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 com.google.common.math.IntMath.ceilingPowerOfTwo;
  12 import static java.util.Objects.requireNonNull;
  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.io.ChunkedByteArray;
  33 import org.opendaylight.controller.cluster.io.ChunkedOutputStream;
  34 import org.opendaylight.controller.cluster.raft.protobuff.client.messages.IdentifiablePayload;
  35 import org.opendaylight.yangtools.concepts.Either;
  36 import org.opendaylight.yangtools.yang.data.api.schema.stream.ReusableStreamReceiver;
  37 import org.opendaylight.yangtools.yang.data.impl.schema.ReusableImmutableNormalizedNodeStreamWriter;
  38 import org.opendaylight.yangtools.yang.data.tree.api.DataTreeCandidate;
  39 import org.slf4j.Logger;
  40 import org.slf4j.LoggerFactory;
  41
  42 /**
  43  * Payload persisted when a transaction commits. It contains the transaction identifier and the
  44  * {@link DataTreeCandidate}
  45  *
  46  * @author Robert Varga
  47  */
  48 @Beta
  49 public abstract class CommitTransactionPayload extends IdentifiablePayload<TransactionIdentifier>
  50         implements Serializable {
  51     private static final Logger LOG = LoggerFactory.getLogger(CommitTransactionPayload.class);
  52     private static final long serialVersionUID = 1L;
  53
  54     private static final int MAX_ARRAY_SIZE = ceilingPowerOfTwo(Integer.getInteger(
  55         "org.opendaylight.controller.cluster.datastore.persisted.max-array-size", 256 * 1024));
  56
  57     private volatile Entry<TransactionIdentifier, DataTreeCandidateWithVersion> candidate = null;
  58
  59     CommitTransactionPayload() {
  60
  61     }
  62
  63     public static @NonNull CommitTransactionPayload create(final TransactionIdentifier transactionId,
  64             final DataTreeCandidate candidate, final PayloadVersion version, final int initialSerializedBufferCapacity)
  65                     throws IOException {
  66         final ChunkedOutputStream cos = new ChunkedOutputStream(initialSerializedBufferCapacity, MAX_ARRAY_SIZE);
  67         try (DataOutputStream dos = new DataOutputStream(cos)) {
  68             transactionId.writeTo(dos);
  69             DataTreeCandidateInputOutput.writeDataTreeCandidate(dos, version, candidate);
  70         }
  71
  72         final Either<byte[], ChunkedByteArray> source = cos.toVariant();
  73         LOG.debug("Initial buffer capacity {}, actual serialized size {}", initialSerializedBufferCapacity, cos.size());
  74         return source.isFirst() ? new Simple(source.getFirst()) : new Chunked(source.getSecond());
  75     }
  76
  77     @VisibleForTesting
  78     public static @NonNull CommitTransactionPayload create(final TransactionIdentifier transactionId,
  79             final DataTreeCandidate candidate, final PayloadVersion version) throws IOException {
  80         return create(transactionId, candidate, version, 512);
  81     }
  82
  83     @VisibleForTesting
  84     public static @NonNull CommitTransactionPayload create(final TransactionIdentifier transactionId,
  85             final DataTreeCandidate candidate) throws IOException {
  86         return create(transactionId, candidate, PayloadVersion.current());
  87     }
  88
  89     public @NonNull Entry<TransactionIdentifier, DataTreeCandidateWithVersion> getCandidate() throws IOException {
  90         Entry<TransactionIdentifier, DataTreeCandidateWithVersion> localCandidate = candidate;
  91         if (localCandidate == null) {
  92             synchronized (this) {
  93                 localCandidate = candidate;
  94                 if (localCandidate == null) {
  95                     candidate = localCandidate = getCandidate(ReusableImmutableNormalizedNodeStreamWriter.create());
  96                 }
  97             }
  98         }
  99         return localCandidate;
 100     }
 101
 102     public final @NonNull Entry<TransactionIdentifier, DataTreeCandidateWithVersion> getCandidate(
 103             final ReusableStreamReceiver receiver) throws IOException {
 104         final DataInput in = newDataInput();
 105         return new SimpleImmutableEntry<>(TransactionIdentifier.readFrom(in),
 106                 DataTreeCandidateInputOutput.readDataTreeCandidate(in, receiver));
 107     }
 108
 109     @Override
 110     public TransactionIdentifier getIdentifier() {
 111         try  {
 112             return getCandidate().getKey();
 113         } catch (IOException e) {
 114             throw new IllegalStateException("Candidate deserialization failed.", e);
 115         }
 116     }
 117
 118     /**
 119      * The cached candidate needs to be cleared after it is done applying to the DataTree, otherwise it would be keeping
 120      * deserialized in memory which are not needed anymore leading to wasted memory. This lets the payload know that
 121      * this was the last time the candidate was needed ant it is safe to be cleared.
