content: /**
   * 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 com.alibaba.wasp.master.handler;
  
  import com.alibaba.wasp.ChildrenExistException;
  import com.alibaba.wasp.EntityGroupInfo;
  import com.alibaba.wasp.ServerName;
  import com.alibaba.wasp.TableLockedException;
  import com.alibaba.wasp.TableNotDisabledException;
  import com.alibaba.wasp.TableNotFoundException;
  import com.alibaba.wasp.executor.EventHandler;
  import com.alibaba.wasp.master.AssignmentManager;
  import com.alibaba.wasp.master.FMasterServices;
  import com.alibaba.wasp.master.FServerManager;
  import com.alibaba.wasp.master.TableLockManager;
  import com.alibaba.wasp.meta.FMetaEditor;
  import com.alibaba.wasp.meta.FMetaReader;
  import com.alibaba.wasp.meta.FTable;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.hbase.util.Bytes;
  import org.apache.hadoop.hbase.util.Threads;
  import org.apache.zookeeper.KeeperException;
  
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.List;
  
  /**
   * Handler to delete a table.
   */
  public class DeleteTableHandler extends EventHandler {
    private static final Log LOG = LogFactory.getLog(DeleteTableHandler.class);
    private final byte[] tableName;
    private final String tableNameStr;
    private final AssignmentManager assignmentManager;
    private FTable ftable;
    private TableLockManager tableLockManager;
  
    public DeleteTableHandler(byte[] tableName, FMasterServices server,
        AssignmentManager assignmentManager) throws TableNotFoundException,
        IOException {
      super(server, EventType.C_M_DELETE_TABLE);
      this.tableName = tableName;
      this.tableNameStr = Bytes.toString(tableName);
      this.assignmentManager = assignmentManager;
      this.tableLockManager = server.getTableLockManager();
  
      // Check if table exists
      if (!FMetaReader.tableExists(server.getConfiguration(), this.tableNameStr)) {
        throw new TableNotFoundException(tableNameStr);
      }
      if (!this.assignmentManager.getZKTable().isDisabledTable(tableNameStr)) {
        throw new TableNotDisabledException(tableNameStr);
      }
      ftable = FMetaReader.getTable(server.getConfiguration(), tableNameStr);
      if (ftable.isRootTable()) {
        List<FTable> childTables = FMetaReader.getChildTable(
            server.getConfiguration(), tableNameStr);
        if (childTables != null && childTables.size() > 0) {
          throw new ChildrenExistException(tableNameStr + " has child");
        }
      }
      if (tableLockManager.lockTable(tableNameStr)) {
        LOG.info("lock table '" + tableNameStr + "' by DeleteTableHandler");
      } else {
        throw new TableLockedException(tableNameStr + " has been locked. ");
      }
    }
  
    @Override
    public void process() throws IOException {
      try {
        LOG.info("Attempting to delete the table " + this.tableNameStr);
        handleDeleteTable();
      } catch (IOException e) {
        LOG.error("Error trying to delete the table " + this.tableNameStr, e);
      } catch (KeeperException e) {
        LOG.error("Error trying to delete the table " + this.tableNameStr, e);
      } finally {
        tableLockManager.unlockTable(tableNameStr);
      }
    }
  
    protected void handleDeleteTable()
        throws IOException, KeeperException {
      List<EntityGroupInfo> egis = null;
      if (ftable.isRootTable()) {
        egis = FMetaReader.getTableEntityGroups(
            server.getConfiguration(), Bytes.toBytes(tableNameStr));
      } else {
        egis = new ArrayList<EntityGroupInfo>();
      }
  
      long waitTime = server.getConfiguration().getLong(
          "wasp.master.wait.on.entityGroup", 5 * 60 * 1000);
      for (EntityGroupInfo entityGroup : egis) {
        long done = System.currentTimeMillis() + waitTime;
        while (System.currentTimeMillis() < done) {
          if (!assignmentManager.getEntityGroupStates().isEntityGroupInTransition(entityGroup))
            break;
          Threads.sleep(waitingTimeForEvents);
          LOG.debug("Waiting on entityGroup to clear entityGroups in transition; "
              + assignmentManager.getEntityGroupStates().getEntityGroupTransitionState(entityGroup));
        }
        if (assignmentManager.getEntityGroupStates().isEntityGroupInTransition(entityGroup)) {
          throw new IOException("Waited wasp.master.wait.on.entityGroup (" + waitTime
              + "ms) for entityGroup to leave entityGroup "
              + entityGroup.getEntityGroupNameAsString() + " in transitions");
        }
        LOG.debug("Deleting entityGroup "
            + entityGroup.getEntityGroupNameAsString() + " from FMETA and FS");
        // Remove entityGroup from FMETA
        FMetaEditor.deleteEntityGroup(server.getConfiguration(), entityGroup);
        // Delete entityGroup from FS
  
      }
      LOG.debug("Deleting table" + tableNameStr + " from fmeta");
      // Delete table from FMETA
      FMetaEditor.dropTable(server.getConfiguration(), tableNameStr);
  
      // notify server to clean the table's meta cache.
      FServerManager serverManager = ((FMasterServices) server)
          .getFServerManager();
      for (ServerName serverName : serverManager.getOnlineServersList()) {
        serverManager.sendDisableTable(serverName, tableNameStr);
      }
  
      LOG.debug("Setting table" + tableNameStr + " deleted on ZK");
      // If entry for this table in zk, and up in AssignmentManager, remove it.
      assignmentManager.getZKTable().setDeletedTable(Bytes.toString(tableName));
      tableLockManager.unlockTable(tableNameStr);
      LOG.debug("Successfully delete table" + tableNameStr);
    }
  
    @Override
    public String toString() {
      String name = "UnknownServerName";
      if (server != null && server.getServerName() != null) {
        name = server.getServerName().toString();
      }
      return getClass().getSimpleName() + "-" + name + "-" + getSeqid() + "-"
          + tableNameStr;
    }
  
  }
  