WrappedVec.java

package water.fvec;

import water.Key;
import water.DKV;
/** 
 * A simple wrapper over another Vec.  Transforms either data values or rows.
 */
public abstract class WrappedVec extends Vec {
  /** A key for underlying vector which contains values which are transformed by this vector. */
  final Key  _masterVecKey;
  /** Cached instances of underlying vector. */
  transient Vec _masterVec;
  public WrappedVec(Key masterVecKey, Key key, long[] espc) {
    super(key, espc);
    _masterVecKey = masterVecKey;
  }

  @Override public Vec masterVec() {
    if( _masterVec==null ) _masterVec = DKV.get(_masterVecKey).get();
    return _masterVec;
  }
  // Map from chunk-index to Chunk.  These wrappers are making custom Chunks
  abstract public Chunk chunkForChunkIdx(int cidx);
}