/**
    * 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.procedure;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  import java.security.PrivilegedExceptionAction;
  import java.util.List;
  import java.util.concurrent.ExecutorService;
  import java.util.concurrent.atomic.AtomicBoolean;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.hbase.HRegionInfo;
  import org.apache.hadoop.hbase.MetaTableAccessor;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.TableNotEnabledException;
  import org.apache.hadoop.hbase.TableNotFoundException;
  import org.apache.hadoop.hbase.TableStateManager;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.constraint.ConstraintException;
  import org.apache.hadoop.hbase.executor.EventType;
  import org.apache.hadoop.hbase.exceptions.HBaseException;
  import org.apache.hadoop.hbase.master.AssignmentManager;
  import org.apache.hadoop.hbase.master.BulkAssigner;
  import org.apache.hadoop.hbase.master.MasterCoprocessorHost;
  import org.apache.hadoop.hbase.master.RegionState;
  import org.apache.hadoop.hbase.master.RegionStates;
  import org.apache.hadoop.hbase.procedure2.StateMachineProcedure;
  import org.apache.hadoop.hbase.protobuf.ProtobufUtil;
  import org.apache.hadoop.hbase.protobuf.generated.MasterProcedureProtos;
  import org.apache.hadoop.hbase.protobuf.generated.MasterProcedureProtos.DisableTableState;
  import org.apache.hadoop.hbase.protobuf.generated.ZooKeeperProtos;
  import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
  import org.apache.hadoop.security.UserGroupInformation;
  import org.apache.htrace.Trace;
  
  @InterfaceAudience.Private
  public class DisableTableProcedure
      extends StateMachineProcedure<MasterProcedureEnv, DisableTableState>
      implements TableProcedureInterface {
    private static final Log LOG = LogFactory.getLog(DisableTableProcedure.class);
  
    private final AtomicBoolean aborted = new AtomicBoolean(false);
  
    // This is for back compatible with 1.0 asynchronized operations.
    private final ProcedurePrepareLatch syncLatch;
  
    private TableName tableName;
    private boolean skipTableStateCheck;
    private UserGroupInformation user;
  
    private Boolean traceEnabled = null;
  
    enum MarkRegionOfflineOpResult {
      MARK_ALL_REGIONS_OFFLINE_SUCCESSFUL,
      BULK_ASSIGN_REGIONS_FAILED,
      MARK_ALL_REGIONS_OFFLINE_INTERRUPTED,
    }
  
    public DisableTableProcedure() {
      syncLatch = null;
    }
  
    /**
     * Constructor
     * @param env MasterProcedureEnv
     * @param tableName the table to operate on
     * @param skipTableStateCheck whether to check table state
     */
    public DisableTableProcedure(final MasterProcedureEnv env, final TableName tableName,
        final boolean skipTableStateCheck) {
      this(env, tableName, skipTableStateCheck, null);
    }
  
    /**
     * Constructor
     * @param env MasterProcedureEnv
     * @param tableName the table to operate on
     * @param skipTableStateCheck whether to check table state
     */
    public DisableTableProcedure(final MasterProcedureEnv env, final TableName tableName,
       final boolean skipTableStateCheck, final ProcedurePrepareLatch syncLatch) {
     this.tableName = tableName;
     this.skipTableStateCheck = skipTableStateCheck;
     this.user = env.getRequestUser().getUGI();
     this.setOwner(this.user.getShortUserName());
 
     // Compatible with 1.0: We use latch to make sure that this procedure implementation is
     // compatible with 1.0 asynchronized operations. We need to lock the table and check
     // whether the Disable operation could be performed (table exists and online; table state
     // is ENABLED). Once it is done, we are good to release the latch and the client can
     // start asynchronously wait for the operation.
     //
     // Note: the member syncLatch could be null if we are in failover or recovery scenario.
     // This is ok for backward compatible, as 1.0 client would not able to peek at procedure.
     this.syncLatch = syncLatch;
   }
 
