ONOS-885: Group store interface definition and in-memory store implementation

Change-Id: I1125fbc23f1e58bcb8aaf5f67c02da610fa7ef25

ONOS-885: Group store interface definition and in-memory store implementation

Change-Id: Id3794bed63785e10ed86c0b5d90bf875d127224c
diff --git a/core/api/src/main/java/org/onosproject/net/group/GroupStore.java b/core/api/src/main/java/org/onosproject/net/group/GroupStore.java
new file mode 100644
index 0000000..22914f9
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/group/GroupStore.java
@@ -0,0 +1,105 @@
+/*
+ * Copyright 2015 Open Networking Laboratory
+ *
+ * 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.
+ */
+package org.onosproject.net.group;
+
+import org.onosproject.net.DeviceId;
+import org.onosproject.store.Store;
+
+/**
+ * Manages inventory of groups per device; not intended for direct use.
+ */
+public interface GroupStore extends Store<GroupEvent, GroupStoreDelegate> {
+
+    public enum UpdateType {
+        /**
+         * Modify existing group entry by adding provided information.
+         */
+        ADD,
+        /**
+         * Modify existing group by removing provided information from it.
+         */
+        REMOVE
+    }
+
+    /**
+     * Returns the number of groups for the specified device in the store.
+     *
+     * @param deviceId the device ID
+     * @return number of groups for the specified device
+     */
+    int getGroupCount(DeviceId deviceId);
+
+    /**
+     * Returns the groups associated with a device.
+     *
+     * @param deviceId the device ID
+     * @return the group entries
+     */
+    Iterable<Group> getGroups(DeviceId deviceId);
+
+    /**
+     * Returns the stored group entry.
+     *
+     * @param deviceId the device ID
+     * @param appCookie the group key
+     * @return a group associated with the key
+     */
+    Group getGroup(DeviceId deviceId, GroupKey appCookie);
+
+    /**
+     * Stores a new group entry using the information from group description.
+     *
+     * @param groupDesc group description to be used to store group entry
+     */
+    void storeGroupDescription(GroupDescription groupDesc);
+
+    /**
+     * Updates the existing group entry with the information
+     * from group description.
+     *
+     * @param deviceId the device ID
+     * @param oldAppCookie the current group key
+     * @param type update type
+     * @param newGroupDesc group description with updates
+     */
+    void updateGroupDescription(DeviceId deviceId,
+                                GroupKey oldAppCookie,
+                                UpdateType type,
+                                GroupDescription newGroupDesc);
+
+    /**
+     * Triggers deleting the existing group entry.
+     *
+     * @param deviceId the device ID
+     * @param appCookie the group key
+     */
+    void deleteGroupDescription(DeviceId deviceId,
+                                GroupKey appCookie);
+
+    /**
+     * Stores a new group entry, or updates an existing entry.
+     *
+     * @param group group entry
+     */
+    void addOrUpdateGroupEntry(Group group);
+
+    /**
+     * Removes the group entry from store.
+     *
+     * @param group group entry
+     */
+    void removeGroupEntry(Group group);
+}