/**
    *
    * 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.coprocessor;
  
  import static org.apache.hadoop.hbase.HBaseTestingUtility.fam1;
  import static org.apache.hadoop.hbase.HBaseTestingUtility.fam2;
  import static org.apache.hadoop.hbase.HBaseTestingUtility.fam3;
  import static org.junit.Assert.assertFalse;
  import static org.junit.Assert.assertNotNull;
  import static org.junit.Assert.assertNull;
  import static org.junit.Assert.assertTrue;
  import static org.junit.Assert.fail;
  import static org.mockito.Mockito.when;
  
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.List;
  import java.util.Map;
  import java.util.concurrent.ConcurrentMap;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.fs.Path;
  import org.apache.hadoop.hbase.Cell;
  import org.apache.hadoop.hbase.Coprocessor;
  import org.apache.hadoop.hbase.CoprocessorEnvironment;
  import org.apache.hadoop.hbase.HBaseTestCase;
  import org.apache.hadoop.hbase.HBaseTestingUtility;
  import org.apache.hadoop.hbase.HColumnDescriptor;
  import org.apache.hadoop.hbase.HConstants;
  import org.apache.hadoop.hbase.HRegionInfo;
  import org.apache.hadoop.hbase.HTableDescriptor;
  import org.apache.hadoop.hbase.Server;
  import org.apache.hadoop.hbase.testclassification.SmallTests;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.client.Get;
  import org.apache.hadoop.hbase.client.Scan;
  import org.apache.hadoop.hbase.regionserver.HRegion;
  import org.apache.hadoop.hbase.regionserver.InternalScanner;
  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.ScanType;
  import org.apache.hadoop.hbase.regionserver.ScannerContext;
  import org.apache.hadoop.hbase.regionserver.SplitTransaction;
  import org.apache.hadoop.hbase.regionserver.SplitTransactionFactory;
  import org.apache.hadoop.hbase.regionserver.Store;
  import org.apache.hadoop.hbase.regionserver.StoreFile;
  import org.apache.hadoop.hbase.util.PairOfSameType;
  import org.junit.Rule;
  import org.junit.Test;
  import org.junit.experimental.categories.Category;
  import org.junit.rules.TestName;
  import org.mockito.Mockito;
  
  @Category(SmallTests.class)
  public class TestCoprocessorInterface {
    @Rule public TestName name = new TestName();
    private static final Log LOG = LogFactory.getLog(TestCoprocessorInterface.class);
    private static final HBaseTestingUtility TEST_UTIL = HBaseTestingUtility.createLocalHTU();
    static final Path DIR = TEST_UTIL.getDataTestDir();
  
    private static class CustomScanner implements RegionScanner {
  
      private RegionScanner delegate;
  
      public CustomScanner(RegionScanner delegate) {
        this.delegate = delegate;
      }
  
      @Override
      public boolean next(List<Cell> results) throws IOException {
        return delegate.next(results);
      }
  
      @Override
      public boolean next(List<Cell> result, ScannerContext scannerContext)
          throws IOException {
        return delegate.next(result, scannerContext);
      }
  
     @Override
     public boolean nextRaw(List<Cell> result)
         throws IOException {
       return delegate.nextRaw(result);
     }
 
     @Override
     public boolean nextRaw(List<Cell> result, ScannerContext context)
         throws IOException {
       return delegate.nextRaw(result, context);
     }
 
     @Override
     public void close() throws IOException {
       delegate.close();
     }
 
     @Override
     public HRegionInfo getRegionInfo() {
       return delegate.getRegionInfo();
     }
 
     @Override
     public boolean isFilterDone() throws IOException {
       return delegate.isFilterDone();
     }
 
     @Override
     public boolean reseek(byte[] row) throws IOException {
       return false;
     }
 
     @Override
     public long getMaxResultSize() {
       return delegate.getMaxResultSize();
     }
 
     @Override
     public long getMvccReadPoint() {
       return delegate.getMvccReadPoint();
     }
 
     @Override
     public int getBatch() {
       return delegate.getBatch();
     }
   }
 
   public static class CoprocessorImpl extends BaseRegionObserver {
 
     private boolean startCalled;
     private boolean stopCalled;
     private boolean preOpenCalled;
     private boolean postOpenCalled;
     private boolean preCloseCalled;
     private boolean postCloseCalled;
     private boolean preCompactCalled;
     private boolean postCompactCalled;
     private boolean preFlushCalled;
     private boolean postFlushCalled;
     private boolean preSplitCalled;
     private boolean postSplitCalled;
     private boolean preSplitWithSplitRowCalled;
     private ConcurrentMap<String, Object> sharedData;
 
