org.apache.lucene.codecs

Class PostingsReaderBase

java.lang.Object

org.apache.lucene.codecs.PostingsReaderBase

All Implemented Interfaces:

Closeable, AutoCloseable, Accountable

Direct Known Subclasses:

Lucene84PostingsReader

public abstract class PostingsReaderBase
extends Object
implements Closeable, Accountable

The core terms dictionaries (BlockTermsReader, BlockTreeTermsReader) interact with a single instance of this class to manage creation of PostingsEnum and PostingsEnum instances. It provides an IndexInput (termsIn) where this class may read any previously stored data that it had written in its corresponding PostingsWriterBase at indexing time.

WARNING: This API is experimental and might change in incompatible ways in the next release.

Field Summary

Fields inherited from interface org.apache.lucene.util.Accountable

NULL_ACCOUNTABLE

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	PostingsReaderBase() Sole constructor.

Method Summary

Modifier and Type	Method and Description
abstract void	checkIntegrity() Checks consistency of this reader.
abstract void	close()
abstract void	decodeTerm(DataInput in, FieldInfo fieldInfo, BlockTermState state, boolean absolute) Actually decode metadata for next term
abstract ImpactsEnum	impacts(FieldInfo fieldInfo, BlockTermState state, int flags) Return a ImpactsEnum that computes impacts with scorer.
abstract void	init(IndexInput termsIn, SegmentReadState state) Performs any initialization, such as reading and verifying the header from the provided terms dictionary IndexInput.
abstract BlockTermState	newTermState() Return a newly created empty TermState
abstract PostingsEnum	postings(FieldInfo fieldInfo, BlockTermState state, PostingsEnum reuse, int flags) Must fully consume state, since after this call that TermState may be reused.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.lucene.util.Accountable

getChildResources, ramBytesUsed

Constructor Detail

PostingsReaderBase

protected PostingsReaderBase()

Sole constructor. (For invocation by subclass constructors, typically implicit.)

Method Detail

init

public abstract void init(IndexInput termsIn,
                          SegmentReadState state)
                   throws IOException

Performs any initialization, such as reading and verifying the header from the provided terms dictionary IndexInput.

Throws:

IOException

newTermState

public abstract BlockTermState newTermState()
                                     throws IOException

Return a newly created empty TermState

Throws:

IOException

decodeTerm

public abstract void decodeTerm(DataInput in,
                                FieldInfo fieldInfo,
                                BlockTermState state,
                                boolean absolute)
                         throws IOException

Actually decode metadata for next term

Throws:

IOException

See Also:

PostingsWriterBase.encodeTerm(org.apache.lucene.store.DataOutput, org.apache.lucene.index.FieldInfo, org.apache.lucene.codecs.BlockTermState, boolean)

postings

public abstract PostingsEnum postings(FieldInfo fieldInfo,
                                      BlockTermState state,
                                      PostingsEnum reuse,
                                      int flags)
                               throws IOException

Must fully consume state, since after this call that TermState may be reused.

Throws:

IOException

impacts

public abstract ImpactsEnum impacts(FieldInfo fieldInfo,
                                    BlockTermState state,
                                    int flags)
                             throws IOException

Return a ImpactsEnum that computes impacts with scorer.

Throws:

IOException

See Also:

postings(FieldInfo, BlockTermState, PostingsEnum, int)

checkIntegrity

public abstract void checkIntegrity()
                             throws IOException

Checks consistency of this reader.

Note that this may be costly in terms of I/O, e.g. may involve computing a checksum value against large data files.

Throws:

IOException

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

close

public abstract void close()
                    throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException