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.nio.charset.Charset;
30 import java.nio.file.ClosedWatchServiceException;
31 import java.nio.file.FileSystems;
32 import java.nio.file.Files;
33 import java.nio.file.Path;
34 import java.nio.file.WatchKey;
35 import java.nio.file.WatchService;
36 import java.util.List;
37 import java.util.function.Consumer;
38 import static java.nio.file.StandardWatchEventKinds.ENTRY_CREATE;
39 import static java.nio.file.StandardWatchEventKinds.ENTRY_DELETE;
40 import static java.nio.file.StandardWatchEventKinds.ENTRY_MODIFY;
41
42 final class ExternalEditor {
43 private final Consumer<String> errorHandler;
44 private final Consumer<String> saveHandler;
45 private final Console input;
46
47 private WatchService watcher;
48 private Thread watchedThread;
49 private Path dir;
50 private Path tmpfile;
51
52 ExternalEditor(final Consumer<String> errorHandler, final Consumer<String> saveHandler, final Console input) {
53 this.errorHandler = errorHandler;
54 this.saveHandler = saveHandler;
55 this.input = input;
56 }
57
58 private void edit(final String cmd, final String initialText) {
59 try {
60 setupWatch(initialText);
61 launch(cmd);
62 } catch (IOException ex) {
63 errorHandler.accept(ex.getMessage());
64 }
65 }
66
67 /**
68 * Creates a WatchService and registers the given directory
69 */
70 private void setupWatch(final String initialText) throws IOException {
71 this.watcher = FileSystems.getDefault().newWatchService();
72 this.dir = Files.createTempDirectory("REPL");
73 this.tmpfile = Files.createTempFile(dir, null, ".js");
74 Files.write(tmpfile, initialText.getBytes(Charset.forName("UTF-8")));
75 dir.register(watcher,
76 ENTRY_CREATE,
77 ENTRY_DELETE,
78 ENTRY_MODIFY);
79 watchedThread = new Thread(() -> {
80 for (;;) {
81 WatchKey key;
82 try {
83 key = watcher.take();
84 } catch (final ClosedWatchServiceException ex) {
85 break;
86 } catch (final InterruptedException ex) {
87 continue; // tolerate an intrupt
88 }
89
90 if (!key.pollEvents().isEmpty()) {
91 if (!input.terminalEditorRunning()) {
92 saveFile();
93 }
94 }
95
96 boolean valid = key.reset();
97 if (!valid) {
98 errorHandler.accept("Invalid key");
99 break;
100 }
101 }
102 });
103 watchedThread.start();
104 }
105
106 private void launch(final String cmd) throws IOException {
107 ProcessBuilder pb = new ProcessBuilder(cmd, tmpfile.toString());
108 pb = pb.inheritIO();
109
110 try {
111 input.suspend();
112 Process process = pb.start();
113 process.waitFor();
114 } catch (final IOException ex) {
115 errorHandler.accept("process IO failure: " + ex.getMessage());
116 } catch (final InterruptedException ex) {
117 errorHandler.accept("process interrupt: " + ex.getMessage());
118 } finally {
119 try {
120 watcher.close();
121 watchedThread.join(); //so that saveFile() is finished.
122 saveFile();
123 } catch (InterruptedException ex) {
124 errorHandler.accept("process interrupt: " + ex.getMessage());
125 } finally {
126 input.resume();
127 }
128 }
129 }
130
131 private void saveFile() {
132 List<String> lines;
133 try {
134 lines = Files.readAllLines(tmpfile);
135 } catch (final IOException ex) {
136 errorHandler.accept("Failure read edit file: " + ex.getMessage());
137 return ;
138 }
139 StringBuilder sb = new StringBuilder();
140 for (String ln : lines) {
141 sb.append(ln);
142 sb.append('\n');
143 }
144 saveHandler.accept(sb.toString());
145 }
146
147 static void edit(final String cmd, final Consumer<String> errorHandler, final String initialText,
148 final Consumer<String> saveHandler, final Console input) {
149 ExternalEditor ed = new ExternalEditor(errorHandler, saveHandler, input);
150 ed.edit(cmd, initialText);
151 }
152 }