SEBA-405 Convert synchronizer framework to library

Change-Id: If8562f23dc15c7d18d7a8b040b33756708b3c5ec
diff --git a/lib/xos-synchronizer/xossynchronizer/apiaccessor.py b/lib/xos-synchronizer/xossynchronizer/apiaccessor.py
new file mode 100644
index 0000000..a56381b
--- /dev/null
+++ b/lib/xos-synchronizer/xossynchronizer/apiaccessor.py
@@ -0,0 +1,92 @@
+# Copyright 2017-present Open Networking Foundation
+#
+# 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.
+
+
+from modelaccessor import ModelAccessor
+import datetime
+import time
+
+
+class CoreApiModelAccessor(ModelAccessor):
+    def __init__(self, orm):
+        self.orm = orm
+        super(CoreApiModelAccessor, self).__init__()
+
+    def get_all_model_classes(self):
+        all_model_classes = {}
+        for k in self.orm.all_model_names:
+            all_model_classes[k] = getattr(self.orm, k)
+        return all_model_classes
+
+    def fetch_pending(self, main_objs, deletion=False):
+        if not isinstance(main_objs, list):
+            main_objs = [main_objs]
+
+        objs = []
+        for main_obj in main_objs:
+            if not deletion:
+                lobjs = main_obj.objects.filter_special(
+                    main_obj.objects.SYNCHRONIZER_DIRTY_OBJECTS
+                )
+            else:
+                lobjs = main_obj.objects.filter_special(
+                    main_obj.objects.SYNCHRONIZER_DELETED_OBJECTS
+                )
+            objs.extend(lobjs)
+
+        return objs
+
+    def fetch_policies(self, main_objs, deletion=False):
+        if not isinstance(main_objs, list):
+            main_objs = [main_objs]
+
+        objs = []
+        for main_obj in main_objs:
+            if not deletion:
+                lobjs = main_obj.objects.filter_special(
+                    main_obj.objects.SYNCHRONIZER_DIRTY_POLICIES
+                )
+            else:
+                lobjs = main_obj.objects.filter_special(
+                    main_obj.objects.SYNCHRONIZER_DELETED_POLICIES
+                )
+            objs.extend(lobjs)
+
+        return objs
+
+    def obj_exists(self, o):
+        # gRPC will default id to '0' for uninitialized objects
+        return (o.id is not None) and (o.id != 0)
+
+    def obj_in_list(self, o, olist):
+        ids = [x.id for x in olist]
+        return o.id in ids
+
+    def now(self):
+        """ Return the current time for timestamping purposes """
+        return (
+            datetime.datetime.utcnow() - datetime.datetime.fromtimestamp(0)
+        ).total_seconds()
+
+    def is_type(self, obj, name):
+        return obj._wrapped_class.__class__.__name__ == name
+
+    def is_instance(self, obj, name):
+        return name in obj.class_names.split(",")
+
+    def get_content_type_id(self, obj):
+        return obj.self_content_type_id
+
+    def create_obj(self, cls, **kwargs):
+        return cls.objects.new(**kwargs)