/*
    * 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.regionserver;
  
  import java.io.IOException;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.List;
  import java.util.Map;
  
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.Cell;
  import org.apache.hadoop.hbase.DoNotRetryIOException;
  import org.apache.hadoop.hbase.client.Delete;
  import org.apache.hadoop.hbase.client.Durability;
  import org.apache.hadoop.hbase.client.Mutation;
  import org.apache.hadoop.hbase.client.Put;
  import org.apache.hadoop.hbase.protobuf.generated.MultiRowMutationProtos.MultiRowMutationProcessorRequest;
  import org.apache.hadoop.hbase.protobuf.generated.MultiRowMutationProtos.MultiRowMutationProcessorResponse;
  import org.apache.hadoop.hbase.regionserver.wal.WALEdit;
  import org.apache.hadoop.hbase.util.Bytes;
  
  /**
   * A <code>MultiRowProcessor</code> that performs multiple puts and deletes.
   */
  @InterfaceAudience.Private
  class MultiRowMutationProcessor extends BaseRowProcessor<MultiRowMutationProcessorRequest,
  MultiRowMutationProcessorResponse> {
    Collection<byte[]> rowsToLock;
    Collection<Mutation> mutations;
    MiniBatchOperationInProgress<Mutation> miniBatch;
  
    MultiRowMutationProcessor(Collection<Mutation> mutations,
                              Collection<byte[]> rowsToLock) {
      this.rowsToLock = rowsToLock;
      this.mutations = mutations;
    }
  
    @Override
    public Collection<byte[]> getRowsToLock() {
      return rowsToLock;
    }
  
    @Override
    public boolean readOnly() {
      return false;
    }
    
    @Override
    public MultiRowMutationProcessorResponse getResult() {
      return MultiRowMutationProcessorResponse.getDefaultInstance();
    }
  
    @Override
    public void process(long now,
                        HRegion region,
                        List<Mutation> mutationsToApply,
                        WALEdit walEdit) throws IOException {
      byte[] byteNow = Bytes.toBytes(now);
      // Check mutations
      for (Mutation m : this.mutations) {
        if (m instanceof Put) {
          Map<byte[], List<Cell>> familyMap = m.getFamilyCellMap();
          region.checkFamilies(familyMap.keySet());
          region.checkTimestamps(familyMap, now);
          region.updateCellTimestamps(familyMap.values(), byteNow);
        } else if (m instanceof Delete) {
          Delete d = (Delete) m;
          region.prepareDelete(d);
          region.prepareDeleteTimestamps(d, d.getFamilyCellMap(), byteNow);
        } else {
          throw new DoNotRetryIOException("Action must be Put or Delete. But was: "
              + m.getClass().getName());
        }
        mutationsToApply.add(m);
      }
      // Apply edits to a single WALEdit
      for (Mutation m : mutations) {
        for (List<Cell> cells : m.getFamilyCellMap().values()) {
          boolean writeToWAL = m.getDurability() != Durability.SKIP_WAL;
          for (Cell cell : cells) {
            if (writeToWAL) walEdit.add(cell);
          }
        }
     }
   }
 
   @Override
   public void preProcess(HRegion region, WALEdit walEdit) throws IOException {
     RegionCoprocessorHost coprocessorHost = region.getCoprocessorHost();
     if (coprocessorHost != null) {
       for (Mutation m : mutations) {
         if (m instanceof Put) {
           if (coprocessorHost.prePut((Put) m, walEdit, m.getDurability())) {
             // by pass everything
             return;
           }
         } else if (m instanceof Delete) {
           Delete d = (Delete) m;
           region.prepareDelete(d);
           if (coprocessorHost.preDelete(d, walEdit, d.getDurability())) {
             // by pass everything
             return;
           }
         }
       }
     }
   }
 
   @Override
   public void preBatchMutate(HRegion region, WALEdit walEdit) throws IOException {
     // TODO we should return back the status of this hook run to HRegion so that those Mutations
     // with OperationStatus as SUCCESS or FAILURE should not get applied to memstore.
     RegionCoprocessorHost coprocessorHost = region.getCoprocessorHost();
     OperationStatus[] opStatus = new OperationStatus[mutations.size()];
     Arrays.fill(opStatus, OperationStatus.NOT_RUN);
     WALEdit[] walEditsFromCP = new WALEdit[mutations.size()];
     if (coprocessorHost != null) {
       miniBatch = new MiniBatchOperationInProgress<Mutation>(
           mutations.toArray(new Mutation[mutations.size()]), opStatus, walEditsFromCP, 0,
           mutations.size());
       coprocessorHost.preBatchMutate(miniBatch);
     }
     // Apply edits to a single WALEdit
     for (int i = 0; i < mutations.size(); i++) {
       if (opStatus[i] == OperationStatus.NOT_RUN) {
         // Other OperationStatusCode means that Mutation is already succeeded or failed in CP hook
         // itself. No need to apply again to region
         if (walEditsFromCP[i] != null) {
           // Add the WALEdit created by CP hook
           for (Cell walCell : walEditsFromCP[i].getCells()) {
             walEdit.add(walCell);
           }
         }
       }
     }
   }
 
   @Override
   public void postBatchMutate(HRegion region) throws IOException {
     RegionCoprocessorHost coprocessorHost = region.getCoprocessorHost();
     if (coprocessorHost != null) {
       assert miniBatch != null;
       // Use the same miniBatch state used to call the preBatchMutate()
       coprocessorHost.postBatchMutate(miniBatch);
     }
   }
 
   @Override
   public void postProcess(HRegion region, WALEdit walEdit, boolean success) throws IOException {
     RegionCoprocessorHost coprocessorHost = region.getCoprocessorHost();
     if (coprocessorHost != null) {
       for (Mutation m : mutations) {
         if (m instanceof Put) {
           coprocessorHost.postPut((Put) m, walEdit, m.getDurability());
         } else if (m instanceof Delete) {
           coprocessorHost.postDelete((Delete) m, walEdit, m.getDurability());
         }
       }
       // At the end call the CP hook postBatchMutateIndispensably
       if (miniBatch != null) {
         // Directly calling this hook, with out calling pre/postBatchMutate() when Processor do a
         // read only process. Then no need to call this batch based CP hook also.
         coprocessorHost.postBatchMutateIndispensably(miniBatch, success);
       }
     }
   }
 
   @Override
   public MultiRowMutationProcessorRequest getRequestData() {
     return MultiRowMutationProcessorRequest.getDefaultInstance();
   }
 
   @Override
   public void initialize(MultiRowMutationProcessorRequest msg) {
     //nothing
   }
 
   @Override
   public Durability useDurability() {
     // return true when at least one mutation requested a WAL flush (default)
     Durability durability = Durability.USE_DEFAULT;
     for (Mutation m : mutations) {
       if (m.getDurability().ordinal() > durability.ordinal()) {
         durability = m.getDurability();
       }
     }
     return durability;
   }
 }