1 /* 2 * Copyright 2014 Google Inc. 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 17 package com.google.common.jimfs; 18 19 import java.nio.channels.AsynchronousFileChannel; 20 import java.nio.channels.FileChannel; 21 import java.nio.channels.SeekableByteChannel; 22 import java.nio.file.DirectoryStream; 23 import java.nio.file.Files; 24 import java.nio.file.OpenOption; 25 import java.nio.file.Path; 26 import java.nio.file.SecureDirectoryStream; 27 import java.nio.file.attribute.FileAttribute; 28 import java.util.Set; 29 import java.util.concurrent.ExecutorService; 30 31 /** 32 * Optional file system features that may be supported or unsupported by a Jimfs file system 33 * instance. 34 * 35 * @author Colin Decker 36 */ 37 public enum Feature { 38 39 /** 40 * Feature controlling support for hard links to regular files. 41 * 42 * <p>Affected method: 43 * 44 * <ul> 45 * <li>{@link Files#createLink(Path, Path)} 46 * </ul> 47 * 48 * <p>If this feature is not enabled, this method will throw {@link 49 * UnsupportedOperationException}. 50 */ 51 LINKS, 52 53 /** 54 * Feature controlling support for symbolic links. 55 * 56 * <p>Affected methods: 57 * 58 * <ul> 59 * <li>{@link Files#createSymbolicLink(Path, Path, FileAttribute...)} 60 * <li>{@link Files#readSymbolicLink(Path)} 61 * </ul> 62 * 63 * <p>If this feature is not enabled, these methods will throw {@link 64 * UnsupportedOperationException}. 65 */ 66 SYMBOLIC_LINKS, 67 68 /** 69 * Feature controlling support for {@link SecureDirectoryStream}. 70 * 71 * <p>Affected methods: 72 * 73 * <ul> 74 * <li>{@link Files#newDirectoryStream(Path)} 75 * <li>{@link Files#newDirectoryStream(Path, DirectoryStream.Filter)} 76 * <li>{@link Files#newDirectoryStream(Path, String)} 77 * </ul> 78 * 79 * <p>If this feature is enabled, the {@link DirectoryStream} instances returned by these methods 80 * will also implement {@link SecureDirectoryStream}. 81 */ 82 SECURE_DIRECTORY_STREAM, 83 84 /** 85 * Feature controlling support for {@link FileChannel}. 86 * 87 * <p>Affected methods: 88 * 89 * <ul> 90 * <li>{@link Files#newByteChannel(Path, OpenOption...)} 91 * <li>{@link Files#newByteChannel(Path, Set, FileAttribute...)} 92 * <li>{@link FileChannel#open(Path, OpenOption...)} 93 * <li>{@link FileChannel#open(Path, Set, FileAttribute...)} 94 * <li>{@link AsynchronousFileChannel#open(Path, OpenOption...)} 95 * <li>{@link AsynchronousFileChannel#open(Path, Set, ExecutorService, FileAttribute...)} 96 * </ul> 97 * 98 * <p>If this feature is not enabled, the {@link SeekableByteChannel} instances returned by the 99 * {@code Files} methods will not be {@code FileChannel} instances and the {@code 100 * FileChannel.open} and {@code AsynchronousFileChannel.open} methods will throw {@link 101 * UnsupportedOperationException}. 102 */ 103 // TODO(cgdecker): Should support for AsynchronousFileChannel be a separate feature? 104 FILE_CHANNEL 105 } 106