Sync memorycache and timeutils from oslo.

Change-Id: Ibc61b07fe65d97f9a0eb60e514e29bc12b2f9f4a

keystoneclient/openstack/common/memorycache.py

@@ -0,0 +1,96 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright 2010 United States Government as represented by the
+# Administrator of the National Aeronautics and Space Administration.
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+"""Super simple fake memcache client."""
+
+from oslo.config import cfg
+
+from keystoneclient.openstack.common import timeutils
+
+memcache_opts = [
+    cfg.ListOpt('memcached_servers',
+                default=None,
+                help='Memcached servers or None for in process cache.'),
+]
+
+CONF = cfg.CONF
+CONF.register_opts(memcache_opts)
+
+
+def get_client(memcached_servers=None):
+    client_cls = Client
+
+    if not memcached_servers:
+        memcached_servers = CONF.memcached_servers
+    if memcached_servers:
+        try:
+            import memcache
+            client_cls = memcache.Client
+        except ImportError:
+            pass
+
+    return client_cls(memcached_servers, debug=0)
+
+
+class Client(object):
+    """Replicates a tiny subset of memcached client interface."""
+
+    def __init__(self, *args, **kwargs):
+        """Ignores the passed in args."""
+        self.cache = {}
+
+    def get(self, key):
+        """Retrieves the value for a key or None.
+
+        this expunges expired keys during each get"""
+
+        now = timeutils.utcnow_ts()
+        for k in self.cache.keys():
+            (timeout, _value) = self.cache[k]
+            if timeout and now >= timeout:
+                del self.cache[k]
+
+        return self.cache.get(key, (0, None))[1]
+
+    def set(self, key, value, time=0, min_compress_len=0):
+        """Sets the value for a key."""
+        timeout = 0
+        if time != 0:
+            timeout = timeutils.utcnow_ts() + time
+        self.cache[key] = (timeout, value)
+        return True
+
+    def add(self, key, value, time=0, min_compress_len=0):
+        """Sets the value for a key if it doesn't exist."""
+        if self.get(key) is not None:
+            return False
+        return self.set(key, value, time, min_compress_len)
+
+    def incr(self, key, delta=1):
+        """Increments the value for a key."""
+        value = self.get(key)
+        if value is None:
+            return None
+        new_value = int(value) + delta
+        self.cache[key] = (self.cache[key][0], str(new_value))
+        return new_value
+
+    def delete(self, key, time=0):
+        """Deletes the value associated with a key."""
+        if key in self.cache:
+            del self.cache[key]

keystoneclient/openstack/common/timeutils.py

@@ -71,11 +71,15 @@ def normalize_time(timestamp):
 
 def is_older_than(before, seconds):
     """Return True if before is older than seconds."""
+    if isinstance(before, basestring):
+        before = parse_strtime(before).replace(tzinfo=None)
     return utcnow() - before > datetime.timedelta(seconds=seconds)
 
 
 def is_newer_than(after, seconds):
     """Return True if after is newer than seconds."""
+    if isinstance(after, basestring):
+        after = parse_strtime(after).replace(tzinfo=None)
     return after - utcnow() > datetime.timedelta(seconds=seconds)
 
 
@@ -87,22 +91,37 @@ def utcnow_ts():
 def utcnow():
     """Overridable version of utils.utcnow."""
     if utcnow.override_time:
-        return utcnow.override_time
+        try:
+            return utcnow.override_time.pop(0)
+        except AttributeError:
+            return utcnow.override_time
     return datetime.datetime.utcnow()
 
 
+def iso8601_from_timestamp(timestamp):
+    """Returns a iso8601 formated date from timestamp"""
+    return isotime(datetime.datetime.utcfromtimestamp(timestamp))
+
+
 utcnow.override_time = None
 
 
 def set_time_override(override_time=datetime.datetime.utcnow()):
-    """Override utils.utcnow to return a constant time."""
+    """
+    Override utils.utcnow to return a constant time or a list thereof,
+    one at a time.
+    """
     utcnow.override_time = override_time
 
 
 def advance_time_delta(timedelta):
     """Advance overridden time using a datetime.timedelta."""
     assert(not utcnow.override_time is None)
-    utcnow.override_time += timedelta
+    try:
+        for dt in utcnow.override_time:
+            dt += timedelta
+    except TypeError:
+        utcnow.override_time += timedelta
 
 
 def advance_time_seconds(seconds):
@@ -135,3 +154,29 @@ def unmarshall_time(tyme):
                              minute=tyme['minute'],
                              second=tyme['second'],
                              microsecond=tyme['microsecond'])
+
+
+def delta_seconds(before, after):
+    """
+    Compute the difference in seconds between two date, time, or
+    datetime objects (as a float, to microsecond resolution).
+    """
+    delta = after - before
+    try:
+        return delta.total_seconds()
+    except AttributeError:
+        return ((delta.days * 24 * 3600) + delta.seconds +
+                float(delta.microseconds) / (10 ** 6))
+
+
+def is_soon(dt, window):
+    """
+    Determines if time is going to happen in the next window seconds.
+
+    :params dt: the time
+    :params window: minimum seconds to remain to consider the time not soon
+
+    :return: True if expiration is within the given duration
+    """
+    soon = (utcnow() + datetime.timedelta(seconds=window))
+    return normalize_time(dt) <= soon