[02/22] incubator-rya git commit: RYA-449 Create QueryChangeLogSource

[pu...@apache.org]

RYA-449 Create QueryChangeLogSource


Project: http://git-wip-us.apache.org/repos/asf/incubator-rya/repo
Commit: http://git-wip-us.apache.org/repos/asf/incubator-rya/commit/d6d6d04b
Tree: http://git-wip-us.apache.org/repos/asf/incubator-rya/tree/d6d6d04b
Diff: http://git-wip-us.apache.org/repos/asf/incubator-rya/diff/d6d6d04b

Branch: refs/heads/master
Commit: d6d6d04b3b7efe4ef6a6112e5eaa12058b4e0427
Parents: 5b489dc
Author: Andrew Smith <sm...@gmail.com>
Authored: Thu Jan 18 17:51:40 2018 -0500
Committer: Valiyil <Pu...@parsons.com>
Committed: Fri Mar 9 12:59:33 2018 -0500

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 .../querymanager/QueryChangeLogSource.java      | 76 ++++++++++++++++++++
 1 file changed, 76 insertions(+)
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http://git-wip-us.apache.org/repos/asf/incubator-rya/blob/d6d6d04b/extras/rya.streams/query-manager/src/main/java/org/apache/rya/streams/querymanager/QueryChangeLogSource.java
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diff --git a/extras/rya.streams/query-manager/src/main/java/org/apache/rya/streams/querymanager/QueryChangeLogSource.java b/extras/rya.streams/query-manager/src/main/java/org/apache/rya/streams/querymanager/QueryChangeLogSource.java
new file mode 100644
index 0000000..73e5d12
--- /dev/null
+++ b/extras/rya.streams/query-manager/src/main/java/org/apache/rya/streams/querymanager/QueryChangeLogSource.java
@@ -0,0 +1,76 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.rya.streams.querymanager;
+
+import org.apache.rya.streams.api.queries.QueryChangeLog;
+
+import com.google.common.util.concurrent.Service;
+
+import edu.umd.cs.findbugs.annotations.DefaultAnnotation;
+import edu.umd.cs.findbugs.annotations.NonNull;
+
+/**
+ * A {@link QueryChangeLog} source represents a storage where the change logs reside, but it
+ * does not provide a way to create or remove them. Instead, subscribed {@link SourceListener}s
+ * are notified whenever a change log is created or removed from the storage.
+ */
+@DefaultAnnotation(NonNull.class)
+public interface QueryChangeLogSource extends Service {
+
+    /**
+     * Adds a {@link SourceListener} to be notified when {@link QueryChangeLog}s
+     * have been found.
+     * <p>
+     * When a new subscriber is added, it will be notified with the existing {@link QueryChangeLog}s.
+     *
+     * @param listener - The {@link SourceListener} to add. (not null)
+     */
+    public void subscribe(final SourceListener listener);
+
+    /**
+     * Removes a {@link SourceListener}.
+     *
+     * @param listener - The {@link SourceListener} to remove. (not null)
+     */
+    public void unsubscribe(final SourceListener listener);
+
+    /**
+     * A listener that is notified when a {@link QueryChangeLog} has
+     * been added or removed from a {@link QueryChangeLogSource}.
+     */
+    @DefaultAnnotation(NonNull.class)
+    public interface SourceListener {
+        /**
+         * Notifies the subscriber that there is a new {@link QueryChangeLog} in the
+         * {@link QueryChangeLogSource}.
+         *
+         * @param ryaInstanceName - The Rya Instance name the {@link QueryChangeLog} belongs to. (not null)
+         * @param log - The new {@link QueryChangeLog}. (not null)
+         */
+        public void notifyCreate(final String ryaInstanceName, final QueryChangeLog log);
+
+        /**
+         * Notifies the subscriber that a {@link QueryChangeLog} has been deleted
+         * from the {@link QueryChangeLogSource}.
+         *
+         * @param ryaInstanceName - The rya instance whose {@link QueryChangeLog} was removed. (not null)
+         */
+        public void notifyDelete(final String ryaInstanceName);
+    }
+}