HBASE-19047 CP exposed Scanner types should not extend Shipper.

hbase-endpoint/src/main/java/org/apache/hadoop/hbase/coprocessor/Export.java

@@ -389,10 +389,8 @@ public class Export extends ExportProtos.ExportService implements RegionCoproces
       if (region.getCoprocessorHost() == null) {
         scanner = region.getScanner(scan);
       } else {
-        scanner = region.getCoprocessorHost().preScannerOpen(scan);
+        region.getCoprocessorHost().preScannerOpen(scan);
-        if (scanner == null) {
         scanner = region.getScanner(scan);
-        }
         scanner = region.getCoprocessorHost().postScannerOpen(scan, scanner);
       }
       if (scanner == null) {

hbase-it/src/test/java/org/apache/hadoop/hbase/mapreduce/IntegrationTestBulkLoad.java

@@ -62,7 +62,6 @@ import org.apache.hadoop.hbase.coprocessor.RegionCoprocessorEnvironment;
 import org.apache.hadoop.hbase.coprocessor.RegionObserver;
 import org.apache.hadoop.hbase.io.ImmutableBytesWritable;
 import org.apache.hadoop.hbase.regionserver.InternalScanner;
-import org.apache.hadoop.hbase.regionserver.RegionScanner;
 import org.apache.hadoop.hbase.testclassification.IntegrationTests;
 import org.apache.hadoop.hbase.tool.LoadIncrementalHFiles;
 import org.apache.hadoop.hbase.util.Bytes;
@@ -170,12 +169,11 @@ public class IntegrationTestBulkLoad extends IntegrationTestBase {
     }
 
     @Override
-    public RegionScanner preScannerOpen(final ObserverContext<RegionCoprocessorEnvironment> e,
+    public void preScannerOpen(final ObserverContext<RegionCoprocessorEnvironment> e,
-        final Scan scan, final RegionScanner s) throws IOException {
+        final Scan scan) throws IOException {
       if (countOfOpen.incrementAndGet() == 2) { //slowdown openScanner randomly
         slowdownCode(e);
       }
-      return s;
     }
 
     @Override

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

@@ -733,8 +733,6 @@ public interface RegionObserver {
   /**
    * Called before the client opens a new scanner.
    * <p>
-   * Call CoprocessorEnvironment#bypass to skip default actions
-   * <p>
    * Call CoprocessorEnvironment#complete to skip any subsequent chained
    * coprocessors
    * <p>
@@ -742,13 +740,9 @@ public interface RegionObserver {
    * invocation. If need a Cell reference for later use, copy the cell and use that.
    * @param c the environment provided by the region server
    * @param scan the Scan specification
-   * @param s if not null, the base scanner
-   * @return an RegionScanner instance to use instead of the base scanner if
-   * overriding default behavior, null otherwise
    */
-  default RegionScanner preScannerOpen(ObserverContext<RegionCoprocessorEnvironment> c, Scan scan,
+  default void preScannerOpen(ObserverContext<RegionCoprocessorEnvironment> c, Scan scan)
-      RegionScanner s) throws IOException {
+      throws IOException {
-    return s;
   }
 
   /**

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

@@ -2836,17 +2836,17 @@ public class HRegion implements HeapSize, PropagatingConfigurationObserver, Regi
   //////////////////////////////////////////////////////////////////////////////
 
   @Override
-  public RegionScanner getScanner(Scan scan) throws IOException {
+  public RegionScannerImpl getScanner(Scan scan) throws IOException {
    return getScanner(scan, null);
   }
 
   @Override
-  public RegionScanner getScanner(Scan scan, List<KeyValueScanner> additionalScanners)
+  public RegionScannerImpl getScanner(Scan scan, List<KeyValueScanner> additionalScanners)
       throws IOException {
     return getScanner(scan, additionalScanners, HConstants.NO_NONCE, HConstants.NO_NONCE);
   }
 
