Initial revision

From-SVN: r102074

libjava/classpath/java/nio/charset/CoderResult.java

@@ -0,0 +1,189 @@
+/* CoderResult.java -- 
+   Copyright (C) 2002, 2004 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package java.nio.charset;
+
+import java.lang.ref.WeakReference;
+import java.nio.BufferOverflowException;
+import java.nio.BufferUnderflowException;
+import java.util.HashMap;
+
+/**
+ * @author Jesse Rosenstock
+ * @since 1.4
+ */
+public class CoderResult
+{ 
+  private static final int TYPE_MALFORMED  = 0;
+  private static final int TYPE_OVERFLOW   = 1;
+  private static final int TYPE_UNDERFLOW  = 2;
+  private static final int TYPE_UNMAPPABLE = 3;
+
+  public static final CoderResult OVERFLOW
+    = new CoderResult (TYPE_OVERFLOW, 0);
+  public static final CoderResult UNDERFLOW
+    = new CoderResult (TYPE_UNDERFLOW, 0);
+  
+  private static final String[] names
+    = { "MALFORMED", "OVERFLOW", "UNDERFLOW", "UNMAPPABLE" };
+
+  private static final Cache malformedCache
+    = new Cache ()
+      {
+        protected CoderResult make (int length)
+        {
+          return new CoderResult (TYPE_MALFORMED, length);
+        }
+      };
+
+  private static final Cache unmappableCache
+    = new Cache ()
+      {
+        protected CoderResult make (int length)
+        {
+          return new CoderResult (TYPE_UNMAPPABLE, length);
+        }
+      };
+
+  private final int type;
+  private final int length;
+
+  // Package-private to avoid a trampoline constructor.
+  CoderResult (int type, int length)
+  {
+    this.type = type;
+    this.length = length;
+  }
+
+  public boolean isError ()
+  {
+    return length > 0;
+  }
+
+  public boolean isMalformed ()
+  {
+    return type == TYPE_MALFORMED;
+  }
+
+  public boolean isOverflow ()
+  {
+    return type == TYPE_OVERFLOW;
+  }
+
+  public boolean isUnderflow ()
+  {
+    return type == TYPE_UNDERFLOW;
+  }
+
+  public boolean isUnmappable ()
+  {
+    return type == TYPE_UNMAPPABLE;
+  }
+
+  public int length ()
+  {
+    if (length <= 0)
+      throw new UnsupportedOperationException ();
+    else
+      return length;
+  }
+
+  public static CoderResult malformedForLength (int length)
+  {
+    return malformedCache.get (length);
+  }
+    
+  public void throwException ()
+    throws CharacterCodingException
+  {
+    switch (type)
+      {
+        case TYPE_MALFORMED:
+          throw new MalformedInputException (length);
+        case TYPE_OVERFLOW:
+          throw new BufferOverflowException ();
+        case TYPE_UNDERFLOW:
+          throw new BufferUnderflowException ();
+        case TYPE_UNMAPPABLE:
+          throw new UnmappableCharacterException (length);
+      }
+  }
+
+  public String toString ()
+  {
+    String name = names[type];
+    return (length > 0) ? name + '[' + length + ']' : name;
+  }
+
+  public static CoderResult unmappableForLength (int length)
+  {
+    return unmappableCache.get (length);
+  }    
+
+  private abstract static class Cache
+  {
+    private final HashMap cache;
+
+    // Package-private to avoid a trampoline constructor.
+    Cache ()
+    {
+      cache = new HashMap ();
+    }
+
+    // Package-private to avoid a trampoline.
+    synchronized CoderResult get (int length)
+    {
+      if (length <= 0)
+        throw new IllegalArgumentException ("Non-positive length");
+
+      Integer len = new Integer (length);
+      CoderResult cr = null;
+      Object o;
+      if ((o = cache.get (len)) != null)
+        cr = (CoderResult) ((WeakReference) o).get ();
+      if (cr == null)
+        {
+          cr = make (length);
+          cache.put (len, new WeakReference (cr));
+        }
+
+      return cr;
+    }
+
+    protected abstract CoderResult make (int length);
+  }
+}