Package org.apache.lucene.store

Class RateLimitedDirectoryWrapper

java.lang.Object

org.apache.lucene.store.Directory

org.apache.lucene.store.FilterDirectory

org.apache.lucene.store.RateLimitedDirectoryWrapper

All Implemented Interfaces:

Closeable, AutoCloseable

public final class RateLimitedDirectoryWrapper
extends FilterDirectory

A Directory wrapper that allows IndexOutput rate limiting using IO context specific rate limiters.

See Also:

setRateLimiter(RateLimiter, IOContext.Context)

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.store.Directory

Directory.IndexInputSlicer

Field Summary

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

in

Constructor Summary

Constructors

Constructor	Description
RateLimitedDirectoryWrapper(Directory wrapped)

Method Summary

Modifier and Type	Method	Description
void	copy(Directory to, String src, String dest, IOContext context)	Copies the file src to Directory to under the new file name dest.
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.
Double	getMaxWriteMBPerSec(IOContext.Context context)	See setMaxWriteMBPerSec(java.lang.Double, org.apache.lucene.store.IOContext.Context).
void	setMaxWriteMBPerSec(Double mbPerSec, IOContext.Context context)	Sets the maximum (approx) MB/sec allowed by all write IO performed by IndexOutput created with the given IOContext.Context.
void	setRateLimiter(RateLimiter mergeWriteRateLimiter, IOContext.Context context)	Sets the rate limiter to be used to limit (approx) MB/sec allowed by all IO performed with the given context.

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

clearLock, close, deleteFile, fileExists, fileLength, getDelegate, getLockFactory, getLockID, listAll, makeLock, openInput, setLockFactory, sync, toString

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

ensureOpen

Methods inherited from class java.lang.Object

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

Constructor Detail

RateLimitedDirectoryWrapper

public RateLimitedDirectoryWrapper(Directory wrapped)

Method Detail

createOutput

public IndexOutput createOutput(String name,
                                IOContext context)
                         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.

Overrides:

createOutput in class FilterDirectory

Throws:

IOException

createSlicer

public Directory.IndexInputSlicer createSlicer(String name,
                                               IOContext context)
                                        throws IOException

Description copied from class: Directory

Creates an Directory.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.

Must throw FileNotFoundException if the file does not exist (not java.nio.file.NoSuchFileException of Java 7).

Overrides:

createSlicer in class Directory

Throws:

IOException - if an IOException occurs

copy

public void copy(Directory to,
                 String src,
                 String dest,
                 IOContext context)
          throws IOException

Description copied from class: Directory

Copies the file src to Directory to under the new file name dest.

If you want to copy the entire source directory to the destination one, you can do so like this:

 Directory to; // the directory to copy to
 for (String file : dir.listAll()) {
   dir.copy(to, file, newFile, IOContext.DEFAULT); // newFile can be either file, or a new name
 }
 

NOTE: this method does not check whether dest exist and will overwrite it if it does.

Overrides:

copy in class Directory

Throws:

IOException

setMaxWriteMBPerSec

public void setMaxWriteMBPerSec(Double mbPerSec,
                                IOContext.Context context)

Sets the maximum (approx) MB/sec allowed by all write IO performed by IndexOutput created with the given IOContext.Context. Pass null to have no limit.

NOTE: For already created IndexOutput instances there is no guarantee this new rate will apply to them; it will only be guaranteed to apply for new created IndexOutput instances.

NOTE: this is an optional operation and might not be respected by all Directory implementations. Currently only buffered Directory implementations use rate-limiting.

Throws:

IllegalArgumentException - if context is null

AlreadyClosedException - if the Directory is already closed

setRateLimiter

public void setRateLimiter(RateLimiter mergeWriteRateLimiter,
                           IOContext.Context context)

Sets the rate limiter to be used to limit (approx) MB/sec allowed by all IO performed with the given context. Pass null to have no limit.

Passing an instance of rate limiter compared to setting it using setMaxWriteMBPerSec(Double, IOContext.Context) allows to use the same limiter instance across several directories globally limiting IO across them.

Throws:

IllegalArgumentException - if context is null

AlreadyClosedException - if the Directory is already closed

getMaxWriteMBPerSec

public Double getMaxWriteMBPerSec(IOContext.Context context)

See setMaxWriteMBPerSec(java.lang.Double, org.apache.lucene.store.IOContext.Context).

Throws:

IllegalArgumentException - if context is null

AlreadyClosedException - if the Directory is already closed