Package com.illumon.util.datastructures.cache

Class BoundedArrayBackedOffsetLookupCache<VALUE_TYPE,EXTRA_INPUT_TYPE>

java.lang.Object

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

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

All Implemented Interfaces:

OffsetLookupCache<VALUE_TYPE,EXTRA_INPUT_TYPE>

@Deprecated
public class BoundedArrayBackedOffsetLookupCache<VALUE_TYPE,EXTRA_INPUT_TYPE>
extends BaseOffsetLookupCache<VALUE_TYPE,EXTRA_INPUT_TYPE>

Deprecated.

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 indexed by (offset % array size), and is well-optimized for sequential access patterns with limited look-behind.

Note: This performed adequately. It obviously can't compete with an unbounded cache of hard references for repeated full column accesses, however. Overall memory vs. performance trade-off conclusions are not yet obvious. For the workloads it's well suited for, it does very well. For the rest, it's pretty abyssmal.

Constructor Summary

Constructors

Constructor	Description
BoundedArrayBackedOffsetLookupCache(Class<VALUE_TYPE> valueType, OffsetLookup<VALUE_TYPE,EXTRA_INPUT_TYPE> lookupFunction)	Deprecated. 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()	Deprecated. Release all resources held by the cache.
VALUE_TYPE	get(long index, EXTRA_INPUT_TYPE extra)	Deprecated. 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

BoundedArrayBackedOffsetLookupCache

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

Deprecated.

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)

Deprecated.

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()

Deprecated.

Description copied from interface: OffsetLookupCache

Release all resources held by the cache.