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/*
* Copyright (c) 2007 through 2024 David Berkman
*
* This file is part of the SmallMind Code Project.
*
* The SmallMind Code Project is free software, you can redistribute
* it and/or modify it under either, at your discretion...
*
* 1) The terms of GNU Affero General Public License as published by the
* Free Software Foundation, either version 3 of the License, or (at
* your option) any later version.
*
* ...or...
*
* 2) The terms of the Apache License, Version 2.0.
*
* The SmallMind Code Project is distributed in the hope that it will
* be useful, but WITHOUT ANY WARRANTY; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License or Apache License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* and the Apache License along with the SmallMind Code Project. If not, see
* .
*
* Additional permission under the GNU Affero GPL version 3 section 7
* ------------------------------------------------------------------
* If you modify this Program, or any covered work, by linking or
* combining it with other code, such other code is not for that reason
* alone subject to any of the requirements of the GNU Affero GPL
* version 3.
*/
package org.smallmind.file.ephemeral;
import java.net.URI;
import java.nio.file.FileSystem;
import java.nio.file.InvalidPathException;
import java.nio.file.LinkOption;
import java.nio.file.NoSuchFileException;
import java.nio.file.NotDirectoryException;
import java.nio.file.Path;
import java.nio.file.WatchEvent;
import java.nio.file.WatchKey;
import java.nio.file.WatchService;
import java.util.Arrays;
import java.util.LinkedList;
import org.smallmind.file.ephemeral.watch.EphemeralWatchKey;
import org.smallmind.file.ephemeral.watch.EphemeralWatchService;
public class EphemeralPath implements Path {
private static final String[] NO_NAMES = new String[0];
private static final String SEPARATOR = "/";
private final EphemeralFileSystem fileSystem;
private final String[] names;
private final boolean absolute;
protected EphemeralPath (EphemeralFileSystem fileSystem) {
this.fileSystem = fileSystem;
absolute = true;
names = NO_NAMES;
}
public EphemeralPath (EphemeralFileSystem fileSystem, String first, String... more) {
this.fileSystem = fileSystem;
if (first == null) {
throw new NullPointerException();
} else {
LinkedList nameList = new LinkedList<>();
absolute = first.startsWith(SEPARATOR);
split(nameList, first, absolute);
if ((more != null) && (more.length > 0)) {
for (String another : more) {
split(nameList, another, false);
}
}
names = nameList.toArray(new String[0]);
}
}
private EphemeralPath (EphemeralPath path, int begin, int end) {
fileSystem = (EphemeralFileSystem)path.getFileSystem();
absolute = path.isAbsolute();
names = new String[end - begin];
int to = 0;
for (int from = begin; from < end; from++) {
names[to++] = path.getNames()[from];
}
}
private EphemeralPath (EphemeralFileSystem fileSystem, String[] names, boolean absolute) {
this.fileSystem = fileSystem;
this.names = names;
this.absolute = absolute;
}
public static char getSeparatorChar () {
return SEPARATOR.charAt(0);
}
public static String getSeparator () {
return SEPARATOR;
}
private void split (LinkedList nameList, String text, boolean absolute) {
if (text.length() == 0) {
throw new InvalidPathException(text, "Empty path component");
} else {
int index = 0;
for (String segment : text.split(SEPARATOR, -1)) {
if (segment.length() == 0) {
if ((!absolute) || (index > 0)) {
throw new InvalidPathException(text, "Empty path component");
}
} else {
nameList.add(segment);
index++;
}
}
}
}
public String[] getNames () {
return names;
}
@Override
public FileSystem getFileSystem () {
return fileSystem;
}
@Override
public boolean isAbsolute () {
return absolute;
}
@Override
public EphemeralPath getRoot () {
return absolute ? new EphemeralPath(fileSystem) : null;
}
@Override
public EphemeralPath getFileName () {
return (names.length == 0) ? null : new EphemeralPath(fileSystem, names[names.length - 1]);
}
@Override
public EphemeralPath getParent () {
return (names.length == 0) ? null : (names.length > 1) ? new EphemeralPath(this, 0, names.length - 1) : absolute ? new EphemeralPath(fileSystem) : null;
}
@Override
public int getNameCount () {
return names.length;
}
@Override
public EphemeralPath getName (int index) {
if ((index < 0) || (index >= names.length)) {
throw new IllegalArgumentException("Illegal index value");
}
return new EphemeralPath(fileSystem, names[index]);
}
@Override
public EphemeralPath subpath (int beginIndex, int endIndex) {
if ((beginIndex < 0) || (beginIndex >= names.length) || (endIndex <= beginIndex) || (endIndex > names.length)) {
throw new IllegalArgumentException("Illegal index value");
} else {
