Bug 7449: Add message slicing/re-assembly classes

[controller.git] / opendaylight / md-sal / sal-clustering-commons / src / main / java / org / opendaylight / controller / cluster / messaging / MessageSlice.java

diff --git a/opendaylight/md-sal/sal-clustering-commons/src/main/java/org/opendaylight/controller/cluster/messaging/MessageSlice.java b/opendaylight/md-sal/sal-clustering-commons/src/main/java/org/opendaylight/controller/cluster/messaging/MessageSlice.java
new file mode 100644 (file)
index 0000000..00ab31d
--- /dev/null
+++ b/opendaylight/md-sal/sal-clustering-commons/src/main/java/org/opendaylight/controller/cluster/messaging/MessageSlice.java
@@ -0,0 +1,127 @@
+/*
+ * Copyright (c) 2017 Inocybe Technologies 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.messaging;
+
+import akka.actor.ActorRef;
+import akka.serialization.JavaSerializer;
+import akka.serialization.Serialization;
+import com.google.common.base.Preconditions;
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+import java.io.Externalizable;
+import java.io.IOException;
+import java.io.ObjectInput;
+import java.io.ObjectOutput;
+import java.io.Serializable;
+import org.opendaylight.yangtools.concepts.Identifier;
+
+/**
+ * Represents a sliced message chunk.
+ *
+ * @author Thomas Pantelis
+ */
+public class MessageSlice implements Serializable {
+    private static final long serialVersionUID = 1L;
+
+    private final Identifier identifier;
+    private final byte[] data;
+    private final int sliceIndex;
+    private final int totalSlices;
+    private final int lastSliceHashCode;
+    private final ActorRef replyTo;
+
+    public MessageSlice(Identifier identifier, byte[] data, int sliceIndex, int totalSlices, int lastSliceHashCode,
+            final ActorRef replyTo) {
+        this.identifier = Preconditions.checkNotNull(identifier);
+        this.data = Preconditions.checkNotNull(data);
+        this.sliceIndex = sliceIndex;
+        this.totalSlices = totalSlices;
+        this.lastSliceHashCode = lastSliceHashCode;
+        this.replyTo = Preconditions.checkNotNull(replyTo);
+    }
+
+    public Identifier getIdentifier() {
+        return identifier;
+    }
+
+    @SuppressFBWarnings(value = "EI_EXPOSE_REP", justification = "Exposes a mutable object stored in a field but "
+            + "this is OK since this class is merely a DTO and does not process the byte[] internally."
+            + "Also it would be inefficient to create a return copy as the byte[] could be large.")
+    public byte[] getData() {
+        return data;
+    }
+
+    public int getSliceIndex() {
+        return sliceIndex;
+    }
+
+    public int getTotalSlices() {
+        return totalSlices;
+    }
+
+    public int getLastSliceHashCode() {
+        return lastSliceHashCode;
+    }
+
+    public ActorRef getReplyTo() {
+        return replyTo;
+    }
+
+    @Override
+    public String toString() {
+        return "MessageSlice [identifier=" + identifier + ", data.length=" + data.length + ", sliceIndex="
+                + sliceIndex + ", totalSlices=" + totalSlices + ", lastSliceHashCode=" + lastSliceHashCode
+                + ", replyTo=" + replyTo + "]";
+    }
+
+    private Object writeReplace() {
+        return new Proxy(this);
+    }
+
+    private static class Proxy implements Externalizable {
+        private static final long serialVersionUID = 1L;
+
+        private MessageSlice messageSlice;
+
+        // checkstyle flags the public modifier as redundant which really doesn't make sense since it clearly isn't
+        // redundant. It is explicitly needed for Java serialization to be able to create instances via reflection.
+        @SuppressWarnings("checkstyle:RedundantModifier")
+        public Proxy() {
+        }
+
+        Proxy(MessageSlice messageSlice) {
+            this.messageSlice = messageSlice;
+        }
+
+        @Override
+        public void writeExternal(ObjectOutput out) throws IOException {
+            out.writeObject(messageSlice.identifier);
+            out.writeInt(messageSlice.sliceIndex);
+            out.writeInt(messageSlice.totalSlices);
+            out.writeInt(messageSlice.lastSliceHashCode);
+            out.writeObject(messageSlice.data);
+            out.writeObject(Serialization.serializedActorPath(messageSlice.replyTo));
+        }
+
+        @Override
+        public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
+            Identifier identifier = (Identifier) in.readObject();
+            int sliceIndex = in.readInt();
+            int totalSlices = in.readInt();
+            int lastSliceHashCode = in.readInt();
+            byte[] data = (byte[])in.readObject();
+            ActorRef replyTo = JavaSerializer.currentSystem().value().provider()
+                    .resolveActorRef((String) in.readObject());
+
+            messageSlice = new MessageSlice(identifier, data, sliceIndex, totalSlices, lastSliceHashCode, replyTo);
+        }
+
+        private Object readResolve() {
+            return messageSlice;
+        }
+    }
+}