BUG-8538: rework transaction abort paths
[controller.git] / opendaylight / md-sal / sal-distributed-datastore / src / main / java / org / opendaylight / controller / cluster / databroker / actors / dds / LocalProxyTransaction.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.databroker.actors.dds;
9
10 import com.google.common.base.Optional;
11 import com.google.common.base.Preconditions;
12 import com.google.common.util.concurrent.CheckedFuture;
13 import com.google.common.util.concurrent.Futures;
14 import java.util.function.Consumer;
15 import javax.annotation.Nullable;
16 import javax.annotation.concurrent.NotThreadSafe;
17 import org.opendaylight.controller.cluster.access.commands.AbortLocalTransactionRequest;
18 import org.opendaylight.controller.cluster.access.commands.AbstractLocalTransactionRequest;
19 import org.opendaylight.controller.cluster.access.commands.CommitLocalTransactionRequest;
20 import org.opendaylight.controller.cluster.access.commands.ExistsTransactionRequest;
21 import org.opendaylight.controller.cluster.access.commands.ExistsTransactionSuccess;
22 import org.opendaylight.controller.cluster.access.commands.IncrementTransactionSequenceRequest;
23 import org.opendaylight.controller.cluster.access.commands.ModifyTransactionRequest;
24 import org.opendaylight.controller.cluster.access.commands.ReadTransactionRequest;
25 import org.opendaylight.controller.cluster.access.commands.ReadTransactionSuccess;
26 import org.opendaylight.controller.cluster.access.commands.TransactionPurgeRequest;
27 import org.opendaylight.controller.cluster.access.commands.TransactionRequest;
28 import org.opendaylight.controller.cluster.access.concepts.Response;
29 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
30 import org.opendaylight.controller.cluster.datastore.util.AbstractDataTreeModificationCursor;
31 import org.opendaylight.mdsal.common.api.ReadFailedException;
32 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
33 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
34 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
35 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeModification;
36 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeSnapshot;
37 import org.slf4j.Logger;
38 import org.slf4j.LoggerFactory;
39
40 /**
41  * An {@link AbstractProxyTransaction} for dispatching a transaction towards a shard leader which is co-located with
42  * the client instance.
43  *
44  * <p>
45  * It requires a {@link DataTreeSnapshot}, which is used to instantiated a new {@link DataTreeModification}. Operations
46  * are then performed on this modification and once the transaction is submitted, the modification is sent to the shard
47  * leader.
48  *
49  * <p>
50  * This class is not thread-safe as usual with transactions. Since it does not interact with the backend until the
51  * transaction is submitted, at which point this class gets out of the picture, this is not a cause for concern.
52  *
53  * @author Robert Varga
54  */
55 @NotThreadSafe
56 abstract class LocalProxyTransaction extends AbstractProxyTransaction {
57     private static final Logger LOG = LoggerFactory.getLogger(LocalProxyTransaction.class);
58
59     private final TransactionIdentifier identifier;
60
61     LocalProxyTransaction(final ProxyHistory parent, final TransactionIdentifier identifier) {
62         super(parent);
63         this.identifier = Preconditions.checkNotNull(identifier);
64     }
65
66     @Override
67     public final TransactionIdentifier getIdentifier() {
68         return identifier;
69     }
70
71     abstract DataTreeSnapshot readOnlyView();
72
73     abstract void applyForwardedModifyTransactionRequest(ModifyTransactionRequest request,
74             @Nullable Consumer<Response<?, ?>> callback);
75
76     abstract void replayModifyTransactionRequest(ModifyTransactionRequest request,
77             @Nullable Consumer<Response<?, ?>> callback, long enqueuedTicks);
78
79     @Override
80     final CheckedFuture<Boolean, ReadFailedException> doExists(final YangInstanceIdentifier path) {
81         return Futures.immediateCheckedFuture(readOnlyView().readNode(path).isPresent());
82     }
83
84     @Override
85     final CheckedFuture<Optional<NormalizedNode<?, ?>>, ReadFailedException> doRead(final YangInstanceIdentifier path) {
86         return Futures.immediateCheckedFuture(readOnlyView().readNode(path));
87     }
88
89     @Override
90     final AbortLocalTransactionRequest abortRequest() {
91         return new AbortLocalTransactionRequest(identifier, localActor());
92     }
93
94     @Override
95     void handleReplayedLocalRequest(final AbstractLocalTransactionRequest<?> request,
96             final Consumer<Response<?, ?>> callback, final long enqueuedTicks) {
97         if (request instanceof AbortLocalTransactionRequest) {
98             enqueueAbort(request, callback, enqueuedTicks);
99         } else {
100             throw new IllegalArgumentException("Unhandled request" + request);
101         }
102     }
103
104     private boolean handleReadRequest(final TransactionRequest<?> request,
105             final @Nullable Consumer<Response<?, ?>> callback) {
106         // Note we delay completion of read requests to limit the scope at which the client can run, as they have
107         // listeners, which we do not want to execute while we are reconnecting.
108         if (request instanceof ReadTransactionRequest) {
109             final YangInstanceIdentifier path = ((ReadTransactionRequest) request).getPath();
110             final Optional<NormalizedNode<?, ?>> result = readOnlyView().readNode(path);
111             if (callback != null) {
112                 // XXX: FB does not see that callback is final, on stack and has be check for non-null.
