java.lang.Object
- org.apache.lucene.index.MergePolicy.OneMerge

Enclosing class:

MergePolicy
```
public static class MergePolicy.OneMerge
extends java.lang.Object
```
OneMerge provides the information necessary to perform an individual primitive merge operation, resulting in a single new segment. The merge spec includes the subset of segments to be merged as well as whether the new segment should use the compound file format.

Field Summary

Fields
Modifier and Type	Field	Description
`(package private) java.lang.Throwable`	`error`
`long`	`estimatedMergeBytes`	Estimated size in bytes of the merged segment.
`(package private) SegmentCommitInfo`	`info`
`(package private) boolean`	`isExternal`
`(package private) int`	`maxNumSegments`
`private java.util.concurrent.CompletableFuture<java.lang.Boolean>`	`mergeCompleted`
`(package private) long`	`mergeGen`
`private MergePolicy.OneMergeProgress`	`mergeProgress`	Control used to pause/stop/resume the merge thread.
`private java.util.List<MergePolicy.MergeReader>`	`mergeReaders`
`(package private) long`	`mergeStartNS`
`(package private) boolean`	`registerDone`
`java.util.List<SegmentCommitInfo>`	`segments`	Segments to be merged.
`(package private) int`	`totalMaxDoc`	Total number of documents in segments to be merged, not accounting for deletions.
`(package private) long`	`totalMergeBytes`

Constructor Summary

Constructors
Constructor Description

OneMerge(java.util.List<SegmentCommitInfo> segments)
Sole constructor.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`(package private) boolean`	`await(long timeout, java.util.concurrent.TimeUnit timeUnit)`	Waits for this merge to be completed
`void`	`checkAborted()`	Checks if merge has been aborted and throws a merge exception if so.
`(package private) void`	`close(boolean success, boolean segmentDropped, IOUtils.IOConsumer<MergePolicy.MergeReader> readerConsumer)`	Closes this merge and releases all merge readers
`(package private) java.lang.Throwable`	`getException()`	Retrieve previous exception set by `setException(java.lang.Throwable)`.
`SegmentCommitInfo`	`getMergeInfo()`	Returns the `SegmentCommitInfo` for the merged segment, or null if it hasn't been set yet.
`MergePolicy.OneMergeProgress`	`getMergeProgress()`	Returns a `MergePolicy.OneMergeProgress` instance for this merge, which provides statistics of the merge threads (run time vs.
`(package private) java.util.List<MergePolicy.MergeReader>`	`getMergeReader()`	Returns the merge readers or an empty list if the readers were not initialized yet.
`MergeInfo`	`getStoreMergeInfo()`	Return `MergeInfo` describing this merge.
`(package private) java.util.Optional<java.lang.Boolean>`	`hasCompletedSuccessfully()`	Returns true iff the merge completed successfully or false if the merge succeeded with a failure.
`(package private) boolean`	`hasFinished()`	Returns true if the merge has finished or false if it's still running or has not been started.
`(package private) void`	`initMergeReaders(IOUtils.IOFunction<SegmentCommitInfo,MergePolicy.MergeReader> readerFactory)`	Sets the merge readers for this merge.
`boolean`	`isAborted()`	Returns true if this merge was or should be aborted.
`void`	`mergeFinished(boolean success, boolean segmentDropped)`	Called by `IndexWriter` after the merge is done and all readers have been closed.
`void`	`mergeInit()`	Called by `IndexWriter` after the merge started and from the thread that will be executing the merge.
`(package private) void`	`onMergeComplete()`	Called just before the merge is applied to IndexWriter's SegmentInfos
`java.lang.String`	`segString()`	Returns a readable description of the current merge state.
`void`	`setAborted()`	Marks this merge as aborted.
`(package private) void`	`setException(java.lang.Throwable error)`	Record that an exception occurred while executing this merge
`void`	`setMergeInfo(SegmentCommitInfo info)`	Expert: Sets the `SegmentCommitInfo` of the merged segment.
`long`	`totalBytesSize()`	Returns the total size in bytes of this merge.
`int`	`totalNumDocs()`	Returns the total number of documents that are included with this merge.
`CodecReader`	`wrapForMerge(CodecReader reader)`	Wrap the reader in order to add/remove information to the merged segment.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - mergeCompleted
```
private final java.util.concurrent.CompletableFuture<java.lang.Boolean> mergeCompleted
```
  - info
```
SegmentCommitInfo info
```
  - registerDone
```
boolean registerDone
```
  - mergeGen
```
long mergeGen
```
  - isExternal
```
boolean isExternal
```
  - maxNumSegments
```
int maxNumSegments
```
  - estimatedMergeBytes
```
public volatile long estimatedMergeBytes
```
    Estimated size in bytes of the merged segment.
  - totalMergeBytes
```
volatile long totalMergeBytes
```
  - mergeReaders
```
private java.util.List<MergePolicy.MergeReader> mergeReaders
```
  - segments
```
public final java.util.List<SegmentCommitInfo> segments
```
    Segments to be merged.
  - mergeProgress
```
private final MergePolicy.OneMergeProgress mergeProgress
```
    Control used to pause/stop/resume the merge thread.
  - mergeStartNS
```
volatile long mergeStartNS
```
  - totalMaxDoc
```
final int totalMaxDoc
```
    Total number of documents in segments to be merged, not accounting for deletions.
  - error
```
java.lang.Throwable error
```
- Constructor Detail
  - OneMerge
```
public OneMerge(java.util.List<SegmentCommitInfo> segments)
```
    Sole constructor.
    