-  private RegionScanner getScanner(Scan scan, List<KeyValueScanner> additionalScanners,
+  private RegionScannerImpl getScanner(Scan scan, List<KeyValueScanner> additionalScanners,
       long nonceGroup, long nonce) throws IOException {
     startRegionOperation(Operation.SCAN);
     try {
@@ -2873,7 +2873,7 @@ public class HRegion implements HeapSize, PropagatingConfigurationObserver, Regi
       HConstants.NO_NONCE);
   }
 
-  protected RegionScanner instantiateRegionScanner(Scan scan,
+  protected RegionScannerImpl instantiateRegionScanner(Scan scan,
       List<KeyValueScanner> additionalScanners, long nonceGroup, long nonce) throws IOException {
     if (scan.isReversed()) {
       if (scan.getFilter() != null) {
@@ -5862,7 +5862,8 @@ public class HRegion implements HeapSize, PropagatingConfigurationObserver, Regi
   /**
    * RegionScannerImpl is used to combine scanners from multiple Stores (aka column families).
    */
-  class RegionScannerImpl implements RegionScanner, org.apache.hadoop.hbase.ipc.RpcCallback {
+  class RegionScannerImpl
+      implements RegionScanner, Shipper, org.apache.hadoop.hbase.ipc.RpcCallback {
     // Package local for testability
     KeyValueHeap storeHeap = null;
     /** Heap of key-values that are not essential for the provided filters and are thus read

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

@@ -348,18 +348,18 @@ public class RSRpcServices implements HBaseRPCErrorHandler,
   private class RegionScannerShippedCallBack implements RpcCallback {
 
     private final String scannerName;
-    private final RegionScanner scanner;
+    private final Shipper shipper;
     private final Lease lease;
 
-    public RegionScannerShippedCallBack(String scannerName, RegionScanner scanner, Lease lease) {
+    public RegionScannerShippedCallBack(String scannerName, Shipper shipper, Lease lease) {
       this.scannerName = scannerName;
-      this.scanner = scanner;
+      this.shipper = shipper;
       this.lease = lease;
     }
 
     @Override
     public void run() throws IOException {
-      this.scanner.shipped();
+      this.shipper.shipped();
       // We're done. On way out re-add the above removed lease. The lease was temp removed for this
       // Rpc call and we are at end of the call now. Time to add it back.
       if (scanners.containsKey(scannerName)) {
@@ -1332,11 +1332,11 @@ public class RSRpcServices implements HBaseRPCErrorHandler,
     return lastBlock;
   }
 
