org.apache.lucene.index
Class IndexReaderContext

java.lang.Object
  extended by 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
 int docBaseInParent
          the doc base for this reader in the parent, 0 if parent is null
 boolean isTopLevel
          true if this context struct represents the top level reader within the hierarchical context
 int ordInParent
          the ord for this reader in the parent, 0 if parent is null
 CompositeReaderContext parent
          The reader context for this reader's immediate parent, or null if none
 
Method Summary
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 Detail

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 Detail

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.



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