Bug 629: Introduction of Configuration Commit Handler

[controller.git] / opendaylight / md-sal / sal-common-api / src / main / java / org / opendaylight / controller / md / sal / common / api / data / AsyncConfigurationCommitHandler.java

diff --git a/opendaylight/md-sal/sal-common-api/src/main/java/org/opendaylight/controller/md/sal/common/api/data/AsyncConfigurationCommitHandler.java b/opendaylight/md-sal/sal-common-api/src/main/java/org/opendaylight/controller/md/sal/common/api/data/AsyncConfigurationCommitHandler.java
new file mode 100644 (file)
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+++ b/opendaylight/md-sal/sal-common-api/src/main/java/org/opendaylight/controller/md/sal/common/api/data/AsyncConfigurationCommitHandler.java
@@ -0,0 +1,121 @@
+/*
+ * Copyright (c) 2014 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.md.sal.common.api.data;
+
+import org.opendaylight.yangtools.concepts.Path;
+
+import com.google.common.util.concurrent.CheckedFuture;
+
+/**
+ * User-supplied participant in three-phase commit of transaction for configuration data tree
+ *
+ * Client-supplied implementation of commit handler for subtree, which
+ * is responsible for processing CAN-COMMIT phase of three-phase commit protocol
+ * and return CommitCohort, which provides access to additional transitions
+ * such as PRE-COMMIT, COMMIT and ABORT.
+ *
+ * @param <P>
+ *            Type of path (subtree identifier), which represents location in
+ *            tree
+ * @param <D>
+ *            Type of data (payload), which represents data payload
+ */
+public interface AsyncConfigurationCommitHandler<P extends Path<P>, D> {
+
+    /**
+     *
+     * Requests a can commit phase
+     *
+     * Implementations SHOULD NOT do any blocking operation during
+     * processing this callback.
+     *
+     * <b>Implementation Notes</b>
+     * <ul>
+     * <li>Implementation are REQUIRED to use <code>request</code> object for any data related access</li>
+     * <li>Implementations SHOULD NOT use any other state stored outside configuration subtree for validation</li>
+     * <li>Validation should happen asynchronously, outside callback call by updating returned {@link CheckedFuture}
+     *     object.</li>
+     * <li>If validation (CAN_COMMIT) phase:
+     * <ul>
+     * <li><b>is successful</b> - invocation of {@link CheckedFuture#checkedGet()} on returned future MUST
+     *     return {@link AsyncConfigurationCommitCohort} associated with request.</li>
+     * <li><b>is unsuccessful</b> - invocation of {@link CheckedFuture#checkedGet()} must throw instance of {@link DataValidationFailedException}
+     * with human readable explanaition of error condition.
+     * </li>
+     * </ul>
+     * </li>
+     * @param request
+     *            Commit Request submitted by client, which contains
+     *            information about modifications and read-only view as
+     *            if transaction happened.
+     * @return CheckedFuture which contains client-supplied implementation of {@link AsyncConfigurationCommitCohort}
+     *         associated with submitted request, if can commit phase is
+     *         successful, if can commit was unsuccessful, future must fail with
+     *         {@link TransactionCommitFailedException} exception.
+     */
+    CheckedFuture<AsyncConfigurationCommitCohort<P, D>, DataValidationFailedException> canCommit(
+            ConfigurationCommitRequest<P, D> request);
+
+    /**
+     *
+     * Commit Request as was submitted by client code
+     *
+     * Commit Request contains list view of created / updated / removed
+     * path and read-only view of proposed client transaction,
+     * which may be used to retrieve modified or referenced data.
+     *
+     *
+     * @param <P>
+     *            Type of path (subtree identifier), which represents location
+     *            in tree
+     * @param <D>
+     *            Type of data (payload), which represents data payload
+     */
+    static interface ConfigurationCommitRequest<P extends Path<P>, D> {
+
+        /**
+         *
+         * Read-only transaction which provides access only to configuration
+         * data tree as if submitted transaction successfully happened and
+         * no other concurrent modifications happened between allocation
+         * of client transactions and write of client transactions.
+         *
+         * Implementations of Commit Handlers are REQUIRED to use this
+         * read-only view to access any data from configuration data tree,
+         * in order to capture them as preconditions for this transaction.
+         *
+         * @return Read-only transaction which provides access only to configuration
+         * data tree as if submitted transaction successfully happened
+         */
+        AsyncReadTransaction<P, D> getReadOnlyView();
+
+        /**
+         *
+         * Returns iteration of paths, to data which was introduced by this transaction.
+         *
+         * @return Iteration of paths, which was introduced by this transaction.
+         */
+        Iterable<P> getCreatedPaths();
+        /**
+         *
+         * Returns iteration of paths, to data which was updated by this transaction.
+         *
+         * @return Iteration of paths, which was updated by this transaction.
+         */
+        Iterable<P> getUpdatedPaths();
+
+        /**
+         *
+         * Returns iteration of paths, to data which was removed by this transaction.
+         *
+         * @return Iteration of paths, which was removed by this transaction.
+         */
+        Iterable<P> getRemovedPaths();
+    }
+
+}