Package io.deephaven.parquet.table.pagestore

Class PageCache<ATTR extends Any>

java.lang.Object

io.deephaven.util.datastructures.intrusive.IntrusiveSoftLRU<PageCache.IntrusivePage<ATTR>>

io.deephaven.parquet.table.pagestore.PageCache<ATTR>

public class PageCache<ATTR extends Any>
extends IntrusiveSoftLRU<PageCache.IntrusivePage<ATTR>>

A cache for IntrusivePages. This data structure stores pages as soft references and maintains them as an LRU cache. External references to cached pages should be held via weak references so that as memory pressure builds the pages can be evicted from the cache.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	PageCache.IntrusivePage<ATTR extends Any>	Intrusive data structure for page caching.

Nested classes/interfaces inherited from class io.deephaven.util.datastructures.intrusive.IntrusiveSoftLRU

IntrusiveSoftLRU.Adapter<T>, IntrusiveSoftLRU.Node<T extends IntrusiveSoftLRU.Node<T>>

Constructor Summary

Constructors

Constructor	Description
PageCache(int initialCapacity, int maxCapacity)

Method Summary

Modifier and Type	Method	Description
<ATTR2 extends Any> PageCache<ATTR2>	castAttr()
static <ATTR extends Any> WeakReference<PageCache.IntrusivePage<ATTR>>	getNullPage()

Methods inherited from class io.deephaven.util.datastructures.intrusive.IntrusiveSoftLRU

clear, touch

Methods inherited from class java.lang.Object

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

Constructor Details

PageCache

public PageCache(int initialCapacity,
 int maxCapacity)

Method Details

getNullPage

public static <ATTR extends Any>
WeakReference<PageCache.IntrusivePage<ATTR>> getNullPage()

Returns:

The null page sentinel

castAttr

public <ATTR2 extends Any> PageCache<ATTR2> castAttr()