   @Override
   protected Flow executeFromState(final MasterProcedureEnv env, final DisableTableState state) {
     if (isTraceEnabled()) {
       LOG.trace(this + " execute state=" + state);
     }
 
     try {
       switch (state) {
       case DISABLE_TABLE_PREPARE:
         if (prepareDisable(env)) {
           setNextState(DisableTableState.DISABLE_TABLE_PRE_OPERATION);
         } else {
           assert isFailed() : "disable should have an exception here";
           return Flow.NO_MORE_STATE;
         }
         break;
       case DISABLE_TABLE_PRE_OPERATION:
         preDisable(env, state);
         setNextState(DisableTableState.DISABLE_TABLE_SET_DISABLING_TABLE_STATE);
         break;
       case DISABLE_TABLE_SET_DISABLING_TABLE_STATE:
         setTableStateToDisabling(env, tableName);
         setNextState(DisableTableState.DISABLE_TABLE_MARK_REGIONS_OFFLINE);
         break;
       case DISABLE_TABLE_MARK_REGIONS_OFFLINE:
         if (markRegionsOffline(env, tableName, true) ==
             MarkRegionOfflineOpResult.MARK_ALL_REGIONS_OFFLINE_SUCCESSFUL) {
           setNextState(DisableTableState.DISABLE_TABLE_SET_DISABLED_TABLE_STATE);
         } else {
           LOG.trace("Retrying later to disable the missing regions");
         }
         break;
       case DISABLE_TABLE_SET_DISABLED_TABLE_STATE:
         setTableStateToDisabled(env, tableName);
         setNextState(DisableTableState.DISABLE_TABLE_POST_OPERATION);
         break;
       case DISABLE_TABLE_POST_OPERATION:
         postDisable(env, state);
         return Flow.NO_MORE_STATE;
       default:
         throw new UnsupportedOperationException("unhandled state=" + state);
       }
     } catch (InterruptedException|HBaseException|IOException e) {
       LOG.warn("Retriable error trying to disable table=" + tableName + " state=" + state, e);
     }
     return Flow.HAS_MORE_STATE;
   }
 
   @Override
   protected void rollbackState(final MasterProcedureEnv env, final DisableTableState state)
       throws IOException {
     if (state == DisableTableState.DISABLE_TABLE_PREPARE) {
       undoTableStateChange(env);
       ProcedurePrepareLatch.releaseLatch(syncLatch, this);
       return;
     }
 
     // The delete doesn't have a rollback. The execution will succeed, at some point.
     throw new UnsupportedOperationException("unhandled state=" + state);
   }
 
   @Override
   protected DisableTableState getState(final int stateId) {
     return DisableTableState.valueOf(stateId);
   }
 
   @Override
   protected int getStateId(final DisableTableState state) {
     return state.getNumber();
   }
 
   @Override
   protected DisableTableState getInitialState() {
     return DisableTableState.DISABLE_TABLE_PREPARE;
   }
 
   @Override
   protected void setNextState(final DisableTableState state) {
     if (aborted.get()) {
       setAbortFailure("disable-table", "abort requested");
     } else {
       super.setNextState(state);
     }
   }
 
   @Override
   public boolean abort(final MasterProcedureEnv env) {
     aborted.set(true);
     return true;
   }
 
   @Override
   protected boolean acquireLock(final MasterProcedureEnv env) {
     if (!env.isInitialized()) return false;
     return env.getProcedureQueue().tryAcquireTableWrite(
       tableName,
       EventType.C_M_DISABLE_TABLE.toString());
   }
 
   @Override
   protected void releaseLock(final MasterProcedureEnv env) {
     env.getProcedureQueue().releaseTableWrite(tableName);
   }
 
   @Override
   public void serializeStateData(final OutputStream stream) throws IOException {
     super.serializeStateData(stream);
 
     MasterProcedureProtos.DisableTableStateData.Builder disableTableMsg =
         MasterProcedureProtos.DisableTableStateData.newBuilder()
             .setUserInfo(MasterProcedureUtil.toProtoUserInfo(user))
             .setTableName(ProtobufUtil.toProtoTableName(tableName))
             .setSkipTableStateCheck(skipTableStateCheck);
 
     disableTableMsg.build().writeDelimitedTo(stream);
   }
 
   @Override
   public void deserializeStateData(final InputStream stream) throws IOException {
     super.deserializeStateData(stream);
 