113                 final Consumer<Response<?, ?>> fbIsStupid = Preconditions.checkNotNull(callback);
114                 executeInActor(() -> fbIsStupid.accept(new ReadTransactionSuccess(request.getTarget(),
115                     request.getSequence(), result)));
116             }
117             return true;
118         } else if (request instanceof ExistsTransactionRequest) {
119             final YangInstanceIdentifier path = ((ExistsTransactionRequest) request).getPath();
120             final boolean result = readOnlyView().readNode(path).isPresent();
121             if (callback != null) {
122                 // XXX: FB does not see that callback is final, on stack and has be check for non-null.
123                 final Consumer<Response<?, ?>> fbIsStupid = Preconditions.checkNotNull(callback);
124                 executeInActor(() -> fbIsStupid.accept(new ExistsTransactionSuccess(request.getTarget(),
125                     request.getSequence(), result)));
126             }
127             return true;
128         } else {
129             return false;
130         }
131     }
132
133     @Override
134     void handleReplayedRemoteRequest(final TransactionRequest<?> request,
135             final @Nullable Consumer<Response<?, ?>> callback, final long enqueuedTicks) {
136         if (request instanceof ModifyTransactionRequest) {
137             replayModifyTransactionRequest((ModifyTransactionRequest) request, callback, enqueuedTicks);
138         } else if (handleReadRequest(request, callback)) {
139             // No-op
140         } else if (request instanceof TransactionPurgeRequest) {
141             enqueuePurge(callback, enqueuedTicks);
142         } else if (request instanceof IncrementTransactionSequenceRequest) {
143             // Local transactions do not have non-replayable requests which would be visible to the backend,
144             // hence we can skip sequence increments.
145             LOG.debug("Not replaying {}", request);
146         } else {
147             throw new IllegalArgumentException("Unhandled request " + request);
148         }
149     }
150
151     /**
152      * Remote-to-local equivalent of {@link #handleReplayedRemoteRequest(TransactionRequest, Consumer, long)},
153      * except it is invoked in the forwarding path from
154      * {@link RemoteProxyTransaction#forwardToLocal(LocalProxyTransaction, TransactionRequest, Consumer)}.
155      *
156      * @param request Forwarded request
157      * @param callback Callback to be invoked once the request completes
158      */
159     void handleForwardedRemoteRequest(final TransactionRequest<?> request, final Consumer<Response<?, ?>> callback) {
160         if (request instanceof ModifyTransactionRequest) {
161             applyForwardedModifyTransactionRequest((ModifyTransactionRequest) request, callback);
162         } else if (handleReadRequest(request, callback)) {
163             // No-op
164         } else if (request instanceof TransactionPurgeRequest) {
165             sendPurge(callback);
166         } else {
167             throw new IllegalArgumentException("Unhandled request " + request);
168         }
169     }
170
171     @Override
172     final void forwardToRemote(final RemoteProxyTransaction successor, final TransactionRequest<?> request,
173                          final Consumer<Response<?, ?>> callback) {
174         if (request instanceof CommitLocalTransactionRequest) {
175             final CommitLocalTransactionRequest req = (CommitLocalTransactionRequest) request;
176             final DataTreeModification mod = req.getModification();
177
178             LOG.debug("Applying modification {} to successor {}", mod, successor);
179             mod.applyToCursor(new AbstractDataTreeModificationCursor() {
180                 @Override
181                 public void write(final PathArgument child, final NormalizedNode<?, ?> data) {
182                     successor.write(current().node(child), data);
183                 }
184
185                 @Override
186                 public void merge(final PathArgument child, final NormalizedNode<?, ?> data) {
187                     successor.merge(current().node(child), data);
188                 }
189
190                 @Override
191                 public void delete(final PathArgument child) {
192                     successor.delete(current().node(child));
193                 }
194             });
195
196             successor.ensureSealed();
197
198             final ModifyTransactionRequest successorReq = successor.commitRequest(req.isCoordinated());
199             successor.sendRequest(successorReq, callback);
200         } else if (request instanceof AbortLocalTransactionRequest) {
201             LOG.debug("Forwarding abort {} to successor {}", request, successor);
202             successor.abort();
203         } else if (request instanceof TransactionPurgeRequest) {
204             LOG.debug("Forwarding purge {} to successor {}", request, successor);
205             successor.sendPurge(callback);
206         } else {
207             throw new IllegalArgumentException("Unhandled request" + request);
208         }
209     }
210
211     @Override
212     void forwardToLocal(final LocalProxyTransaction successor, final TransactionRequest<?> request,
213             final Consumer<Response<?, ?>> callback) {
214         if (request instanceof AbortLocalTransactionRequest) {
215             successor.sendAbort(request, callback);
216         } else if (request instanceof TransactionPurgeRequest) {
217             successor.sendPurge(callback);
218         } else {
219             throw new IllegalArgumentException("Unhandled request" + request);
220         }
221
222         LOG.debug("Forwarded request {} to successor {}", request, successor);
223     }
224
225     void sendAbort(final TransactionRequest<?> request, final Consumer<Response<?, ?>> callback) {
226         sendRequest(request, callback);
227     }
228
229     void enqueueAbort(final TransactionRequest<?> request, final Consumer<Response<?, ?>> callback,
230             final long enqueuedTicks) {
231         enqueueRequest(request, callback, enqueuedTicks);
232     }
233 }

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