org.apache.lucene.search

Class ControlledRealTimeReopenThread<T>

java.lang.Object

java.lang.Thread

org.apache.lucene.search.ControlledRealTimeReopenThread<T>

All Implemented Interfaces:

Closeable, AutoCloseable, Runnable

public class ControlledRealTimeReopenThread<T>
extends Thread
implements Closeable

Utility class that runs a thread to manage periodicc reopens of a ReferenceManager, with methods to wait for a specific index changes to become visible. To use this class you must first wrap your IndexWriter with a TrackingIndexWriter and always use it to make changes to the index, saving the returned generation. Then, when a given search request needs to see a specific index change, call the {#waitForGeneration} to wait for that change to be visible. Note that this will only scale well if most searches do not need to wait for a specific index generation.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Thread

Thread.State, Thread.UncaughtExceptionHandler

Field Summary

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

Constructors

Constructor and Description
ControlledRealTimeReopenThread(TrackingIndexWriter writer, ReferenceManager<T> manager, double targetMaxStaleSec, double targetMinStaleSec) Create ControlledRealTimeReopenThread, to periodically reopen the a ReferenceManager.

Method Summary

Methods

Modifier and Type	Method and Description
void	close()
long	getSearchingGen() Returns which generation the current searcher is guaranteed to include.
void	run()
void	waitForGeneration(long targetGen) Waits for the target generation to become visible in the searcher.
boolean	waitForGeneration(long targetGen, int maxMS) Waits for the target generation to become visible in the searcher, up to a maximum specified milli-seconds.

Methods inherited from class java.lang.Thread

activeCount, checkAccess, clone, countStackFrames, currentThread, destroy, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

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

Constructor Detail

ControlledRealTimeReopenThread

public ControlledRealTimeReopenThread(TrackingIndexWriter writer,
                              ReferenceManager<T> manager,
                              double targetMaxStaleSec,
                              double targetMinStaleSec)

Create ControlledRealTimeReopenThread, to periodically reopen the a ReferenceManager.

Parameters:

targetMaxStaleSec - Maximum time until a new reader must be opened; this sets the upper bound on how slowly reopens may occur, when no caller is waiting for a specific generation to become visible.

targetMinStaleSec - Mininum time until a new reader can be opened; this sets the lower bound on how quickly reopens may occur, when a caller is waiting for a specific generation to become visible.

Method Detail

close

public void close()

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

waitForGeneration

public void waitForGeneration(long targetGen)
                       throws InterruptedException

Waits for the target generation to become visible in the searcher. If the current searcher is older than the target generation, this method will block until the searcher is reopened, by another via ReferenceManager.maybeRefresh() or until the ReferenceManager is closed.

Parameters:

targetGen - the generation to wait for

Throws:

InterruptedException

waitForGeneration

public boolean waitForGeneration(long targetGen,
                        int maxMS)
                          throws InterruptedException

Waits for the target generation to become visible in the searcher, up to a maximum specified milli-seconds. If the current searcher is older than the target generation, this method will block until the searcher has been reopened by another thread via ReferenceManager.maybeRefresh(), the given waiting time has elapsed, or until the ReferenceManager is closed.

NOTE: if the waiting time elapses before the requested target generation is available the current SearcherManager is returned instead.

Parameters:

targetGen - the generation to wait for

maxMS - maximum milliseconds to wait, or -1 to wait indefinitely

Returns:

true if the targetGeneration is now available, or false if maxMS wait time was exceeded

Throws:

InterruptedException

run

public void run()

Specified by:

run in interface Runnable

Overrides:

run in class Thread

getSearchingGen

public long getSearchingGen()

Returns which generation the current searcher is guaranteed to include.