org.apache.lucene.search

## Class DocValuesStats<T>

- java.lang.Object
- - org.apache.lucene.search.DocValuesStats<T>

- Direct Known Subclasses:
    DocValuesStats.NumericDocValuesStats, DocValuesStats.SortedDocValuesStats, DocValuesStats.SortedNumericDocValuesStats, DocValuesStats.SortedSetDocValuesStats

      public abstract class DocValuesStats<T>
      extends Object

  Holds statistics for a DocValues field.

- - ### Nested Class Summary

    Nested Classes
    Modifier and Type | Class and Description
    --- | ---
    `static class` | `DocValuesStats.DoubleDocValuesStats` Holds DocValues statistics for a numeric field storing `double` values.
    `static class` | `DocValuesStats.LongDocValuesStats` Holds DocValues statistics for a numeric field storing `long` values.
    `static class` | `DocValuesStats.NumericDocValuesStats<T extends Number>` Holds statistics for a numeric DocValues field.
    `static class` | `DocValuesStats.SortedDocValuesStats` Holds statistics for a sorted DocValues field.
    `static class` | `DocValuesStats.SortedDoubleDocValuesStats` Holds DocValues statistics for a sorted-numeric field storing `double` values.
    `static class` | `DocValuesStats.SortedLongDocValuesStats` Holds DocValues statistics for a sorted-numeric field storing `long` values.
    `static class` | `DocValuesStats.SortedNumericDocValuesStats<T extends Number>` Holds statistics for a sorted-numeric DocValues field.
    `static class` | `DocValuesStats.SortedSetDocValuesStats` Holds statistics for a sorted-set DocValues field.

  - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `protected String` | `field`
    `protected T` | `max`
    `protected T` | `min`

  - ### Constructor Summary

    Constructors
    Modifier | Constructor and Description
    --- | ---
    `protected` | `DocValuesStats(String field, T initialMin, T initialMax)`

  - ### Method Summary

    All Methods Instance Methods Abstract Methods Concrete Methods
    Modifier and Type | Method and Description
    --- | ---
    `int` | `count()` The number of documents which have a value of the field.
    `protected abstract void` | `doAccumulate(int count)` Called after `accumulate(int)` was processed and verified that the document has a value for the field.
    `String` | `field()` The field for which these stats were computed.
    `protected abstract boolean` | `hasValue(int doc)` Returns whether the given document has a value for the requested DocValues field.
    `protected abstract boolean` | `init(LeafReaderContext context)` Initializes this object with the given reader context.
    `T` | `max()` The maximum value of the field.
    `T` | `min()` The minimum value of the field.
    `int` | `missing()` The number of documents which do not have a value of the field.

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

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

- - ### Field Detail

    - #### field

          protected final String field

    - #### min

          protected T min

    - #### max

          protected T max

  - ### Constructor Detail

    - #### DocValuesStats

          protected DocValuesStats(String field,
                                   T initialMin,
                                   T initialMax)

  - ### Method Detail

    - #### doAccumulate

          protected abstract void doAccumulate(int count)
                                        throws IOException

      Called after `accumulate(int)` was processed and verified that the document has a value for the field. Implementations should update the statistics based on the value of the current document.
      Parameters:
        `count` - the updated number of documents with value for this field.
      Throws:
        `IOException`

    - #### init

          protected abstract boolean init(LeafReaderContext context)
                                   throws IOException

      Initializes this object with the given reader context. Returns whether stats can be computed for this segment (i.e. it does have the requested DocValues field).
      Throws:
        `IOException`

    - #### hasValue

          protected abstract boolean hasValue(int doc)
                                       throws IOException

      Returns whether the given document has a value for the requested DocValues field.
      Throws:
        `IOException`

    - #### field

          public final String field()

      The field for which these stats were computed.

    - #### count

          public final int count()

      The number of documents which have a value of the field.

    - #### missing

          public final int missing()

      The number of documents which do not have a value of the field.

    - #### min

          public final T min()

      The minimum value of the field. Undefined when `count()` is zero.

    - #### max

          public final T max()

      The maximum value of the field. Undefined when `count()` is zero.

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