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 org.apache.carbondata.core.stream;
  
  import java.io.File;
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.BitSet;
  import java.util.List;
  
  import org.apache.carbondata.common.annotations.InterfaceAudience;
  import org.apache.carbondata.core.datastore.block.SegmentProperties;
  import org.apache.carbondata.core.datastore.impl.FileFactory;
  import org.apache.carbondata.core.index.Segment;
  import org.apache.carbondata.core.metadata.schema.table.CarbonTable;
  import org.apache.carbondata.core.metadata.schema.table.column.CarbonColumn;
  import org.apache.carbondata.core.metadata.schema.table.column.CarbonDimension;
  import org.apache.carbondata.core.metadata.schema.table.column.ColumnSchema;
  import org.apache.carbondata.core.reader.CarbonIndexFileReader;
  import org.apache.carbondata.core.scan.filter.FilterUtil;
  import org.apache.carbondata.core.scan.filter.executer.FilterExecutor;
  import org.apache.carbondata.core.scan.filter.resolver.FilterResolverIntf;
  import org.apache.carbondata.core.util.CarbonMetadataUtil;
  import org.apache.carbondata.core.util.path.CarbonTablePath;
  import org.apache.carbondata.format.BlockIndex;
  
  @InterfaceAudience.Internal
  public class StreamPruner {
  
    private CarbonTable carbonTable;
    private FilterExecutor filterExecutor;
  
    private int totalFileNums = 0;
  
    public StreamPruner(CarbonTable carbonTable) {
      this.carbonTable = carbonTable;
    }
  
    public void init(FilterResolverIntf filterExp) {
      if (filterExp != null) {
        // cache all columns
        List<CarbonColumn> minMaxCacheColumns = new ArrayList<>();
        for (CarbonDimension dimension : carbonTable.getVisibleDimensions()) {
          if (!dimension.isComplex()) {
            minMaxCacheColumns.add(dimension);
          }
        }
        minMaxCacheColumns.addAll(carbonTable.getVisibleMeasures());
        // prepare cardinality of all dimensions
        List<ColumnSchema> listOfColumns =
            carbonTable.getTableInfo().getFactTable().getListOfColumns();
        // initial filter executor
        SegmentProperties segmentProperties = new SegmentProperties(listOfColumns);
        filterExecutor = FilterUtil.getFilterExecutorTree(
            filterExp, segmentProperties, null, minMaxCacheColumns, false);
      }
    }
  
    public List<StreamFile> prune(List<Segment> segments) throws IOException {
      if (filterExecutor == null) {
        // if filter is null, list all steam files
        return listAllStreamFiles(segments, false);
      } else {
        List<StreamFile> streamFileList = new ArrayList<>();
        for (StreamFile streamFile : listAllStreamFiles(segments, true)) {
          if (isScanRequire(streamFile)) {
            // if stream file is required to scan
            streamFileList.add(streamFile);
            streamFile.setMinMaxIndex(null);
          }
        }
        return streamFileList;
      }
    }
  
    private boolean isScanRequire(StreamFile streamFile) {
      // backward compatibility, old stream file without min/max index
      if (streamFile.getMinMaxIndex() == null) {
        return true;
      }
      byte[][] maxValue = streamFile.getMinMaxIndex().getMaxValues();
      byte[][] minValue = streamFile.getMinMaxIndex().getMinValues();
      BitSet bitSet = filterExecutor
          .isScanRequired(maxValue, minValue, streamFile.getMinMaxIndex().getIsMinMaxSet());
      return !bitSet.isEmpty();
    }
  
    // TODO optimize and move the code to StreamSegment , but it's in the streaming module.
    private List<StreamFile> listAllStreamFiles(List<Segment> segments, boolean withMinMax)
        throws IOException {
      List<StreamFile> streamFileList = new ArrayList<>();
      for (Segment segment : segments) {
        String segmentDir = CarbonTablePath.getSegmentPath(
            carbonTable.getAbsoluteTableIdentifier().getTablePath(), segment.getSegmentNo());
        String indexFile = CarbonTablePath.getCarbonStreamIndexFilePath(segmentDir);
        if (FileFactory.isFileExist(indexFile)) {
          CarbonIndexFileReader indexReader = new CarbonIndexFileReader();
          indexReader.openThriftReader(indexFile);
          try {
            while (indexReader.hasNext()) {
              BlockIndex blockIndex = indexReader.readBlockIndexInfo();
              String filePath = segmentDir + File.separator + blockIndex.getFile_name();
              long length = blockIndex.getFile_size();
              StreamFile streamFile = new StreamFile(segment.getSegmentNo(), filePath, length);
              streamFileList.add(streamFile);
              if (withMinMax) {
                if (blockIndex.getBlock_index() != null
                    && blockIndex.getBlock_index().getMin_max_index() != null) {
                  streamFile.setMinMaxIndex(CarbonMetadataUtil
                      .convertExternalMinMaxIndex(blockIndex.getBlock_index().getMin_max_index()));
                }
              }
            }
          } finally {
            indexReader.closeThriftReader();
          }
        }
      }
      totalFileNums = streamFileList.size();
      return streamFileList;
    }
  
    public int getTotalFileNums() {
      return totalFileNums;
    }
  }
  