HBASE-28346: Expose checkQuota to Coprocessor Endpoints (apache#6066)…

… (addendum)

Add default implementations of the new methods so that a custom implementation of
RegionCoprocessorEnvironment will not fail to compile after upgrade.

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

@@ -135,13 +135,23 @@ public interface RegionCoprocessorEnvironment extends CoprocessorEnvironment<Reg
   /**
    * Returns an RpcQuotaManager that can be used to apply quota checks against the workloads
    * generated by the coprocessor.
+   * <p>
+   * Introduced in 2.6.1. Any custom implementations of this class should implement this method in
+   * order to take advantage of the new behavior.
+   * </p>
    * @return the RpcQuotaManager
    */
-  RpcQuotaManager getRpcQuotaManager();
+  default RpcQuotaManager getRpcQuotaManager() {
+    throw new UnsupportedOperationException("Not implemented");
+  }
 
   /**
    * Check the quota for the current (rpc-context) user. Returns the OperationQuota used to get the
    * available quota and to report the data/usage of the operation.
+   * <p>
+   * Introduced in 2.6.1. Any custom implementations of this class should implement this method in
+   * order to take advantage of the new behavior.
+   * </p>
    * @param scan                            the scan to be estimated against the quota
    * @param maxBlockBytesScanned            the maximum bytes scanned in a single RPC call by the
    *                                        scanner
@@ -150,33 +160,47 @@ public interface RegionCoprocessorEnvironment extends CoprocessorEnvironment<Reg
    * @return the OperationQuota
    * @throws RpcThrottlingException if the operation cannot be executed due to quota exceeded.
    */
-  OperationQuota checkScanQuota(Scan scan, long maxBlockBytesScanned,
-    long prevBlockBytesScannedDifference) throws IOException, RpcThrottlingException;
+  default OperationQuota checkScanQuota(Scan scan, long maxBlockBytesScanned,
+    long prevBlockBytesScannedDifference) throws IOException, RpcThrottlingException {
+    throw new UnsupportedOperationException("Not implemented");
+  }
 
   /**
    * Check the quota for the current (rpc-context) user. Returns the OperationQuota used to get the
    * available quota and to report the data/usage of the operation. This method does not support
    * scans because estimating a scan's workload is more complicated than estimating the workload of
    * a get/put.
+   * <p>
+   * Introduced in 2.6.1. Any custom implementations of this class should implement this method in
+   * order to take advantage of the new behavior.
+   * </p>
    * @param region the region where the operation will be performed
    * @param type   the operation type
    * @return the OperationQuota
    * @throws RpcThrottlingException if the operation cannot be executed due to quota exceeded.
    */
-  OperationQuota checkBatchQuota(final Region region, final OperationQuota.OperationType type)
-    throws IOException, RpcThrottlingException;
+  default OperationQuota checkBatchQuota(final Region region,
+    final OperationQuota.OperationType type) throws IOException, RpcThrottlingException {
+    throw new UnsupportedOperationException("Not implemented");
+  }
 
   /**
    * Check the quota for the current (rpc-context) user. Returns the OperationQuota used to get the
    * available quota and to report the data/usage of the operation. This method does not support
    * scans because estimating a scan's workload is more complicated than estimating the workload of
    * a get/put.
+   * <p>
+   * Introduced in 2.6.1. Any custom implementations of this class should implement this method in
+   * order to take advantage of the new behavior.
+   * </p>
    * @param region    the region where the operation will be performed
    * @param numWrites number of writes to count against quota
    * @param numReads  number of reads to count against quota
    * @return the OperationQuota
    * @throws RpcThrottlingException if the operation cannot be executed due to quota exceeded.
    */
-  OperationQuota checkBatchQuota(final Region region, int numWrites, int numReads)
-    throws IOException, RpcThrottlingException;
+  default OperationQuota checkBatchQuota(final Region region, int numWrites, int numReads)
+    throws IOException, RpcThrottlingException {
+    throw new UnsupportedOperationException("Not implemented");
+  }
 }