     MasterProcedureProtos.DisableTableStateData disableTableMsg =
         MasterProcedureProtos.DisableTableStateData.parseDelimitedFrom(stream);
     user = MasterProcedureUtil.toUserInfo(disableTableMsg.getUserInfo());
     tableName = ProtobufUtil.toTableName(disableTableMsg.getTableName());
     skipTableStateCheck = disableTableMsg.getSkipTableStateCheck();
   }
 
   @Override
   public void toStringClassDetails(StringBuilder sb) {
     sb.append(getClass().getSimpleName());
     sb.append(" (table=");
     sb.append(tableName);
     sb.append(")");
   }
 
   @Override
   public TableName getTableName() {
     return tableName;
   }
 
   @Override
   public TableOperationType getTableOperationType() {
     return TableOperationType.DISABLE;
   }
 
   /**
    * Action before any real action of disabling table. Set the exception in the procedure instead
    * of throwing it.  This approach is to deal with backward compatible with 1.0.
    * @param env MasterProcedureEnv
    * @throws HBaseException
    * @throws IOException
    */
   private boolean prepareDisable(final MasterProcedureEnv env) throws HBaseException, IOException {
     boolean canTableBeDisabled = true;
     if (tableName.equals(TableName.META_TABLE_NAME)) {
       setFailure("master-disable-table", new ConstraintException("Cannot disable catalog table"));
       canTableBeDisabled = false;
     } else if (!MetaTableAccessor.tableExists(env.getMasterServices().getConnection(), tableName)) {
       setFailure("master-disable-table", new TableNotFoundException(tableName));
       canTableBeDisabled = false;
     } else if (!skipTableStateCheck) {
       // There could be multiple client requests trying to disable or enable
       // the table at the same time. Ensure only the first request is honored
       // After that, no other requests can be accepted until the table reaches
       // DISABLED or ENABLED.
       //
       // Note: A quick state check should be enough for us to move forward. However, instead of
       // calling TableStateManager.isTableState() to just check the state, we called
       // TableStateManager.setTableStateIfInStates() to set the state to DISABLING from ENABLED.
       // This is because we treat empty state as enabled from 0.92-clusters. See
       // ZKTableStateManager.setTableStateIfInStates() that has a hack solution to work around
       // this issue.
       TableStateManager tsm =
         env.getMasterServices().getAssignmentManager().getTableStateManager();
       if (!tsm.setTableStateIfInStates(tableName, ZooKeeperProtos.Table.State.DISABLING,
             ZooKeeperProtos.Table.State.DISABLING, ZooKeeperProtos.Table.State.ENABLED)) {
         LOG.info("Table " + tableName + " isn't enabled; skipping disable");
         setFailure("master-disable-table", new TableNotEnabledException(tableName));
         canTableBeDisabled = false;
       }
     }
 
     // We are done the check. Future actions in this procedure could be done asynchronously.
     ProcedurePrepareLatch.releaseLatch(syncLatch, this);
 
     return canTableBeDisabled;
   }
 
   /**
    * Rollback of table state change in prepareDisable()
    * @param env MasterProcedureEnv
    */
   private void undoTableStateChange(final MasterProcedureEnv env) {
     if (!skipTableStateCheck) {
       try {
         // If the state was changed, undo it.
         if (env.getMasterServices().getAssignmentManager().getTableStateManager().isTableState(
             tableName, ZooKeeperProtos.Table.State.DISABLING)) {
           EnableTableProcedure.setTableStateToEnabled(env, tableName);
         }
       } catch (Exception e) {
         // Ignore exception.
       }
     }
   }
 