 122      */
 123     public Entry<TransactionIdentifier, DataTreeCandidateWithVersion> acquireCandidate() throws IOException {
 124         final Entry<TransactionIdentifier, DataTreeCandidateWithVersion> localCandidate = getCandidate();
 125         candidate = null;
 126         return localCandidate;
 127     }
 128
 129     abstract void writeBytes(ObjectOutput out) throws IOException;
 130
 131     abstract DataInput newDataInput();
 132
 133     final Object writeReplace() {
 134         return new Proxy(this);
 135     }
 136
 137     private static final class Simple extends CommitTransactionPayload {
 138         private static final long serialVersionUID = 1L;
 139
 140         private final byte[] serialized;
 141
 142         Simple(final byte[] serialized) {
 143             this.serialized = requireNonNull(serialized);
 144         }
 145
 146         @Override
 147         public int size() {
 148             return serialized.length;
 149         }
 150
 151         @Override
 152         DataInput newDataInput() {
 153             return ByteStreams.newDataInput(serialized);
 154         }
 155
 156         @Override
 157         void writeBytes(final ObjectOutput out) throws IOException {
 158             out.write(serialized);
 159         }
 160     }
 161
 162     private static final class Chunked extends CommitTransactionPayload {
 163         private static final long serialVersionUID = 1L;
 164
 165         @SuppressFBWarnings(value = "SE_BAD_FIELD", justification = "Handled via serialization proxy")
 166         private final ChunkedByteArray source;
 167
 168         Chunked(final ChunkedByteArray source) {
 169             this.source = requireNonNull(source);
 170         }
 171
 172         @Override
 173         void writeBytes(final ObjectOutput out) throws IOException {
 174             source.copyTo(out);
 175         }
 176
 177         @Override
 178         public int size() {
 179             return source.size();
 180         }
 181
 182         @Override
 183         DataInput newDataInput() {
 184             return new DataInputStream(source.openStream());
 185         }
 186     }
 187
 188     private static final class Proxy implements Externalizable {
 189         private static final long serialVersionUID = 1L;
 190
 191         private CommitTransactionPayload payload;
 192
 193         // checkstyle flags the public modifier as redundant which really doesn't make sense since it clearly isn't
 194         // redundant. It is explicitly needed for Java serialization to be able to create instances via reflection.
 195         @SuppressWarnings("checkstyle:RedundantModifier")
 196         public Proxy() {
 197             // For Externalizable
 198         }
 199
 200         Proxy(final CommitTransactionPayload payload) {
 201             this.payload = requireNonNull(payload);
 202         }
 203
 204         @Override
 205         public void writeExternal(final ObjectOutput out) throws IOException {
 206             out.writeInt(payload.size());
 207             payload.writeBytes(out);
 208         }
 209
 210         @Override
 211         public void readExternal(final ObjectInput in) throws IOException {
 212             final int length = in.readInt();
 213             if (length < 0) {
 214                 throw new StreamCorruptedException("Invalid payload length " + length);
 215             } else if (length < MAX_ARRAY_SIZE) {
 216                 final byte[] serialized = new byte[length];
 217                 in.readFully(serialized);
 218                 payload = new Simple(serialized);
 219             } else {
 220                 payload = new Chunked(ChunkedByteArray.readFrom(in, length, MAX_ARRAY_SIZE));
 221             }
 222         }
 223
 224         private Object readResolve() {
 225             return verifyNotNull(payload);
 226         }
 227     }
 228 }