Package io.deephaven.util.datastructures.cache

Class SoftArrayBackedOffsetLookupCache<VALUE_TYPE,EXTRA_INPUT_TYPE>

java.lang.Object
io.deephaven.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 Object
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 Details

    • SoftArrayBackedOffsetLookupCache

      public SoftArrayBackedOffsetLookupCache(@NotNull @NotNull Class<VALUE_TYPE> valueType, @NotNull @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(int 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.