   /**
    * Action before disabling table.
    * @param env MasterProcedureEnv
    * @param state the procedure state
    * @throws IOException
    * @throws InterruptedException
    */
   protected void preDisable(final MasterProcedureEnv env, final DisableTableState state)
       throws IOException, InterruptedException {
     runCoprocessorAction(env, state);
   }
 
   /**
    * Mark table state to Disabling
    * @param env MasterProcedureEnv
    * @throws IOException
    */
   protected static void setTableStateToDisabling(
       final MasterProcedureEnv env,
       final TableName tableName) throws HBaseException, IOException {
     // Set table disabling flag up in zk.
     env.getMasterServices().getAssignmentManager().getTableStateManager().setTableState(
       tableName,
       ZooKeeperProtos.Table.State.DISABLING);
   }
 
   /**
    * Mark regions of the table offline with retries
    * @param env MasterProcedureEnv
    * @param tableName the target table
    * @param retryRequired whether to retry if the first run failed
    * @return whether the operation is fully completed or being interrupted.
    * @throws IOException
    */
   protected static MarkRegionOfflineOpResult markRegionsOffline(
       final MasterProcedureEnv env,
       final TableName tableName,
       final Boolean retryRequired) throws IOException {
     // Dev consideration: add a config to control max number of retry. For now, it is hard coded.
     int maxTry = (retryRequired ? 10 : 1);
     MarkRegionOfflineOpResult operationResult =
         MarkRegionOfflineOpResult.BULK_ASSIGN_REGIONS_FAILED;
     do {
       try {
         operationResult = markRegionsOffline(env, tableName);
         if (operationResult == MarkRegionOfflineOpResult.MARK_ALL_REGIONS_OFFLINE_SUCCESSFUL) {
           break;
         }
         maxTry--;
       } catch (Exception e) {
         LOG.warn("Received exception while marking regions online. tries left: " + maxTry, e);
         maxTry--;
         if (maxTry > 0) {
           continue; // we still have some retry left, try again.
         }
         throw e;
       }
     } while (maxTry > 0);
 
     if (operationResult != MarkRegionOfflineOpResult.MARK_ALL_REGIONS_OFFLINE_SUCCESSFUL) {
       LOG.warn("Some or all regions of the Table '" + tableName + "' were still online");
     }
 
     return operationResult;
   }
 
   /**
    * Mark regions of the table offline
    * @param env MasterProcedureEnv
    * @param tableName the target table
    * @return whether the operation is fully completed or being interrupted.
    * @throws IOException
    */
   private static MarkRegionOfflineOpResult markRegionsOffline(
       final MasterProcedureEnv env,
       final TableName tableName) throws IOException {
     // Get list of online regions that are of this table.  Regions that are
     // already closed will not be included in this list; i.e. the returned
     // list is not ALL regions in a table, its all online regions according
     // to the in-memory state on this master.
     MarkRegionOfflineOpResult operationResult =
         MarkRegionOfflineOpResult.MARK_ALL_REGIONS_OFFLINE_SUCCESSFUL;
     final List<HRegionInfo> regions =
         env.getMasterServices().getAssignmentManager().getRegionStates()
             .getRegionsOfTable(tableName);
     if (regions.size() > 0) {
       LOG.info("Offlining " + regions.size() + " regions.");
 
       BulkDisabler bd = new BulkDisabler(env, tableName, regions);
       try {
         if (!bd.bulkAssign()) {
           operationResult = MarkRegionOfflineOpResult.BULK_ASSIGN_REGIONS_FAILED;
         }
       } catch (InterruptedException e) {
         LOG.warn("Disable was interrupted");
         // Preserve the interrupt.
         Thread.currentThread().interrupt();
         operationResult = MarkRegionOfflineOpResult.MARK_ALL_REGIONS_OFFLINE_INTERRUPTED;
       }
     }
     return operationResult;
   }
 
   /**
    * Mark table state to Disabled
    * @param env MasterProcedureEnv
    * @throws IOException
    */
   protected static void setTableStateToDisabled(
       final MasterProcedureEnv env,
       final TableName tableName) throws HBaseException, IOException {
     // Flip the table to disabled
     env.getMasterServices().getAssignmentManager().getTableStateManager().setTableState(
       tableName,
       ZooKeeperProtos.Table.State.DISABLED);
     LOG.info("Disabled table, " + tableName + ", is completed.");
   }
 
