org.apache.lucene.store.instantiated
Class InstantiatedIndexReader

java.lang.Object
  org.apache.lucene.index.IndexReader
      org.apache.lucene.store.instantiated.InstantiatedIndexReader

All Implemented Interfaces:

Closeable, Cloneable

public class InstantiatedIndexReader
extends IndexReader

An InstantiatedIndexReader is not a snapshot in time, it is completely in sync with the latest commit to the store!

Consider using InstantiatedIndex as if it was immutable.

Nested Class Summary

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

IndexReader.FieldOption

Field Summary

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

hasChanges

Constructor Summary

InstantiatedIndexReader(InstantiatedIndex index)

Method Summary

Directory	directory() Returns the directory associated with this index.
int	docFreq(Term t) Returns the number of documents containing the term t.
protected void	doClose() Implements close.
protected void	doCommit(Map commitUserData) Implements commit.
Document	document(int n) Returns the stored fields of the nth Document in this index.
Document	document(int n, FieldSelector fieldSelector) Return the Document at the nth position.
protected void	doDelete(int docNum) Implements deletion of the document numbered docNum.
protected void	doSetNorm(int doc, String field, byte value) Implements setNorm in subclass.
protected void	doUndeleteAll() Implements actual undeleteAll() in subclass.
Collection	getFieldNames(IndexReader.FieldOption fieldOption) Get a list of unique field names that exist in this index and have the specified field option information.
InstantiatedIndex	getIndex()
TermFreqVector	getTermFreqVector(int docNumber, String field) Return a term frequency vector for the specified document and field.
void	getTermFreqVector(int docNumber, String field, TermVectorMapper mapper) Load the Term Vector into a user-defined data structure instead of relying on the parallel arrays of the TermFreqVector.
void	getTermFreqVector(int docNumber, TermVectorMapper mapper) Map all the term vectors for all fields in a Document
TermFreqVector[]	getTermFreqVectors(int docNumber) Return an array of term frequency vectors for the specified document.
long	getVersion() An InstantiatedIndexReader is not a snapshot in time, it is completely in sync with the latest commit to the store!
boolean	hasDeletions() Returns true if any documents have been deleted
boolean	isCurrent() An InstantiatedIndexReader is always current! Check whether this IndexReader is still using the current (i.e., most recently committed) version of the index.
boolean	isDeleted(int n) Returns true if document n has been deleted
boolean	isOptimized() Checks is the index is optimized (if it has a single segment and no deletions).
int	maxDoc() Returns one greater than the largest possible document number.
byte[]	norms(String field) never ever touch these values.
void	norms(String field, byte[] bytes, int offset) Reads the byte-encoded normalization factor for the named field of every document.
int	numDocs() Returns the number of documents in this index.
TermDocs	termDocs() Returns an unpositioned TermDocs enumerator.
TermDocs	termDocs(Term term) Returns an enumeration of all the documents which contain term.
TermPositions	termPositions() Returns an unpositioned TermPositions enumerator.
TermEnum	terms() Returns an enumeration of all the terms in the index.
TermEnum	terms(Term t) Returns an enumeration of all terms starting at a given term.

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

acquireWriteLock, clone, clone, close, commit, commit, decRef, deleteDocument, deleteDocuments, ensureOpen, flush, flush, getCommitUserData, getCommitUserData, getCurrentVersion, getDeletesCacheKey, getFieldCacheKey, getIndexCommit, getRefCount, getSequentialSubReaders, getTermInfosIndexDivisor, getUniqueTermCount, hasNorms, incRef, indexExists, lastModified, listCommits, main, numDeletedDocs, open, open, open, open, open, open, open, reopen, reopen, reopen, setNorm, setNorm, termPositions, undeleteAll

Methods inherited from class java.lang.Object

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

Constructor Detail

InstantiatedIndexReader

public InstantiatedIndexReader(InstantiatedIndex index)

Method Detail

isOptimized

public boolean isOptimized()

Description copied from class: IndexReader

Checks is the index is optimized (if it has a single segment and no deletions). Not implemented in the IndexReader base class.

Overrides:

isOptimized in class IndexReader

Returns:

always true.

getVersion

public long getVersion()

An InstantiatedIndexReader is not a snapshot in time, it is completely in sync with the latest commit to the store!

Overrides:

getVersion in class IndexReader

Returns:

output from InstantiatedIndex.getVersion() in associated instantiated index.

directory

public Directory directory()

Description copied from class: IndexReader

Returns the directory associated with this index. The Default implementation returns the directory specified by subclasses when delegating to the IndexReader(Directory) constructor, or throws an UnsupportedOperationException if one was not specified.