     @Override
     public void start(CoprocessorEnvironment e) {
       sharedData = ((RegionCoprocessorEnvironment)e).getSharedData();
       // using new String here, so that there will be new object on each invocation
       sharedData.putIfAbsent("test1", new Object());
       startCalled = true;
     }
 
     @Override
     public void stop(CoprocessorEnvironment e) {
       sharedData = null;
       stopCalled = true;
     }
 
     @Override
     public void preOpen(ObserverContext<RegionCoprocessorEnvironment> e) {
       preOpenCalled = true;
     }
     @Override
     public void postOpen(ObserverContext<RegionCoprocessorEnvironment> e) {
       postOpenCalled = true;
     }
     @Override
     public void preClose(ObserverContext<RegionCoprocessorEnvironment> e, boolean abortRequested) {
       preCloseCalled = true;
     }
     @Override
     public void postClose(ObserverContext<RegionCoprocessorEnvironment> e, boolean abortRequested) {
       postCloseCalled = true;
     }
     @Override
     public InternalScanner preCompact(ObserverContext<RegionCoprocessorEnvironment> e,
         Store store, InternalScanner scanner, ScanType scanType) {
       preCompactCalled = true;
       return scanner;
     }
     @Override
     public void postCompact(ObserverContext<RegionCoprocessorEnvironment> e,
         Store store, StoreFile resultFile) {
       postCompactCalled = true;
     }
     @Override
     public void preFlush(ObserverContext<RegionCoprocessorEnvironment> e) {
       preFlushCalled = true;
     }
     @Override
     public void postFlush(ObserverContext<RegionCoprocessorEnvironment> e) {
       postFlushCalled = true;
     }
     @Override
     public void preSplit(ObserverContext<RegionCoprocessorEnvironment> e) {
       preSplitCalled = true;
     }
     
     @Override
     public void preSplit(ObserverContext<RegionCoprocessorEnvironment> c,
         byte[] splitRow) throws IOException {
       preSplitWithSplitRowCalled = true;
     }
     @Override
     public void postSplit(ObserverContext<RegionCoprocessorEnvironment> e, Region l, Region r) {
       postSplitCalled = true;
     }
 
     @Override
     public RegionScanner postScannerOpen(final ObserverContext<RegionCoprocessorEnvironment> e,
         final Scan scan, final RegionScanner s) throws IOException {
       return new CustomScanner(s);
     }
 
     boolean wasStarted() {
       return startCalled;
     }
     boolean wasStopped() {
       return stopCalled;
     }
     boolean wasOpened() {
       return (preOpenCalled && postOpenCalled);
     }
     boolean wasClosed() {
       return (preCloseCalled && postCloseCalled);
     }
     boolean wasFlushed() {
       return (preFlushCalled && postFlushCalled);
     }
     boolean wasCompacted() {
       return (preCompactCalled && postCompactCalled);
     }
     boolean wasSplit() {
       return (preSplitCalled && postSplitCalled && preSplitWithSplitRowCalled);
     }
     Map<String, Object> getSharedData() {
       return sharedData;
     }
   }
 
   public static class CoprocessorII extends BaseRegionObserver {
     private ConcurrentMap<String, Object> sharedData;
     @Override
     public void start(CoprocessorEnvironment e) {
       sharedData = ((RegionCoprocessorEnvironment)e).getSharedData();
       sharedData.putIfAbsent("test2", new Object());
     }
     @Override
     public void stop(CoprocessorEnvironment e) {
       sharedData = null;
     }
     @Override
     public void preGetOp(final ObserverContext<RegionCoprocessorEnvironment> e,
         final Get get, final List<Cell> results) throws IOException {
       throw new RuntimeException();
     }
 
     Map<String, Object> getSharedData() {
       return sharedData;
     }
   }
 
   @Test
   public void testSharedData() throws IOException {
     TableName tableName = TableName.valueOf(name.getMethodName());
     byte [][] families = { fam1, fam2, fam3 };
 
     Configuration hc = initSplit();
     Region region = initHRegion(tableName, name.getMethodName(), hc,
       new Class<?>[]{}, families);
 
     for (int i = 0; i < 3; i++) {
       HBaseTestCase.addContent(region, fam3);
       region.flush(true);
     }
 
     region.compact(false);
 
