Initial import

1 files changed, 131 insertions, 0 deletions

diff --git a/heatclient/common/base.py b/heatclient/common/base.py
new file mode 100644
index 0000000..3cedd32
--- /dev/null
+++ b/heatclient/common/base.py
@@ -0,0 +1,131 @@
+# Copyright 2012 OpenStack LLC.
+# 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.
+
+"""
+Base utilities to build API operation managers and objects on top of.
+"""
+
+import copy
+
+
+# Python 2.4 compat
+try:
+    all
+except NameError:
+    def all(iterable):
+        return True not in (not x for x in iterable)
+
+
+def getid(obj):
+    """
+    Abstracts the common pattern of allowing both an object or an object's ID
+    (UUID) as a parameter when dealing with relationships.
+    """
+    try:
+        return obj.id
+    except AttributeError:
+        return obj
+
+
+class Manager(object):
+    """
+    Managers interact with a particular type of API (servers, flavors, images,
+    etc.) and provide CRUD operations for them.
+    """
+    resource_class = None
+
+    def __init__(self, api):
+        self.api = api
+
+    def _list(self, url, response_key, obj_class=None, body=None):
+        resp, body = self.api.json_request('GET', url)
+
+        if obj_class is None:
+            obj_class = self.resource_class
+
+        data = body[response_key]
+        return [obj_class(self, res, loaded=True) for res in data if res]
+
+    def _delete(self, url):
+        self.api.raw_request('DELETE', url)
+
+    def _update(self, url, body, response_key=None):
+        resp, body = self.api.json_request('PUT', url, body=body)
+        # PUT requests may not return a body
+        if body:
+            return self.resource_class(self, body[response_key])
+
+
+class Resource(object):
+    """
+    A resource represents a particular instance of an object (tenant, user,
+    etc). This is pretty much just a bag for attributes.
+
+    :param manager: Manager object
+    :param info: dictionary representing resource attributes
+    :param loaded: prevent lazy-loading if set to True
+    """
+    def __init__(self, manager, info, loaded=False):
+        self.manager = manager
+        self._info = info
+        self._add_details(info)
+        self._loaded = loaded
+
+    def _add_details(self, info):
+        for (k, v) in info.iteritems():
+            setattr(self, k, v)
+
+    def __getattr__(self, k):
+        if k not in self.__dict__:
+            #NOTE(bcwaldon): disallow lazy-loading if already loaded once
+            if not self.is_loaded():
+                self.get()
+                return self.__getattr__(k)
+
+            raise AttributeError(k)
+        else:
+            return self.__dict__[k]
+
+    def __repr__(self):
+        reprkeys = sorted(k for k in self.__dict__.keys() if k[0] != '_' and
+                                                                k != 'manager')
+        info = ", ".join("%s=%s" % (k, getattr(self, k)) for k in reprkeys)
+        return "<%s %s>" % (self.__class__.__name__, info)
+
+    def get(self):
+        # set_loaded() first ... so if we have to bail, we know we tried.
+        self.set_loaded(True)
+        if not hasattr(self.manager, 'get'):
+            return
+
+        new = self.manager.get(self.id)
+        if new:
+            self._add_details(new._info)
+
+    def __eq__(self, other):
+        if not isinstance(other, self.__class__):
+            return False
+        if hasattr(self, 'id') and hasattr(other, 'id'):
+            return self.id == other.id
+        return self._info == other._info
+
+    def is_loaded(self):
+        return self._loaded
+
+    def set_loaded(self, val):
+        self._loaded = val
+
+    def to_dict(self):
+        return copy.deepcopy(self._info)