Separate lazy-versioned NormalizedNodeDataInput

[controller.git] / opendaylight / md-sal / sal-clustering-commons / src / main / java / org / opendaylight / controller / cluster / datastore / node / utils / stream / VersionedNormalizedNodeDataInput.java

diff --git a/opendaylight/md-sal/sal-clustering-commons/src/main/java/org/opendaylight/controller/cluster/datastore/node/utils/stream/VersionedNormalizedNodeDataInput.java b/opendaylight/md-sal/sal-clustering-commons/src/main/java/org/opendaylight/controller/cluster/datastore/node/utils/stream/VersionedNormalizedNodeDataInput.java
new file mode 100644 (file)
index 0000000..860fe39
--- /dev/null
+++ b/opendaylight/md-sal/sal-clustering-commons/src/main/java/org/opendaylight/controller/cluster/datastore/node/utils/stream/VersionedNormalizedNodeDataInput.java
@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2019 PANTHEON.tech, s.r.o. 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.datastore.node.utils.stream;
+
+import static java.util.Objects.requireNonNull;
+
+import java.io.DataInput;
+import java.io.IOException;
+
+final class VersionedNormalizedNodeDataInput extends ForwardingNormalizedNodeDataInput {
+    private DataInput input;
+    private NormalizedNodeDataInput delegate;
+
+    VersionedNormalizedNodeDataInput(final DataInput input) {
+        this.input = requireNonNull(input);
+    }
+
+    @Override
+    NormalizedNodeDataInput delegate() throws IOException {
+        if (delegate != null) {
+            return delegate;
+        }
+
+        final byte marker = input.readByte();
+        if (marker != TokenTypes.SIGNATURE_MARKER) {
+            throw defunct("Invalid signature marker: %d", marker);
+        }
+
+        final short version = input.readShort();
+        final NormalizedNodeDataInput ret;
+        switch (version) {
+            case TokenTypes.LITHIUM_VERSION:
+                ret = new NormalizedNodeInputStreamReader(input);
+                break;
+            default:
+                throw defunct("Unhandled stream version %s", version);
+        }
+
+        setDelegate(ret);
+        return ret;
+    }
+
+    private InvalidNormalizedNodeStreamException defunct(final String format, final Object... args) {
+        final InvalidNormalizedNodeStreamException ret = new InvalidNormalizedNodeStreamException(
+            String.format(format, args));
+        // Make sure the stream is not touched
+        setDelegate(new ForwardingNormalizedNodeDataInput() {
+            @Override
+            NormalizedNodeDataInput delegate() throws IOException {
+                throw new InvalidNormalizedNodeStreamException("Stream is not usable", ret);
+            }
+        });
+        return ret;
+    }
+
+    private void setDelegate(final NormalizedNodeDataInput delegate) {
+        this.delegate = requireNonNull(delegate);
+        input = null;
+    }
+}