#9410 Improved toString() and javadoc

Signed-off-by: Ludovic Orban <lorban@bitronix.be>

jetty-core/jetty-io/src/main/java/org/eclipse/jetty/io/AbstractRetainableByteBuffer.java

@@ -73,6 +73,6 @@ public abstract class AbstractRetainableByteBuffer implements RetainableByteBuff
     @Override
     public String toString()
     {
-        return "%s@%x[r=%d,%s]".formatted(getClass().getSimpleName(), hashCode(), refCount.get(), BufferUtil.toDetailString(byteBuffer));
+        return "%s@%x[rc=%d,%s]".formatted(getClass().getSimpleName(), hashCode(), refCount.get(), BufferUtil.toDetailString(byteBuffer));
     }
 }

jetty-core/jetty-io/src/main/java/org/eclipse/jetty/io/Content.java

@@ -333,6 +333,7 @@ public class Content
          * the content reader reads a content chunk, via an {@link Chunk.Error} instance.</p>
          * <p>If {@link #read()} has returned a last chunk, this is a no operation.</p>
          * <p>Typical failure: the content being aborted by user code, or idle timeouts.</p>
+         * <p>If this method has already been called, then it is a no operation.</p>
          *
          * @param failure the cause of the failure
          */

jetty-core/jetty-io/src/main/java/org/eclipse/jetty/io/internal/ByteBufferChunk.java

@@ -82,6 +82,12 @@ public abstract class ByteBufferChunk implements Content.Chunk
         {
             return references.release();
         }
+
+        @Override
+        public String toString()
+        {
+            return "%s[rc=%d]".formatted(super.toString(), references.get());
+        }
     }
 
     public static class ReleasedByRunnable extends ByteBufferChunk.WithReferenceCount
@@ -159,5 +165,11 @@ public abstract class ByteBufferChunk implements Content.Chunk
         {
             return retainable.release();
         }
+
+        @Override
+        public String toString()
+        {
+            return "%s[%s]".formatted(super.toString(), retainable);
+        }
     }
 }