Package org.apache.druid.segment.loading

Class StorageLocation.ReservationHold<TEntry extends CacheEntry>

java.lang.Object

org.apache.druid.segment.loading.StorageLocation.ReservationHold<TEntry>

All Implemented Interfaces:

Closeable, AutoCloseable

Enclosing class:

StorageLocation

public static class StorageLocation.ReservationHold<TEntry extends CacheEntry>
extends Object
implements Closeable

A Closeable CacheEntry wrapper representing both the entry and a 'hold' that is placed on it to prevent the entry from being dropped by StorageLocation.reclaim(long) at least until the wrapper is closed.

In practice, if the entry is StorageLocation.weakCacheEntries the entry contained in this object was placed under a hold with StorageLocation.WeakCacheEntry.hold(), and close() with then call StorageLocation.WeakCacheEntry.release() to finish the hold. If the entry is instead StorageLocation.staticCacheEntries, a hold is not necessary since these entries will not be removed automatically during StorageLocation.reclaim(long), and instead are only ever being dropped if StorageLocation.release(CacheEntry) is explicitly called. Close is a no-op for these entries.

Callers MUST be sure to close this object when finished to release the hold

Constructor Summary

Constructors

Constructor	Description
ReservationHold(TEntry entry, Runnable releaseHold)

Method Summary

Modifier and Type	Method	Description
void	close()
TEntry	getEntry()

Methods inherited from class java.lang.Object

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

Constructor Details

ReservationHold

public ReservationHold(TEntry entry,
 Runnable releaseHold)

Method Details

getEntry

public TEntry getEntry()

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable