FieldCacheDocIdSet (Lucene 3.6.2 API)

java.lang.Object
- org.apache.lucene.search.DocIdSet
- - org.apache.lucene.search.FieldCacheDocIdSet

```
public abstract class FieldCacheDocIdSet
extends DocIdSet
```
Base class for DocIdSet to be used with FieldCache. The implementation of its iterator is very stupid and slow if the implementation of the matchDoc(int) method is not optimized, as iterators simply increment the document id until matchDoc(int) returns true. Because of this matchDoc(int) must be as fast as possible and in no case do any I/O.

NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

Field Summary

Fields
Modifier and Type Field Description

protected IndexReader reader
- Fields inherited from class org.apache.lucene.search.DocIdSet
  EMPTY_DOCIDSET

Constructor Summary

Constructors
Constructor Description

FieldCacheDocIdSet(IndexReader reader)

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method	Description
`boolean`	`isCacheable()`	this DocIdSet is cacheable, if it works solely with FieldCache and no TermDocs
`DocIdSetIterator`	`iterator()`	Provides a `DocIdSetIterator` to access the set.
`protected abstract boolean`	`matchDoc(int doc)`	this method checks, if a doc is a hit

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

- Field Detail
  - reader
```
protected final IndexReader reader
```
- Constructor Detail
  - FieldCacheDocIdSet
```
public FieldCacheDocIdSet(IndexReader reader)
```
- Method Detail
  - matchDoc
```
protected abstract boolean matchDoc(int doc)
```
    this method checks, if a doc is a hit
  - isCacheable
```
public final boolean isCacheable()
```
    this DocIdSet is cacheable, if it works solely with FieldCache and no TermDocs
    
    Overrides:
    
    isCacheable in class DocIdSet
  - iterator
```
public final DocIdSetIterator iterator()
                                throws IOException
```
    Description copied from class: DocIdSet
    
    Provides a DocIdSetIterator to access the set. This implementation can return null or DocIdSet.EMPTY_DOCIDSET.iterator() if there are no docs that match.
    
    Specified by:
    
    iterator in class DocIdSet
    
    Throws:
    
    IOException