     byte [] splitRow = ((HRegion)region).checkSplit();
     assertNotNull(splitRow);
     Region [] regions = split(region, splitRow);
     for (int i = 0; i < regions.length; i++) {
       regions[i] = reopenRegion(regions[i], CoprocessorImpl.class, CoprocessorII.class);
     }
     Coprocessor c = regions[0].getCoprocessorHost().
         findCoprocessor(CoprocessorImpl.class.getName());
     Coprocessor c2 = regions[0].getCoprocessorHost().
         findCoprocessor(CoprocessorII.class.getName());
     Object o = ((CoprocessorImpl)c).getSharedData().get("test1");
     Object o2 = ((CoprocessorII)c2).getSharedData().get("test2");
     assertNotNull(o);
     assertNotNull(o2);
     // to coprocessors get different sharedDatas
     assertFalse(((CoprocessorImpl)c).getSharedData() == ((CoprocessorII)c2).getSharedData());
     for (int i = 1; i < regions.length; i++) {
       c = regions[i].getCoprocessorHost().
           findCoprocessor(CoprocessorImpl.class.getName());
       c2 = regions[i].getCoprocessorHost().
           findCoprocessor(CoprocessorII.class.getName());
       // make sure that all coprocessor of a class have identical sharedDatas
       assertTrue(((CoprocessorImpl)c).getSharedData().get("test1") == o);
       assertTrue(((CoprocessorII)c2).getSharedData().get("test2") == o2);
     }
     // now have all Environments fail
     for (int i = 0; i < regions.length; i++) {
       try {
         byte [] r = regions[i].getRegionInfo().getStartKey();
         if (r == null || r.length <= 0) {
           // Its the start row.  Can't ask for null.  Ask for minimal key instead.
           r = new byte [] {0};
         }
         Get g = new Get(r);
         regions[i].get(g);
         fail();
       } catch (org.apache.hadoop.hbase.DoNotRetryIOException xc) {
       }
       assertNull(regions[i].getCoprocessorHost().
           findCoprocessor(CoprocessorII.class.getName()));
     }
     c = regions[0].getCoprocessorHost().
         findCoprocessor(CoprocessorImpl.class.getName());
     assertTrue(((CoprocessorImpl)c).getSharedData().get("test1") == o);
     c = c2 = null;
     // perform a GC
     System.gc();
     // reopen the region
     region = reopenRegion(regions[0], CoprocessorImpl.class, CoprocessorII.class);
     c = region.getCoprocessorHost().
         findCoprocessor(CoprocessorImpl.class.getName());
     // CPimpl is unaffected, still the same reference
     assertTrue(((CoprocessorImpl)c).getSharedData().get("test1") == o);
     c2 = region.getCoprocessorHost().
         findCoprocessor(CoprocessorII.class.getName());
     // new map and object created, hence the reference is different
     // hence the old entry was indeed removed by the GC and new one has been created
     Object o3 = ((CoprocessorII)c2).getSharedData().get("test2");
     assertFalse(o3 == o2);
   }
 
   @Test
   public void testCoprocessorInterface() throws IOException {
     TableName tableName = TableName.valueOf(name.getMethodName());
     byte [][] families = { fam1, fam2, fam3 };
 
     Configuration hc = initSplit();
     Region region = initHRegion(tableName, name.getMethodName(), hc,
       new Class<?>[]{CoprocessorImpl.class}, families);
     for (int i = 0; i < 3; i++) {
       HBaseTestCase.addContent(region, fam3);
       region.flush(true);
     }
 
     region.compact(false);
 
     byte [] splitRow = ((HRegion)region).checkSplit();
 
     assertNotNull(splitRow);
     Region [] regions = split(region, splitRow);
     for (int i = 0; i < regions.length; i++) {
       regions[i] = reopenRegion(regions[i], CoprocessorImpl.class);
     }
     HRegion.closeHRegion((HRegion)region);
     Coprocessor c = region.getCoprocessorHost().
       findCoprocessor(CoprocessorImpl.class.getName());
 
     // HBASE-4197
     Scan s = new Scan();
     RegionScanner scanner = regions[0].getCoprocessorHost().postScannerOpen(s, regions[0].getScanner(s));
     assertTrue(scanner instanceof CustomScanner);
     // this would throw an exception before HBASE-4197
     scanner.next(new ArrayList<Cell>());
 
     assertTrue("Coprocessor not started", ((CoprocessorImpl)c).wasStarted());
     assertTrue("Coprocessor not stopped", ((CoprocessorImpl)c).wasStopped());
     assertTrue(((CoprocessorImpl)c).wasOpened());
     assertTrue(((CoprocessorImpl)c).wasClosed());
     assertTrue(((CoprocessorImpl)c).wasFlushed());
     assertTrue(((CoprocessorImpl)c).wasCompacted());
     assertTrue(((CoprocessorImpl)c).wasSplit());
 
     for (int i = 0; i < regions.length; i++) {
       HRegion.closeHRegion((HRegion)regions[i]);
       c = region.getCoprocessorHost()
             .findCoprocessor(CoprocessorImpl.class.getName());
       assertTrue("Coprocessor not started", ((CoprocessorImpl)c).wasStarted());
       assertTrue("Coprocessor not stopped", ((CoprocessorImpl)c).wasStopped());
       assertTrue(((CoprocessorImpl)c).wasOpened());
       assertTrue(((CoprocessorImpl)c).wasClosed());
       assertTrue(((CoprocessorImpl)c).wasCompacted());
     }
   }
 
