Package org.apache.lucene.store

Class FilterDirectory

  • All Implemented Interfaces:
    java.io.Closeable, java.lang.AutoCloseable
    Direct Known Subclasses:
    RateLimitedDirectoryWrapper, TrackingDirectoryWrapper
    public class FilterDirectory
extends Directory
    Directory implementation that delegates calls to another directory. This class can be used to add limitations on top of an existing Directory implementation such as rate limiting or to add additional sanity checks for tests. However, if you plan to write your own Directory implementation, you should consider extending directly Directory or BaseDirectory rather than try to reuse functionality of existing Directorys by extending this class.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void clearLock​(java.lang.String name)
      Attempt to clear (forcefully unlock and remove) the specified lock.
      void close()
      Closes the store.
      IndexOutput createOutput​(java.lang.String name, IOContext context)
      Creates a new, empty file in the directory with the given name.
      void deleteFile​(java.lang.String name)
      Removes an existing file in the directory.
      boolean fileExists​(java.lang.String name)
      Returns true iff a file with the given name exists.
      long fileLength​(java.lang.String name)
      Returns the length of a file in the directory.
      Directory getDelegate()
      Return the wrapped Directory.
      LockFactory getLockFactory()
      Get the LockFactory that this Directory instance is using for its locking implementation.
      java.lang.String getLockID()
      Return a string identifier that uniquely differentiates this Directory instance from other Directory instances.
      java.lang.String[] listAll()
      Returns an array of strings, one for each file in the directory.
      Lock makeLock​(java.lang.String name)
      Construct a Lock.
      IndexInput openInput​(java.lang.String name, IOContext context)
      Returns a stream reading an existing file, with the specified read buffer size.
      void setLockFactory​(LockFactory lockFactory)
      Set the LockFactory that this Directory instance should use for its locking implementation.
      void sync​(java.util.Collection<java.lang.String> names)
      Ensure that any writes to these files are moved to stable storage.
      java.lang.String toString()  

      • Methods inherited from class java.lang.Object

        equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

    • Method Detail

      • fileExists

        public boolean fileExists​(java.lang.String name)
                   throws java.io.IOException
        Description copied from class: Directory
        Returns true iff a file with the given name exists.
        Specified by:
        fileExists in class Directory
        Throws:
        java.io.IOException

      • deleteFile

        public void deleteFile​(java.lang.String name)
                throws java.io.IOException
        Description copied from class: Directory
        Removes an existing file in the directory.
        Specified by:
        deleteFile in class Directory
        Throws:
        java.io.IOException

      • fileLength

        public long fileLength​(java.lang.String name)
                throws java.io.IOException
        Description copied from class: Directory
        Returns the length of a file in the directory. This method follows the following contract:
        • Must throw FileNotFoundException if the file does not exist (not java.nio.file.NoSuchFileException of Java 7).
        • Returns a value ≥0 if the file exists, which specifies its length.
        Specified by:
        fileLength in class Directory
        Parameters:
        name - the name of the file for which to return the length.
        Throws:
        java.io.IOException - if there was an IO error while retrieving the file's length.

      • createOutput

        public IndexOutput createOutput​(java.lang.String name,
                                IOContext context)
                         throws java.io.IOException
        Description copied from class: Directory
        Creates a new, empty file in the directory with the given name. Returns a stream writing this file.
        Specified by:
        createOutput in class Directory
        Throws:
        java.io.IOException

      • sync

        public void sync​(java.util.Collection<java.lang.String> names)
          throws java.io.IOException
        Description copied from class: Directory
        Ensure that any writes to these files are moved to stable storage. Lucene uses this to properly commit changes to the index, to prevent a machine/OS crash from corrupting the index.

        NOTE: Clients may call this method for same files over and over again, so some impls might optimize for that. For other impls the operation can be a noop, for various reasons.
        Specified by:
        sync in class Directory
        Throws:
        java.io.IOException

      • openInput

        public IndexInput openInput​(java.lang.String name,
                            IOContext context)
                     throws java.io.IOException
        Description copied from class: Directory
        Returns a stream reading an existing file, with the specified read buffer size. The particular Directory implementation may ignore the buffer size. Currently the only Directory implementations that respect this parameter are FSDirectory and CompoundFileDirectory.
      • Must throw FileNotFoundException if the file does not exist (not java.nio.file.NoSuchFileException of Java 7).
Specified by:
openInput in class Directory
Throws:
java.io.IOException