-  private RegionScannerHolder addScanner(String scannerName, RegionScanner s, HRegion r,
+  private RegionScannerHolder addScanner(String scannerName, RegionScanner s, Shipper shipper,
-      boolean needCursor) throws LeaseStillHeldException {
+      HRegion r, boolean needCursor) throws LeaseStillHeldException {
     Lease lease = regionServer.leases.createLease(scannerName, this.scannerLeaseTimeoutPeriod,
       new ScannerListener(scannerName));
-    RpcCallback shippedCallback = new RegionScannerShippedCallBack(scannerName, s, lease);
+    RpcCallback shippedCallback = new RegionScannerShippedCallBack(scannerName, shipper, lease);
     RpcCallback closeCallback;
     if (s instanceof RpcCallback) {
       closeCallback = (RpcCallback) s;
@@ -2470,7 +2470,7 @@ public class RSRpcServices implements HBaseRPCErrorHandler,
     if (scan.getLoadColumnFamiliesOnDemandValue() == null) {
       scan.setLoadColumnFamiliesOnDemand(region.isLoadingCfsOnDemandDefault());
     }
-    RegionScanner scanner = null;
+    RegionScannerImpl scanner = null;
     try {
       scanner = region.getScanner(scan);
       scanner.next(results);
@@ -2481,8 +2481,7 @@ public class RSRpcServices implements HBaseRPCErrorHandler,
           // RpcCallContext. The rpc callback will take care of closing the
           // scanner, for eg in case
           // of get()
-          assert scanner instanceof org.apache.hadoop.hbase.ipc.RpcCallback;
+          context.setCallBack(scanner);
-          context.setCallBack((RegionScannerImpl) scanner);
         } else {
           // The call is from multi() where the results from the get() are
           // aggregated and then send out to the
@@ -2898,13 +2897,14 @@ public class RSRpcServices implements HBaseRPCErrorHandler,
         scan.addFamily(family);
       }
     }
-    RegionScanner scanner = null;
     if (region.getCoprocessorHost() != null) {
-      scanner = region.getCoprocessorHost().preScannerOpen(scan);
+      // preScannerOpen is not allowed to return a RegionScanner. Only post hook can create a
-    }
+      // wrapper for the core created RegionScanner
-    if (scanner == null) {
+      region.getCoprocessorHost().preScannerOpen(scan);
-      scanner = region.getScanner(scan);
     }
+    RegionScannerImpl coreScanner = region.getScanner(scan);
+    Shipper shipper = coreScanner;
+    RegionScanner scanner = coreScanner;
     if (region.getCoprocessorHost() != null) {
       scanner = region.getCoprocessorHost().postScannerOpen(scan, scanner);
     }
@@ -2913,7 +2913,7 @@ public class RSRpcServices implements HBaseRPCErrorHandler,
     builder.setMvccReadPoint(scanner.getMvccReadPoint());
     builder.setTtl(scannerLeaseTimeoutPeriod);
     String scannerName = String.valueOf(scannerId);
-    return addScanner(scannerName, scanner, region, scan.isNeedCursorResult());
+    return addScanner(scannerName, scanner, shipper, region, scan.isNeedCursorResult());
   }
 
   private void checkScanNextCallSeq(ScanRequest request, RegionScannerHolder rsh)

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

@@ -1150,16 +1150,13 @@ public class RegionCoprocessorHost
 
   /**
    * @param scan the Scan specification
-   * @return scanner id to return to client if default operation should be
-   * bypassed, null otherwise
    * @exception IOException Exception
    */
-  public RegionScanner preScannerOpen(final Scan scan) throws IOException {
+  public void preScannerOpen(final Scan scan) throws IOException {
-    return execOperationWithResult(true, null, coprocEnvironments.isEmpty() ? null :
+    execOperation(coprocEnvironments.isEmpty() ? null : new RegionObserverOperation() {
-        new ObserverOperationWithResult<RegionObserver, RegionScanner>(regionObserverGetter) {
       @Override
-          public RegionScanner call(RegionObserver observer) throws IOException {
+      public void call(RegionObserver observer) throws IOException {
-            return observer.preScannerOpen(this, scan, getResult());
+        observer.preScannerOpen(this, scan);
       }
     });
   }

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

@@ -32,7 +32,7 @@ import org.apache.yetus.audience.InterfaceStability;
  */
 @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.COPROC)
 @InterfaceStability.Evolving
-public interface RegionScanner extends InternalScanner, Shipper {
+public interface RegionScanner extends InternalScanner {
   /**
    * @return The RegionInfo for this scanner.
    */
@@ -115,13 +115,4 @@ public interface RegionScanner extends InternalScanner, Shipper {
    */
   boolean nextRaw(List<Cell> result, ScannerContext scannerContext)
       throws IOException;
-
-  /**
-   * Empty implementation to provide compatibility for user migrating from 1.X
-   * @see <a href="https://issues.apache.org/jira/browse/HBASE-16626">HBASE-16626</a>
-   */
-  @Override
-  default void shipped() throws IOException {
-    // do nothing
-  }
 }

hbase-server/src/main/java/org/apache/hadoop/hbase/security/access/AccessController.java

@@ -2104,10 +2104,9 @@ public class AccessController implements MasterCoprocessor, RegionCoprocessor,
   }
 
