2 * Copyright (c) 2015 Cisco Systems, Inc. and others. All rights reserved.
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
8 package org.opendaylight.mdsal.dom.api;
10 import static java.util.Objects.requireNonNull;
12 import com.google.common.annotations.Beta;
13 import com.google.common.util.concurrent.FluentFuture;
14 import java.util.Collection;
15 import org.eclipse.jdt.annotation.NonNull;
16 import org.opendaylight.mdsal.common.api.DataValidationFailedException;
17 import org.opendaylight.mdsal.common.api.PostCanCommitStep;
18 import org.opendaylight.yangtools.util.concurrent.ExceptionMapper;
19 import org.opendaylight.yangtools.yang.model.api.SchemaContext;
22 * Commit cohort participating in commit of data modification, which can validate data tree
23 * modifications, with option to reject supplied modification, and with callbacks describing state
26 * <h2>Performance implications</h2>
27 * {@link DOMDataTreeCommitCohort}s are hooked up into commit of data tree changes and MAY
28 * negatively affect performance of data broker / store.
29 * Implementations of this interface are discouraged, unless you really need ability to veto data
30 * tree changes, or to provide external state change in sync with visibility of committed data.
32 * <h2>Implementation requirements</h2>
33 * <h3>Correctness assumptions</h3> Implementation SHOULD use only the {@link DOMDataTreeCandidate} instances and
34 * provided {@link SchemaContext} for validation purposes.
35 * Use of any other external mutable state is discouraged, implementation MUST NOT use any
36 * transaction related APIs on same data broker / data store instance during invocation of
37 * callbacks, except ones provided as argument. Note that this MAY BE enforced by some
38 * implementations of {@link DOMDataBroker} or DOMDataCommitCoordinator
39 * Note that this may be enforced by some implementations of {@link DOMDataTreeCommitCohortRegistry}
40 * and such calls may fail.
41 * <h3>Correct model usage</h3> If implementation is performing YANG-model driven validation
42 * implementation SHOULD use provided schema context.
43 * Any other instance of {@link SchemaContext} obtained by other means, may not be valid for the
44 * associated DOMDataTreeCandidates and it may lead to incorrect validation or processing of provided
46 * <h3>DataTreeCandidate assumptions</h3> Implementation SHOULD NOT make any assumptions on a
47 * {@link DOMDataTreeCandidate} being successfully committed until associated
48 * {@link PostCanCommitStep#preCommit()} and
49 * {@link org.opendaylight.mdsal.common.api.PostPreCommitStep#commit()} callback was invoked.
50 * <h2>Usage patterns</h2>
51 * <h3>Data Tree Validator</h3>
52 * Validator is implementation, which only validates {@link DOMDataTreeCandidate} instances and does not
53 * retain any state derived from edited data - does not care if a {@link DOMDataTreeCandidate} was
54 * rejected afterwards or transaction was cancelled.
55 * Implementation may opt-out from receiving {@code preCommit()}, {@code commit()}, {@code abort()}
56 * callbacks by returning {@link PostCanCommitStep#NOOP}.
61 // TODO: Provide example and describe more usage patterns
63 public interface DOMDataTreeCommitCohort {
66 * Validates the supplied data tree modifications and associates the cohort-specific steps with data broker
70 * If {@link DataValidationFailedException} is thrown by implementation, the commit of the supplied data
71 * will be prevented, with the DataBroker transaction providing the thrown exception as the cause of failure.
74 * Note the implementations are expected to do validation and processing asynchronous. Implementations SHOULD do
75 * processing fast, and are discouraged from blocking on any external resources. Implementation MUST NOT access
76 * any data transaction related APIs during invocation of the callback. Note that this may be enforced by some
77 * implementations of {@link DOMDataTreeCommitCohortRegistry} and such calls may fail.
80 * Implementation MAY opt-out from implementing other steps by returning
81 * {@link PostCanCommitStep#NOOP}. Otherwise implementation MUST return instance of
82 * {@link PostCanCommitStep}, which will be used to invoke
83 * {@link org.opendaylight.mdsal.common.api.PostPreCommitStep#commit()} or
84 * {@link PostCanCommitStep#abort()} based on accepting data by data broker and or other commit cohorts.
86 * @param txId Transaction identifier. SHOULD be used only for reporting and correlation.
87 * Implementation MUST NOT use {@code txId} for validation.
88 * @param candidates Data Tree candidates to be validated and committed.
89 * @param ctx Schema Context to which Data Tree candidate should conform.
90 * @return a FluentFuture which will successfully complete with the user-supplied implementation of
91 * {@link PostCanCommitStep} if all candidates are valid, or a failed future with a
92 * {@link DataValidationFailedException} if and only if a provided
93 * {@link DOMDataTreeCandidate} instance did not pass validation. Users are encouraged to use
94 * more specific subclasses of this exception to provide additional information about
95 * validation failure reason.
97 @NonNull FluentFuture<PostCanCommitStep> canCommit(@NonNull Object txId,
98 @NonNull SchemaContext ctx, @NonNull Collection<DOMDataTreeCandidate> candidates);
101 * An ExceptionMapper that translates an Exception to a DataValidationFailedException.
103 class DataValidationFailedExceptionMapper extends ExceptionMapper<DataValidationFailedException> {
104 private final @NonNull DOMDataTreeIdentifier failedTreeId;
106 public DataValidationFailedExceptionMapper(final String opName, final DOMDataTreeIdentifier failedTreeId) {
107 super(opName, DataValidationFailedException.class);
108 this.failedTreeId = requireNonNull(failedTreeId);
112 protected DataValidationFailedException newWithCause(final String message, final Throwable cause) {
113 return new DataValidationFailedException(DOMDataTreeIdentifier.class, failedTreeId, message, cause);