CopyOnWriteFileSystem.java

net.minecraft.util.filefix.virtualfilesystem.CopyOnWriteFileSystem

信息

• 全限定名：net.minecraft.util.filefix.virtualfilesystem.CopyOnWriteFileSystem
• 类型：public class
• 包：net.minecraft.util.filefix.virtualfilesystem
• 源码路径：src/main/java/net/minecraft/util/filefix/virtualfilesystem/CopyOnWriteFileSystem.java
• 起始行号：L28
• 继承：FileSystem
• 职责：

  TODO

字段/常量

• FILE_ATTRIBUTE_VIEWS

  • 类型: Set<String>
  • 修饰符: private static final
  • 源码定位: L29
  • 说明:

    TODO

• LOGGER

  • 类型: Logger
  • 修饰符: private static final
  • 源码定位: L30
  • 说明:

    TODO

• store

  • 类型: CopyOnWriteFileStore
  • 修饰符: private final
  • 源码定位: L31
  • 说明:

    TODO

• provider

  • 类型: CopyOnWriteFSProvider
  • 修饰符: private final
  • 源码定位: L32
  • 说明:

    TODO

• baseDirectory

  • 类型: Path
  • 修饰符: private final
  • 源码定位: L33
  • 说明:

    TODO

• skippedPaths

  • 类型: PathMatcher
  • 修饰符: private final
  • 源码定位: L34
  • 说明:

    TODO

• tmpDirectory

  • 类型: Path
  • 修饰符: private final
  • 源码定位: L35
  • 说明:

    TODO

• rootPath

  • 类型: CopyOnWriteFSPath
  • 修饰符: private final
  • 源码定位: L36
  • 说明:

    TODO

• tmpFileIndex

  • 类型: AtomicInteger
  • 修饰符: private final
  • 源码定位: L37
  • 说明:

    TODO

• fileTree

  • 类型: DirectoryNode
  • 修饰符: private
  • 源码定位: L38
  • 说明:

    TODO

内部类/嵌套类型

• net.minecraft.util.filefix.virtualfilesystem.CopyOnWriteFileSystem.Moves
  • 类型: record
  • 修饰符: public
  • 源码定位: L294
  • 说明:

    TODO

构造器

private CopyOnWriteFileSystem(String name, Path baseDirectory, Path tmpDirectory, PathMatcher skippedPaths) @ L40

• 构造器名：CopyOnWriteFileSystem
• 源码定位：L40
• 修饰符：private

参数:

• name: String
• baseDirectory: Path
• tmpDirectory: Path
• skippedPaths: PathMatcher

说明:

TODO

方法

下面的方法块按源码顺序生成。

public static CopyOnWriteFileSystem create(String name, Path baseDirectory, Path tmpDirectory, PathMatcher skippedPaths) @ L50

• 方法名：create
• 源码定位：L50
• 返回类型：CopyOnWriteFileSystem
• 修饰符：public static

参数:

• name: String
• baseDirectory: Path
• tmpDirectory: Path
• skippedPaths: PathMatcher

说明:

TODO

private DirectoryNode buildFileTreeFrom(Path baseDirectory) @ L60

• 方法名：buildFileTreeFrom
• 源码定位：L60
• 返回类型：DirectoryNode
• 修饰符：private

参数:

• baseDirectory: Path

说明:

TODO

protected void resetFileTreeToBaseFolderContent() @ L108

• 方法名：resetFileTreeToBaseFolderContent
• 源码定位：L108
• 返回类型：void
• 修饰符：protected

参数:

• 无

说明:

TODO

public CopyOnWriteFSProvider provider() @ L113

• 方法名：provider
• 源码定位：L113
• 返回类型：CopyOnWriteFSProvider
• 修饰符：public

参数:

• 无

说明:

TODO

public void close() @ L117

• 方法名：close
• 源码定位：L117
• 返回类型：void
• 修饰符：public

参数:

• 无

说明:

TODO

public boolean isOpen() @ L124

• 方法名：isOpen
• 源码定位：L124
• 返回类型：boolean
• 修饰符：public

参数:

