How to use

getIfPresent

method

in

org.apache.carbondata.core.cache.Cache

/**
 * This method will return the value for the given key. It will not check and load
 * the data for the given key
 *
 * @param key
 * @return
 */
public V getIfPresent(K key) {
 V value = cache.getIfPresent(key);
 if (value != null) {
  segmentSet.add(key);
 }
 return value;
}

 @Override
 public List<DataMapDistributable> getAllUncachedDistributables(
   List<DataMapDistributable> distributables) throws IOException {
  List<DataMapDistributable> distributablesToBeLoaded = new ArrayList<>(distributables.size());
  for (DataMapDistributable distributable : distributables) {
   Segment segment = distributable.getSegment();
   Set<TableBlockIndexUniqueIdentifier> tableBlockIndexUniqueIdentifiers =
     getTableBlockIndexUniqueIdentifiers(segment);
   // filter out the tableBlockIndexUniqueIdentifiers based on distributable
   TableBlockIndexUniqueIdentifier validIdentifier = BlockletDataMapUtil
     .filterIdentifiersBasedOnDistributable(tableBlockIndexUniqueIdentifiers,
       (BlockletDataMapDistributable) distributable);
   if (null == cache.getIfPresent(
     new TableBlockIndexUniqueIdentifierWrapper(validIdentifier, this.getCarbonTable()))) {
    ((BlockletDataMapDistributable) distributable)
      .setTableBlockIndexUniqueIdentifier(validIdentifier);
    distributablesToBeLoaded.add(distributable);
   }
  }
  return distributablesToBeLoaded;
 }
}

@Override
public void clear(Segment segment) {
 Set<TableBlockIndexUniqueIdentifier> blockIndexes = segmentMap.remove(segment.getSegmentNo());
 if (blockIndexes != null) {
  for (TableBlockIndexUniqueIdentifier blockIndex : blockIndexes) {
   TableBlockIndexUniqueIdentifierWrapper blockIndexWrapper =
     new TableBlockIndexUniqueIdentifierWrapper(blockIndex, this.getCarbonTable());
   BlockletDataMapIndexWrapper wrapper = cache.getIfPresent(blockIndexWrapper);
   if (null != wrapper) {
    List<BlockDataMap> dataMaps = wrapper.getDataMaps();
    for (DataMap dataMap : dataMaps) {
     if (dataMap != null) {
      cache.invalidate(blockIndexWrapper);
      dataMap.clear();
     }
    }
   }
  }
 }
}