public class NRTCachingDirectory extends Directory
RAMDirectory
around any provided delegate directory, to
be used during NRT search.
This class is likely only useful in a near-real-time context, where indexing rate is lowish but reopen rate is highish, resulting in many tiny files being written. This directory keeps such segments (as well as the segments produced by merging them, as long as they are small enough), in RAM.
This is safe to use: when your app calls {IndexWriter#commit}, all cached files will be flushed from the cached and sync'd.
Here's a simple example usage:
Directory fsDir = FSDirectory.open(new File("/path/to/index"));
NRTCachingDirectory cachedFSDir = new NRTCachingDirectory(fsDir, 5.0, 60.0);
IndexWriterConfig conf = new IndexWriterConfig(Version.LUCENE_47, analyzer);
IndexWriter writer = new IndexWriter(cachedFSDir, conf);
This will cache all newly flushed segments, all merges whose expected segment size is <= 5 MB, unless the net cached bytes exceeds 60 MB at which point all writes will not be cached (until the net bytes falls below 60 MB).
Directory.IndexInputSlicer| Constructor and Description |
|---|
NRTCachingDirectory(Directory delegate,
double maxMergeSizeMB,
double maxCachedMB)
We will cache a newly created output if 1) it's a
flush or a merge and the estimated size of the merged segment is <=
maxMergeSizeMB, and 2) the total cached bytes is <=
maxCachedMB
|
| Modifier and Type | Method and Description |
|---|---|
void |
clearLock(String name)
Attempt to clear (forcefully unlock and remove) the
specified lock.
|
void |
close()
Close this directory, which flushes any cached files
to the delegate and then closes the delegate.
|
IndexOutput |
createOutput(String name,
IOContext context)
Creates a new, empty file in the directory with the given name.
|
Directory.IndexInputSlicer |
createSlicer(String name,
IOContext context)
Creates an
Directory.IndexInputSlicer for the given file 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.
|
Directory |
getDelegate() |
LockFactory |
getLockFactory()
Get the LockFactory that this Directory instance is
using for its locking implementation.
|
String |
getLockID()
Return a string identifier that uniquely differentiates
this Directory instance from other Directory instances.
|
String[] |
listAll()
Returns an array of strings, one for each file in the directory.
|
String[] |
listCachedFiles() |
Lock |
makeLock(String name)
Construct a
Lock. |
IndexInput |
openInput(String name,
IOContext context)
Returns a stream reading an existing file, with the
specified read buffer size.
|
void |
setLockFactory(LockFactory lf)
Set the LockFactory that this Directory instance should
use for its locking implementation.
|
long |
sizeInBytes()
Returns how many bytes are being used by the
RAMDirectory cache
|
void |
sync(Collection<String> fileNames)
Ensure that any writes to these files are moved to
stable storage.
|
String |
toString() |
public NRTCachingDirectory(Directory delegate, double maxMergeSizeMB, double maxCachedMB)
public Directory getDelegate()
public LockFactory getLockFactory()
DirectorygetLockFactory in class Directorypublic void setLockFactory(LockFactory lf) throws IOException
DirectorysetLockFactory in class Directorylf - instance of LockFactory.IOExceptionpublic String getLockID()
Directorypublic Lock makeLock(String name)
DirectoryLock.public void clearLock(String name) throws IOException
DirectoryclearLock in class Directoryname - name of the lock to be cleared.IOExceptionpublic String[] listAll() throws IOException
DirectorylistAll in class DirectoryNoSuchDirectoryException - if the directory is not prepared for any
write operations (such as Directory.createOutput(String, IOContext)).IOException - in case of other IO errorspublic long sizeInBytes()
public boolean fileExists(String name) throws IOException
DirectoryfileExists in class DirectoryIOExceptionpublic void deleteFile(String name) throws IOException
DirectorydeleteFile in class DirectoryIOExceptionpublic long fileLength(String name) throws IOException
DirectoryFileNotFoundException if the file does not exist
(not java.nio.file.NoSuchFileException of Java 7).
fileLength in class Directoryname - the name of the file for which to return the length.IOException - if there was an IO error while retrieving the file's
length.public String[] listCachedFiles()
public IndexOutput createOutput(String name, IOContext context) throws IOException
DirectorycreateOutput in class DirectoryIOExceptionpublic void sync(Collection<String> fileNames) throws IOException
Directorysync in class DirectoryIOExceptionpublic IndexInput openInput(String name, IOContext context) throws IOException
DirectoryFSDirectory and CompoundFileDirectory.
FileNotFoundException if the file does not exist
(not java.nio.file.NoSuchFileException of Java 7).openInput in class DirectoryIOExceptionpublic Directory.IndexInputSlicer createSlicer(String name, IOContext context) throws IOException
DirectoryDirectory.IndexInputSlicer for the given file name.
IndexInputSlicer allows other Directory implementations to
efficiently open one or more sliced IndexInput instances from a
single file handle. The underlying file handle is kept open until the
Directory.IndexInputSlicer is closed.
FileNotFoundException if the file does not exist
(not java.nio.file.NoSuchFileException of Java 7).createSlicer in class DirectoryIOException - if an IOException occurspublic void close()
throws IOException
close in interface Closeableclose in interface AutoCloseableclose in class DirectoryIOExceptionCopyright © 2010 - 2020 Adobe. All Rights Reserved