1 /*

     2  * Copyright (c) 2016, 2018, 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.internal.tool;

    27 

    28 import java.io.PrintWriter;

    29 

    30 abstract class StructuredWriter {

    31     private final static String LINE_SEPARATOR = String.format("%n");

    32 

    33     private final PrintWriter out;

    34     private final StringBuilder builder = new StringBuilder(4000);

    35 

    36     private char[] indentionArray = new char[0];

    37     private int indent = 0;

    38     private int column;

    39     // print first event immediately so tool feels responsive

    40     private boolean first = true;

    41 

    42     StructuredWriter(PrintWriter p) {

    43         out = p;

    44     }

    45 

    46     final protected int getColumn() {

    47         return column;

    48     }

    49 

    50     // Flush to print writer

    51     public final void flush(boolean hard) {

    52         if (hard) {

    53             out.print(builder.toString());

    54             builder.setLength(0);

    55             return;

    56         }

    57         if (first || builder.length() > 100_000) {

    58             out.print(builder.toString());

    59             builder.setLength(0);

    60             first = false;

    61         }

    62     }

    63 

    64     final public void printIndent() {

    65         builder.append(indentionArray, 0, indent);

    66         column += indent;

    67     }

    68 

    69     final public void println() {

    70         builder.append(LINE_SEPARATOR);

    71         column = 0;

    72     }

    73 

    74     final public void print(String... texts) {

    75         for (String text : texts) {

    76             print(text);

    77         }

    78     }

    79 

    80     final public void printAsString(Object o) {

    81         print(String.valueOf(o));

    82     }

    83 

    84     final public void print(String text) {

    85         builder.append(text);

    86         column += text.length();

    87     }

    88 

    89     final public void print(char c) {

    90         builder.append(c);

    91         column++;

    92     }

    93 

    94     final public void print(int value) {

    95         print(String.valueOf(value));

    96     }

    97 

    98     final public void indent() {

    99         indent += 2;

   100         updateIndent();

   101     }

   102 

   103     final public void retract() {

   104         indent -= 2;

   105         updateIndent();

   106     }

   107 

   108     final public void println(String text) {

   109         print(text);

   110         println();

   111     }

   112 

   113     private void updateIndent() {

   114         if (indent > indentionArray.length) {

   115             indentionArray = new char[indent];

   116             for (int i = 0; i < indentionArray.length; i++) {

   117                 indentionArray[i] = ' ';

   118             }

   119         }

   120     }

   121 }