• 无

说明:

TODO

public boolean isReadOnly() @ L129

• 方法名：isReadOnly
• 源码定位：L129
• 返回类型：boolean
• 修饰符：public

参数:

• 无

说明:

TODO

public String getSeparator() @ L134

• 方法名：getSeparator
• 源码定位：L134
• 返回类型：String
• 修饰符：public

参数:

• 无

说明:

TODO

public Iterable<Path> getRootDirectories() @ L139

• 方法名：getRootDirectories
• 源码定位：L139
• 返回类型：Iterable
• 修饰符：public

参数:

• 无

说明:

TODO

public Iterable<FileStore> getFileStores() @ L144

• 方法名：getFileStores
• 源码定位：L144
• 返回类型：Iterable
• 修饰符：public

参数:

• 无

说明:

TODO

public Set<String> supportedFileAttributeViews() @ L149

• 方法名：supportedFileAttributeViews
• 源码定位：L149
• 返回类型：Set
• 修饰符：public

参数:

• 无

说明:

TODO

public CopyOnWriteFSPath getPath(String first, String... more) @ L154

• 方法名：getPath
• 源码定位：L154
• 返回类型：CopyOnWriteFSPath
• 修饰符：public

参数:

• first: String
• more: String…

说明:

TODO

public PathMatcher getPathMatcher(String syntaxAndPattern) @ L158

• 方法名：getPathMatcher
• 源码定位：L158
• 返回类型：PathMatcher
• 修饰符：public

参数:

• syntaxAndPattern: String

说明:

TODO

public UserPrincipalLookupService getUserPrincipalLookupService() @ L163

• 方法名：getUserPrincipalLookupService
• 源码定位：L163
• 返回类型：UserPrincipalLookupService
• 修饰符：public

参数:

• 无

说明:

TODO

public WatchService newWatchService() @ L168

• 方法名：newWatchService
• 源码定位：L168
• 返回类型：WatchService
• 修饰符：public

参数:

• 无

说明:

TODO

public CopyOnWriteFileStore store() @ L173

• 方法名：store
• 源码定位：L173
• 返回类型：CopyOnWriteFileStore
• 修饰符：public

参数:

• 无

说明:

TODO

public CopyOnWriteFSPath rootPath() @ L177

• 方法名：rootPath
• 源码定位：L177
• 返回类型：CopyOnWriteFSPath
• 修饰符：public

参数:

• 无

说明:

TODO

DirectoryNode fileTree() @ L181

• 方法名：fileTree
• 源码定位：L181
• 返回类型：DirectoryNode
• 修饰符：package-private

参数:

• 无

说明:

TODO

public Path baseDirectory() @ L185

• 方法名：baseDirectory
• 源码定位：L185
• 返回类型：Path
• 修饰符：public

参数:

• 无

说明:

TODO

public Path tmpDirectory() @ L189

• 方法名：tmpDirectory
• 源码定位：L189
• 返回类型：Path
• 修饰符：public

参数:

• 无

说明:

TODO

Path createTemporaryFilePath() @ L193

• 方法名：createTemporaryFilePath
• 源码定位：L193
• 返回类型：Path
• 修饰符：package-private

参数:

• 无

说明:

TODO

public FileSystem backingFileSystem() @ L197

• 方法名：backingFileSystem
• 源码定位：L197
• 返回类型：FileSystem
• 修饰符：public

参数:

• 无

说明:

TODO

public CopyOnWriteFileSystem.Moves collectMoveOperations(Path outPath) @ L201

• 方法名：collectMoveOperations
• 源码定位：L201
• 返回类型：CopyOnWriteFileSystem.Moves
• 修饰符：public

参数:

• outPath: Path

说明:

TODO

private void collectMoveOperations(Path outPath, DirectoryNode folder, CopyOnWriteFileSystem.Moves result) @ L207

• 方法名：collectMoveOperations
• 源码定位：L207
• 返回类型：void
• 修饰符：private

参数:

