org.apache.lucene.codecs

Class PostingsReaderBase

java.lang.Object

org.apache.lucene.codecs.PostingsReaderBase

All Implemented Interfaces:

Closeable, AutoCloseable

Direct Known Subclasses:

Lucene40PostingsReader, Lucene41PostingsReader

public abstract class PostingsReaderBase
extends Object
implements Closeable

The core terms dictionaries (BlockTermsReader, BlockTreeTermsReader) interact with a single instance of this class to manage creation of DocsEnum and DocsAndPositionsEnum 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.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	PostingsReaderBase() Sole constructor.

Method Summary

Methods

Modifier and Type	Method and Description
abstract void	checkIntegrity() Checks consistency of this reader.
abstract void	close()
abstract void	decodeTerm(long[] longs, DataInput in, FieldInfo fieldInfo, BlockTermState state, boolean absolute) Actually decode metadata for next term
abstract DocsEnum	docs(FieldInfo fieldInfo, BlockTermState state, Bits skipDocs, DocsEnum reuse, int flags) Must fully consume state, since after this call that TermState may be reused.
abstract DocsAndPositionsEnum	docsAndPositions(FieldInfo fieldInfo, BlockTermState state, Bits skipDocs, DocsAndPositionsEnum reuse, int flags) Must fully consume state, since after this call that TermState may be reused.
abstract void	init(IndexInput termsIn) 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 long	ramBytesUsed() Returns approximate RAM bytes used

Methods inherited from class java.lang.Object

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

Constructor Detail

PostingsReaderBase

protected PostingsReaderBase()

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

Method Detail

init

public abstract void init(IndexInput termsIn)
                   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(long[] longs,
              DataInput in,
              FieldInfo fieldInfo,
              BlockTermState state,
              boolean absolute)
                         throws IOException

Actually decode metadata for next term

Throws:

IOException

See Also:

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

docs

public abstract DocsEnum docs(FieldInfo fieldInfo,
            BlockTermState state,
            Bits skipDocs,
            DocsEnum reuse,
            int flags)
                       throws IOException

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

Throws:

IOException

docsAndPositions

public abstract DocsAndPositionsEnum docsAndPositions(FieldInfo fieldInfo,
                                    BlockTermState state,
                                    Bits skipDocs,
                                    DocsAndPositionsEnum reuse,
                                    int flags)
                                               throws IOException

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

Throws:

IOException

ramBytesUsed

public abstract long ramBytesUsed()

Returns approximate RAM bytes used

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