[ONOS-7683] Initial commit of openstacktelemetry with service interfaces

Change-Id: Ic1d40107fbdf2e77fd5e52c83d06f04251e868ba
diff --git a/apps/openstacktelemetry/api/src/main/java/org/onosproject/openstacktelemetry/api/ByteBufferCodec.java b/apps/openstacktelemetry/api/src/main/java/org/onosproject/openstacktelemetry/api/ByteBufferCodec.java
new file mode 100644
index 0000000..fc5c5407
--- /dev/null
+++ b/apps/openstacktelemetry/api/src/main/java/org/onosproject/openstacktelemetry/api/ByteBufferCodec.java
@@ -0,0 +1,46 @@
+/*
+ * Copyright 2018-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.
+ */
+package org.onosproject.openstacktelemetry.api;
+
+import java.nio.ByteBuffer;
+
+/**
+ * Abstraction of a codec capable for encoding/decoding arbitrary objects to/from ByteBuffer.
+ */
+public abstract class ByteBufferCodec<T> {
+
+    /**
+     * Encodes the specified entity into ByteBuffer.
+     *
+     * @param entity entity to encode
+     * @return ByteBuffer
+     * @throws java.lang.UnsupportedOperationException if the codec does not
+     *                                                  support encode operations
+     */
+    public ByteBuffer encode(T entity) {
+        throw new UnsupportedOperationException("encode() not supported");
+    }
+
+    /**
+     * Decodes the specified entity from ByteBuffer.
+     *
+     * @param buffer ByteBuffer to decode
+     * @return decoded entity
+     */
+    public T decode(ByteBuffer buffer) {
+        throw new UnsupportedOperationException("decode() not supported");
+    }
+}