Overrides:

directory in class IndexReader

isCurrent

public boolean isCurrent()
                  throws IOException

An InstantiatedIndexReader is always current! Check whether this IndexReader is still using the current (i.e., most recently committed) version of the index. If a writer has committed any changes to the index since this reader was opened, this will return false, in which case you must open a new IndexReader in order to see the changes. See the description of the autoCommit flag which controls when the IndexWriter actually commits changes to the index.

Overrides:

isCurrent in class IndexReader

Returns:

always true

Throws:

CorruptIndexException - if the index is corrupt

IOException - if there is a low-level IO error

UnsupportedOperationException - unless overridden in subclass

getIndex

public InstantiatedIndex getIndex()

numDocs

public int numDocs()

Description copied from class: IndexReader

Returns the number of documents in this index.

Specified by:

numDocs in class IndexReader

maxDoc

public int maxDoc()

Description copied from class: IndexReader

Returns one greater than the largest possible document number. This may be used to, e.g., determine how big to allocate an array which will have an element for every document number in an index.

Specified by:

maxDoc in class IndexReader

hasDeletions

public boolean hasDeletions()

Description copied from class: IndexReader

Returns true if any documents have been deleted

Specified by:

hasDeletions in class IndexReader

isDeleted

public boolean isDeleted(int n)

Description copied from class: IndexReader

Returns true if document n has been deleted

Specified by:

isDeleted in class IndexReader

doDelete

protected void doDelete(int docNum)
                 throws IOException

Description copied from class: IndexReader

Implements deletion of the document numbered docNum. Applications should call IndexReader.deleteDocument(int) or IndexReader.deleteDocuments(Term).

Specified by:

doDelete in class IndexReader

Throws:

IOException

doUndeleteAll

protected void doUndeleteAll()
                      throws IOException

Description copied from class: IndexReader

Implements actual undeleteAll() in subclass.

Specified by:

doUndeleteAll in class IndexReader

Throws:

IOException

doCommit

protected void doCommit(Map commitUserData)
                 throws IOException

Description copied from class: IndexReader

Implements commit.

Specified by:

doCommit in class IndexReader

Throws:

IOException

doClose

protected void doClose()
                throws IOException

Description copied from class: IndexReader

Implements close.

Specified by:

doClose in class IndexReader

Throws:

IOException

getFieldNames

public Collection getFieldNames(IndexReader.FieldOption fieldOption)

Description copied from class: IndexReader

Get a list of unique field names that exist in this index and have the specified field option information.

Specified by:

getFieldNames in class IndexReader

Parameters:

fieldOption - specifies which field option should be available for the returned fields

Returns:

Collection of Strings indicating the names of the fields.

See Also:

IndexReader.FieldOption

document

public Document document(int n,
                         FieldSelector fieldSelector)
                  throws CorruptIndexException,
                         IOException

Return the Document at the n^th position.

Warning! The resulting document is the actual stored document instance and not a deserialized clone as retuned by an IndexReader over a Directory. I.e., if you need to touch the document, clone it first!

This can also be seen as a feature for live changes of stored values, but be careful! Adding a field with an name unknown to the index or to a field with previously no stored values will make getFieldNames(org.apache.lucene.index.IndexReader.FieldOption) out of sync, causing problems for instance when merging the instantiated index to another index.

This implementation ignores the field selector! All stored fields are always returned!

Specified by:

document in class IndexReader

Parameters:

n - document number

fieldSelector - ignored

Returns:

The stored fields of the Document at the nth position

Throws:

CorruptIndexException - if the index is corrupt

IOException - if there is a low-level IO error

See Also:

Fieldable, FieldSelector, SetBasedFieldSelector, LoadFirstFieldSelector

document

public Document document(int n)
                  throws IOException

Returns the stored fields of the n^th Document in this index.

Warning! The resulting document is the actual stored document instance and not a deserialized clone as retuned by an IndexReader over a Directory. I.e., if you need to touch the document, clone it first!

This can also be seen as a feature for live changes of stored values, but be careful! Adding a field with an name unknown to the index or to a field with previously no stored values will make getFieldNames(org.apache.lucene.index.IndexReader.FieldOption) out of sync, causing problems for instance when merging the instantiated index to another index.

Overrides:

document in class IndexReader

Throws:

CorruptIndexException - if the index is corrupt

IOException - if there is a low-level IO error

norms

public byte[] norms(String field)
             throws IOException

never ever touch these values. it is the true values, unless norms have been touched.

Specified by:

norms in class IndexReader

Throws:

IOException

See Also:

AbstractField.setBoost(float)

norms

public void norms(String field,
                  byte[] bytes,
                  int offset)
           throws IOException

Description copied from class: IndexReader

Reads the byte-encoded normalization factor for the named field of every document. This is used by the search code to score documents.

Specified by:

norms in class IndexReader

Throws:

IOException

See Also:

AbstractField.setBoost(float)

doSetNorm

protected void doSetNorm(int doc,
                         String field,
                         byte value)
                  throws IOException

Description copied from class: IndexReader

Implements setNorm in subclass.

