org.apache.druid.segment.SegmentReference

public class SegmentReference extends Object implements Closeable

Wrapper for a SegmentDescriptor and Optional<Segment>. For regular segments, the latter is typically created by a ReferenceCountedSegmentProvider that may have a SegmentMapFunction applied to it. If the SegmentMapFunction you want to apply is not available at the time the SegmentReference is created, use map(SegmentMapFunction) to apply it. Closing this object closes both the getSegmentReference() and any closeables attached from the process of creating this object, such as from AcquireSegmentAction. The object from getSegmentReference() should not be closed directly by callers.

Constructor Details
- SegmentReference
  
  public SegmentReference(SegmentDescriptor segmentDescriptor, Optional<Segment> segmentReference, @Nullable Closeable cleanupHold)
Method Details
- missing
  
  public static SegmentReference missing(SegmentDescriptor segmentDescriptor)
- getSegmentDescriptor
  
  public SegmentDescriptor getSegmentDescriptor()
- getSegmentReference
  
  public Optional<Segment> getSegmentReference()
  
  Returns the actual segment. Do not close the Segment when you are done with it, only close the SegmentReference.
- map
  
  public SegmentReference map(SegmentMapFunction segmentMapFn)
  
  Maps the wrapped segment and returns a reference to it. Closes the reference if the SegmentMapFunction throws an exception. Regardless of success or failure of this method, the old reference should be discarded. Do not call close() on the old reference, only call it on the new one.
- close
  
  public void close() throws IOException
  
  Specified by:
  
  close in interface AutoCloseable
  
  Specified by:
  
  close in interface Closeable
  
  Throws:
  
  IOException

Class SegmentReference

Constructor Summary