Package org.apache.druid.segment

Class WrappedSegmentReference

java.lang.Object

org.apache.druid.segment.WrappedSegmentReference

All Implemented Interfaces:

Closeable, AutoCloseable, ReferenceCountedObject, Segment, SegmentReference

public class WrappedSegmentReference
extends Object
implements SegmentReference

This class is used as a wrapper for other classes that just want to modify the storage adapter for a datasource. Examples include: UnnestDataSource, FilteredDataSource

Constructor Summary

Constructors

Constructor	Description
WrappedSegmentReference(SegmentReference delegate, Function<StorageAdapter,StorageAdapter> storageAdapterWrapperFunction)

Method Summary

Modifier and Type	Method	Description
Optional<Closeable>	acquireReferences()	This method is expected to increment a reference count and provide a Closeable that decrements the reference count when closed.
QueryableIndex	asQueryableIndex()
StorageAdapter	asStorageAdapter()
void	close()
org.joda.time.Interval	getDataInterval()
SegmentId	getId()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.druid.segment.Segment

as, asString

Constructor Detail

WrappedSegmentReference

public WrappedSegmentReference(SegmentReference delegate,
                               Function<StorageAdapter,StorageAdapter> storageAdapterWrapperFunction)

Method Detail

acquireReferences

public Optional<Closeable> acquireReferences()

Description copied from interface: ReferenceCountedObject

This method is expected to increment a reference count and provide a Closeable that decrements the reference count when closed. This is likely just a wrapper around ReferenceCountingCloseableObject.incrementReferenceAndDecrementOnceCloseable(), but may also include any other associated references which should be incremented when this method is called, and decremented/released by the closeable. IMPORTANT NOTE: to fulfill the contract of this method, implementors must return a closeable to indicate that the reference can be acquired, even if there is nothing to close. Implementors should avoid allowing this method or the Closeable it creates to throw exceptions. For callers: if this method returns non-empty, IT MUST BE CLOSED, else reference counts can potentially leak.

Specified by:

acquireReferences in interface ReferenceCountedObject

getId

public SegmentId getId()

Specified by:

getId in interface Segment

getDataInterval

public org.joda.time.Interval getDataInterval()

Specified by:

getDataInterval in interface Segment

asQueryableIndex

@Nullable
public QueryableIndex asQueryableIndex()

Specified by:

asQueryableIndex in interface Segment

asStorageAdapter

public StorageAdapter asStorageAdapter()

Specified by:

asStorageAdapter in interface Segment

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Throws:

IOException