org.apache.lucene.codecs.uniformsplit

Class IntersectBlockReader

java.lang.Object

org.apache.lucene.index.TermsEnum

org.apache.lucene.index.BaseTermsEnum

org.apache.lucene.codecs.uniformsplit.BlockReader

org.apache.lucene.codecs.uniformsplit.IntersectBlockReader

All Implemented Interfaces:

Accountable, BytesRefIterator

Direct Known Subclasses:

STIntersectBlockReader

public class IntersectBlockReader
extends BlockReader

The "intersect" TermsEnum response to UniformSplitTerms.intersect(CompiledAutomaton, BytesRef), intersecting the terms with an automaton.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	IntersectBlockReader.AutomatonNextTermCalculator This is a copy of AutomatonTermsEnum.

Nested classes/interfaces inherited from class org.apache.lucene.index.TermsEnum

TermsEnum.SeekStatus

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	beyondCommonPrefix Whether the current term is beyond the automaton common prefix.
protected int	blockPrefixLen
protected int	blockPrefixRunAutomatonState
protected BytesRef	commonPrefixRef
protected BytesRef	commonSuffixRef
protected IntersectBlockReader.AutomatonNextTermCalculator	nextStringCalculator
protected int	numBytesAccepted Number of bytes accepted by the last call to runAutomatonForState(byte[], int, int, int).
protected ByteRunAutomaton	runAutomaton
protected BytesRef	seekTerm Set this when our current mode is seeking to this term.
protected BytesRef	startTerm

Fields inherited from class org.apache.lucene.codecs.uniformsplit.BlockReader

blockDecoder, blockFirstLineStart, blockHeader, blockInput, blockLine, blockLineReader, blockReadBuffer, blockStartFP, dictionaryBrowser, dictionaryBrowserSupplier, fieldMetadata, forcedTerm, lineIndexInBlock, postingsReader, scratchBlockBytes, scratchTermState, termState, termStateForced, termStateSerializer, termStatesReadBuffer

Fields inherited from class org.apache.lucene.index.TermsEnum

EMPTY

Constructor Summary

Constructors

Constructor and Description
IntersectBlockReader(CompiledAutomaton compiled, BytesRef startTerm, DictionaryBrowserSupplier dictionaryBrowserSupplier, IndexInput blockInput, PostingsReaderBase postingsReader, FieldMetadata fieldMetadata, BlockDecoder blockDecoder)

Method Summary

Modifier and Type	Method and Description
protected boolean	isBeyondCommonPrefix(BytesRef bytesRef) Determines if the provided BytesRef is beyond the automaton common prefix.
BytesRef	next() Increments the iteration to the next BytesRef in the iterator.
protected boolean	nextBlockMatchingPrefix() Find the next block that appears to contain terms that could match the automata.
protected BytesRef	nextTermInBlockMatching() Find the next block line that matches, or null when at end of block.
protected int	runAutomatonForState(byte[] s, int offset, int length, int initialState) Run the automaton and return the final state (not necessary accepted).
protected boolean	runAutomatonFromPrefix(BytesRef term)
TermsEnum.SeekStatus	seekCeil(BytesRef text) Seeks to the specified term, if it exists, or to the next (ceiling) term.
boolean	seekExact(BytesRef text) Attempts to seek to the exact term, returning true if the term is found.
void	seekExact(BytesRef term, TermState state) Positions this BlockReader without re-seeking the term dictionary.
void	seekExact(long ord) Not supported.

Methods inherited from class org.apache.lucene.codecs.uniformsplit.BlockReader

clearTermState, compareToMiddleAndJump, decodeBlockBytesIfNeeded, docFreq, getOrCreateDictionaryBrowser, impacts, initializeBlockReadLazily, initializeHeader, isBeyondLastTerm, isCurrentTerm, nextTerm, ord, postings, ramBytesUsed, readHeader, readLineInBlock, readTermState, readTermStateIfNotRead, seekInBlock, seekInBlock, term, termState, totalTermFreq

Methods inherited from class org.apache.lucene.index.BaseTermsEnum

attributes

Methods inherited from class org.apache.lucene.index.TermsEnum

postings

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

Field Detail

nextStringCalculator

protected final IntersectBlockReader.AutomatonNextTermCalculator nextStringCalculator

runAutomaton

protected final ByteRunAutomaton runAutomaton

commonSuffixRef

protected final BytesRef commonSuffixRef

commonPrefixRef

protected final BytesRef commonPrefixRef

startTerm

protected final BytesRef startTerm

seekTerm

protected BytesRef seekTerm

Set this when our current mode is seeking to this term. Set to null after.

