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 static com.google.common.base.Verify.verifyNotNull;
  11 import static java.util.Objects.requireNonNull;
  12 import static org.opendaylight.controller.cluster.datastore.persisted.ChunkedOutputStream.MAX_ARRAY_SIZE;
  13
  14 import com.google.common.annotations.Beta;
  15 import com.google.common.annotations.VisibleForTesting;
  16 import com.google.common.io.ByteStreams;
  17 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
  18 import java.io.DataInput;
  19 import java.io.DataInputStream;
  20 import java.io.DataOutputStream;
  21 import java.io.Externalizable;
  22 import java.io.IOException;
  23 import java.io.ObjectInput;
  24 import java.io.ObjectOutput;
  25 import java.io.Serializable;
  26 import java.io.StreamCorruptedException;
  27 import java.util.AbstractMap.SimpleImmutableEntry;
  28 import java.util.Map.Entry;
  29 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
  30 import org.opendaylight.controller.cluster.datastore.persisted.DataTreeCandidateInputOutput.DataTreeCandidateWithVersion;
  31 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.IdentifiablePayload;
  32 import org.opendaylight.yangtools.concepts.Variant;
  33 import org.opendaylight.yangtools.yang.data.api.schema.stream.ReusableStreamReceiver;
  34 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  35 import org.opendaylight.yangtools.yang.data.impl.schema.ReusableImmutableNormalizedNodeStreamWriter;
  36 import org.slf4j.Logger;
  37 import org.slf4j.LoggerFactory;
  38
  39 /**
  40  * Payload persisted when a transaction commits. It contains the transaction identifier and the
  41  * {@link DataTreeCandidate}
  42  *
  43  * @author Robert Varga
  44  */
  45 @Beta
  46 public abstract class CommitTransactionPayload extends IdentifiablePayload<TransactionIdentifier>
  47         implements Serializable {
  48     private static final Logger LOG = LoggerFactory.getLogger(CommitTransactionPayload.class);
  49     private static final long serialVersionUID = 1L;
  50
  51     private volatile Entry<TransactionIdentifier, DataTreeCandidateWithVersion> candidate = null;
  52
  53     CommitTransactionPayload() {
  54
  55     }
  56
  57     public static CommitTransactionPayload create(final TransactionIdentifier transactionId,
  58             final DataTreeCandidate candidate, final int initialSerializedBufferCapacity) throws IOException {
  59
  60         final ChunkedOutputStream cos = new ChunkedOutputStream(initialSerializedBufferCapacity);
  61         try (DataOutputStream dos = new DataOutputStream(cos)) {
  62             transactionId.writeTo(dos);
  63             DataTreeCandidateInputOutput.writeDataTreeCandidate(dos, candidate);
  64         }
  65
  66         final Variant<byte[], ChunkedByteArray> source = cos.toVariant();
  67         LOG.debug("Initial buffer capacity {}, actual serialized size {}", initialSerializedBufferCapacity, cos.size());
  68         return source.isFirst() ? new Simple(source.getFirst()) : new Chunked(source.getSecond());
  69     }
  70
  71     @VisibleForTesting
  72     public static CommitTransactionPayload create(final TransactionIdentifier transactionId,
  73             final DataTreeCandidate candidate) throws IOException {
  74         return create(transactionId, candidate, 512);
  75     }
  76
  77     public Entry<TransactionIdentifier, DataTreeCandidateWithVersion> getCandidate() throws IOException {
  78         Entry<TransactionIdentifier, DataTreeCandidateWithVersion> localCandidate = candidate;
  79         if (localCandidate == null) {
  80             synchronized (this) {
  81                 localCandidate = candidate;
  82                 if (localCandidate == null) {
  83                     candidate = localCandidate = getCandidate(ReusableImmutableNormalizedNodeStreamWriter.create());
  84                 }
  85             }
  86         }
  87         return localCandidate;
  88     }
  89
  90     public final Entry<TransactionIdentifier, DataTreeCandidateWithVersion> getCandidate(
  91             final ReusableStreamReceiver receiver) throws IOException {
  92         final DataInput in = newDataInput();
  93         return new SimpleImmutableEntry<>(TransactionIdentifier.readFrom(in),
  94                 DataTreeCandidateInputOutput.readDataTreeCandidate(in, receiver));
  95     }
  96
  97     @Override
  98     public TransactionIdentifier getIdentifier() {
  99         try  {
 100             return getCandidate().getKey();
 101         } catch (IOException e) {
 102             throw new IllegalStateException("Candidate deserialization failed.", e);
 103         }
 104     }
 105
 106     abstract void writeBytes(ObjectOutput out) throws IOException;
 107
 108     abstract DataInput newDataInput();
 109
 110     final Object writeReplace() {
 111         return new Proxy(this);
 112     }
 113
 114     private static final class Simple extends CommitTransactionPayload {
 115         private static final long serialVersionUID = 1L;
 116
 117         private final byte[] serialized;
 118
 119         Simple(final byte[] serialized) {
 120             this.serialized = requireNonNull(serialized);
 121         }
 122
 123         @Override
 124         public int size() {
 125             return serialized.length;
 126         }
 127
 128         @Override
 129         DataInput newDataInput() {
 130             return ByteStreams.newDataInput(serialized);
 131         }
 132
 133         @Override
 134         void writeBytes(final ObjectOutput out) throws IOException {
 135             out.write(serialized);
 136         }
 137     }
 138
 139     private static final class Chunked extends CommitTransactionPayload {
 140         private static final long serialVersionUID = 1L;
 141
 142         @SuppressFBWarnings(value = "SE_BAD_FIELD", justification = "Handled via serialization proxy")
 143         private final ChunkedByteArray source;
 144
 145         Chunked(final ChunkedByteArray source) {
 146             this.source = requireNonNull(source);
 147         }
 148
 149         @Override
 150         void writeBytes(final ObjectOutput out) throws IOException {
 151             source.copyTo(out);
 152         }
 153
 154         @Override
 155         public int size() {
 156             return source.size();
 157         }
 158
 159         @Override
 160         DataInput newDataInput() {
 161             return new DataInputStream(source.openStream());
 162         }
 163     }
 164
 165     private static final class Proxy implements Externalizable {
 166         private static final long serialVersionUID = 1L;
 167
 168         private CommitTransactionPayload payload;
 169
 170         // checkstyle flags the public modifier as redundant which really doesn't make sense since it clearly isn't
 171         // redundant. It is explicitly needed for Java serialization to be able to create instances via reflection.
 172         @SuppressWarnings("checkstyle:RedundantModifier")
 173         public Proxy() {
 174             // For Externalizable
 175         }
 176
 177         Proxy(final CommitTransactionPayload payload) {
 178             this.payload = requireNonNull(payload);
 179         }
 180
 181         @Override
 182         public void writeExternal(final ObjectOutput out) throws IOException {
 183             out.writeInt(payload.size());
 184             payload.writeBytes(out);
 185         }
 186
 187         @Override
 188         public void readExternal(final ObjectInput in) throws IOException {
 189             final int length = in.readInt();
 190             if (length < 0) {
 191                 throw new StreamCorruptedException("Invalid payload length " + length);
 192             } else if (length < MAX_ARRAY_SIZE) {
 193                 final byte[] serialized = new byte[length];
 194                 in.readFully(serialized);
 195                 payload = new Simple(serialized);
 196             } else {
 197                 payload = new Chunked(ChunkedByteArray.readFrom(in, length, MAX_ARRAY_SIZE));
 198             }
 199         }
 200
 201         private Object readResolve() {
 202             return verifyNotNull(payload);
 203         }
 204     }
 205 }