org.apache.lucene.codecs.compressing

## Class CompressingTermVectorsFormat

- java.lang.Object
- - org.apache.lucene.codecs.TermVectorsFormat
  - - org.apache.lucene.codecs.compressing.CompressingTermVectorsFormat

- Direct Known Subclasses:
    Lucene42TermVectorsFormat

      public class CompressingTermVectorsFormat
      extends TermVectorsFormat

  A `TermVectorsFormat` that compresses chunks of documents together in order to improve the compression ratio.
  WARNING: This API is experimental and might change in incompatible ways in the next release.

- - ### Constructor Summary

    Constructors
    Constructor and Description
    `CompressingTermVectorsFormat(String formatName, String segmentSuffix, CompressionMode compressionMode, int chunkSize)` Create a new `CompressingTermVectorsFormat`.

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `String` | `toString()`
    `TermVectorsReader` | `vectorsReader(Directory directory, SegmentInfo segmentInfo, FieldInfos fieldInfos, IOContext context)` Returns a `TermVectorsReader` to read term vectors.
    `TermVectorsWriter` | `vectorsWriter(Directory directory, SegmentInfo segmentInfo, IOContext context)` Returns a `TermVectorsWriter` to write term vectors.

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

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

- - ### Constructor Detail

    - #### CompressingTermVectorsFormat

          public CompressingTermVectorsFormat(String formatName,
                                      String segmentSuffix,
                                      CompressionMode compressionMode,
                                      int chunkSize)

      Create a new `CompressingTermVectorsFormat`.

      `formatName` is the name of the format. This name will be used in the file formats to perform `codec header checks`.

      The `compressionMode` parameter allows you to choose between compression algorithms that have various compression and decompression speeds so that you can pick the one that best fits your indexing and searching throughput. You should never instantiate two `CompressingTermVectorsFormat`s that have the same name but different `CompressionMode`s.

      `chunkSize` is the minimum byte size of a chunk of documents. Higher values of `chunkSize` should improve the compression ratio but will require more memory at indexing time and might make document loading a little slower (depending on the size of your OS cache compared to the size of your index).

      Parameters:
        `formatName` - the name of the `StoredFieldsFormat`
        `segmentSuffix` - a suffix to append to files created by this format
        `compressionMode` - the `CompressionMode` to use
        `chunkSize` - the minimum number of bytes of a single chunk of stored documents
      See Also:
        `CompressionMode`

  - ### Method Detail

    - #### vectorsReader

          public final TermVectorsReader vectorsReader(Directory directory,
                                        SegmentInfo segmentInfo,
                                        FieldInfos fieldInfos,
                                        IOContext context)
                                                throws IOException

      Description copied from class: `TermVectorsFormat`
      Returns a `TermVectorsReader` to read term vectors.
      Specified by:
        `vectorsReader` in class `TermVectorsFormat`
      Throws:
        `IOException`

    - #### vectorsWriter

          public final TermVectorsWriter vectorsWriter(Directory directory,
                                        SegmentInfo segmentInfo,
                                        IOContext context)
                                                throws IOException

      Description copied from class: `TermVectorsFormat`
      Returns a `TermVectorsWriter` to write term vectors.
      Specified by:
        `vectorsWriter` in class `TermVectorsFormat`
      Throws:
        `IOException`

    - #### toString

          public String toString()

      Overrides:
        `toString` in class `Object`

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