1 /*
2 * Copyright (C) 2005-2015 Schlichtherle IT Services.
3 * All rights reserved. Use is subject to license terms.
4 */
5 package net.java.truevfs.kernel.spec;
6
7 import java.util.Set;
8 import javax.annotation.Nullable;
9 import net.java.truecommons.cio.Entry;
10 import net.java.truecommons.shed.BitField;
11 import net.java.truecommons.shed.ImplementationsShouldExtend;
12
13 /**
14 * A file system node is an entry which can implement multiple entry types and
15 * list directory members.
16 *
17 * @author Christian Schlichtherle
18 */
19 @ImplementationsShouldExtend(FsAbstractNode.class)
20 public interface FsNode extends Entry {
21
22 /**
23 * Returns a string representation of the
24 * {@link FsNodeName file system node name}.
25 *
26 * @return A string representation of the
27 * {@link FsNodeName file system node name}.
28 */
29 @Override
30 String getName();
31
32 /**
33 * Returns a bit field of types implemented by this file system node.
34 * <p>
35 * Some file system types allow a node to implement multiple types.
36 * For example, a ZIP or TAR file may contain an archive entry with the
37 * name {@code foo} and a directory archive entry with the name {@code foo/}.
38 * Yes, this is strange, but sh*t happens!
39 * In this case then, a virtual file system should collapse this into one
40 * file system node which returns {@code true} for both
41 * {@code isType(FILE)} and {@code isType(DIRECTORY)}.
42 *
43 * @return A bit field of types implemented by this file system node.
44 */
45 BitField<Type> getTypes();
46
47 /**
48 * Returns {@code true} if and only if this file system node implements
49 * the given type.
50 *
51 * @param type the type to test.
52 * @return {@code true} if and only if this file system node implements
53 * the given type.
54 * @see #getTypes()
55 */
56 boolean isType(Type type);
57
58 /**
59 * Returns a set of strings with the base names of the members of this
60 * directory node or {@code null} if and only if this is not a directory
61 * node.
62 * Whether or not modifying the returned set is supported and the effect
63 * on the file system is implementation specific.
64 *
65 * @return A set of strings with the base names of the members of this
66 * directory node or {@code null} if and only if this is not a
67 * directory node.
68 */
69 @Nullable Set<String> getMembers();
70 }