   @Override
-  public RegionScanner preScannerOpen(final ObserverContext<RegionCoprocessorEnvironment> c,
+  public void preScannerOpen(final ObserverContext<RegionCoprocessorEnvironment> c, final Scan scan)
-      final Scan scan, final RegionScanner s) throws IOException {
+      throws IOException {
     internalPreRead(c, scan, OpType.SCAN);
-    return s;
   }
 
   @Override

hbase-server/src/main/java/org/apache/hadoop/hbase/security/visibility/VisibilityController.java

@@ -534,14 +534,14 @@ public class VisibilityController implements MasterCoprocessor, RegionCoprocesso
   }
 
   @Override
-  public RegionScanner preScannerOpen(ObserverContext<RegionCoprocessorEnvironment> e, Scan scan,
+  public void preScannerOpen(ObserverContext<RegionCoprocessorEnvironment> e, Scan scan)
-      RegionScanner s) throws IOException {
+      throws IOException {
     if (!initialized) {
       throw new VisibilityControllerNotReadyException("VisibilityController not yet initialized!");
     }
     // Nothing to do if authorization is not enabled
     if (!authorizationEnabled) {
-      return s;
+      return;
     }
     Region region = e.getEnvironment().getRegion();
     Authorizations authorizations = null;
@@ -556,7 +556,7 @@ public class VisibilityController implements MasterCoprocessor, RegionCoprocesso
       // filtering. Checking visibility labels for META and NAMESPACE table is not needed.
       TableName table = region.getRegionInfo().getTable();
       if (table.isSystemTable() && !table.equals(LABELS_TABLE_NAME)) {
-        return s;
+        return;
       }
     }
 
@@ -570,7 +570,6 @@ public class VisibilityController implements MasterCoprocessor, RegionCoprocesso
         scan.setFilter(visibilityLabelFilter);
       }
     }
-    return s;
   }
 
   @Override

hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestAsyncNonMetaRegionLocatorConcurrenyLimit.java

@@ -43,7 +43,6 @@ import org.apache.hadoop.hbase.coprocessor.RegionCoprocessor;
 import org.apache.hadoop.hbase.coprocessor.RegionCoprocessorEnvironment;
 import org.apache.hadoop.hbase.coprocessor.RegionObserver;
 import org.apache.hadoop.hbase.regionserver.InternalScanner;
-import org.apache.hadoop.hbase.regionserver.RegionScanner;
 import org.apache.hadoop.hbase.security.User;
 import org.apache.hadoop.hbase.testclassification.ClientTests;
 import org.apache.hadoop.hbase.testclassification.MediumTests;
@@ -83,8 +82,8 @@ public class TestAsyncNonMetaRegionLocatorConcurrenyLimit {
     }
 
     @Override
-    public RegionScanner preScannerOpen(ObserverContext<RegionCoprocessorEnvironment> e, Scan scan,
+    public void preScannerOpen(ObserverContext<RegionCoprocessorEnvironment> e, Scan scan)
-        RegionScanner s) throws IOException {
+        throws IOException {
       if (e.getEnvironment().getRegionInfo().isMetaRegion()) {
         int concurrency = CONCURRENCY.incrementAndGet();
         for (;;) {
@@ -98,7 +97,6 @@ public class TestAsyncNonMetaRegionLocatorConcurrenyLimit {
         }
         Threads.sleepWithoutInterrupt(10);
       }
-      return s;
     }
 
     @Override

hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestAsyncRegionLocatorTimeout.java

@@ -41,7 +41,6 @@ import org.apache.hadoop.hbase.coprocessor.RegionCoprocessor;
 import org.apache.hadoop.hbase.coprocessor.RegionCoprocessorEnvironment;
 import org.apache.hadoop.hbase.coprocessor.RegionObserver;
 import org.apache.hadoop.hbase.exceptions.TimeoutIOException;
-import org.apache.hadoop.hbase.regionserver.RegionScanner;
 import org.apache.hadoop.hbase.security.User;
 import org.apache.hadoop.hbase.testclassification.ClientTests;
 import org.apache.hadoop.hbase.testclassification.MediumTests;
@@ -74,12 +73,11 @@ public class TestAsyncRegionLocatorTimeout {
     }
 