   Region reopenRegion(final Region closedRegion, Class<?> ... implClasses)
       throws IOException {
     //HRegionInfo info = new HRegionInfo(tableName, null, null, false);
     Region r = HRegion.openHRegion(closedRegion, null);
 
     // this following piece is a hack. currently a coprocessorHost
     // is secretly loaded at OpenRegionHandler. we don't really
     // start a region server here, so just manually create cphost
     // and set it to region.
     Configuration conf = TEST_UTIL.getConfiguration();
     RegionCoprocessorHost host = new RegionCoprocessorHost(r, null, conf);
     ((HRegion)r).setCoprocessorHost(host);
 
     for (Class<?> implClass : implClasses) {
       host.load(implClass, Coprocessor.PRIORITY_USER, conf);
     }
     // we need to manually call pre- and postOpen here since the
     // above load() is not the real case for CP loading. A CP is
     // expected to be loaded by default from 1) configuration; or 2)
     // HTableDescriptor. If it's loaded after HRegion initialized,
     // the pre- and postOpen() won't be triggered automatically.
     // Here we have to call pre and postOpen explicitly.
     host.preOpen();
     host.postOpen();
     return r;
   }
 
   Region initHRegion (TableName tableName, String callingMethod,
       Configuration conf, Class<?> [] implClasses, byte [][] families)
       throws IOException {
     HTableDescriptor htd = new HTableDescriptor(tableName);
     for(byte [] family : families) {
       htd.addFamily(new HColumnDescriptor(family));
     }
     HRegionInfo info = new HRegionInfo(tableName, null, null, false);
     Path path = new Path(DIR + callingMethod);
     HRegion r = HRegion.createHRegion(info, path, conf, htd);
 
     // this following piece is a hack.
     RegionCoprocessorHost host = new RegionCoprocessorHost(r, null, conf);
     r.setCoprocessorHost(host);
 
     for (Class<?> implClass : implClasses) {
       host.load(implClass, Coprocessor.PRIORITY_USER, conf);
       Coprocessor c = host.findCoprocessor(implClass.getName());
       assertNotNull(c);
     }
 
     // Here we have to call pre and postOpen explicitly.
     host.preOpen();
     host.postOpen();
     return r;
   }
 
   Configuration initSplit() {
     // Always compact if there is more than one store file.
     TEST_UTIL.getConfiguration().setInt("hbase.hstore.compactionThreshold", 2);
     // Make lease timeout longer, lease checks less frequent
     TEST_UTIL.getConfiguration().setInt(
         "hbase.master.lease.thread.wakefrequency", 5 * 1000);
     TEST_UTIL.getConfiguration().setInt(HConstants.HBASE_CLIENT_SCANNER_TIMEOUT_PERIOD, 10 * 1000);
     // Increase the amount of time between client retries
     TEST_UTIL.getConfiguration().setLong("hbase.client.pause", 15 * 1000);
     // This size should make it so we always split using the addContent
     // below.  After adding all data, the first region is 1.3M
     TEST_UTIL.getConfiguration().setLong(HConstants.HREGION_MAX_FILESIZE,
         1024 * 128);
     TEST_UTIL.getConfiguration().setBoolean("hbase.testing.nocluster",
         true);
     TEST_UTIL.getConfiguration().setBoolean(CoprocessorHost.ABORT_ON_ERROR_KEY, false);
 
     return TEST_UTIL.getConfiguration();
   }
 
   private Region [] split(final Region r, final byte [] splitRow) throws IOException {
     Region[] regions = new Region[2];
 
     SplitTransaction st = new SplitTransactionFactory(TEST_UTIL.getConfiguration())
       .create(r, splitRow);
     int i = 0;
 
     if (!st.prepare()) {
       // test fails.
       assertTrue(false);
     }
     try {
       Server mockServer = Mockito.mock(Server.class);
       when(mockServer.getConfiguration()).thenReturn(TEST_UTIL.getConfiguration());
       PairOfSameType<Region> daughters = st.execute(mockServer, null);
       for (Region each_daughter: daughters) {
         regions[i] = each_daughter;
         i++;
       }
     } catch (IOException ioe) {
       LOG.info("Split transaction of " + r.getRegionInfo().getRegionNameAsString() +
           " failed:" + ioe.getMessage());
       assertTrue(false);
     } catch (RuntimeException e) {
       LOG.info("Failed rollback of failed split of " +
           r.getRegionInfo().getRegionNameAsString() + e.getMessage());
     }
 
     assertTrue(i == 2);
     return regions;
   }
 
 }