    Parameters:
    
    segments - List of SegmentCommitInfos to be merged.
- Method Detail
  - mergeInit
```
public void mergeInit()
               throws java.io.IOException
```
    Called by IndexWriter after the merge started and from the thread that will be executing the merge.
    
    Throws:
    
    java.io.IOException
  - mergeFinished
```
public void mergeFinished(boolean success,
                          boolean segmentDropped)
                   throws java.io.IOException
```
    Called by IndexWriter after the merge is done and all readers have been closed.
    
    Parameters:
    
    success - true iff the merge finished successfully ie. was committed
    
    segmentDropped - true iff the merged segment was dropped since it was fully deleted
    
    Throws:
    
    java.io.IOException
  - close
```
final void close(boolean success,
                 boolean segmentDropped,
                 IOUtils.IOConsumer<MergePolicy.MergeReader> readerConsumer)
          throws java.io.IOException
```
    Closes this merge and releases all merge readers
    
    Throws:
    
    java.io.IOException
  - wrapForMerge
```
public CodecReader wrapForMerge(CodecReader reader)
                         throws java.io.IOException
```
    Wrap the reader in order to add/remove information to the merged segment.
    
    Throws:
    
    java.io.IOException
  - setMergeInfo
```
public void setMergeInfo(SegmentCommitInfo info)
```
    Expert: Sets the SegmentCommitInfo of the merged segment. Allows sub-classes to e.g. set diagnostics properties.
  - getMergeInfo
```
public SegmentCommitInfo getMergeInfo()
```
    Returns the SegmentCommitInfo for the merged segment, or null if it hasn't been set yet.
  - setException
```
void setException(java.lang.Throwable error)
```
    Record that an exception occurred while executing this merge
  - getException
```
java.lang.Throwable getException()
```
    Retrieve previous exception set by setException(java.lang.Throwable).
  - segString
```
public java.lang.String segString()
```
    Returns a readable description of the current merge state.
  - totalBytesSize
```
public long totalBytesSize()
```
    Returns the total size in bytes of this merge. Note that this does not indicate the size of the merged segment, but the input total size. This is only set once the merge is initialized by IndexWriter.
  - totalNumDocs
```
public int totalNumDocs()
```
    Returns the total number of documents that are included with this merge. Note that this does not indicate the number of documents after the merge.
  - getStoreMergeInfo
```
public MergeInfo getStoreMergeInfo()
```
    Return MergeInfo describing this merge.
  - isAborted
```
public boolean isAborted()
```
    Returns true if this merge was or should be aborted.
  - setAborted
```
public void setAborted()
```
    Marks this merge as aborted. The merge thread should terminate at the soonest possible moment.
  - checkAborted
```
public void checkAborted()
                  throws MergePolicy.MergeAbortedException
```
    Checks if merge has been aborted and throws a merge exception if so.
    
    Throws:
    
    MergePolicy.MergeAbortedException
  - getMergeProgress
```
public MergePolicy.OneMergeProgress getMergeProgress()
```
    Returns a MergePolicy.OneMergeProgress instance for this merge, which provides statistics of the merge threads (run time vs. sleep time) if merging is throttled.
  - await
```
boolean await(long timeout,
              java.util.concurrent.TimeUnit timeUnit)
```
    Waits for this merge to be completed
    
    Returns:
    
    true if the merge finished within the specified timeout
  - hasFinished
```
boolean hasFinished()
```
    Returns true if the merge has finished or false if it's still running or has not been started. This method will not block.
  - hasCompletedSuccessfully
```
java.util.Optional<java.lang.Boolean> hasCompletedSuccessfully()
```
    Returns true iff the merge completed successfully or false if the merge succeeded with a failure. This method will not block and return an empty Optional if the merge has not finished yet
  - onMergeComplete
```
void onMergeComplete()
              throws java.io.IOException
```
    Called just before the merge is applied to IndexWriter's SegmentInfos
    
    Throws:
    
    java.io.IOException
  - initMergeReaders
```
void initMergeReaders(IOUtils.IOFunction<SegmentCommitInfo,MergePolicy.MergeReader> readerFactory)
               throws java.io.IOException
```
    Sets the merge readers for this merge.
    
    Throws:
    
    java.io.IOException
  - getMergeReader
```
java.util.List<MergePolicy.MergeReader> getMergeReader()
```
    Returns the merge readers or an empty list if the readers were not initialized yet.

Class MergePolicy.OneMerge

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

mergeCompleted

info

registerDone

mergeGen

isExternal

maxNumSegments

estimatedMergeBytes

totalMergeBytes

mergeReaders

segments

mergeProgress

mergeStartNS

totalMaxDoc

error

Constructor Detail

OneMerge

Method Detail

mergeInit

mergeFinished

close

wrapForMerge

setMergeInfo

getMergeInfo

setException

getException

segString

totalBytesSize

totalNumDocs

getStoreMergeInfo

isAborted

setAborted

checkAborted

getMergeProgress

await

hasFinished

hasCompletedSuccessfully

onMergeComplete

initMergeReaders

getMergeReader