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.eclipse.jdt.annotation.NonNull;
  30 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
  31 import org.opendaylight.controller.cluster.datastore.persisted.DataTreeCandidateInputOutput.DataTreeCandidateWithVersion;
  32 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.IdentifiablePayload;
  33 import org.opendaylight.yangtools.concepts.Variant;
  34 import org.opendaylight.yangtools.yang.data.api.schema.stream.ReusableStreamReceiver;
  35 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  36 import org.opendaylight.yangtools.yang.data.impl.schema.ReusableImmutableNormalizedNodeStreamWriter;
  37 import org.slf4j.Logger;
  38 import org.slf4j.LoggerFactory;
  39
  40 /**
  41  * Payload persisted when a transaction commits. It contains the transaction identifier and the
  42  * {@link DataTreeCandidate}
  43  *
  44  * @author Robert Varga
  45  */
  46 @Beta
  47 public abstract class CommitTransactionPayload extends IdentifiablePayload<TransactionIdentifier>
  48         implements Serializable {
  49     private static final Logger LOG = LoggerFactory.getLogger(CommitTransactionPayload.class);
  50     private static final long serialVersionUID = 1L;
  51
  52     private volatile Entry<TransactionIdentifier, DataTreeCandidateWithVersion> candidate = null;
  53
  54     CommitTransactionPayload() {
  55
  56     }
  57
  58     public static @NonNull CommitTransactionPayload create(final TransactionIdentifier transactionId,
  59             final DataTreeCandidate candidate, final PayloadVersion version, final int initialSerializedBufferCapacity)
  60                     throws IOException {
  61         final ChunkedOutputStream cos = new ChunkedOutputStream(initialSerializedBufferCapacity);
  62         try (DataOutputStream dos = new DataOutputStream(cos)) {
  63             transactionId.writeTo(dos);
  64             DataTreeCandidateInputOutput.writeDataTreeCandidate(dos, version, candidate);
  65         }
  66
  67         final Variant<byte[], ChunkedByteArray> source = cos.toVariant();
  68         LOG.debug("Initial buffer capacity {}, actual serialized size {}", initialSerializedBufferCapacity, cos.size());
  69         return source.isFirst() ? new Simple(source.getFirst()) : new Chunked(source.getSecond());
  70     }
  71
  72     @VisibleForTesting
  73     public static @NonNull CommitTransactionPayload create(final TransactionIdentifier transactionId,
  74             final DataTreeCandidate candidate, final PayloadVersion version) throws IOException {
  75         return create(transactionId, candidate, version, 512);
  76     }
  77
  78     @VisibleForTesting
  79     public static @NonNull CommitTransactionPayload create(final TransactionIdentifier transactionId,
  80             final DataTreeCandidate candidate) throws IOException {
  81         return create(transactionId, candidate, PayloadVersion.current());
  82     }
  83
  84     public @NonNull Entry<TransactionIdentifier, DataTreeCandidateWithVersion> getCandidate() throws IOException {
  85         Entry<TransactionIdentifier, DataTreeCandidateWithVersion> localCandidate = candidate;
  86         if (localCandidate == null) {
  87             synchronized (this) {
  88                 localCandidate = candidate;
  89                 if (localCandidate == null) {
  90                     candidate = localCandidate = getCandidate(ReusableImmutableNormalizedNodeStreamWriter.create());
  91                 }
  92             }
  93         }
  94         return localCandidate;
  95     }
  96
  97     public final @NonNull Entry<TransactionIdentifier, DataTreeCandidateWithVersion> getCandidate(
  98             final ReusableStreamReceiver receiver) throws IOException {
  99         final DataInput in = newDataInput();
 100         return new SimpleImmutableEntry<>(TransactionIdentifier.readFrom(in),
 101                 DataTreeCandidateInputOutput.readDataTreeCandidate(in, receiver));
 102     }
 103
 104     @Override
 105     public TransactionIdentifier getIdentifier() {
 106         try  {
 107             return getCandidate().getKey();
 108         } catch (IOException e) {
 109             throw new IllegalStateException("Candidate deserialization failed.", e);
 110         }
 111     }
 112
 113     /**
 114      * The cached candidate needs to be cleared after it is done applying to the DataTree, otherwise it would be keeping
 115      * deserialized in memory which are not needed anymore leading to wasted memory. This lets the payload know that
 116      * this was the last time the candidate was needed ant it is safe to be cleared.
