImportError:
+            pass
+        else:
+            return memcache.Client(servers)
+
+        try:
+            import libmc
+        except ImportError:
+            pass
+        else:
+            return libmc.Client(servers)
+
+
+# backwards compatibility
+GAEMemcachedCache = MemcachedCache
+
+
+class RedisCache(BaseCache):
+    """Uses the Redis key-value store as a cache backend.
+
+    The first argument can be either a string denoting address of the Redis
+    server or an object resembling an instance of a redis.Redis class.
+
+    Note: Python Redis API already takes care of encoding unicode strings on
+    the fly.
+
+    .. versionadded:: 0.7
+
+    .. versionadded:: 0.8
+       `key_prefix` was added.
+
+    .. versionchanged:: 0.8
+       This cache backend now properly serializes objects.
+
+    .. versionchanged:: 0.8.3
+       This cache backend now supports password authentication.
+
+    .. versionchanged:: 0.10
+        ``**kwargs`` is now passed to the redis object.
+
+    :param host: address of the Redis server or an object which API is
+                 compatible with the official Python Redis client (redis-py).
+    :param port: port number on which Redis server listens for connections.
+    :param password: password authentication for the Redis server.
+    :param db: db (zero-based numeric index) on Redis Server to connect.
+    :param default_timeout: the default timeout that is used if no timeout is
+                            specified on :meth:`~BaseCache.set`. A timeout of
+                            0 indicates that the cache never expires.
+    :param key_prefix: A prefix that should be added to all keys.
+
+    Any additional keyword arguments will be passed to ``redis.Redis``.
+    """
+
+    def __init__(
+        self,
+        host="localhost",
+        port=6379,
+        password=None,
+        db=0,
+        default_timeout=300,
+        key_prefix=None,
+        **kwargs
+    ):
+        BaseCache.__init__(self, default_timeout)
+        if host is None:
+            raise ValueError("RedisCache host parameter may not be None")
+        if isinstance(host, string_types):
+            try:
+                import redis
+            except ImportError:
+                raise RuntimeError("no redis module found")
+            if kwargs.get("decode_responses", None):
+                raise ValueError("decode_responses is not supported by RedisCache.")
+            self._client = redis.Redis(
+                host=host, port=port, password=password, db=db, **kwargs
+            )
+        else:
+            self._client = host
+        self.key_prefix = key_prefix or ""
+
+    def _normalize_timeout(self, timeout):
+        timeout = BaseCache._normalize_timeout(self, timeout)
+        if timeout == 0:
+            timeout = -1
+        return timeout
+
+    def dump_object(self, value):
+        """Dumps an object into a string for redis.  By default it serializes
+        integers as regular string and pickle dumps everything else.
+        """
+        t = type(value)
+        if t in integer_types:
+            return str(value).encode("ascii")
+        return b"!" + pickle.dumps(value)
+
+    def load_object(self, value):
+        """The reversal of :meth:`dump_object`.  This might be called with
+        None.
+        """
+        if value is None:
+            return None
+        if value.startswith(b"!"):
+            try:
+                return pickle.loads(value[1:])
+            except pickle.PickleError:
+                return None
+        try:
+            return int(value)
+        except ValueError:
+            # before 0.8 we did not have serialization.  Still support that.