• outPath: Path
• folder: DirectoryNode
• result: CopyOnWriteFileSystem.Moves

说明:

TODO

public static void createDirectories(List<Path> directories) @ L229

• 方法名：createDirectories
• 源码定位：L229
• 返回类型：void
• 修饰符：public static

参数:

• directories: List

说明:

TODO

public static void hardLinkFiles(List<FileMove> moves) @ L235

• 方法名：hardLinkFiles
• 源码定位：L235
• 返回类型：void
• 修饰符：public static

参数:

• moves: List

说明:

TODO

public static void moveFiles(List<FileMove> moves) @ L247

• 方法名：moveFiles
• 源码定位：L247
• 返回类型：void
• 修饰符：public static

参数:

• moves: List

说明:

TODO

public static void moveFilesWithRetry(List<FileMove> moves, CopyOption... options) @ L253

• 方法名：moveFilesWithRetry
• 源码定位：L253
• 返回类型：void
• 修饰符：public static

参数:

• moves: List
• options: CopyOption…

说明:

TODO

public static List<FileMove> tryRevertMoves(List<FileMove> moves, CopyOption... options) @ L265

• 方法名：tryRevertMoves
• 源码定位：L265
• 返回类型：List
• 修饰符：public static

参数:

• moves: List
• options: CopyOption…

说明:

TODO

代码

public class CopyOnWriteFileSystem extends FileSystem {
    private static final Set<String> FILE_ATTRIBUTE_VIEWS = Set.of("basic");
    private static final Logger LOGGER = LogUtils.getLogger();
    private final CopyOnWriteFileStore store;
    private final CopyOnWriteFSProvider provider;
    private final Path baseDirectory;
    private final PathMatcher skippedPaths;
    private final Path tmpDirectory;
    private final CopyOnWriteFSPath rootPath;
    private final AtomicInteger tmpFileIndex = new AtomicInteger();
    private DirectoryNode fileTree;
 
    private CopyOnWriteFileSystem(String name, Path baseDirectory, Path tmpDirectory, PathMatcher skippedPaths) throws IOException {
        this.baseDirectory = baseDirectory;
        this.tmpDirectory = tmpDirectory;
        this.skippedPaths = skippedPaths;
        this.provider = new CopyOnWriteFSProvider(this);
        this.store = new CopyOnWriteFileStore(name, this);
        this.rootPath = this.getPath("/");
        this.fileTree = this.buildFileTreeFrom(baseDirectory);
    }
 
    public static CopyOnWriteFileSystem create(String name, Path baseDirectory, Path tmpDirectory, PathMatcher skippedPaths) throws IOException {
        if (Files.exists(tmpDirectory)) {
            throw new CowFSCreationException("Temporary directory already exists: " + tmpDirectory);
        } else {
            CopyOnWriteFileSystem fileSystem = new CopyOnWriteFileSystem(name, baseDirectory, tmpDirectory, skippedPaths);
            Files.createDirectory(tmpDirectory);
            return fileSystem;
        }
    }
 
    private DirectoryNode buildFileTreeFrom(Path baseDirectory) throws IOException {
        final DirectoryNode fileTree = new DirectoryNode(this.rootPath);
        Files.walkFileTree(baseDirectory, new SimpleFileVisitor<Path>() {
            {
                Objects.requireNonNull(CopyOnWriteFileSystem.this);
            }
 
            public FileVisitResult visitFile(Path realPath, BasicFileAttributes attrs) throws IOException {
                checkAttributes(realPath, attrs);
                if (CopyOnWriteFileSystem.this.skippedPaths.matches(realPath)) {
                    return FileVisitResult.CONTINUE;
                } else {
                    CopyOnWriteFSPath cowPath = this.toCowPath(realPath);
                    DirectoryNode parentNode = fileTree.directoryByPath(Objects.requireNonNull(cowPath.getParent()));
                    parentNode.addChild(new FileNode(cowPath, realPath, false));
                    return FileVisitResult.CONTINUE;
                }
            }
 
