BUG-5280: introduce base Transaction request/success

[controller.git] / opendaylight / md-sal / cds-access-api / src / main / java / org / opendaylight / controller / cluster / access / commands / PersistenceProtocol.java

diff --git a/opendaylight/md-sal/cds-access-api/src/main/java/org/opendaylight/controller/cluster/access/commands/PersistenceProtocol.java b/opendaylight/md-sal/cds-access-api/src/main/java/org/opendaylight/controller/cluster/access/commands/PersistenceProtocol.java
new file mode 100644 (file)
index 0000000..36acfb2
--- /dev/null
+++ b/opendaylight/md-sal/cds-access-api/src/main/java/org/opendaylight/controller/cluster/access/commands/PersistenceProtocol.java
@@ -0,0 +1,85 @@
+/*
+ * Copyright (c) 2016 Cisco Systems, Inc. and others.  All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+package org.opendaylight.controller.cluster.access.commands;
+
+import com.google.common.annotations.Beta;
+import java.io.DataInput;
+import java.io.DataOutput;
+import java.io.IOException;
+import org.opendaylight.yangtools.concepts.WritableObject;
+
+/**
+ * Enumeration of transaction persistence protocols. These govern which protocol is executed between the frontend
+ * and backend to drive persistence of a particular transaction.
+ *
+ * @author Robert Varga
+ */
+@Beta
+public enum PersistenceProtocol implements WritableObject {
+    /**
+     * Abort protocol. The transaction has been aborted on the frontend and its effects should not be visible
+     * in the global history. This is a simple request/reply protocol.
+     */
+    ABORT {
+        @Override
+        byte byteValue() {
+            return 1;
+        }
+    },
+    /**
+     * Simple commit protocol. The transaction should be committed to the global history. The receiving backend
+     * it the only entity which needs to persist its effects, hence a simple request/reply protocol is sufficient.
+     */
+    SIMPLE {
+        @Override
+        byte byteValue() {
+            return 2;
+        }
+    },
+    /**
+     * Three-phase commit protocol (3PC). The transaction should be committed to the global history, but it is a part
+     * of a transaction spanning multiple entities and coordination is needed to drive persistence.
+     */
+    THREE_PHASE {
+        @Override
+        byte byteValue() {
+            return 3;
+        }
+
+    };
+
+    @Override
+    public final void writeTo(final DataOutput out) throws IOException {
+        out.writeByte(byteValue());
+    }
+
+    abstract byte byteValue();
+
+    public static PersistenceProtocol readFrom(final DataInput in) throws IOException {
+        return valueOf(in.readByte());
+    }
+
+    static int byteValue(final PersistenceProtocol finish) {
+        return finish == null ? 0 : finish.byteValue();
+    }
+
+    static PersistenceProtocol valueOf(final byte b) {
+        switch (b) {
+            case 0:
+                return null;
+            case 1:
+                return ABORT;
+            case 2:
+                return SIMPLE;
+            case 3:
+                return THREE_PHASE;
+            default:
+                throw new IllegalArgumentException("Unhandled byte value " + b);
+        }
+    }
+}