Package org.apache.lucene.index

Class MergePolicy.MergeObserver

java.lang.Object

org.apache.lucene.index.MergePolicy.MergeObserver

Enclosing class:

MergePolicy

public static final class MergePolicy.MergeObserver
extends Object

Observer for merge operations returned by IndexWriter.forceMergeDeletes(boolean). Provides methods to query merge status and wait for completion.

When no merges are needed, numMerges() returns 0. In this case, await() returns true immediately since there is nothing to wait for.

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

Method Summary

Modifier and Type	Method	Description
boolean	await()	Waits for all merges in this specification to complete.
boolean	await(long timeout, TimeUnit unit)	Waits for all merges in this specification to complete, with timeout.
CompletableFuture<Void>	awaitAsync()	Returns a CompletableFuture that completes when all merges finish.
int	numCompletedMerges()	Returns the number of completed merges in this specification.
int	numMerges()	Returns the number of merges in this specification.
String	toString()

Methods inherited from class java.lang.Object

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

Method Details

numMerges

public int numMerges()

Returns the number of merges in this specification.

Returns:

number of merges, or 0 if no merges were scheduled

numCompletedMerges

public int numCompletedMerges()

Returns the number of completed merges in this specification. Useful for tracking merge progress: numCompletedMerges() / numMerges().

Returns:

number of completed merges

await

public boolean await()

Waits for all merges in this specification to complete. Returns immediately if no merges were scheduled.

Returns:

true if all merges completed successfully or no merges were needed, false on error

await

public boolean await(long timeout,
 TimeUnit unit)

Waits for all merges in this specification to complete, with timeout. Returns immediately if no merges were scheduled.

Parameters:

timeout - maximum time to wait

unit - time unit for timeout

Returns:

true if all merges completed within timeout or no merges were needed, false on timeout or error

awaitAsync

public CompletableFuture<Void> awaitAsync()

Returns a CompletableFuture that completes when all merges finish. Returns an already-completed future if no merges were scheduled.

Returns:

future that completes when merges finish

toString

public String toString()

Overrides:

toString in class Object