            public FileVisitResult preVisitDirectory(Path realPath, BasicFileAttributes attrs) throws IOException {
                checkAttributes(realPath, attrs);
                if (CopyOnWriteFileSystem.this.skippedPaths.matches(realPath)) {
                    return FileVisitResult.SKIP_SUBTREE;
                } else if (realPath.equals(baseDirectory)) {
                    return FileVisitResult.CONTINUE;
                } else {
                    CopyOnWriteFSPath cowPath = this.toCowPath(realPath);
                    DirectoryNode parentNode = fileTree.directoryByPath(Objects.requireNonNull(cowPath.getParent()));
                    parentNode.addChild(new DirectoryNode(cowPath));
                    return FileVisitResult.CONTINUE;
                }
            }
 
            private static void checkAttributes(Path realPath, BasicFileAttributes attrs) throws CowFSCreationException {
                if (!attrs.isRegularFile() && !attrs.isDirectory()) {
                    throw new CowFSSymlinkException("Cannot build copy-on-write file system when symlink is present: " + realPath);
                } else if (!Files.isWritable(realPath)) {
                    throw new CowFSCreationException("Cannot build copy-on-write file system, missing write access for file: " + realPath);
                }
            }
 
            private CopyOnWriteFSPath toCowPath(Path realPath) {
                return fileTree.path().resolve(baseDirectory.relativize(realPath).toString());
            }
        });
        return fileTree;
    }
 
    @VisibleForTesting
    protected void resetFileTreeToBaseFolderContent() throws IOException {
        this.fileTree = this.buildFileTreeFrom(this.baseDirectory);
    }
 
    public CopyOnWriteFSProvider provider() {
        return this.provider;
    }
 
    @Override
    public void close() throws IOException {
        if (Files.exists(this.tmpDirectory)) {
            PathUtils.deleteDirectory(this.tmpDirectory);
        }
    }
 
    @Override
    public boolean isOpen() {
        return true;
    }
 
    @Override
    public boolean isReadOnly() {
        return false;
    }
 
    @Override
    public String getSeparator() {
        return this.backingFileSystem().getSeparator();
    }
 
    @Override
    public Iterable<Path> getRootDirectories() {
        return List.of(this.rootPath());
    }
 
    @Override
    public Iterable<FileStore> getFileStores() {
        return List.of(this.store);
    }
 
    @Override
    public Set<String> supportedFileAttributeViews() {
        return FILE_ATTRIBUTE_VIEWS;
    }
 
    public CopyOnWriteFSPath getPath(String first, String... more) {
        return CopyOnWriteFSPath.of(this, first, more);
    }
 
    @Override
    public PathMatcher getPathMatcher(String syntaxAndPattern) {
        throw new UnsupportedOperationException();
    }
 
    @Override
    public UserPrincipalLookupService getUserPrincipalLookupService() {
        throw new UnsupportedOperationException();
    }
 
    @Override
    public WatchService newWatchService() {
        throw new UnsupportedOperationException();
    }
 
    public CopyOnWriteFileStore store() {
        return this.store;
    }
 
    public CopyOnWriteFSPath rootPath() {
        return this.rootPath;
    }
 
    DirectoryNode fileTree() {
        return this.fileTree;
    }
 
    public Path baseDirectory() {
        return this.baseDirectory;
    }
 
    public Path tmpDirectory() {
        return this.tmpDirectory;
    }
 
    Path createTemporaryFilePath() {
        return this.tmpDirectory.resolve("tmp_" + this.tmpFileIndex.incrementAndGet());
    }
 
    public FileSystem backingFileSystem() {
        return this.tmpDirectory.getFileSystem();
    }
 
    public CopyOnWriteFileSystem.Moves collectMoveOperations(Path outPath) {
        CopyOnWriteFileSystem.Moves result = new CopyOnWriteFileSystem.Moves(new ArrayList<>(), new ArrayList<>(), new ArrayList<>());
        this.collectMoveOperations(outPath, this.fileTree, result);
        return result;
    }
 