+            return value
+
+    def get(self, key):
+        return self.load_object(self._client.get(self.key_prefix + key))
+
+    def get_many(self, *keys):
+        if self.key_prefix:
+            keys = [self.key_prefix + key for key in keys]
+        return [self.load_object(x) for x in self._client.mget(keys)]
+
+    def set(self, key, value, timeout=None):
+        timeout = self._normalize_timeout(timeout)
+        dump = self.dump_object(value)
+        if timeout == -1:
+            result = self._client.set(name=self.key_prefix + key, value=dump)
+        else:
+            result = self._client.setex(
+                name=self.key_prefix + key, value=dump, time=timeout
+            )
+        return result
+
+    def add(self, key, value, timeout=None):
+        timeout = self._normalize_timeout(timeout)
+        dump = self.dump_object(value)
+        return self._client.setnx(
+            name=self.key_prefix + key, value=dump
+        ) and self._client.expire(name=self.key_prefix + key, time=timeout)
+
+    def set_many(self, mapping, timeout=None):
+        timeout = self._normalize_timeout(timeout)
+        # Use transaction=False to batch without calling redis MULTI
+        # which is not supported by twemproxy
+        pipe = self._client.pipeline(transaction=False)
+
+        for key, value in _items(mapping):
+            dump = self.dump_object(value)
+            if timeout == -1:
+                pipe.set(name=self.key_prefix + key, value=dump)
+            else:
+                pipe.setex(name=self.key_prefix + key, value=dump, time=timeout)
+        return pipe.execute()
+
+    def delete(self, key):
+        return self._client.delete(self.key_prefix + key)
+
+    def delete_many(self, *keys):
+        if not keys:
+            return
+        if self.key_prefix:
+            keys = [self.key_prefix + key for key in keys]
+        return self._client.delete(*keys)
+
+    def has(self, key):
+        return self._client.exists(self.key_prefix + key)
+
+    def clear(self):
+        status = False
+        if self.key_prefix:
+            keys = self._client.keys(self.key_prefix + "*")
+            if keys:
+                status = self._client.delete(*keys)
+        else:
+            status = self._client.flushdb()
+        return status
+
+    def inc(self, key, delta=1):
+        return self._client.incr(name=self.key_prefix + key, amount=delta)
+
+    def dec(self, key, delta=1):
+        return self._client.decr(name=self.key_prefix + key, amount=delta)
+
+
+class FileSystemCache(BaseCache):
+    """A cache that stores the items on the file system.  This cache depends
+    on being the only user of the `cache_dir`.  Make absolutely sure that
+    nobody but this cache stores files there or otherwise the cache will
+    randomly delete files therein.
+
+    :param cache_dir: the directory where cache files are stored.
+    :param threshold: the maximum number of items the cache stores before
+                      it starts deleting some. A threshold value of 0
+                      indicates no threshold.
+    :param default_timeout: the default timeout that is used if no timeout is
+                            specified on :meth:`~BaseCache.set`. A timeout of
+                            0 indicates that the cache never expires.
+    :param mode: the file mode wanted for the cache files, default 0600
+    """
+
+    #: used for temporary files by the FileSystemCache
+    _fs_transaction_suffix = ".__wz_cache"
+    #: keep amount of files in a cache element
+    _fs_count_file = "__wz_cache_count"
+
+    def __init__(self, cache_dir, threshold=500, default_timeout=300, mode=0o600):
+        BaseCache.__init__(self, default_timeout)
+        self._path = cache_dir
+        self._threshold = threshold
+        self._mode = mode
+
+        try:
+            os.makedirs(self._path)
+        except OSError as ex:
+            if ex.errno != errno.EEXIST:
+                raise
+
+        self._update_count(value=len(self._list_dir()))
+
+    @property
+    def _file_count(self):
+        return self.get(self._fs_count_file) or 0
+
+    def _update_count(self, delta=None, value=None):
+        # If we have no threshold, don't count files
+        if self._threshold == 0:
+            return
+
+        if delta:
+            new_count = self._file_count + delta
+        else:
+            new_count = value or 0
+        self.set(self._fs_count_file, new_count, mgmt_element=True)
+
+    def _normalize_timeout(self, timeout):
+        timeout = BaseCache._normalize_timeout(self, timeout)
+        if timeout != 0:
+            timeout = time() + timeout
+        return int(timeout)
+
+    def _list_dir(self):
+        """return a list of (fully qualified) cache filenames
+        """
+        mgmt_files = [
+            self._get_filename(name).split("/")[-1] for name in (self._fs_count_file,)
+        ]
+        return [
+            os.path.join(self._path, fn)
+            for fn in os.listdir(self._path)
+            if not fn.endswith(self._fs_transaction_suffix) and fn not in mgmt_files
+        ]
+
+    def _prune(self):
+        if self._threshold == 0 or not self._file_count > self._threshold:
+            return
+
+        entries = self._list_dir()
+        now = time()
+        for idx, fname in enumerate(entries):
+            try:
+                remove = False
