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8198966: To make CoderResult.Cache.cache final and allocate it eagerly

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Reviewed-by: redestad
This commit is contained in:
Xueming Shen 2018-03-04 00:32:53 -08:00
parent 3e166182e0
commit d4d8c255b2
1 changed files with 11 additions and 36 deletions

47
src/java.base/share/classes/java/nio/charset/CoderResult.java

@ -25,8 +25,8 @@
package java.nio.charset;
import java.lang.ref.WeakReference;
import java.nio.*;
import java.nio.BufferOverflowException;
import java.nio.BufferUnderflowException;
import java.util.concurrent.ConcurrentHashMap;
import java.util.Map;
@ -190,35 +190,14 @@ public class CoderResult {
public static final CoderResult OVERFLOW
= new CoderResult(CR_OVERFLOW, 0);
private abstract static class Cache {
private static final class Cache {
static final Cache INSTANCE = new Cache();
private Cache() {}
private Map<Integer,WeakReference<CoderResult>> cache = null;
protected abstract CoderResult create(int len);
private CoderResult get(int len) {
Integer k = len;
WeakReference<CoderResult> w;
CoderResult e = null;
if (cache == null) {
cache = new ConcurrentHashMap<>();
} else if ((w = cache.get(k)) != null) {
e = w.get();
}
if (e == null) {
e = create(len);
cache.put(k, new WeakReference<>(e));
}
return e;
}
final Map<Integer, CoderResult> unmappable = new ConcurrentHashMap<>();
final Map<Integer, CoderResult> malformed = new ConcurrentHashMap<>();
}
private static final Cache malformedCache
= new Cache() {
public CoderResult create(int len) {
return new CoderResult(CR_MALFORMED, len);
}};
private static final CoderResult[] malformed4 = new CoderResult[] {
new CoderResult(CR_MALFORMED, 1),
new CoderResult(CR_MALFORMED, 2),
@ -240,15 +219,10 @@ public class CoderResult {
throw new IllegalArgumentException("Non-positive length");
if (length <= 4)
return malformed4[length - 1];
return malformedCache.get(length);
return Cache.INSTANCE.malformed.computeIfAbsent(length,
n -> new CoderResult(CR_MALFORMED, n));
}
private static final Cache unmappableCache
= new Cache() {
public CoderResult create(int len) {
return new CoderResult(CR_UNMAPPABLE, len);
}};
private static final CoderResult[] unmappable4 = new CoderResult[] {
new CoderResult(CR_UNMAPPABLE, 1),
new CoderResult(CR_UNMAPPABLE, 2),
@ -270,7 +244,8 @@ public class CoderResult {
throw new IllegalArgumentException("Non-positive length");
if (length <= 4)
return unmappable4[length - 1];
return unmappableCache.get(length);
return Cache.INSTANCE.unmappable.computeIfAbsent(length,
n -> new CoderResult(CR_UNMAPPABLE, n));
}
/**