HBASE-26270 Provide getConfiguration method for Region and Store interface (#3671)

Signed-off-by: Duo Zhang <zhangduo@apache.org>
Signed-off-by: Anoop Sam John <anoopsamjohn@apache.org>

hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/ReadOnlyConfiguration.java

@@ -44,10 +44,10 @@ import org.apache.yetus.audience.InterfaceAudience;
  * Wraps a Configuration to make it read-only.
  */
 @InterfaceAudience.Private
-class ReadOnlyConfiguration extends Configuration {
+public class ReadOnlyConfiguration extends Configuration {
   private final Configuration conf;
 
-  ReadOnlyConfiguration(final Configuration conf) {
+  public ReadOnlyConfiguration(final Configuration conf) {
     this.conf = conf;
   }
 

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HRegion.java

@@ -119,6 +119,7 @@ import org.apache.hadoop.hbase.client.TableDescriptorBuilder;
 import org.apache.hadoop.hbase.conf.ConfigurationManager;
 import org.apache.hadoop.hbase.conf.PropagatingConfigurationObserver;
 import org.apache.hadoop.hbase.coprocessor.CoprocessorHost;
+import org.apache.hadoop.hbase.coprocessor.ReadOnlyConfiguration;
 import org.apache.hadoop.hbase.errorhandling.ForeignExceptionSnare;
 import org.apache.hadoop.hbase.exceptions.FailedSanityCheckException;
 import org.apache.hadoop.hbase.exceptions.TimeoutIOException;
@@ -1962,6 +1963,11 @@ public class HRegion implements HeapSize, PropagatingConfigurationObserver, Regi
     }
   }
 
+  @Override
+  public Configuration getReadOnlyConfiguration() {
+    return new ReadOnlyConfiguration(this.conf);
+  }
+
   private ThreadPoolExecutor getStoreOpenAndCloseThreadPool(
       final String threadNamePrefix) {
     int numStores = Math.max(1, this.htableDescriptor.getColumnFamilyCount());

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/HStore.java

@@ -69,6 +69,7 @@ import org.apache.hadoop.hbase.client.RegionInfo;
 import org.apache.hadoop.hbase.client.Scan;
 import org.apache.hadoop.hbase.conf.ConfigurationManager;
 import org.apache.hadoop.hbase.conf.PropagatingConfigurationObserver;
+import org.apache.hadoop.hbase.coprocessor.ReadOnlyConfiguration;
 import org.apache.hadoop.hbase.io.HeapSize;
 import org.apache.hadoop.hbase.io.compress.Compression;
 import org.apache.hadoop.hbase.io.crypto.Encryption;
@@ -2801,6 +2802,11 @@ public class HStore implements Store, HeapSize, StoreConfigInformation,
     return mixedRowReadsCount.sum();
   }
 
+  @Override
+  public Configuration getReadOnlyConfiguration() {
+    return new ReadOnlyConfiguration(this.conf);
+  }
+
   void updateMetricsStore(boolean memstoreRead) {
     if (memstoreRead) {
       memstoreOnlyRowReadsCount.increment();

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/Region.java

@@ -22,6 +22,7 @@ import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 
+import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.CellComparator;
 import org.apache.hadoop.hbase.CompareOperator;
@@ -597,4 +598,10 @@ public interface Region extends ConfigurationObserver {
    * max wait time period.
    */
   boolean waitForFlushes(long timeout);
+
+  /**
+   * @return a read only configuration of this region; throws {@link UnsupportedOperationException}
+   *         if you try to set a configuration.
+   */
+  Configuration getReadOnlyConfiguration();
 }

hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/Store.java

@@ -22,6 +22,7 @@ import java.util.Collection;
 import java.util.OptionalDouble;
 import java.util.OptionalLong;
 
+import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.hbase.CellComparator;
 import org.apache.hadoop.hbase.HBaseInterfaceAudience;
@@ -292,4 +293,10 @@ public interface Store {
    * @return the number of read requests from the files under this store.
    */
   long getMixedRowReadsCount();
+
+  /**
+   * @return a read only configuration of this store; throws {@link UnsupportedOperationException}
+   *         if you try to set a configuration.
+   */
+  Configuration getReadOnlyConfiguration();
 }