blockPrefixRunAutomatonState

protected int blockPrefixRunAutomatonState

blockPrefixLen

protected int blockPrefixLen

numBytesAccepted

protected int numBytesAccepted

Number of bytes accepted by the last call to runAutomatonForState(byte[], int, int, int).

beyondCommonPrefix

protected boolean beyondCommonPrefix

Whether the current term is beyond the automaton common prefix. If true this means the enumeration should stop immediately.

Constructor Detail

IntersectBlockReader

public IntersectBlockReader(CompiledAutomaton compiled,
                            BytesRef startTerm,
                            DictionaryBrowserSupplier dictionaryBrowserSupplier,
                            IndexInput blockInput,
                            PostingsReaderBase postingsReader,
                            FieldMetadata fieldMetadata,
                            BlockDecoder blockDecoder)
                     throws java.io.IOException

Throws:

java.io.IOException

Method Detail

next

public BytesRef next()
              throws java.io.IOException

Description copied from interface: BytesRefIterator

Increments the iteration to the next BytesRef in the iterator. Returns the resulting BytesRef or null if the end of the iterator is reached. The returned BytesRef may be re-used across calls to next. After this method returns null, do not call it again: the results are undefined.

Specified by:

next in interface BytesRefIterator

Overrides:

next in class BlockReader

Returns:

the next BytesRef in the iterator or null if the end of the iterator is reached.

Throws:

java.io.IOException - If there is a low-level I/O error.

nextBlockMatchingPrefix

protected boolean nextBlockMatchingPrefix()
                                   throws java.io.IOException

Find the next block that appears to contain terms that could match the automata. The prefix is the primary clue. Returns true if at one, or false for no more (EOF).

Throws:

java.io.IOException

nextTermInBlockMatching

protected BytesRef nextTermInBlockMatching()
                                    throws java.io.IOException

Find the next block line that matches, or null when at end of block.

Throws:

java.io.IOException

runAutomatonFromPrefix

protected boolean runAutomatonFromPrefix(BytesRef term)

runAutomatonForState

protected int runAutomatonForState(byte[] s,
                                   int offset,
                                   int length,
                                   int initialState)

Run the automaton and return the final state (not necessary accepted). -1 signifies no state / no match. Sets numBytesAccepted with the offset of the first byte rejected by the automaton; or (offset + length) if no byte is rejected.

isBeyondCommonPrefix

protected boolean isBeyondCommonPrefix(BytesRef bytesRef)

Determines if the provided BytesRef is beyond the automaton common prefix. This method must be called after a call to runAutomatonForState(byte[], int, int, int) because it uses numBytesAccepted value.

seekExact

public boolean seekExact(BytesRef text)

Description copied from class: TermsEnum

Attempts to seek to the exact term, returning true if the term is found. If this returns false, the enum is unpositioned. For some codecs, seekExact may be substantially faster than TermsEnum.seekCeil(org.apache.lucene.util.BytesRef).

Overrides:

seekExact in class BlockReader

Returns:

true if the term is found; return false if the enum is unpositioned.

seekExact

public void seekExact(long ord)

Description copied from class: BlockReader

Not supported.

Overrides:

seekExact in class BlockReader

seekCeil

public TermsEnum.SeekStatus seekCeil(BytesRef text)

Description copied from class: TermsEnum

Seeks to the specified term, if it exists, or to the next (ceiling) term. Returns SeekStatus to indicate whether exact term was found, a different term was found, or EOF was hit. The target term may be before or after the current term. If this returns SeekStatus.END, the enum is unpositioned.

Overrides:

seekCeil in class BlockReader

seekExact

public void seekExact(BytesRef term,
                      TermState state)

Description copied from class: BlockReader

Positions this BlockReader without re-seeking the term dictionary.

The block containing the term is not read by this method. It will be read lazily only if needed, for example if BlockReader.next() is called. Calling BlockReader.postings(org.apache.lucene.index.PostingsEnum, int) after this method does require the block to be read.

Overrides:

seekExact in class BlockReader

Parameters:

term - the term the TermState corresponds to

state - the TermState