opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/persisted/CommitTransactionPayload.java

   1 /*
   2  * Copyright (c) 2016 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.controller.cluster.datastore.persisted;
   9
  10 import com.google.common.annotations.Beta;
  11 import com.google.common.annotations.VisibleForTesting;
  12 import com.google.common.base.Preconditions;
  13 import com.google.common.io.ByteArrayDataOutput;
  14 import com.google.common.io.ByteStreams;
  15 import java.io.DataInput;
  16 import java.io.Externalizable;
  17 import java.io.IOException;
  18 import java.io.ObjectInput;
  19 import java.io.ObjectOutput;
  20 import java.io.Serializable;
  21 import java.util.AbstractMap.SimpleImmutableEntry;
  22 import java.util.Map.Entry;
  23 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
  24 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.Payload;
  25 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  26 import org.slf4j.Logger;
  27 import org.slf4j.LoggerFactory;
  28
  29 /**
  30  * Payload persisted when a transaction commits. It contains the transaction identifier and the
  31  * {@link DataTreeCandidate}
  32  *
  33  * @author Robert Varga
  34  */
  35 @Beta
  36 public final class CommitTransactionPayload extends Payload implements Serializable {
  37     private static final Logger LOG = LoggerFactory.getLogger(CommitTransactionPayload.class);
  38
  39     private static final class Proxy implements Externalizable {
  40         private static final long serialVersionUID = 1L;
  41         private byte[] serialized;
  42
  43         // checkstyle flags the public modifier as redundant which really doesn't make sense since it clearly isn't
  44         // redundant. It is explicitly needed for Java serialization to be able to create instances via reflection.
  45         @SuppressWarnings("checkstyle:RedundantModifier")
  46         public Proxy() {
  47             // For Externalizable
  48         }
  49
  50         Proxy(final byte[] serialized) {
  51             this.serialized = Preconditions.checkNotNull(serialized);
  52         }
  53
  54         @Override
  55         public void writeExternal(final ObjectOutput out) throws IOException {
  56             out.writeInt(serialized.length);
  57             out.write(serialized);
  58         }
  59
  60         @Override
  61         public void readExternal(final ObjectInput in) throws IOException {
  62             final int length = in.readInt();
  63             serialized = new byte[length];
  64             in.readFully(serialized);
  65         }
  66
  67         private Object readResolve() {
  68             return new CommitTransactionPayload(serialized);
  69         }
  70     }
  71
  72     private static final long serialVersionUID = 1L;
  73
  74     private final byte[] serialized;
  75
  76     CommitTransactionPayload(final byte[] serialized) {
  77         this.serialized = Preconditions.checkNotNull(serialized);
  78     }
  79
  80     public static CommitTransactionPayload create(final TransactionIdentifier transactionId,
  81             final DataTreeCandidate candidate, final int initialSerializedBufferCapacity) throws IOException {
  82         final ByteArrayDataOutput out = ByteStreams.newDataOutput(initialSerializedBufferCapacity);
  83         transactionId.writeTo(out);
  84         DataTreeCandidateInputOutput.writeDataTreeCandidate(out, candidate);
  85         final byte[] serialized = out.toByteArray();
  86
  87         LOG.debug("Initial buffer capacity {}, actual serialized size {}",
  88                 initialSerializedBufferCapacity, serialized.length);
  89
  90         return new CommitTransactionPayload(serialized);
  91     }
  92
  93     @VisibleForTesting
  94     public static CommitTransactionPayload create(final TransactionIdentifier transactionId,
  95             final DataTreeCandidate candidate) throws IOException {
  96         return create(transactionId, candidate, 512);
  97     }
  98
  99     public Entry<TransactionIdentifier, DataTreeCandidate> getCandidate() throws IOException {
 100         final DataInput in = ByteStreams.newDataInput(serialized);
 101         return new SimpleImmutableEntry<>(TransactionIdentifier.readFrom(in),
 102                 DataTreeCandidateInputOutput.readDataTreeCandidate(in));
 103     }
 104
 105     @Override
 106     public int size() {
 107         return serialized.length;
 108     }
 109
 110     private Object writeReplace() {
 111         return new Proxy(serialized);
 112     }
 113 }