DbDirectory (Lucene 2.9.4 API)

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

```
public class DbDirectory
extends org.apache.lucene.store.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

Fields
Modifier and Type	Field and Description
`protected com.sleepycat.db.internal.Db`	`blocks`
`protected com.sleepycat.db.internal.Db`	`files`
`protected int`	`flags`
`protected java.util.Set`	`openFiles`
`protected com.sleepycat.db.internal.DbTxn`	`txn`

Fields inherited from class org.apache.lucene.store.Directory
isOpen, lockFactory

Constructor Summary

Constructors
Constructor and Description
`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

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`close()`
`org.apache.lucene.store.IndexOutput`	`createOutput(java.lang.String name)`
`void`	`deleteFile(java.lang.String name)`
`boolean`	`fileExists(java.lang.String name)`
`long`	`fileLength(java.lang.String name)`
`long`	`fileModified(java.lang.String name)`
`void`	`flush()` Flush the currently open files.
`java.lang.String[]`	`list()`
`org.apache.lucene.store.Lock`	`makeLock(java.lang.String name)`
`org.apache.lucene.store.IndexInput`	`openInput(java.lang.String name)`
`void`	`renameFile(java.lang.String from, java.lang.String to)`
`void`	`setTransaction(com.sleepycat.db.internal.DbTxn txn)` Once a transaction handle was committed it is no longer valid.
`void`	`setTransaction(com.sleepycat.db.Transaction txn)` Once a transaction handle was committed it is no longer valid.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(java.lang.String name)`

Methods inherited from class org.apache.lucene.store.Directory
clearLock, copy, ensureOpen, getLockFactory, getLockID, listAll, openInput, setLockFactory, sync, toString

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - openFiles
```
protected java.util.Set 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 java.io.IOException
```
    Specified by:
    
    close in class org.apache.lucene.store.Directory
    
    Throws:
    
    java.io.IOException
  - flush
```
public void flush()
           throws java.io.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:
    
    java.io.IOException
    
    See Also:
    
    setTransaction(com.sleepycat.db.Transaction)
  - createOutput
```
public org.apache.lucene.store.IndexOutput createOutput(java.lang.String name)
                                                 throws java.io.IOException
```
    Specified by:
    
    createOutput in class org.apache.lucene.store.Directory
    
    Throws:
    
    java.io.IOException
  - deleteFile
```
public void deleteFile(java.lang.String name)
                throws java.io.IOException
```
    Specified by:
    
    deleteFile in class org.apache.lucene.store.Directory
    
    Throws:
    
    java.io.IOException
  - fileExists
```
public boolean fileExists(java.lang.String name)
                   throws java.io.IOException
```
    Specified by:
    
    fileExists in class org.apache.lucene.store.Directory
    
    Throws:
    
    java.io.IOException
  - fileLength
```
public long fileLength(java.lang.String name)
                throws java.io.IOException
```
    Specified by:
    
    fileLength in class org.apache.lucene.store.Directory
    
    Throws:
    
    java.io.IOException
  - fileModified
```
public long fileModified(java.lang.String name)
                  throws java.io.IOException
```
    Specified by:
    
    fileModified in class org.apache.lucene.store.Directory
    
    Throws:
    
    java.io.IOException
  - list
```
public java.lang.String[] list()
                        throws java.io.IOException
```
    Specified by:
    
    list in class org.apache.lucene.store.Directory
    
    Throws:
    
    java.io.IOException
  - openInput
```
public org.apache.lucene.store.IndexInput openInput(java.lang.String name)
                                             throws java.io.IOException
```
    Specified by:
    
    openInput in class org.apache.lucene.store.Directory
    
    Throws:
    
    java.io.IOException
  - makeLock
```
public org.apache.lucene.store.Lock makeLock(java.lang.String name)
```
    Overrides:
    
    makeLock in class org.apache.lucene.store.Directory
  - renameFile
```
public void renameFile(java.lang.String from,
                       java.lang.String to)
                throws java.io.IOException
```
    Specified by:
    
    renameFile in class org.apache.lucene.store.Directory
    
    Throws:
    
    java.io.IOException
  - touchFile
```
public void touchFile(java.lang.String name)
               throws java.io.IOException
```
    Specified by:
    
    touchFile in class org.apache.lucene.store.Directory
    
    Throws:
    
    java.io.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

Class DbDirectory

Field Summary

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

Constructor Summary

Method Summary

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

Methods inherited from class java.lang.Object

Field Detail

openFiles

files

blocks

txn

flags

Constructor Detail

DbDirectory

DbDirectory

DbDirectory

Method Detail

close

flush

createOutput

deleteFile

fileExists

fileLength

fileModified

list

openInput

makeLock

renameFile

touchFile

setTransaction

setTransaction