/*
* Copyright (c) 2001, 2004, Oracle and/or its affiliates. All rights reserved.
* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
*
*
*
*
*
*
*
*
*
*
*
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*
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*
*
*
*/
package com.sun.corba.se.impl.encoding;
import java.nio.charset.CharsetDecoder;
import java.nio.charset.CharsetEncoder;
import java.util.Map;
import java.util.WeakHashMap;
/**
* Thread local cache of sun.io code set converters for performance.
*
* The thread local class contains a single reference to a Map[]
* containing two WeakHashMaps. One for CharsetEncoders and
* one for CharsetDecoders. Constants are defined for indexing.
*
* This is used internally by CodeSetConversion.
*/
class CodeSetCache
{
/**
* The ThreadLocal data is a 2 element Map array indexed
* by BTC_CACHE_MAP and CTB_CACHE_MAP.
*/
private ThreadLocal converterCaches = new ThreadLocal() {
public java.lang.Object initialValue() {
return new Map[] { new WeakHashMap(), new WeakHashMap() };
}
};
/**
* Index in the thread local converterCaches array for
* the byte to char converter Map. A key is the Java
* name corresponding to the desired code set.
*/
private static final int BTC_CACHE_MAP = 0;
/**
* Index in the thread local converterCaches array for
* the char to byte converter Map. A key is the Java
* name corresponding to the desired code set.
*/
private static final int CTB_CACHE_MAP = 1;
/**
* Retrieve a CharsetDecoder from the Map using the given key.
*/
CharsetDecoder getByteToCharConverter(Object key) {
Map btcMap = ((Map[])converterCaches.get())[BTC_CACHE_MAP];
return (CharsetDecoder)btcMap.get(key);
}
/**
* Retrieve a CharsetEncoder from the Map using the given key.
*/
CharsetEncoder getCharToByteConverter(Object key) {
Map ctbMap = ((Map[])converterCaches.get())[CTB_CACHE_MAP];
return (CharsetEncoder)ctbMap.get(key);
}
/**
* Stores the given CharsetDecoder in the thread local cache,
* and returns the same converter.
*/
CharsetDecoder setConverter(Object key, CharsetDecoder converter) {
Map btcMap = ((Map[])converterCaches.get())[BTC_CACHE_MAP];
btcMap.put(key, converter);
return converter;
}
/**
* Stores the given CharsetEncoder in the thread local cache,
* and returns the same converter.
*/
CharsetEncoder setConverter(Object key, CharsetEncoder converter) {
Map ctbMap = ((Map[])converterCaches.get())[CTB_CACHE_MAP];
ctbMap.put(key, converter);
return converter;
}
}