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

*** 23,34 ****
   * questions.
   */
  
  package java.nio.charset;
  
! import java.lang.ref.WeakReference;
! import java.nio.*;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.Map;
  
  /**
   * A description of the result state of a coder.
--- 23,34 ----
   * questions.
   */
  
  package java.nio.charset;
  
! import java.nio.BufferOverflowException;
! import java.nio.BufferUnderflowException;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.Map;
  
  /**
   * A description of the result state of a coder.
*** 188,225 ****
       * room in the output buffer.
       */
      public static final CoderResult OVERFLOW
          = new CoderResult(CR_OVERFLOW, 0);
  
!     private abstract static class 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;
          }
-     }
- 
-     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),
          new CoderResult(CR_MALFORMED, 3),
--- 188,204 ----
       * room in the output buffer.
       */
      public static final CoderResult OVERFLOW
          = new CoderResult(CR_OVERFLOW, 0);
  
!     private static final class Cache {
!         static final Cache INSTANCE = new Cache();
!         private Cache() {}
  
!         final Map<Integer, CoderResult> unmappable = new ConcurrentHashMap<>();
!         final Map<Integer, CoderResult> malformed  = new ConcurrentHashMap<>();
      }
  
      private static final CoderResult[] malformed4 = new CoderResult[] {
          new CoderResult(CR_MALFORMED, 1),
          new CoderResult(CR_MALFORMED, 2),
          new CoderResult(CR_MALFORMED, 3),
*** 238,256 ****
      public static CoderResult malformedForLength(int length) {
          if (length <= 0)
              throw new IllegalArgumentException("Non-positive length");
          if (length <= 4)
              return malformed4[length - 1];
!         return malformedCache.get(length);
      }
  
-     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),
          new CoderResult(CR_UNMAPPABLE, 3),
          new CoderResult(CR_UNMAPPABLE, 4),
--- 217,230 ----
      public static CoderResult malformedForLength(int length) {
          if (length <= 0)
              throw new IllegalArgumentException("Non-positive length");
          if (length <= 4)
              return malformed4[length - 1];
!         return Cache.INSTANCE.malformed.computeIfAbsent(length,
!                 n -> new CoderResult(CR_MALFORMED, n));
      }
  
      private static final CoderResult[] unmappable4 = new CoderResult[] {
          new CoderResult(CR_UNMAPPABLE, 1),
          new CoderResult(CR_UNMAPPABLE, 2),
          new CoderResult(CR_UNMAPPABLE, 3),
          new CoderResult(CR_UNMAPPABLE, 4),
*** 268,278 ****
      public static CoderResult unmappableForLength(int length) {
          if (length <= 0)
              throw new IllegalArgumentException("Non-positive length");
          if (length <= 4)
              return unmappable4[length - 1];
!         return unmappableCache.get(length);
      }
  
      /**
       * Throws an exception appropriate to the result described by this object.
       *
--- 242,253 ----
      public static CoderResult unmappableForLength(int length) {
          if (length <= 0)
              throw new IllegalArgumentException("Non-positive length");
          if (length <= 4)
              return unmappable4[length - 1];
!         return Cache.INSTANCE.unmappable.computeIfAbsent(length,
!                 n -> new CoderResult(CR_UNMAPPABLE, n));
      }
  
      /**
       * Throws an exception appropriate to the result described by this object.
       *