1/*
2 * Copyright (C) 2017 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.car.test.utils;
18
19import android.annotation.Nullable;
20import android.os.SystemClock;
21import java.io.File;
22import java.io.IOException;
23import java.nio.file.FileVisitResult;
24import java.nio.file.Files;
25import java.nio.file.Path;
26import java.nio.file.SimpleFileVisitor;
27import java.nio.file.attribute.BasicFileAttributes;
28
29/**
30 * A utility class that creates a temporary directory.
31 * The directory, and any files contained within, are automatically deleted when calling close().
32 *
33 * Example usage:
34 *
35 * try (TemporaryDirectory tf = new TemporaryDirectory("myTest")) {
36 *     ...
37 * } // directory gets deleted here
38 */
39public class TemporaryDirectory implements AutoCloseable {
40    private Path mDirectory;
41
42    private static final class DeletingVisitor extends SimpleFileVisitor<Path> {
43        FileVisitResult consume(Path path) throws IOException {
44            Files.delete(path);
45            return FileVisitResult.CONTINUE;
46        }
47
48        @Override
49        public FileVisitResult visitFile(Path path, BasicFileAttributes basicFileAttributes)
50                throws IOException {
51            return consume(path);
52        }
53
54        @Override
55        public FileVisitResult postVisitDirectory(Path path, IOException e)
56                throws IOException {
57            return consume(path);
58        }
59    }
60
61    private static final SimpleFileVisitor<Path> DELETE = new DeletingVisitor();
62
63    TemporaryDirectory(Path directory) throws IOException {
64        mDirectory = Files.createDirectory(directory);
65    }
66
67    public TemporaryDirectory(@Nullable String prefix) throws IOException {
68        if (prefix == null) {
69            prefix = TemporaryDirectory.class.getSimpleName();
70        }
71        prefix += String.valueOf(SystemClock.elapsedRealtimeNanos());
72
73        mDirectory = Files.createTempDirectory(prefix);
74    }
75
76    @Override
77    public void close() throws Exception {
78        Files.walkFileTree(mDirectory, DELETE);
79    }
80
81    public File getDirectory() {
82        return mDirectory.toFile();
83    }
84
85    public Path getPath() { return mDirectory; }
86
87    public TemporaryDirectory getSubdirectory(String name) throws IOException {
88        return new TemporaryDirectory(mDirectory.resolve(name));
89    }
90}
91