     @Override
-    public RegionScanner preScannerOpen(ObserverContext<RegionCoprocessorEnvironment> e, Scan scan,
+    public void preScannerOpen(ObserverContext<RegionCoprocessorEnvironment> e, Scan scan)
-        RegionScanner s) throws IOException {
+        throws IOException {
       if (SLEEP_MS > 0) {
         Threads.sleepWithoutInterrupt(SLEEP_MS);
       }
-      return s;
     }
   }
 

hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestBlockEvictionFromClient.java

@@ -1547,11 +1547,6 @@ public class TestBlockEvictionFromClient {
     public int getBatch() {
       return delegate.getBatch();
     }
-
-    @Override
-    public void shipped() throws IOException {
-      this.delegate.shipped();
-    }
   }
 
   public static class CustomInnerRegionObserverWrapper extends CustomInnerRegionObserver {

hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestReplicaWithCluster.java

@@ -53,7 +53,6 @@ import org.apache.hadoop.hbase.coprocessor.RegionCoprocessor;
 import org.apache.hadoop.hbase.coprocessor.RegionCoprocessorEnvironment;
 import org.apache.hadoop.hbase.coprocessor.RegionObserver;
 import org.apache.hadoop.hbase.ipc.RpcControllerFactory;
-import org.apache.hadoop.hbase.regionserver.RegionScanner;
 import org.apache.hadoop.hbase.regionserver.RegionServerStoppedException;
 import org.apache.hadoop.hbase.regionserver.StorefileRefresherChore;
 import org.apache.hadoop.hbase.regionserver.TestHRegionServerBulkLoad;
@@ -156,11 +155,9 @@ public class TestReplicaWithCluster {
     }
 
     @Override
-    public RegionScanner preScannerOpen(final ObserverContext<RegionCoprocessorEnvironment> e,
+    public void preScannerOpen(final ObserverContext<RegionCoprocessorEnvironment> e,
-        final Scan scan, final RegionScanner s) throws IOException {
+        final Scan scan) throws IOException {
-
       int replicaId = e.getEnvironment().getRegion().getRegionInfo().getReplicaId();
-
       // Fail for the primary replica and replica 1
       if (e.getEnvironment().getRegion().getRegionInfo().getReplicaId() <= 1) {
         LOG.info("Throw Region Server Stopped Exceptoin for replica id " + replicaId);
@@ -169,8 +166,6 @@ public class TestReplicaWithCluster {
       } else {
         LOG.info("We're replica region " + replicaId);
       }
-
-      return null;
     }
   }
 
@@ -208,8 +203,8 @@ public class TestReplicaWithCluster {
     }
 
     @Override
-    public RegionScanner preScannerOpen(final ObserverContext<RegionCoprocessorEnvironment> e,
+    public void preScannerOpen(final ObserverContext<RegionCoprocessorEnvironment> e,
-        final Scan scan, final RegionScanner s) throws IOException {
+        final Scan scan) throws IOException {
 
       int replicaId = e.getEnvironment().getRegion().getRegionInfo().getReplicaId();
 
@@ -238,8 +233,6 @@ public class TestReplicaWithCluster {
       } else {
         LOG.info("Scan, We're replica region " + replicaId);
       }
-
-      return null;
     }
   }
 

hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestReplicasClient.java

@@ -57,7 +57,6 @@ import org.apache.hadoop.hbase.shaded.protobuf.RequestConverter;
 import org.apache.hadoop.hbase.shaded.protobuf.generated.AdminProtos;
 import org.apache.hadoop.hbase.regionserver.HRegionServer;
 import org.apache.hadoop.hbase.regionserver.InternalScanner;
-import org.apache.hadoop.hbase.regionserver.RegionScanner;
 import org.apache.hadoop.hbase.regionserver.StorefileRefresherChore;
 import org.apache.hadoop.hbase.regionserver.TestRegionServerNoMaster;
 import org.apache.hadoop.hbase.testclassification.ClientTests;
@@ -125,10 +124,9 @@ public class TestReplicasClient {
     }
 
