5b47f22971c9af76298e82032202871bb986b96b
[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 applyModifyTransactionRequest(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 void doAbort() {
91         sendAbort(new AbortLocalTransactionRequest(identifier, localActor()),
92             response -> LOG.debug("Transaction {} abort completed with {}", identifier, response));
93     }
94
95     @Override
96     void handleReplayedLocalRequest(final AbstractLocalTransactionRequest<?> request,
97             final Consumer<Response<?, ?>> callback, final long enqueuedTicks) {
98         if (request instanceof AbortLocalTransactionRequest) {
99             enqueueAbort(request, callback, enqueuedTicks);
100         } else {
101             throw new IllegalArgumentException("Unhandled request" + request);
102         }
103     }
104
105     private boolean handleReadRequest(final TransactionRequest<?> request,
106             final @Nullable Consumer<Response<?, ?>> callback) {
107         // Note we delay completion of read requests to limit the scope at which the client can run, as they have
108         // listeners, which we do not want to execute while we are reconnecting.
109         if (request instanceof ReadTransactionRequest) {
110             final YangInstanceIdentifier path = ((ReadTransactionRequest) request).getPath();
111             final Optional<NormalizedNode<?, ?>> result = readOnlyView().readNode(path);
112             if (callback != null) {
113                 // XXX: FB does not see that callback is final, on stack and has be check for non-null.
114                 final Consumer<Response<?, ?>> fbIsStupid = Preconditions.checkNotNull(callback);
115                 executeInActor(() -> fbIsStupid.accept(new ReadTransactionSuccess(request.getTarget(),
116                     request.getSequence(), result)));
117             }
118             return true;
119         } else if (request instanceof ExistsTransactionRequest) {
120             final YangInstanceIdentifier path = ((ExistsTransactionRequest) request).getPath();
121             final boolean result = readOnlyView().readNode(path).isPresent();
122             if (callback != null) {
123                 // XXX: FB does not see that callback is final, on stack and has be check for non-null.
124                 final Consumer<Response<?, ?>> fbIsStupid = Preconditions.checkNotNull(callback);
125                 executeInActor(() -> fbIsStupid.accept(new ExistsTransactionSuccess(request.getTarget(),
126                     request.getSequence(), result)));
127             }
128             return true;
129         } else {
130             return false;
131         }
132     }
133
134     @Override
135     void handleReplayedRemoteRequest(final TransactionRequest<?> request,
136             final @Nullable Consumer<Response<?, ?>> callback, final long enqueuedTicks) {
137         if (request instanceof ModifyTransactionRequest) {
138             replayModifyTransactionRequest((ModifyTransactionRequest) request, callback, enqueuedTicks);
139         } else if (handleReadRequest(request, callback)) {
140             // No-op
141         } else if (request instanceof TransactionPurgeRequest) {
142             enqueuePurge(enqueuedTicks);
143         } else if (request instanceof IncrementTransactionSequenceRequest) {
144             // Local transactions do not have non-replayable requests which would be visible to the backend,
145             // hence we can skip sequence increments.
146             LOG.debug("Not replaying {}", request);
147         } else {
148             throw new IllegalArgumentException("Unhandled request " + request);
149         }
150     }
151
152     /**
153      * Remote-to-local equivalent of {@link #handleReplayedRemoteRequest(TransactionRequest, Consumer, long)},
154      * except it is invoked in the forwarding path from
155      * {@link RemoteProxyTransaction#forwardToLocal(LocalProxyTransaction, TransactionRequest, Consumer)}.
156      *
157      * @param request Forwarded request
158      * @param callback Callback to be invoked once the request completes
159      */
160     void handleForwardedRemoteRequest(final TransactionRequest<?> request, final Consumer<Response<?, ?>> callback) {
161         if (request instanceof ModifyTransactionRequest) {
162             applyModifyTransactionRequest((ModifyTransactionRequest) request, callback);
163         } else if (handleReadRequest(request, callback)) {
164             // No-op
165         } else if (request instanceof TransactionPurgeRequest) {
166             sendPurge();
167         } else {
168             throw new IllegalArgumentException("Unhandled request " + request);
169         }
170     }
171
172     @Override
173     final void forwardToRemote(final RemoteProxyTransaction successor, final TransactionRequest<?> request,
174                          final Consumer<Response<?, ?>> callback) {
175         if (request instanceof CommitLocalTransactionRequest) {
176             final CommitLocalTransactionRequest req = (CommitLocalTransactionRequest) request;
177             final DataTreeModification mod = req.getModification();
178
179             LOG.debug("Applying modification {} to successor {}", mod, successor);
180             mod.applyToCursor(new AbstractDataTreeModificationCursor() {
181                 @Override
182                 public void write(final PathArgument child, final NormalizedNode<?, ?> data) {
183                     successor.write(current().node(child), data);
184                 }
185
186                 @Override
187                 public void merge(final PathArgument child, final NormalizedNode<?, ?> data) {
188                     successor.merge(current().node(child), data);
189                 }
190
191                 @Override
192                 public void delete(final PathArgument child) {
193                     successor.delete(current().node(child));
194                 }
195             });
196
197             successor.ensureSealed();
198
199             final ModifyTransactionRequest successorReq = successor.commitRequest(req.isCoordinated());
200             successor.sendRequest(successorReq, callback);
201         } else if (request instanceof AbortLocalTransactionRequest) {
202             LOG.debug("Forwarding abort {} to successor {}", request, successor);
203             successor.abort();
204         } else if (request instanceof TransactionPurgeRequest) {
205             LOG.debug("Forwarding purge {} to successor {}", request, successor);
206             successor.sendPurge();
207         } else {
208             throw new IllegalArgumentException("Unhandled request" + request);
209         }
210     }
211
212     @Override
213     void forwardToLocal(final LocalProxyTransaction successor, final TransactionRequest<?> request,
214             final Consumer<Response<?, ?>> callback) {
215         if (request instanceof AbortLocalTransactionRequest) {
216             successor.sendAbort(request, callback);
217         } else if (request instanceof TransactionPurgeRequest) {
218             successor.sendPurge();
219         } else {
220             throw new IllegalArgumentException("Unhandled request" + request);
221         }
222
223         LOG.debug("Forwarded request {} to successor {}", request, successor);
224     }
225
226     void sendAbort(final TransactionRequest<?> request, final Consumer<Response<?, ?>> callback) {
227         sendRequest(request, callback);
228     }
229
230     void enqueueAbort(final TransactionRequest<?> request, final Consumer<Response<?, ?>> callback,
231             final long enqueuedTicks) {
232         enqueueRequest(request, callback, enqueuedTicks);
233     }
234 }