Package org.apache.lucene.index

Class IndexReaderContext

java.lang.Object

org.apache.lucene.index.IndexReaderContext

Direct Known Subclasses:

AtomicReaderContext, CompositeReaderContext

public abstract class IndexReaderContext
extends Object

A struct like class that represents a hierarchical relationship between IndexReader instances.

Field Summary

Fields

Modifier and Type	Field	Description
final int	docBaseInParent	the doc base for this reader in the parent, 0 if parent is null
final boolean	isTopLevel	true if this context struct represents the top level reader within the hierarchical context
final int	ordInParent	the ord for this reader in the parent, 0 if parent is null
final CompositeReaderContext	parent	The reader context for this reader's immediate parent, or null if none

Method Summary

Modifier and Type	Method	Description
abstract List<IndexReaderContext>	children()	Returns the context's children iff this context is a composite context otherwise null.
abstract List<AtomicReaderContext>	leaves()	Returns the context's leaves if this context is a top-level context.
abstract IndexReader	reader()	Returns the IndexReader, this context represents.

Methods inherited from class java.lang.Object

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

Field Details

parent

public final CompositeReaderContext parent

The reader context for this reader's immediate parent, or null if none

isTopLevel

public final boolean isTopLevel

true if this context struct represents the top level reader within the hierarchical context

docBaseInParent

public final int docBaseInParent

the doc base for this reader in the parent, 0 if parent is null

ordInParent

public final int ordInParent

the ord for this reader in the parent, 0 if parent is null

Method Details

reader

public abstract IndexReader reader()

Returns the IndexReader, this context represents.

leaves

public abstract List<AtomicReaderContext> leaves()
                                          throws UnsupportedOperationException

Returns the context's leaves if this context is a top-level context. For convenience, if this is an AtomicReaderContext this returns itself as the only leaf.

Note: this is convenience method since leaves can always be obtained by walking the context tree using children().

Throws:

UnsupportedOperationException - if this is not a top-level context.

See Also:

• children()

children

public abstract List<IndexReaderContext> children()

Returns the context's children iff this context is a composite context otherwise null.