   /**
    * Action after disabling table.
    * @param env MasterProcedureEnv
    * @param state the procedure state
    * @throws IOException
    * @throws InterruptedException
    */
   protected void postDisable(final MasterProcedureEnv env, final DisableTableState state)
       throws IOException, InterruptedException {
     runCoprocessorAction(env, state);
   }
 
   /**
    * The procedure could be restarted from a different machine. If the variable is null, we need to
    * retrieve it.
    * @return traceEnabled
    */
   private Boolean isTraceEnabled() {
     if (traceEnabled == null) {
       traceEnabled = LOG.isTraceEnabled();
     }
     return traceEnabled;
   }
 
   /**
    * Coprocessor Action.
    * @param env MasterProcedureEnv
    * @param state the procedure state
    * @throws IOException
    * @throws InterruptedException
    */
   private void runCoprocessorAction(final MasterProcedureEnv env, final DisableTableState state)
       throws IOException, InterruptedException {
     final MasterCoprocessorHost cpHost = env.getMasterCoprocessorHost();
     if (cpHost != null) {
       user.doAs(new PrivilegedExceptionAction<Void>() {
         @Override
         public Void run() throws Exception {
           switch (state) {
           case DISABLE_TABLE_PRE_OPERATION:
             cpHost.preDisableTableHandler(tableName);
             break;
           case DISABLE_TABLE_POST_OPERATION:
             cpHost.postDisableTableHandler(tableName);
             break;
           default:
             throw new UnsupportedOperationException(this + " unhandled state=" + state);
           }
           return null;
         }
       });
     }
   }
 
   /**
    * Run bulk disable.
    */
   private static class BulkDisabler extends BulkAssigner {
     private final AssignmentManager assignmentManager;
     private final List<HRegionInfo> regions;
     private final TableName tableName;
     private final int waitingTimeForEvents;
 
     public BulkDisabler(final MasterProcedureEnv env, final TableName tableName,
         final List<HRegionInfo> regions) {
       super(env.getMasterServices());
       this.assignmentManager = env.getMasterServices().getAssignmentManager();
       this.tableName = tableName;
       this.regions = regions;
       this.waitingTimeForEvents =
           env.getMasterServices().getConfiguration()
               .getInt("hbase.master.event.waiting.time", 1000);
     }
 
     @Override
     protected void populatePool(ExecutorService pool) {
       RegionStates regionStates = assignmentManager.getRegionStates();
       for (final HRegionInfo region : regions) {
         if (regionStates.isRegionInTransition(region)
             && !regionStates.isRegionInState(region, RegionState.State.FAILED_CLOSE)) {
           continue;
         }
         pool.execute(Trace.wrap("DisableTableHandler.BulkDisabler", new Runnable() {
           @Override
           public void run() {
             assignmentManager.unassign(region);
           }
         }));
       }
     }
 
     @Override
     protected boolean waitUntilDone(long timeout) throws InterruptedException {
       long startTime = EnvironmentEdgeManager.currentTime();
       long remaining = timeout;
       List<HRegionInfo> regions = null;
       long lastLogTime = startTime;
       while (!server.isStopped() && remaining > 0) {
         Thread.sleep(waitingTimeForEvents);
         regions = assignmentManager.getRegionStates().getRegionsOfTable(tableName);
         long now = EnvironmentEdgeManager.currentTime();
         // Don't log more than once every ten seconds. Its obnoxious. And only log table regions
         // if we are waiting a while for them to go down...
         if (LOG.isDebugEnabled() && ((now - lastLogTime) > 10000)) {
           lastLogTime = now;
           LOG.debug("Disable waiting until done; " + remaining + " ms remaining; " + regions);
         }
         if (regions.isEmpty()) break;
         remaining = timeout - (now - startTime);
       }
       return regions != null && regions.isEmpty();
     }
   }
 }