org.apache.lucene.store.db
Class DbDirectory

java.lang.Object
  org.apache.lucene.store.Directory
      org.apache.lucene.store.db.DbDirectory

All Implemented Interfaces:

Closeable

public class DbDirectory
extends Directory

A DbDirectory is a Berkeley DB 4.3 based implementation of Directory. It uses two Db database handles, one for storing file records and another for storing file data blocks.

Field Summary

protected com.sleepycat.db.internal.Db	blocks
protected com.sleepycat.db.internal.Db	files
protected int	flags
protected Set<DbIndexOutput>	openFiles
protected com.sleepycat.db.internal.DbTxn	txn

Fields inherited from class org.apache.lucene.store.Directory

isOpen, lockFactory

Constructor Summary

DbDirectory(com.sleepycat.db.internal.DbTxn txn, com.sleepycat.db.internal.Db files, com.sleepycat.db.internal.Db blocks, int flags)
Instantiate a DbDirectory.

DbDirectory(com.sleepycat.db.Transaction txn, com.sleepycat.db.Database files, com.sleepycat.db.Database blocks)

DbDirectory(com.sleepycat.db.Transaction txn, com.sleepycat.db.Database files, com.sleepycat.db.Database blocks, int flags)

Method Summary

void	close() Closes the store.
IndexOutput	createOutput(String name) Creates a new, empty file in the directory with the given name.
void	deleteFile(String name) Removes an existing file in the directory.
boolean	fileExists(String name) Returns true iff a file with the given name exists.
long	fileLength(String name) Returns the length of a file in the directory.
long	fileModified(String name) Returns the time the named file was last modified.
void	flush() Flush the currently open files.
String[]	listAll() Returns an array of strings, one for each file in the directory.
Lock	makeLock(String name) Construct a Lock.
IndexInput	openInput(String name) Returns a stream reading an existing file.
void	setTransaction(com.sleepycat.db.internal.DbTxn txn) Once a transaction handle was committed it is no longer valid.
void	setTransaction(com.sleepycat.db.Transaction txn) Once a transaction handle was committed it is no longer valid.
void	touchFile(String name) Set the modified time of an existing file to now.

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

clearLock, copy, copy, ensureOpen, getLockFactory, getLockID, openInput, setLockFactory, sync, sync, toString

Methods inherited from class java.lang.Object

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

Field Detail

openFiles

protected Set<DbIndexOutput> openFiles

files

protected com.sleepycat.db.internal.Db files

blocks

protected com.sleepycat.db.internal.Db blocks

txn

protected com.sleepycat.db.internal.DbTxn txn

flags

protected int flags

Constructor Detail

DbDirectory

public DbDirectory(com.sleepycat.db.internal.DbTxn txn,
                   com.sleepycat.db.internal.Db files,
                   com.sleepycat.db.internal.Db blocks,
                   int flags)

Instantiate a DbDirectory. The same threading rules that apply to Berkeley DB handles apply to instances of DbDirectory.

Parameters:

txn - a transaction handle that is going to be used for all db operations done by this instance. This parameter may be null.

files - a db handle to store file records.

blocks - a db handle to store file data blocks.

flags - flags used for db read operations.

DbDirectory

public DbDirectory(com.sleepycat.db.Transaction txn,
                   com.sleepycat.db.Database files,
                   com.sleepycat.db.Database blocks,
                   int flags)

DbDirectory

public DbDirectory(com.sleepycat.db.Transaction txn,
                   com.sleepycat.db.Database files,
                   com.sleepycat.db.Database blocks)

Method Detail

close

public void close()
           throws IOException

Description copied from class: Directory

Closes the store.

Specified by:

close in interface Closeable

Specified by:

close in class Directory

Throws:

IOException

flush

public void flush()
           throws IOException

Flush the currently open files. After they have been flushed it is safe to commit the transaction without closing this DbDirectory instance first.

Throws:

IOException

See Also:

setTransaction(com.sleepycat.db.Transaction)

createOutput

public IndexOutput createOutput(String name)
                         throws 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:

IOException

deleteFile

public void deleteFile(String name)
                throws IOException

Description copied from class: Directory

Removes an existing file in the directory.

Specified by:

deleteFile in class Directory

Throws:

IOException

fileExists

public boolean fileExists(String name)
                   throws IOException

Description copied from class: Directory

Returns true iff a file with the given name exists.

Specified by:

fileExists in class Directory

Throws:

IOException

fileLength

public long fileLength(String name)
                throws IOException

Description copied from class: Directory

Returns the length of a file in the directory. This method follows the following contract:

• Throws FileNotFoundException if the file does not exist
• 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:

FileNotFoundException - if the file does not exist.

IOException - if there was an IO error while retrieving the file's length.

fileModified

public long fileModified(String name)
                  throws IOException

Description copied from class: Directory

Returns the time the named file was last modified.

Specified by:

fileModified in class Directory

Throws:

IOException

listAll

public String[] listAll()
                 throws IOException

Description copied from class: Directory

Returns an array of strings, one for each file in the directory.

Specified by:

listAll in class Directory

Throws:

NoSuchDirectoryException - if the directory is not prepared for any write operations (such as Directory.createOutput(String)).

IOException - in case of other IO errors

openInput

public IndexInput openInput(String name)
                     throws IOException

Description copied from class: Directory

Returns a stream reading an existing file.

Specified by:

openInput in class Directory

Throws:

IOException

makeLock

public Lock makeLock(String name)

Description copied from class: Directory

Construct a Lock.

Overrides:

makeLock in class Directory

Parameters:

name - the name of the lock file

touchFile

public void touchFile(String name)
               throws IOException

Description copied from class: Directory

Set the modified time of an existing file to now.

Specified by:

touchFile in class Directory

Throws:

IOException

setTransaction

public void setTransaction(com.sleepycat.db.Transaction txn)

Once a transaction handle was committed it is no longer valid. In order to continue using this DbDirectory instance after a commit, the transaction handle has to be replaced.

Parameters:

txn - the new transaction handle to use

setTransaction

public void setTransaction(com.sleepycat.db.internal.DbTxn txn)

Once a transaction handle was committed it is no longer valid. In order to continue using this DbDirectory instance after a commit, the transaction handle has to be replaced.

Parameters:

txn - the new transaction handle to use