Class ICUResourceBundleReader.ResourceCache

java.lang.Object

com.ibm.icu.impl.ICUResourceBundleReader.ResourceCache

Enclosing class:

ICUResourceBundleReader

private static final class ICUResourceBundleReader.ResourceCache
extends Object

Cache of some of one resource bundle's resources. Avoids creating multiple Java objects for the same resource items, including multiple copies of their contents.

Mutable objects must not be cached and then returned to the caller because the cache must not be writable via the returned reference.

Resources are mapped by their resource integers. Empty resources with offset 0 cannot be mapped. Integers need not and should not be cached. Multiple .res items may share resource offsets (genrb eliminates some duplicates).

Large resource objects are usually stored in SoftReferences.

This replaces the previous custom trie structure (ICU-10932, 2014) with ConcurrentHashMap for lock-free concurrent reads. Benchmarking shows CHM uses ~3x less memory than the trie at typical ICU bundle sizes (~221 entries/cache) due to the trie's sparse power-of-2 Level arrays (5% utilization), while providing ~2x better throughput at 32 threads by eliminating the synchronized bottleneck on every resource lookup.

Field Summary

Fields

Modifier and Type	Field	Description
private final ConcurrentHashMap<Integer,Object>	map

Constructor Summary

Constructors

Constructor	Description
ResourceCache()

Method Summary

Modifier and Type	Method	Description
private static Object	deduplicateItem(Object value, Map<CharBuffer, char[]> charMap, Map<IntBuffer, int[]> intMap, Map<String,String> stringMap)
(package private) void	deduplicateTableArrays()
(package private) Object	get(int res)
(package private) Object	putIfAbsent(int res, Object item, int size)
private static boolean	storeDirectly(int size)

Methods inherited from class Object

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

Field Details

map

private final ConcurrentHashMap<Integer,Object> map

Constructor Details

ResourceCache

ResourceCache()

Method Details

storeDirectly

private static boolean storeDirectly(int size)

get

Object get(int res)

putIfAbsent

Object putIfAbsent(int res,
 Object item,
 int size)

deduplicateTableArrays

void deduplicateTableArrays()

deduplicateItem

private static Object deduplicateItem(Object value,
 Map<CharBuffer, char[]> charMap,
 Map<IntBuffer, int[]> intMap,
 Map<String,String> stringMap)