return new EphemeralPath(this, beginIndex, endIndex);
}
}
@Override
public boolean startsWith (Path other) {
if ((other.getFileSystem() instanceof EphemeralFileSystem) && (other.getNameCount() <= names.length)) {
for (int index = 0; index < other.getNameCount(); index++) {
if (!((EphemeralPath)other).getNames()[index].equals(names[index])) {
return false;
}
}
return true;
}
return false;
}
@Override
public boolean endsWith (Path other) {
if (other.getFileSystem() instanceof EphemeralFileSystem) {
if (absolute || (!other.isAbsolute())) {
if ((other.isAbsolute() && (other.getNameCount() == names.length)) || ((!other.isAbsolute()) && (other.getNameCount() <= names.length))) {
int offset = names.length - other.getNameCount();
for (int index = 0; index < other.getNameCount(); index++) {
if (!((EphemeralPath)other).getNames()[index].equals(names[offset + index])) {
return false;
}
}
return true;
}
}
}
return false;
}
@Override
public EphemeralPath normalize () {
LinkedList namesList = null;
int position = 0;
for (String name : names) {
switch (name) {
case ".":
if (namesList == null) {
namesList = new LinkedList<>(Arrays.asList(names).subList(0, position));
}
break;
case "..":
if (namesList == null) {
namesList = (position > 1) ? new LinkedList<>(Arrays.asList(names).subList(0, position - 1)) : new LinkedList<>();
} else if (!namesList.isEmpty()) {
namesList.removeLast();
}
break;
default:
if (namesList == null) {
position++;
} else {
namesList.add(name);
}
}
}
return (namesList == null) ? this : new EphemeralPath(fileSystem, namesList.toArray(new String[0]), absolute);
}
@Override
public Path resolve (Path other) {
if (other.isAbsolute()) {
return other;
} else if (other.getNameCount() == 0) {
return this;
} else {
String[] resolvedNames = new String[names.length + other.getNameCount()];
System.arraycopy(names, 0, resolvedNames, 0, names.length);
for (int index = 0; index < other.getNameCount(); index++) {
resolvedNames[names.length + index] = other.getName(index).toString();
}
return new EphemeralPath(fileSystem, resolvedNames, absolute);
}
}
@Override
public EphemeralPath relativize (Path other) {
if (absolute != other.isAbsolute()) {
throw new IllegalArgumentException("No relative path can be constructed");
} else {
LinkedList namesList = new LinkedList<>();
int index = 0;
for (String name : names) {
if (name.equals(other.getName(index).toString())) {
index++;
} else {
break;
}
}
if (index < names.length) {
int redacted = names.length - index;
for (int loop = 0; loop < redacted; loop++) {
namesList.add("..");
}
}
if (index < other.getNameCount()) {
for (int loop = index; loop < other.getNameCount(); loop++) {
namesList.add(other.getName(loop).toString());
}
}
return new EphemeralPath(fileSystem, namesList.toArray(new String[0]), false);
}
}
@Override
public URI toUri () {
return URI.create(fileSystem.provider().getScheme() + "://" + toAbsolutePath());
}
@Override
public EphemeralPath toAbsolutePath () {
return absolute ? this : new EphemeralPath(fileSystem, names, true);
}
@Override
public EphemeralPath toRealPath (LinkOption... options) {
// TODO: will need to handle symlinks when/if the file system provide for them
return normalize().toAbsolutePath();
}
@Override
public WatchKey register (WatchService watcher, WatchEvent.Kind[] events, WatchEvent.Modifier... modifiers)
throws NoSuchFileException, NotDirectoryException {
if (!(watcher instanceof EphemeralWatchService)) {
throw new IllegalArgumentException("The watcher is not associated with this file system");
} else {
EphemeralWatchKey watchKey;
// modifiers unused as yet
((EphemeralWatchService)watcher).register(watchKey = new EphemeralWatchKey((EphemeralWatchService)watcher, events, this));
return watchKey;
}
}
@Override
public int compareTo (Path other) {
EphemeralPath otherEphemeralPath = (EphemeralPath)other;
if (names.length == other.getNameCount()) {
for (int index = 0; index < names.length; index++) {
int comparison;
if ((comparison = names[index].compareTo(otherEphemeralPath.getNames()[index])) != 0) {
return comparison;
}
}
return 0;
} else {
return names.length - otherEphemeralPath.getNameCount();
}
}
@Override
public int hashCode () {
return (Arrays.hashCode(names) * 31) + (absolute ? Boolean.TRUE.hashCode() : Boolean.FALSE.hashCode());
}
@Override
public boolean equals (Object obj) {
return (obj instanceof EphemeralPath) && (((EphemeralPath)obj).isAbsolute() == absolute) && Arrays.equals(((EphemeralPath)obj).getNames(), names);
}
@Override
public String toString () {
StringBuilder pathBuilder = new StringBuilder();
for (String name : names) {
if (absolute || (pathBuilder.length() > 0)) {
pathBuilder.append(SEPARATOR);
}
pathBuilder.append(name);
}
return pathBuilder.toString();
}
}