opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/datastore/AbstractFrontendHistory.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;
   9
  10 import com.google.common.base.MoreObjects;
  11 import com.google.common.base.Preconditions;
  12 import com.google.common.base.Ticker;
  13 import java.util.HashMap;
  14 import java.util.Map;
  15 import java.util.Optional;
  16 import javax.annotation.Nullable;
  17 import org.opendaylight.controller.cluster.access.commands.AbstractReadTransactionRequest;
  18 import org.opendaylight.controller.cluster.access.commands.CommitLocalTransactionRequest;
  19 import org.opendaylight.controller.cluster.access.commands.OutOfOrderRequestException;
  20 import org.opendaylight.controller.cluster.access.commands.TransactionPurgeRequest;
  21 import org.opendaylight.controller.cluster.access.commands.TransactionPurgeResponse;
  22 import org.opendaylight.controller.cluster.access.commands.TransactionRequest;
  23 import org.opendaylight.controller.cluster.access.commands.TransactionSuccess;
  24 import org.opendaylight.controller.cluster.access.concepts.LocalHistoryIdentifier;
  25 import org.opendaylight.controller.cluster.access.concepts.RequestEnvelope;
  26 import org.opendaylight.controller.cluster.access.concepts.RequestException;
  27 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
  28 import org.opendaylight.yangtools.concepts.Identifiable;
  29 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification;
  30 import org.slf4j.Logger;
  31 import org.slf4j.LoggerFactory;
  32
  33 /**
  34  * Abstract class for providing logical tracking of frontend local histories. This class is specialized for
  35  * standalone transactions and chained transactions.
  36  *
  37  * @author Robert Varga
  38  */
  39 abstract class AbstractFrontendHistory implements Identifiable<LocalHistoryIdentifier> {
  40     private static final Logger LOG = LoggerFactory.getLogger(AbstractFrontendHistory.class);
  41     private static final OutOfOrderRequestException UNSEQUENCED_START = new OutOfOrderRequestException(0);
  42
  43     private final Map<TransactionIdentifier, FrontendTransaction> transactions = new HashMap<>();
  44     private final String persistenceId;
  45     private final Ticker ticker;
  46
  47     AbstractFrontendHistory(final String persistenceId, final Ticker ticker) {
  48         this.persistenceId = Preconditions.checkNotNull(persistenceId);
  49         this.ticker = Preconditions.checkNotNull(ticker);
  50     }
  51
  52     final String persistenceId() {
  53         return persistenceId;
  54     }
  55
  56     final long readTime() {
  57         return ticker.read();
  58     }
  59
  60     final @Nullable TransactionSuccess<?> handleTransactionRequest(final TransactionRequest<?> request,
  61             final RequestEnvelope envelope, final long now) throws RequestException {
  62         final TransactionIdentifier id = request.getTarget();
  63
  64         FrontendTransaction tx;
  65         if (request instanceof TransactionPurgeRequest) {
  66             tx = transactions.remove(id);
  67             if (tx == null) {
  68                 // We have no record of the transaction, nothing to do
  69                 LOG.debug("{}: no state for transaction {}, purge is complete", persistenceId(), id);
  70                 return new TransactionPurgeResponse(id, request.getSequence());
  71             }
  72         } else {
  73             tx = transactions.get(id);
  74             if (tx == null) {
  75                 // The transaction does not exist and we are about to create it, check sequence number
  76                 if (request.getSequence() != 0) {
  77                     LOG.debug("{}: no transaction state present, unexpected request {}", persistenceId(), request);
  78                     throw UNSEQUENCED_START;
  79                 }
  80
  81                 tx = createTransaction(request, id);
  82                 transactions.put(id, tx);
  83             } else {
  84                 final Optional<TransactionSuccess<?>> maybeReplay = tx.replaySequence(request.getSequence());
  85                 if (maybeReplay.isPresent()) {
  86                     final TransactionSuccess<?> replay = maybeReplay.get();
  87                     LOG.debug("{}: envelope {} replaying response {}", persistenceId(), envelope, replay);
  88                     return replay;
  89                 }
  90             }
  91         }
  92
  93         return tx.handleRequest(request, envelope, now);
  94     }
  95
  96     private FrontendTransaction createTransaction(final TransactionRequest<?> request, final TransactionIdentifier id)
  97             throws RequestException {
  98         if (request instanceof CommitLocalTransactionRequest) {
  99             LOG.debug("{}: allocating new ready transaction {}", persistenceId(), id);
 100             return createReadyTransaction(id, ((CommitLocalTransactionRequest) request).getModification());
 101         }
 102         if (request instanceof AbstractReadTransactionRequest) {
 103             if (((AbstractReadTransactionRequest<?>) request).isSnapshotOnly()) {
 104                 LOG.debug("{}: allocatint new open snapshot {}", persistenceId(), id);
 105                 return createOpenSnapshot(id);
 106             }
 107         }
 108
 109         LOG.debug("{}: allocating new open transaction {}", persistenceId(), id);
 110         return createOpenTransaction(id);
 111     }
 112
 113     abstract FrontendTransaction createOpenSnapshot(TransactionIdentifier id) throws RequestException;
 114
 115     abstract FrontendTransaction createOpenTransaction(TransactionIdentifier id) throws RequestException;
 116
 117     abstract FrontendTransaction createReadyTransaction(TransactionIdentifier id, DataTreeModification mod)
 118         throws RequestException;
 119
 120     abstract ShardDataTreeCohort createReadyCohort(TransactionIdentifier id, DataTreeModification mod);
 121
 122     @Override
 123     public String toString() {
 124         return MoreObjects.toStringHelper(this).omitNullValues().add("identifier", getIdentifier())
 125                 .add("persistenceId", persistenceId).add("transactions", transactions).toString();
 126     }
 127 }