DirectoryLock.java

net.minecraft.util.DirectoryLock

信息

• 全限定名：net.minecraft.util.DirectoryLock
• 类型：public class
• 包：net.minecraft.util
• 源码路径：src/main/java/net/minecraft/util/DirectoryLock.java
• 起始行号：L13
• 实现：AutoCloseable
• 职责：

  TODO

字段/常量

• LOCK_FILE

  • 类型: String
  • 修饰符: public static final
  • 源码定位: L14
  • 说明:

    TODO

• lockFile

  • 类型: FileChannel
  • 修饰符: private final
  • 源码定位: L15
  • 说明:

    TODO

• lock

  • 类型: FileLock
  • 修饰符: private final
  • 源码定位: L16
  • 说明:

    TODO

• DUMMY

  • 类型: ByteBuffer
  • 修饰符: private static final
  • 源码定位: L17
  • 说明:

    TODO

内部类/嵌套类型

• net.minecraft.util.DirectoryLock.LockException
  • 类型: class
  • 修饰符: public static
  • 源码定位: L93
  • 说明:

    TODO

构造器

private DirectoryLock(FileChannel lockFile, FileLock lock) @ L44

• 构造器名：DirectoryLock
• 源码定位：L44
• 修饰符：private

参数:

• lockFile: FileChannel
• lock: FileLock

说明:

TODO

方法

下面的方法块按源码顺序生成。

public static DirectoryLock create(Path dir) @ L19

• 方法名：create
• 源码定位：L19
• 返回类型：DirectoryLock
• 修饰符：public static

参数:

• dir: Path

说明:

TODO

public void close() @ L49

• 方法名：close
• 源码定位：L49
• 返回类型：void
• 修饰符：public

参数:

• 无

说明:

TODO

public boolean isValid() @ L62

• 方法名：isValid
• 源码定位：L62
• 返回类型：boolean
• 修饰符：public

参数:

• 无

说明:

TODO

public static boolean isLocked(Path dir) @ L66

• 方法名：isLocked
• 源码定位：L66
• 返回类型：boolean
• 修饰符：public static

参数:

• dir: Path

说明:

TODO

代码

public class DirectoryLock implements AutoCloseable {
    public static final String LOCK_FILE = "session.lock";
    private final FileChannel lockFile;
    private final FileLock lock;
    private static final ByteBuffer DUMMY;
 
    public static DirectoryLock create(Path dir) throws IOException {
        Path lockPath = dir.resolve("session.lock");
        FileUtil.createDirectoriesSafe(dir);
        FileChannel lockFile = FileChannel.open(lockPath, StandardOpenOption.CREATE, StandardOpenOption.WRITE);
 
        try {
            lockFile.write(DUMMY.duplicate());
            lockFile.force(true);
            FileLock lock = lockFile.tryLock();
            if (lock == null) {
                throw DirectoryLock.LockException.alreadyLocked(lockPath);
            } else {
                return new DirectoryLock(lockFile, lock);
            }
        } catch (IOException var6) {
            try {
                lockFile.close();
            } catch (IOException var5) {
                var6.addSuppressed(var5);
            }
 
            throw var6;
        }
    }
 
    private DirectoryLock(FileChannel lockFile, FileLock lock) {
        this.lockFile = lockFile;
        this.lock = lock;
    }
 
    @Override
    public void close() throws IOException {
        try {
            if (this.lock.isValid()) {
                this.lock.release();
            }
        } finally {
            if (this.lockFile.isOpen()) {
                this.lockFile.close();
            }
        }
    }
 
    public boolean isValid() {
        return this.lock.isValid();
    }
 
    public static boolean isLocked(Path dir) throws IOException {
        Path lockPath = dir.resolve("session.lock");
 
        try {
            boolean var4;
            try (
                FileChannel lockFile = FileChannel.open(lockPath, StandardOpenOption.WRITE);
                FileLock maybeLock = lockFile.tryLock();
            ) {
                var4 = maybeLock == null;
            }
 
            return var4;
        } catch (AccessDeniedException var10) {
            return true;
        } catch (NoSuchFileException var11) {
            return false;
        }
    }
 
    static {
        byte[] chars = "\u2603".getBytes(StandardCharsets.UTF_8);
        DUMMY = ByteBuffer.allocateDirect(chars.length);
        DUMMY.put(chars);
        DUMMY.flip();
    }
 
    public static class LockException extends IOException {
        private LockException(Path path, String message) {
            super(path.toAbsolutePath() + ": " + message);
        }
 
        public static DirectoryLock.LockException alreadyLocked(Path path) {
            return new DirectoryLock.LockException(path, "already locked (possibly by other Minecraft instance?)");
        }
    }
}

引用的其他类

• FileUtil
  • 引用位置: 方法调用
  • 关联成员: FileUtil.createDirectoriesSafe()