     @Override
-    public RegionScanner preScannerOpen(final ObserverContext<RegionCoprocessorEnvironment> e,
+    public void preScannerOpen(final ObserverContext<RegionCoprocessorEnvironment> e,
-        final Scan scan, final RegionScanner s) throws IOException {
+        final Scan scan) throws IOException {
       slowdownCode(e);
-      return s;
     }
 
     @Override

hbase-server/src/test/java/org/apache/hadoop/hbase/coprocessor/SimpleRegionObserver.java

@@ -53,7 +53,6 @@ import org.apache.hadoop.hbase.io.Reference;
 import org.apache.hadoop.hbase.io.hfile.CacheConfig;
 import org.apache.hadoop.hbase.regionserver.FlushLifeCycleTracker;
 import org.apache.hadoop.hbase.regionserver.InternalScanner;
-import org.apache.hadoop.hbase.regionserver.KeyValueScanner;
 import org.apache.hadoop.hbase.regionserver.MiniBatchOperationInProgress;
 import org.apache.hadoop.hbase.regionserver.Region.Operation;
 import org.apache.hadoop.hbase.regionserver.RegionScanner;
@@ -68,8 +67,6 @@ import org.apache.hadoop.hbase.util.Pair;
 import org.apache.hadoop.hbase.wal.WALEdit;
 import org.apache.hadoop.hbase.wal.WALKey;
 
-import org.apache.hadoop.hbase.shaded.com.google.common.collect.ImmutableList;
-
 /**
  * A sample region observer that tests the RegionObserver interface.
  * It works with TestRegionObserverInterface to provide the test case.
@@ -223,11 +220,9 @@ public class SimpleRegionObserver implements RegionCoprocessor, RegionObserver {
   }
 
   @Override
-  public RegionScanner preScannerOpen(final ObserverContext<RegionCoprocessorEnvironment> c,
+  public void preScannerOpen(final ObserverContext<RegionCoprocessorEnvironment> c, final Scan scan)
-      final Scan scan,
+      throws IOException {
-      final RegionScanner s) throws IOException {
     ctPreScannerOpen.incrementAndGet();
-    return null;
   }
 
   @Override

hbase-server/src/test/java/org/apache/hadoop/hbase/coprocessor/TestCoprocessorInterface.java

@@ -146,11 +146,6 @@ public class TestCoprocessorInterface {
     public int getBatch() {
       return delegate.getBatch();
     }
-
-    @Override
-    public void shipped() throws IOException {
-      this.delegate.shipped();
-    }
   }
 
   public static class CoprocessorImpl implements RegionCoprocessor, RegionObserver {

hbase-server/src/test/java/org/apache/hadoop/hbase/coprocessor/TestRegionObserverScannerOpenHook.java

@@ -24,7 +24,6 @@ import static org.junit.Assert.assertNull;
 
 import java.io.IOException;
 import java.util.List;
-import java.util.NavigableSet;
 import java.util.Optional;
 import java.util.concurrent.CountDownLatch;
 
@@ -55,11 +54,9 @@ import org.apache.hadoop.hbase.regionserver.HRegion;
 import org.apache.hadoop.hbase.regionserver.HRegionServer;
 import org.apache.hadoop.hbase.regionserver.HStore;
 import org.apache.hadoop.hbase.regionserver.InternalScanner;
-import org.apache.hadoop.hbase.regionserver.KeyValueScanner;
 import org.apache.hadoop.hbase.regionserver.MemStoreLABImpl;
 import org.apache.hadoop.hbase.regionserver.Region;
 import org.apache.hadoop.hbase.regionserver.RegionCoprocessorHost;
-import org.apache.hadoop.hbase.regionserver.RegionScanner;
 import org.apache.hadoop.hbase.regionserver.RegionServerServices;
 import org.apache.hadoop.hbase.regionserver.ScanType;
 import org.apache.hadoop.hbase.regionserver.ScannerContext;
@@ -131,9 +128,9 @@ public class TestRegionObserverScannerOpenHook {
     }
 
