1 /*
   2  * Copyright (c) 2016, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package jdk.jfr;
  27 
  28 import java.lang.annotation.ElementType;
  29 import java.lang.annotation.Retention;
  30 import java.lang.annotation.RetentionPolicy;
  31 import java.lang.annotation.Target;
  32 
  33 /**
  34  * Event field annotation, specifies that a value represents an amount of data (for example, bytes).
  35  *
  36  * @since 8
  37  */
  38 @MetadataDefinition
  39 @ContentType
  40 @Label("Data Amount")
  41 @Description("Amount of data")
  42 @Retention(RetentionPolicy.RUNTIME)
  43 @Target({ ElementType.FIELD, ElementType.TYPE, ElementType.METHOD})
  44 public @interface DataAmount {
  45     /**
  46      * Unit for bits
  47      */
  48     public static final String BITS = "BITS";
  49     /**
  50      * Unit for bytes
  51      */
  52     public static final String BYTES = "BYTES";
  53 
  54     /**
  55      * Returns the unit for the data amount, by default bytes.
  56      *
  57      * @return the data amount unit, default {@code BYTES}, not {@code null}
  58      */
  59     String value() default BYTES;
  60 }