Class NativeUnixDirectory
- java.lang.Object
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- org.apache.lucene.store.Directory
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- org.apache.lucene.store.BaseDirectory
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- org.apache.lucene.store.FSDirectory
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- org.apache.lucene.store.NativeUnixDirectory
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- All Implemented Interfaces:
java.io.Closeable
,java.lang.AutoCloseable
public class NativeUnixDirectory extends FSDirectory
ADirectory
implementation for all Unixes that uses DIRECT I/O to bypass OS level IO caching during merging. For all other cases (searching, writing) we delegate to the provided Directory instance.See Overview for more details.
To use this you must compile NativePosixUtil.cpp (exposes Linux-specific APIs through JNI) for your platform, by running
ant build-native-unix
, and then putting the resultinglibNativePosixUtil.so
(fromlucene/build/native
) onto your dynamic linker search path.WARNING: this code is very new and quite easily could contain horrible bugs. For example, here's one known issue: if you use seek in
IndexOutput
, and then write more than one buffer's worth of bytes, then the file will be wrong. Lucene does not do this today (only writes small number of bytes after seek), but that may change.This directory passes Solr and Lucene tests on Linux and OS X; other Unixes should work but have not been tested! Use at your own risk.
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Nested Class Summary
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Nested classes/interfaces inherited from class org.apache.lucene.store.Directory
Directory.IndexInputSlicer
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Field Summary
Fields Modifier and Type Field Description static int
DEFAULT_MERGE_BUFFER_SIZE
Default buffer size before writing to disk (256 KB); larger means less IO load but more RAM and direct buffer storage space consumed during merging.static long
DEFAULT_MIN_BYTES_DIRECT
Default min expected merge size before direct IO is used (10 MB):-
Fields inherited from class org.apache.lucene.store.FSDirectory
DEFAULT_READ_CHUNK_SIZE
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Constructor Summary
Constructors Constructor Description NativeUnixDirectory(java.io.File path, int mergeBufferSize, long minBytesDirect, Directory delegate)
Create a new NIOFSDirectory for the named location.NativeUnixDirectory(java.io.File path, Directory delegate)
Create a new NIOFSDirectory for the named location.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description IndexOutput
createOutput(java.lang.String name, IOContext context)
Creates an IndexOutput for the file with the given name.IndexInput
openInput(java.lang.String name, IOContext context)
Returns a stream reading an existing file, with the specified read buffer size.-
Methods inherited from class org.apache.lucene.store.FSDirectory
close, deleteFile, fileExists, fileLength, getDirectory, getLockID, getReadChunkSize, listAll, listAll, open, open, setLockFactory, setReadChunkSize, sync, toString
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Methods inherited from class org.apache.lucene.store.BaseDirectory
clearLock, getLockFactory, makeLock
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Methods inherited from class org.apache.lucene.store.Directory
copy, createSlicer
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Field Detail
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DEFAULT_MERGE_BUFFER_SIZE
public static final int DEFAULT_MERGE_BUFFER_SIZE
Default buffer size before writing to disk (256 KB); larger means less IO load but more RAM and direct buffer storage space consumed during merging.- See Also:
- Constant Field Values
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DEFAULT_MIN_BYTES_DIRECT
public static final long DEFAULT_MIN_BYTES_DIRECT
Default min expected merge size before direct IO is used (10 MB):- See Also:
- Constant Field Values
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Constructor Detail
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NativeUnixDirectory
public NativeUnixDirectory(java.io.File path, int mergeBufferSize, long minBytesDirect, Directory delegate) throws java.io.IOException
Create a new NIOFSDirectory for the named location.- Parameters:
path
- the path of the directorymergeBufferSize
- Size of buffer to use for merging. SeeDEFAULT_MERGE_BUFFER_SIZE
.minBytesDirect
- Merges, or files to be opened for reading, smaller than this will not use direct IO. SeeDEFAULT_MIN_BYTES_DIRECT
delegate
- fallback Directory for non-merges- Throws:
java.io.IOException
- If there is a low-level I/O error
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NativeUnixDirectory
public NativeUnixDirectory(java.io.File path, Directory delegate) throws java.io.IOException
Create a new NIOFSDirectory for the named location.- Parameters:
path
- the path of the directorydelegate
- fallback Directory for non-merges- Throws:
java.io.IOException
- If there is a low-level I/O error
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Method Detail
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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 areFSDirectory
andCompoundFileDirectory
.- Must throw
FileNotFoundException
if the file does not exist (notjava.nio.file.NoSuchFileException
of Java 7). - Must throw
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createOutput
public IndexOutput createOutput(java.lang.String name, IOContext context) throws java.io.IOException
Description copied from class:FSDirectory
Creates an IndexOutput for the file with the given name.- Overrides:
createOutput
in classFSDirectory
- Throws:
java.io.IOException
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