+                with open(fname, "rb") as f:
+                    expires = pickle.load(f)
+                remove = (expires != 0 and expires <= now) or idx % 3 == 0
+
+                if remove:
+                    os.remove(fname)
+            except (IOError, OSError):
+                pass
+        self._update_count(value=len(self._list_dir()))
+
+    def clear(self):
+        for fname in self._list_dir():
+            try:
+                os.remove(fname)
+            except (IOError, OSError):
+                self._update_count(value=len(self._list_dir()))
+                return False
+        self._update_count(value=0)
+        return True
+
+    def _get_filename(self, key):
+        if isinstance(key, text_type):
+            key = key.encode("utf-8")  # XXX unicode review
+        hash = md5(key).hexdigest()
+        return os.path.join(self._path, hash)
+
+    def get(self, key):
+        filename = self._get_filename(key)
+        try:
+            with open(filename, "rb") as f:
+                pickle_time = pickle.load(f)
+                if pickle_time == 0 or pickle_time >= time():
+                    return pickle.load(f)
+                else:
+                    os.remove(filename)
+                    return None
+        except (IOError, OSError, pickle.PickleError):
+            return None
+
+    def add(self, key, value, timeout=None):
+        filename = self._get_filename(key)
+        if not os.path.exists(filename):
+            return self.set(key, value, timeout)
+        return False
+
+    def set(self, key, value, timeout=None, mgmt_element=False):
+        # Management elements have no timeout
+        if mgmt_element:
+            timeout = 0
+
+        # Don't prune on management element update, to avoid loop
+        else:
+            self._prune()
+
+        timeout = self._normalize_timeout(timeout)
+        filename = self._get_filename(key)
+        try:
+            fd, tmp = tempfile.mkstemp(
+                suffix=self._fs_transaction_suffix, dir=self._path
+            )
+            with os.fdopen(fd, "wb") as f:
+                pickle.dump(timeout, f, 1)
+                pickle.dump(value, f, pickle.HIGHEST_PROTOCOL)
+            rename(tmp, filename)
+            os.chmod(filename, self._mode)
+        except (IOError, OSError):
+            return False
+        else:
+            # Management elements should not count towards threshold
+            if not mgmt_element:
+                self._update_count(delta=1)
+            return True
+
+    def delete(self, key, mgmt_element=False):
+        try:
+            os.remove(self._get_filename(key))
+        except (IOError, OSError):
+            return False
+        else:
+            # Management elements should not count towards threshold
+            if not mgmt_element:
+                self._update_count(delta=-1)
+            return True
+
+    def has(self, key):
+        filename = self._get_filename(key)
+        try:
+            with open(filename, "rb") as f:
+                pickle_time = pickle.load(f)
+                if pickle_time == 0 or pickle_time >= time():
+                    return True
+                else:
+                    os.remove(filename)
+                    return False
+        except (IOError, OSError, pickle.PickleError):
+            return False
+
+
+class UWSGICache(BaseCache):
+    """Implements the cache using uWSGI's caching framework.
+
+    .. note::
+        This class cannot be used when running under PyPy, because the uWSGI
+        API implementation for PyPy is lacking the needed functionality.
+
+    :param default_timeout: The default timeout in seconds.
+    :param cache: The name of the caching instance to connect to, for
+        example: mycache@localhost:3031, defaults to an empty string, which
+        means uWSGI will cache in the local instance. If the cache is in the
+        same instance as the werkzeug app, you only have to provide the name of
+        the cache.
+    """
+
+    def __init__(self, default_timeout=300, cache=""):
+        BaseCache.__init__(self, default_timeout)
+
+        if platform.python_implementation() == "PyPy":
+            raise RuntimeError(
+                "uWSGI caching does not work under PyPy, see "
+                "the docs for more details."
+            )
+
+        try:
+            import uwsgi
+
+            self._uwsgi = uwsgi
+        except ImportError:
+            raise RuntimeError(
+                "uWSGI could not be imported, are you running under uWSGI?"
+            )
+
+        self.cache = cache
+
+    def get(self, key):
+        rv = self._uwsgi.cache_get(key, self.cache)
+        if rv is None:
+            return
+        return pickle.loads(rv)
+
+    def delete(self, key):
+        return self._uwsgi.cache_del(key, self.cache)
+
+    def set(self, key, value, timeout=None):
+        return self._uwsgi.cache_update(
+            key, pickle.dumps(value), self._normalize_timeout(timeout), self.cache
+        )
+
+    def add(self, key, value, timeout=None):
+        return self._uwsgi.cache_set(
+            key, pickle.dumps(value), self._normalize_timeout(timeout), self.cache
+        )
+
+    def clear(self):
+        return self._uwsgi.cache_clear(self.cache)
+
+    def has(self, key):
+        return self._uwsgi.cache_exists(key, self.cache) is not None