1 /*
   2  * Copyright (c) 2015, 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.nashorn.tools.jjs;
  27 
  28 import java.io.IOException;
  29 import java.io.InputStream;
  30 import java.io.PrintStream;
  31 import java.util.ArrayList;
  32 import java.util.Arrays;
  33 import java.util.Collections;
  34 import java.util.Iterator;
  35 import java.util.List;
  36 import java.util.prefs.BackingStoreException;
  37 import java.util.prefs.Preferences;
  38 import jdk.internal.jline.console.ConsoleReader;
  39 import jdk.internal.jline.console.history.History.Entry;
  40 import jdk.internal.jline.console.history.MemoryHistory;
  41 
  42 class Console implements AutoCloseable {
  43     private final ConsoleReader in;
  44     private final PersistentHistory history;
  45 
  46     Console(InputStream cmdin, PrintStream cmdout, Preferences prefs) throws IOException {
  47         in = new ConsoleReader(cmdin, cmdout);
  48         in.setExpandEvents(false);
  49         in.setHandleUserInterrupt(true);
  50         in.setHistory(history = new PersistentHistory(prefs));
  51         Runtime.getRuntime().addShutdownHook(new Thread(()->close()));
  52     }
  53 
  54     String readLine(String prompt) throws IOException {
  55         return in.readLine(prompt);
  56     }
  57 
  58 
  59     @Override
  60     public void close() {
  61         history.save();
  62     }
  63 
  64     public static class PersistentHistory extends MemoryHistory {
  65 
  66         private final Preferences prefs;
  67 
  68         protected PersistentHistory(Preferences prefs) {
  69             this.prefs = prefs;
  70             load();
  71         }
  72 
  73         private static final String HISTORY_LINE_PREFIX = "HISTORY_LINE_";
  74 
  75         public final void load() {
  76             try {
  77                 List<String> keys = new ArrayList<>(Arrays.asList(prefs.keys()));
  78                 Collections.sort(keys);
  79                 for (String key : keys) {
  80                     if (!key.startsWith(HISTORY_LINE_PREFIX))
  81                         continue;
  82                     CharSequence line = prefs.get(key, "");
  83                     add(line);
  84                 }
  85             } catch (BackingStoreException ex) {
  86                 throw new IllegalStateException(ex);
  87             }
  88         }
  89 
  90         public void save() {
  91             Iterator<Entry> entries = iterator();
  92             if (entries.hasNext()) {
  93                 int len = (int) Math.ceil(Math.log10(size()+1));
  94                 String format = HISTORY_LINE_PREFIX + "%0" + len + "d";
  95                 while (entries.hasNext()) {
  96                     Entry entry = entries.next();
  97                     prefs.put(String.format(format, entry.index()), entry.value().toString());
  98                 }
  99             }
 100         }
 101 
 102     }
 103 }