org.apache.lucene.store

## Class LockValidatingDirectoryWrapper

- java.lang.Object
- - org.apache.lucene.store.Directory
  - - org.apache.lucene.store.FilterDirectory
    - - org.apache.lucene.store.LockValidatingDirectoryWrapper

- All Implemented Interfaces:
    Closeable, AutoCloseable

      public final class LockValidatingDirectoryWrapper
      extends FilterDirectory

  This class makes a best-effort check that a provided `Lock` is valid before any destructive filesystem operation.

- - ### Field Summary

    - ### Fields inherited from class org.apache.lucene.store.FilterDirectory

      `in`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `LockValidatingDirectoryWrapper(Directory in, Lock writeLock)`

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `void` | `copyFrom(Directory from, String src, String dest, IOContext context)` Copies an existing `src` file from directory `from` to a non-existent file `dest` in this directory.
    `IndexOutput` | `createOutput(String name, IOContext context)` Creates a new, empty file in the directory and returns an `IndexOutput` instance for appending data to this file.
    `void` | `deleteFile(String name)` Removes an existing file in the directory.
    `void` | `rename(String source, String dest)` Renames `source` file to `dest` file where `dest` must not already exist in the directory.
    `void` | `sync(Collection<String> names)` Ensures that any writes to these files are moved to stable storage (made durable).
    `void` | `syncMetaData()` Ensures that directory metadata, such as recent file renames, are moved to stable storage.

    - ### Methods inherited from class org.apache.lucene.store.FilterDirectory

      `close, createTempOutput, fileLength, getDelegate, getPendingDeletions, listAll, obtainLock, openInput, toString, unwrap`

    - ### Methods inherited from class org.apache.lucene.store.Directory

      `ensureOpen, openChecksumInput`

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

- - ### Constructor Detail

    - #### LockValidatingDirectoryWrapper

          public LockValidatingDirectoryWrapper(Directory in,
                                                Lock writeLock)

  - ### Method Detail

    - #### deleteFile

          public void deleteFile(String name)
                          throws IOException

      Description copied from class: `Directory`
      Removes an existing file in the directory. This method must throw either `NoSuchFileException` or `FileNotFoundException` if `name` points to a non-existing file.
      Overrides:
        `deleteFile` in class `FilterDirectory`
      Parameters:
        `name` - the name of an existing file.
      Throws:
        `IOException` - in case of I/O error

    - #### createOutput

          public IndexOutput createOutput(String name,
                                          IOContext context)
                                   throws IOException

      Description copied from class: `Directory`
      Creates a new, empty file in the directory and returns an `IndexOutput` instance for appending data to this file. This method must throw `FileAlreadyExistsException` if the file already exists.
      Overrides:
        `createOutput` in class `FilterDirectory`
      Parameters:
        `name` - the name of the file to create.
      Throws:
        `IOException` - in case of I/O error

    - #### copyFrom

          public void copyFrom(Directory from,
                               String src,
                               String dest,
                               IOContext context)
                        throws IOException

      Description copied from class: `Directory`
      Copies an existing `src` file from directory `from` to a non-existent file `dest` in this directory.
      Overrides:
        `copyFrom` in class `Directory`
      Throws:
        `IOException`

    - #### rename

          public void rename(String source,
                             String dest)
                      throws IOException

      Description copied from class: `Directory`
      Renames `source` file to `dest` file where `dest` must not already exist in the directory. It is permitted for this operation to not be truly atomic, for example both `source` and `dest` can be visible temporarily in `Directory.listAll()`. However, the implementation of this method must ensure the content of `dest` appears as the entire `source` atomically. So once `dest` is visible for readers, the entire content of previous `source` is visible. This method is used by IndexWriter to publish commits.
      Overrides:
        `rename` in class `FilterDirectory`
      Throws:
        `IOException`

    - #### syncMetaData

          public void syncMetaData()
                            throws IOException

      Description copied from class: `Directory`
      Ensures that directory metadata, such as recent file renames, are moved to stable storage.
      Overrides:
        `syncMetaData` in class `FilterDirectory`
      Throws:
        `IOException`
      See Also:
        `Directory.sync(Collection)`

    - #### sync

          public void sync(Collection<String> names)
                    throws IOException

      Description copied from class: `Directory`
      Ensures that any writes to these files are moved to stable storage (made durable). Lucene uses this to properly commit changes to the index, to prevent a machine/OS crash from corrupting the index.
      Overrides:
        `sync` in class `FilterDirectory`
      Throws:
        `IOException`
      See Also:
        `Directory.syncMetaData()`

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