     @Override
-    public RegionScanner preScannerOpen(ObserverContext<RegionCoprocessorEnvironment> c, Scan scan,
+    public void preScannerOpen(ObserverContext<RegionCoprocessorEnvironment> c, Scan scan)
-        RegionScanner s) throws IOException {
+        throws IOException {
-      return c.getEnvironment().getRegion().getScanner(scan.setFilter(new NoDataFilter()));
+      scan.setFilter(new NoDataFilter());
     }
   }
 

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/NoOpScanPolicyObserver.java

@@ -21,7 +21,6 @@ package org.apache.hadoop.hbase.regionserver;
 import java.io.IOException;
 import java.util.Optional;
 
-import org.apache.hadoop.hbase.client.Scan;
 import org.apache.hadoop.hbase.client.TestFromClientSideWithCoprocessor;
 import org.apache.hadoop.hbase.coprocessor.ObserverContext;
 import org.apache.hadoop.hbase.coprocessor.RegionCoprocessor;
@@ -56,9 +55,5 @@ public class NoOpScanPolicyObserver implements RegionCoprocessor, RegionObserver
     return new DelegatingInternalScanner(scanner);
   }
 
-  @Override
+  // TODO add for postScannerOpen
-  public RegionScanner preScannerOpen(ObserverContext<RegionCoprocessorEnvironment> c, Scan scan,
-      RegionScanner s) throws IOException {
-    return c.getEnvironment().getRegion().getScanner(scan);
-  }
 }

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestHRegion.java

@@ -2789,12 +2789,12 @@ public class TestHRegion {
       scan = new Scan();
       scan.addFamily(fam2);
       scan.addFamily(fam4);
-      is = (RegionScannerImpl) region.getScanner(scan);
+      is = region.getScanner(scan);
-      assertEquals(1, ((RegionScannerImpl) is).storeHeap.getHeap().size());
+      assertEquals(1, is.storeHeap.getHeap().size());
 
       scan = new Scan();
-      is = (RegionScannerImpl) region.getScanner(scan);
+      is = region.getScanner(scan);
-      assertEquals(families.length - 1, ((RegionScannerImpl) is).storeHeap.getHeap().size());
+      assertEquals(families.length - 1, is.storeHeap.getHeap().size());
     } finally {
       HBaseTestingUtility.closeRegionAndWAL(this.region);
       this.region = null;
@@ -5688,7 +5688,7 @@ public class TestHRegion {
       // create a reverse scan
       Scan scan = new Scan(Bytes.toBytes("19996"));
       scan.setReversed(true);
-      RegionScanner scanner = region.getScanner(scan);
+      RegionScannerImpl scanner = region.getScanner(scan);
 
       // flush the cache. This will reset the store scanner
       region.flushcache(true, true, FlushLifeCycleTracker.DUMMY);
@@ -5709,7 +5709,7 @@ public class TestHRegion {
         // added here
         if (!assertDone) {
           StoreScanner current =
-              (StoreScanner) (((RegionScannerImpl) scanner).storeHeap).getCurrentForTesting();
+              (StoreScanner) (scanner.storeHeap).getCurrentForTesting();
           List<KeyValueScanner> scanners = current.getAllScannersForTesting();
           assertEquals("There should be only one scanner the store file scanner", 1,
             scanners.size());

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestScanWithBloomError.java

@@ -121,7 +121,7 @@ public class TestScanWithBloomError {
     LOG.info("Scanning column set: " + Arrays.toString(colSet));
     Scan scan = new Scan(ROW_BYTES, ROW_BYTES);
     addColumnSetToScan(scan, colSet);
-    RegionScannerImpl scanner = (RegionScannerImpl) region.getScanner(scan);
+    RegionScannerImpl scanner = region.getScanner(scan);
     KeyValueHeap storeHeap = scanner.getStoreHeapForTesting();
     assertEquals(0, storeHeap.getHeap().size());
     StoreScanner storeScanner =

