org.apache.lucene.index

## Class NoMergeScheduler

- java.lang.Object
- - org.apache.lucene.index.MergeScheduler
  - - org.apache.lucene.index.NoMergeScheduler

- All Implemented Interfaces:
    Closeable, AutoCloseable

      public final class NoMergeScheduler
      extends MergeScheduler

  A `MergeScheduler` which never executes any merges. It is also a singleton and can be accessed through `INSTANCE`. Use it if you want to prevent an `IndexWriter` from ever executing merges, regardless of the `MergePolicy` used. Note that you can achieve the same thing by using `NoMergePolicy`, however with `NoMergeScheduler` you also ensure that no unnecessary code of any `MergeScheduler` implementation is ever executed. Hence it is recommended to use both if you want to disable merges from ever happening.

- - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `static MergeScheduler` | `INSTANCE` The single instance of `NoMergeScheduler`

    - ### Fields inherited from class org.apache.lucene.index.MergeScheduler

      `infoStream`

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `MergeScheduler` | `clone()`
    `void` | `close()` Close this MergeScheduler.
    `void` | `merge(IndexWriter writer, MergeTrigger trigger, boolean newMergesFound)` Run the merges provided by `IndexWriter.getNextMerge()`.
    `Directory` | `wrapForMerge(MergePolicy.OneMerge merge, Directory in)` Wraps the incoming `Directory` so that we can merge-throttle it using `RateLimitedIndexOutput`.

    - ### Methods inherited from class org.apache.lucene.index.MergeScheduler

      `message, verbose`

    - ### Methods inherited from class java.lang.Object

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

- - ### Field Detail

    - #### INSTANCE

          public static final MergeScheduler INSTANCE

      The single instance of `NoMergeScheduler`

  - ### Method Detail

    - #### close

          public void close()

      Description copied from class: `MergeScheduler`
      Close this MergeScheduler.
      Specified by:
        `close` in interface `Closeable`
      Specified by:
        `close` in interface `AutoCloseable`
      Specified by:
        `close` in class `MergeScheduler`

    - #### merge

          public void merge(IndexWriter writer,
                            MergeTrigger trigger,
                            boolean newMergesFound)

      Description copied from class: `MergeScheduler`
      Run the merges provided by `IndexWriter.getNextMerge()`.
      Specified by:
        `merge` in class `MergeScheduler`
      Parameters:
        `writer` - the `IndexWriter` to obtain the merges from.
        `trigger` - the `MergeTrigger` that caused this merge to happen
        `newMergesFound` - `true` iff any new merges were found by the caller otherwise `false`

    - #### wrapForMerge

          public Directory wrapForMerge(MergePolicy.OneMerge merge,
                                        Directory in)

      Description copied from class: `MergeScheduler`
      Wraps the incoming `Directory` so that we can merge-throttle it using `RateLimitedIndexOutput`.
      Overrides:
        `wrapForMerge` in class `MergeScheduler`

    - #### clone

          public MergeScheduler clone()

      Overrides:
        `clone` in class `Object`

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