Package com.illumon.util.datastructures.cache

Class SoftArrayBackedOffsetLookupCache<VALUE_TYPE,EXTRA_INPUT_TYPE>

java.lang.Object

com.illumon.util.datastructures.cache.BaseOffsetLookupCache<VALUE_TYPE,EXTRA_INPUT_TYPE>

com.illumon.util.datastructures.cache.SoftArrayBackedOffsetLookupCache<VALUE_TYPE,EXTRA_INPUT_TYPE>

All Implemented Interfaces:

OffsetLookupCache<VALUE_TYPE,EXTRA_INPUT_TYPE>

public class SoftArrayBackedOffsetLookupCache<VALUE_TYPE,EXTRA_INPUT_TYPE>
extends BaseOffsetLookupCache<VALUE_TYPE,EXTRA_INPUT_TYPE>

Caching data structure for caching int (offset) to Object mappings. For use when lookup is expensive but idempotent, and the range of offset indexes is relatively contiguous. This is only suitable for lookup functions that return fully-initialized, immutable objects (or null).

This implementation stores data in an array of softly-reachable arrays, to enable unused regions to be reclaimed under memory pressure.

Constructor Summary

Constructors

Constructor	Description
SoftArrayBackedOffsetLookupCache(Class<VALUE_TYPE> valueType, OffsetLookup<VALUE_TYPE,EXTRA_INPUT_TYPE> lookupFunction)	Construct a lookup cache for the supplied arguments, using OffsetLookupCache.createPlaceholder(Class) to create a "null" placeholder value.

Method Summary

Modifier and Type	Method	Description
void	clear()	Release all resources held by the cache.
VALUE_TYPE	get(long index, EXTRA_INPUT_TYPE extra)	Lookup the value for index.

Methods inherited from class java.lang.Object

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

Constructor Details

SoftArrayBackedOffsetLookupCache

public SoftArrayBackedOffsetLookupCache(@NotNull Class<VALUE_TYPE> valueType, @NotNull OffsetLookup<VALUE_TYPE,EXTRA_INPUT_TYPE> lookupFunction)

Construct a lookup cache for the supplied arguments, using OffsetLookupCache.createPlaceholder(Class) to create a "null" placeholder value.

Parameters:

valueType - The value type

lookupFunction - The lookup function from index to value, must return a fully-initialized, immutable object or null

Method Details

get

public VALUE_TYPE get(long index, EXTRA_INPUT_TYPE extra)

Description copied from interface: OffsetLookupCache

Lookup the value for index.

Parameters:

index - The offset (must be >= 0)

Returns:

The result of calling the lookup function for index, possibly from cache

clear

public void clear()

Description copied from interface: OffsetLookupCache

Release all resources held by the cache.