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestScannerHeartbeatMessages.java

@@ -35,7 +35,6 @@ import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.CellComparator;
 import org.apache.hadoop.hbase.CellComparatorImpl;
 import org.apache.hadoop.hbase.CellUtil;
-import org.apache.hadoop.hbase.CoordinatedStateManager;
 import org.apache.hadoop.hbase.HBaseTestingUtility;
 import org.apache.hadoop.hbase.HConstants;
 import org.apache.hadoop.hbase.HTableDescriptor;
@@ -465,7 +464,7 @@ public class TestScannerHeartbeatMessages {
 
     // Instantiate the custom heartbeat region scanners
     @Override
-    protected RegionScanner instantiateRegionScanner(Scan scan,
+    protected RegionScannerImpl instantiateRegionScanner(Scan scan,
         List<KeyValueScanner> additionalScanners, long nonceGroup, long nonce) throws IOException {
       if (scan.isReversed()) {
         if (scan.getFilter() != null) {

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestSwitchToStreamRead.java

@@ -91,8 +91,8 @@ public class TestSwitchToStreamRead {
 
   @Test
   public void test() throws IOException {
-    try (RegionScanner scanner = REGION.getScanner(new Scan())) {
+    try (RegionScannerImpl scanner = REGION.getScanner(new Scan())) {
-      StoreScanner storeScanner = (StoreScanner) ((RegionScannerImpl) scanner)
+      StoreScanner storeScanner = (StoreScanner) (scanner)
           .getStoreHeapForTesting().getCurrentForTesting();
       for (KeyValueScanner kvs : storeScanner.getAllScannersForTesting()) {
         if (kvs instanceof StoreFileScanner) {

hbase-server/src/test/java/org/apache/hadoop/hbase/security/access/TestWithDisabledAuthorization.java

@@ -919,7 +919,7 @@ public class TestWithDisabledAuthorization extends SecureTestUtil {
       @Override
       public Object run() throws Exception {
         ACCESS_CONTROLLER.preScannerOpen(ObserverContextImpl.createAndPrepare(RCP_ENV),
-          new Scan(), mock(RegionScanner.class));
+          new Scan());
         return null;
       }
     }, SUPERUSER, USER_ADMIN, USER_RW, USER_RO, USER_OWNER, USER_CREATE, USER_QUAL, USER_NONE);

hbase-server/src/test/java/org/apache/hadoop/hbase/util/TestCoprocessorScanPolicy.java

@@ -51,7 +51,6 @@ import org.apache.hadoop.hbase.regionserver.DelegatingInternalScanner;
 import org.apache.hadoop.hbase.regionserver.FlushLifeCycleTracker;
 import org.apache.hadoop.hbase.regionserver.InternalScanner;
 import org.apache.hadoop.hbase.regionserver.Region;
-import org.apache.hadoop.hbase.regionserver.RegionScanner;
 import org.apache.hadoop.hbase.regionserver.ScanType;
 import org.apache.hadoop.hbase.regionserver.ScannerContext;
 import org.apache.hadoop.hbase.regionserver.Store;
@@ -338,8 +337,8 @@ public class TestCoprocessorScanPolicy {
     }
 
     @Override
-    public RegionScanner preScannerOpen(ObserverContext<RegionCoprocessorEnvironment> c, Scan scan,
+    public void preScannerOpen(ObserverContext<RegionCoprocessorEnvironment> c, Scan scan)
-        RegionScanner s) throws IOException {
+        throws IOException {
       Region region = c.getEnvironment().getRegion();
       TableName tableName = region.getTableDescriptor().getTableName();
       Long ttl = this.ttls.get(tableName);
@@ -350,7 +349,6 @@ public class TestCoprocessorScanPolicy {
       if (version != null) {
         scan.readVersions(version);
       }
-      return region.getScanner(scan);
     }
   }
 }