    private void collectMoveOperations(Path outPath, DirectoryNode folder, CopyOnWriteFileSystem.Moves result) {
        for (Node childNode : folder.children()) {
            Path target = outPath.resolve(Objects.requireNonNull(childNode.name()));
            switch (childNode) {
                case FileNode fileNode:
                    FileMove move = new FileMove(fileNode.storagePath(), target);
                    if (fileNode.isCopy) {
                        result.copiedFiles.add(move);
                    } else {
                        result.preexistingFiles.add(move);
                    }
                    break;
                case DirectoryNode directoryNode:
                    result.directories.add(target);
                    this.collectMoveOperations(target, directoryNode, result);
                    break;
                default:
                    throw new MatchException(null, null);
            }
        }
    }
 
    public static void createDirectories(List<Path> directories) throws IOException {
        for (Path directory : directories) {
            Files.createDirectory(directory);
        }
    }
 
    public static void hardLinkFiles(List<FileMove> moves) throws IOException {
        for (FileMove move : moves) {
            if (!Files.exists(move.to())) {
                if (!Files.isRegularFile(move.from())) {
                    throw new IllegalStateException("Not a regular file: " + move.from());
                }
 
                Files.createLink(move.to(), move.from());
            }
        }
    }
 
    public static void moveFiles(List<FileMove> moves) throws IOException {
        for (FileMove move : moves) {
            Files.move(move.from(), move.to());
        }
    }
 
    public static void moveFilesWithRetry(List<FileMove> moves, CopyOption... options) throws IOException {
        for (FileMove move : moves) {
            if (Files.exists(move.from()) || !Files.exists(move.to())) {
                if (!Files.isRegularFile(move.from())) {
                    throw new IOException("Not a regular file: " + move.from());
                }
 
                Files.move(move.from(), move.to(), options);
            }
        }
    }
 
    public static List<FileMove> tryRevertMoves(List<FileMove> moves, CopyOption... options) {
        List<FileMove> failedMoves = new ArrayList<>();
 
        for (FileMove move : moves) {
            if (Files.exists(move.to()) || !Files.exists(move.from())) {
                if (Files.isRegularFile(move.to())) {
                    boolean success = Util.safeMoveFile(move.to(), move.from(), options);
                    if (success) {
                        LOGGER.info("Reverted move from {} to {}", move.from(), move.to());
                    } else {
                        LOGGER.error("Failed to revert move from {} to {}", move.from(), move.to());
                        failedMoves.add(move);
                    }
                } else {
                    LOGGER.error("Skipping reverting move from {} to {} as it's not a file", move.from(), move.to());
                    failedMoves.add(move);
                }
            }
        }
 
        if (failedMoves.isEmpty()) {
            LOGGER.info("Successfully reverted back to previous world state");
        } else {
            LOGGER.error("Completed reverting with errors");
        }
 
        return failedMoves;
    }
 
    public record Moves(List<Path> directories, List<FileMove> copiedFiles, List<FileMove> preexistingFiles) {
    }
}

引用的其他类

• Util

  • 引用位置: 方法调用
  • 关联成员: Util.safeMoveFile()

• CopyOnWriteFSPath

  • 引用位置: 字段/方法调用/返回值
  • 关联成员: CopyOnWriteFSPath.of()

• CopyOnWriteFSProvider

  • 引用位置: 字段/构造调用/返回值
  • 关联成员: CopyOnWriteFSProvider()

• CopyOnWriteFileStore

  • 引用位置: 字段/构造调用/返回值
  • 关联成员: CopyOnWriteFileStore()

• DirectoryNode

  • 引用位置: 参数/字段/构造调用/返回值
  • 关联成员: DirectoryNode()

• FileMove

  • 引用位置: 参数/构造调用/返回值
  • 关联成员: FileMove()

• FileNode

  • 引用位置: 构造调用
  • 关联成员: FileNode()

• CowFSCreationException

  • 引用位置: 构造调用
  • 关联成员: CowFSCreationException()

• CowFSSymlinkException

  • 引用位置: 构造调用
  • 关联成员: CowFSSymlinkException()