 117      */
 118     public Entry<TransactionIdentifier, DataTreeCandidateWithVersion> acquireCandidate() throws IOException {
 119         final Entry<TransactionIdentifier, DataTreeCandidateWithVersion> localCandidate = getCandidate();
 120         candidate = null;
 121         return localCandidate;
 122     }
 123
 124     abstract void writeBytes(ObjectOutput out) throws IOException;
 125
 126     abstract DataInput newDataInput();
 127
 128     final Object writeReplace() {
 129         return new Proxy(this);
 130     }
 131
 132     private static final class Simple extends CommitTransactionPayload {
 133         private static final long serialVersionUID = 1L;
 134
 135         private final byte[] serialized;
 136
 137         Simple(final byte[] serialized) {
 138             this.serialized = requireNonNull(serialized);
 139         }
 140
 141         @Override
 142         public int size() {
 143             return serialized.length;
 144         }
 145
 146         @Override
 147         DataInput newDataInput() {
 148             return ByteStreams.newDataInput(serialized);
 149         }
 150
 151         @Override
 152         void writeBytes(final ObjectOutput out) throws IOException {
 153             out.write(serialized);
 154         }
 155     }
 156
 157     private static final class Chunked extends CommitTransactionPayload {
 158         private static final long serialVersionUID = 1L;
 159
 160         @SuppressFBWarnings(value = "SE_BAD_FIELD", justification = "Handled via serialization proxy")
 161         private final ChunkedByteArray source;
 162
 163         Chunked(final ChunkedByteArray source) {
 164             this.source = requireNonNull(source);
 165         }
 166
 167         @Override
 168         void writeBytes(final ObjectOutput out) throws IOException {
 169             source.copyTo(out);
 170         }
 171
 172         @Override
 173         public int size() {
 174             return source.size();
 175         }
 176
 177         @Override
 178         DataInput newDataInput() {
 179             return new DataInputStream(source.openStream());
 180         }
 181     }
 182
 183     private static final class Proxy implements Externalizable {
 184         private static final long serialVersionUID = 1L;
 185
 186         private CommitTransactionPayload payload;
 187
 188         // checkstyle flags the public modifier as redundant which really doesn't make sense since it clearly isn't
 189         // redundant. It is explicitly needed for Java serialization to be able to create instances via reflection.
 190         @SuppressWarnings("checkstyle:RedundantModifier")
 191         public Proxy() {
 192             // For Externalizable
 193         }
 194
 195         Proxy(final CommitTransactionPayload payload) {
 196             this.payload = requireNonNull(payload);
 197         }
 198
 199         @Override
 200         public void writeExternal(final ObjectOutput out) throws IOException {
 201             out.writeInt(payload.size());
 202             payload.writeBytes(out);
 203         }
 204
 205         @Override
 206         public void readExternal(final ObjectInput in) throws IOException {
 207             final int length = in.readInt();
 208             if (length < 0) {
 209                 throw new StreamCorruptedException("Invalid payload length " + length);
 210             } else if (length < MAX_ARRAY_SIZE) {
 211                 final byte[] serialized = new byte[length];
 212                 in.readFully(serialized);
 213                 payload = new Simple(serialized);
 214             } else {
 215                 payload = new Chunked(ChunkedByteArray.readFrom(in, length, MAX_ARRAY_SIZE));
 216             }
 217         }
 218
 219         private Object readResolve() {
 220             return verifyNotNull(payload);
 221         }
 222     }
 223 }