HBASE-25184 Move RegionLocationFinder to hbase-balancer (#2543)

Signed-off-by: Yulin Niu <[email protected]>

Author: Apache9

hbase-balancer/pom.xml

@@ -74,6 +74,12 @@
       <type>test-jar</type>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>org.apache.hbase</groupId>
+      <artifactId>hbase-logging</artifactId>
+      <type>test-jar</type>
+      <scope>test</scope>
+    </dependency>
     <dependency>
       <groupId>org.apache.hbase</groupId>
       <artifactId>hbase-common</artifactId>
@@ -92,6 +98,11 @@
       <scope>compile</scope>
       <optional>true</optional>
     </dependency>
+    <dependency>
+      <groupId>org.mockito</groupId>
+      <artifactId>mockito-core</artifactId>
+      <scope>test</scope>
+    </dependency>
     <dependency>
       <groupId>junit</groupId>
       <artifactId>junit</artifactId>

hbase-balancer/src/main/java/org/apache/hadoop/hbase/master/balancer/ClusterInfoProvider.java

@@ -0,0 +1,55 @@
+/**
+ * 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.hadoop.hbase.master.balancer;
+
+import java.io.IOException;
+import java.util.List;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hbase.HDFSBlocksDistribution;
+import org.apache.hadoop.hbase.TableName;
+import org.apache.hadoop.hbase.client.RegionInfo;
+import org.apache.hadoop.hbase.client.TableDescriptor;
+import org.apache.yetus.audience.InterfaceAudience;
+
+/**
+ * This is the cluster we want to balance. It provides methods to let us get the information we
+ * want.
+ */
+@InterfaceAudience.Private
+public interface ClusterInfoProvider {
+
+  /**
+   * Get all the regions of this cluster.
+   * <p/>
+   * Used to refresh region block locations on HDFS.
+   */
+  List<RegionInfo> getAssignedRegions();
+
+  /**
+   * Get the table descriptor for the given table.
+   */
+  TableDescriptor getTableDescriptor(TableName tableName) throws IOException;
+
+  /**
+   * Compute the block distribution for the given region.
+   * <p/>
+   * Used to refresh region block locations on HDFS.
+   */
+  HDFSBlocksDistribution computeHDFSBlocksDistribution(Configuration conf,
+    TableDescriptor tableDescriptor, RegionInfo regionInfo) throws IOException;
+}