Specified by:

doSetNorm in class IndexReader

Throws:

IOException

docFreq

public int docFreq(Term t)
            throws IOException

Description copied from class: IndexReader

Returns the number of documents containing the term t.

Specified by:

docFreq in class IndexReader

Throws:

IOException - if there is a low-level IO error

terms

public TermEnum terms()
               throws IOException

Description copied from class: IndexReader

Returns an enumeration of all the terms in the index. The enumeration is ordered by Term.compareTo(). Each term is greater than all that precede it in the enumeration. Note that after calling terms(), TermEnum.next() must be called on the resulting enumeration before calling other methods such as TermEnum.term().

Specified by:

terms in class IndexReader

Throws:

IOException - if there is a low-level IO error

terms

public TermEnum terms(Term t)
               throws IOException

Description copied from class: IndexReader

Returns an enumeration of all terms starting at a given term. If the given term does not exist, the enumeration is positioned at the first term greater than the supplied term. The enumeration is ordered by Term.compareTo(). Each term is greater than all that precede it in the enumeration.

Specified by:

terms in class IndexReader

Throws:

IOException - if there is a low-level IO error

termDocs

public TermDocs termDocs()
                  throws IOException

Description copied from class: IndexReader

Returns an unpositioned TermDocs enumerator.

Specified by:

termDocs in class IndexReader

Throws:

IOException - if there is a low-level IO error

termDocs

public TermDocs termDocs(Term term)
                  throws IOException

Description copied from class: IndexReader

Returns an enumeration of all the documents which contain term. For each document, the document number, the frequency of the term in that document is also provided, for use in search scoring. If term is null, then all non-deleted docs are returned with freq=1. Thus, this method implements the mapping:

Term => <docNum, freq>^*

The enumeration is ordered by document number. Each document number is greater than all that precede it in the enumeration.

Overrides:

termDocs in class IndexReader

Throws:

IOException - if there is a low-level IO error

termPositions

public TermPositions termPositions()
                            throws IOException

Description copied from class: IndexReader

Returns an unpositioned TermPositions enumerator.

Specified by:

termPositions in class IndexReader

Throws:

IOException - if there is a low-level IO error

getTermFreqVectors

public TermFreqVector[] getTermFreqVectors(int docNumber)
                                    throws IOException

Description copied from class: IndexReader

Return an array of term frequency vectors for the specified document. The array contains a vector for each vectorized field in the document. Each vector contains terms and frequencies for all terms in a given vectorized field. If no such fields existed, the method returns null. The term vectors that are returned may either be of type TermFreqVector or of type TermPositionVector if positions or offsets have been stored.

Specified by:

getTermFreqVectors in class IndexReader

Parameters:

docNumber - document for which term frequency vectors are returned

Returns:

array of term frequency vectors. May be null if no term vectors have been stored for the specified document.

Throws:

IOException - if index cannot be accessed

See Also:

Field.TermVector

getTermFreqVector

public TermFreqVector getTermFreqVector(int docNumber,
                                        String field)
                                 throws IOException

Description copied from class: IndexReader

Return a term frequency vector for the specified document and field. The returned vector contains terms and frequencies for the terms in the specified field of this document, if the field had the storeTermVector flag set. If termvectors had been stored with positions or offsets, a TermPositionVector is returned.

Specified by:

getTermFreqVector in class IndexReader

Parameters:

docNumber - document for which the term frequency vector is returned

field - field for which the term frequency vector is returned.

Returns:

term frequency vector May be null if field does not exist in the specified document or term vector was not stored.

Throws:

IOException - if index cannot be accessed

See Also:

Field.TermVector

getTermFreqVector

public void getTermFreqVector(int docNumber,
                              String field,
                              TermVectorMapper mapper)
                       throws IOException

Description copied from class: IndexReader

Load the Term Vector into a user-defined data structure instead of relying on the parallel arrays of the TermFreqVector.

Specified by:

getTermFreqVector in class IndexReader

Parameters:

docNumber - The number of the document to load the vector for

field - The name of the field to load

mapper - The TermVectorMapper to process the vector. Must not be null

Throws:

IOException - if term vectors cannot be accessed or if they do not exist on the field and doc. specified.

getTermFreqVector

public void getTermFreqVector(int docNumber,
                              TermVectorMapper mapper)
                       throws IOException

Description copied from class: IndexReader

Map all the term vectors for all fields in a Document

Specified by:

getTermFreqVector in class IndexReader

Parameters:

docNumber - The number of the document to load the vector for

mapper - The TermVectorMapper to process the vector. Must not be null

Throws:

IOException - if term vectors cannot be accessed or if they do not exist on the field and doc. specified.