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+/*
+ * Copyright (c) 2013 Cisco Systems, Inc. and others. All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ */
+package org.opendaylight.controller.sal.binding.api.data;
+
+import java.util.Set;
+
+import org.opendaylight.controller.sal.binding.api.BindingAwareProvider;
+import org.opendaylight.controller.sal.binding.api.BindingAwareProvider.ProviderFunctionality;
+import org.opendaylight.controller.sal.common.DataStoreIdentifier;
+import org.opendaylight.yangtools.yang.common.RpcResult;
+
+/**
+ * Two phase commit handler (cohort) of the two-phase commit protocol of data.
+ *
+ * <p>
+ * The provider should expose the implementation of DataCommitHandler if it's
+ * functionality depends on any subset of data stored in data repositories, in
+ * order to participate in {@link DataBrokerService#commit(DataStoreIdentifier)
+ * operation.
+ *
+ * <p>
+ * Operations of two-phase commit handlers should not change data in data store,
+ * this is responsibility of the coordinator (broker or some component of the
+ * broker).
+ *
+ * The commit handlers are responsible for changing the internal state of the
+ * provider to reflect the commited changes in data.
+ *
+ * <h3>Two-phase commit</h3>
+ *
+ * <h4>Commit Request Phase</h4>
+ *
+ * <ol>
+ * <li> <code>Consumer</code> edits data by invocation of
+ * <code>DataBrokerService.editCandidateData(DataStoreIdentifier, DataRoot)</code>
+ * <li> <code>Consumer</code> starts a commit by invoking
+ * <code>DataBrokerService.commit(DataStoreIdentifier)</code>
+ * <li> <code>Broker</code> retrieves a list of all registered
+ * <code>DataCommitHandlers</code>
+ * <li>For each <code>DataCommitHandler</code>
+ * <ol>
+ * <li><code>Broker</code> invokes a
+ * <code>DataCommitHandler.requestCommit(DataStoreIdentifier)</code> operation.
+ * <li><code>DataCommitHandler</code> returns a <code>RpcResult</code> with
+ * <code>CommitTransaction</code>
+ * <li>If the result was successful, broker adds <code>CommitTransaction</code>
+ * to the list of opened transactions. If not, brokers stops a commit request
+ * phase and starts a rollback phase.
+ * </ol>
+ * <li><code>Broker</code> starts a commit finish phase
+ * </ol>
+ *
+ * <h4>Commit Finish Phase</h4>
+ *
+ * <ol>
+ * <li>For each <code>CommitTransaction</code> from Commit Request phase
+ * <ol>
+ * <li><code>Broker</code> broker invokes a
+ * <code>CommitTransaction.finish()</code>
+ * <li>The provider finishes a commit (applies the change) and returns an
+ * <code>RpcResult</code>.
+ * </ol>
+ * <li>
+ * <ul>
+ * <li>If all returned results means successful, the brokers end two-phase
+ * commit by returning a success commit result to the Consumer.
+ * <li>If error occured, the broker starts a commit rollback phase.
+ * </ul>
+ * </ol>
+ *
+ * <h4>Commit Rollback Phase</h4>
+ * <li>For each <code>CommitTransaction</code> from Commit Request phase
+ * <ol>
+ * <li><code>Broker</code>
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
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+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
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+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ * broker invokes a {@link CommitTransaction#finish()}
+ * <li>The provider rollbacks a commit and returns an {@link RpcResult} of
+ * rollback. </ol>
+ * <li>Broker returns a error result to the consumer.
+ *
+ *
+ * <h3>Registration of functionality</h3>
+ * The registration could be done by :
+ * <ul>
+ * <li>returning an instance of implementation in the return value of
+ * {@link Provider#getProviderFunctionality()}
+ * <li>passing an instance of implementation and {@link DataStoreIdentifier} of
+ * rpc as arguments to the
+ * {@link DataProviderService#addCommitHandler(DataStoreIdentifier, DataCommitHandler)}
+ * </ul>
+ *
+ *
+ *
+ */
+public interface DataCommitHandler extends ProviderFunctionality {
+ /**
+ * A set of Data Stores supported by implementation.
+ *
+ * The set of {@link DataStoreIdentifier}s which identifies target data
+ * stores which are supported by this commit handler. This set is used, when
+ * {@link Provider} is registered to the SAL, to register and expose the
+ * commit handler functionality to affected data stores.
+ *
+ * @return Set of Data Store identifiers
+ */
+ Set<DataStoreIdentifier> getSupportedDataStores();
+
+ /**
+ * The provider (commit handler) starts a commit transaction.
+ *
+ * <p>
+ * The commit handler (provider) prepares an commit scenario, rollback
+ * scenario and validates data.
+ *
+ * <p>
+ * If the provider is aware that at this point the commit would not be
+ * successful, the transaction is not created, but list of errors which
+ * prevented the start of transaction are returned.
+ *
+ * @param store
+ * @return Transaction object representing this commit, errors otherwise.
+ */
+ RpcResult<CommitTransaction> requestCommit(DataStoreIdentifier store);
+
+ public interface CommitTransaction {
+ /**
+ *
+ * @return Data store affected by the transaction
+ */
+ DataStoreIdentifier getDataStore();
+
+ /**
+ * Returns the handler associated with this transaction.
+ *
+ * @return Handler
+ */
+ DataCommitHandler getHandler();
+
+ /**
+ *
+ * Finishes a commit.
+ *
+ * The provider (commit handler) should apply all changes to its state
+ * which are a result of data change-
+ *
+ * @return
+ */
+ RpcResult<Void> finish() throws IllegalStateException;
+
+ /**
+ * Rollbacks a commit.
+ *
+ * @return
+ * @throws IllegalStateException
+ * If the method is invoked after {@link #finish()}
+ */
+ RpcResult<Void> rollback() throws IllegalStateException;
+ }
+
+}
Code Review / controller.git / blobdiff