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java.lang.Objectorg.apache.lucene.index.IndexReader
org.apache.lucene.index.ParallelReader
An IndexReader which reads multiple, parallel indexes. Each index added must have the same number of documents, but typically each contains different fields. Each document contains the union of the fields of all documents with the same document number. When searching, matches for a query term are from the first index added that has the field.
This is useful, e.g., with collections that have large fields which change rarely and small fields that change more frequently. The smaller fields may be re-indexed in a new index and both indexes may be searched together.
Warning: It is up to you to make sure all indexes are created and modified the same way. For example, if you add documents to one index, you need to add the same documents in the same order to the other indexes. Failure to do so will result in undefined behavior.
Nested Class Summary |
Nested classes inherited from class org.apache.lucene.index.IndexReader |
IndexReader.FieldOption |
Field Summary |
Fields inherited from class org.apache.lucene.index.IndexReader |
deleter |
Constructor Summary | |
ParallelReader()
Construct a ParallelReader. |
Method Summary | |
void |
add(IndexReader reader)
Add an IndexReader. |
void |
add(IndexReader reader,
boolean ignoreStoredFields)
Add an IndexReader whose stored fields will not be returned. |
int |
docFreq(Term term)
Returns the number of documents containing the term t . |
protected void |
doClose()
Implements close. |
protected void |
doCommit()
Implements commit. |
Document |
document(int n,
FieldSelector fieldSelector)
Get the Document at the n th position. |
protected void |
doDelete(int n)
Implements deletion of the document numbered docNum . |
protected void |
doSetNorm(int n,
String field,
byte value)
Implements setNorm in subclass. |
protected void |
doUndeleteAll()
Implements actual undeleteAll() in subclass. |
Collection |
getFieldNames(IndexReader.FieldOption fieldNames)
Get a list of unique field names that exist in this index and have the specified field option information. |
TermFreqVector |
getTermFreqVector(int n,
String field)
Return a term frequency vector for the specified document and field. |
TermFreqVector[] |
getTermFreqVectors(int n)
Return an array of term frequency vectors for the specified document. |
boolean |
hasDeletions()
Returns true if any documents have been deleted |
boolean |
hasNorms(String field)
Returns true if there are norms stored for this field. |
boolean |
isDeleted(int n)
Returns true if document n has been deleted |
int |
maxDoc()
Returns one greater than the largest possible document number. |
byte[] |
norms(String field)
Returns the byte-encoded normalization factor for the named field of every document. |
void |
norms(String field,
byte[] result,
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. |
TermPositions |
termPositions(Term term)
Returns an enumeration of all the documents which contain term . |
TermEnum |
terms()
Returns an enumeration of all the terms in the index. |
TermEnum |
terms(Term term)
Returns an enumeration of all terms after a given term. |
Methods inherited from class org.apache.lucene.index.IndexReader |
close, commit, deleteDocument, deleteDocuments, directory, document, finalize, getCurrentVersion, getCurrentVersion, getCurrentVersion, getDeleter, getVersion, indexExists, indexExists, indexExists, isCurrent, isLocked, isLocked, isOptimized, lastModified, lastModified, lastModified, main, open, open, open, setDeleter, setNorm, setNorm, undeleteAll, unlock |
Methods inherited from class java.lang.Object |
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Constructor Detail |
public ParallelReader() throws IOException
Method Detail |
public void add(IndexReader reader) throws IOException
IOException
public void add(IndexReader reader, boolean ignoreStoredFields) throws IOException
IllegalArgumentException
- if not all indexes contain the same number
of documents
IllegalArgumentException
- if not all indexes have the same value
of IndexReader.maxDoc()
IOException
public int numDocs()
IndexReader
numDocs
in class IndexReader
public int maxDoc()
IndexReader
maxDoc
in class IndexReader
public boolean hasDeletions()
IndexReader
hasDeletions
in class IndexReader
public boolean isDeleted(int n)
IndexReader
isDeleted
in class IndexReader
protected void doDelete(int n) throws IOException
IndexReader
docNum
.
Applications should call IndexReader.deleteDocument(int)
or IndexReader.deleteDocuments(Term)
.
doDelete
in class IndexReader
IOException
protected void doUndeleteAll() throws IOException
IndexReader
doUndeleteAll
in class IndexReader
IOException
public Document document(int n, FieldSelector fieldSelector) throws IOException
IndexReader
Document
at the n
th position. The FieldSelector
may be used to determine what Field
s to load and how they should be loaded.
NOTE: If this Reader (more specifically, the underlying FieldsReader
is closed before the lazy Field
is
loaded an exception may be thrown. If you want the value of a lazy Field
to be available after closing you must
explicitly load it or fetch the Document again with a new loader.
document
in class IndexReader
n
- Get the document at the n
th positionfieldSelector
- The FieldSelector
to use to determine what Fields should be loaded on the Document. May be null, in which case all Fields will be loaded.
Document
at the nth position
IOException
- If there is a problem reading this documentFieldable
,
FieldSelector
,
SetBasedFieldSelector
,
LoadFirstFieldSelector
public TermFreqVector[] getTermFreqVectors(int n) throws IOException
IndexReader
getTermFreqVectors
in class IndexReader
n
- document for which term frequency vectors are returned
IOException
- if index cannot be accessedField.TermVector
public TermFreqVector getTermFreqVector(int n, String field) throws IOException
IndexReader
getTermFreqVector
in class IndexReader
n
- document for which the term frequency vector is returnedfield
- field for which the term frequency vector is returned.
IOException
- if index cannot be accessedField.TermVector
public boolean hasNorms(String field) throws IOException
IndexReader
hasNorms
in class IndexReader
IOException
public byte[] norms(String field) throws IOException
IndexReader
norms
in class IndexReader
IOException
AbstractField.setBoost(float)
public void norms(String field, byte[] result, int offset) throws IOException
IndexReader
norms
in class IndexReader
IOException
AbstractField.setBoost(float)
protected void doSetNorm(int n, String field, byte value) throws IOException
IndexReader
doSetNorm
in class IndexReader
IOException
public TermEnum terms() throws IOException
IndexReader
terms
in class IndexReader
IOException
public TermEnum terms(Term term) throws IOException
IndexReader
terms
in class IndexReader
IOException
public int docFreq(Term term) throws IOException
IndexReader
t
.
docFreq
in class IndexReader
IOException
public TermDocs termDocs(Term term) throws IOException
IndexReader
term
. For each document, the document number, the frequency of
the term in that document is also provided, for use in search scoring.
Thus, this method implements the mapping:
The enumeration is ordered by document number. Each document number is greater than all that precede it in the enumeration.
termDocs
in class IndexReader
IOException
public TermDocs termDocs() throws IOException
IndexReader
TermDocs
enumerator.
termDocs
in class IndexReader
IOException
public TermPositions termPositions(Term term) throws IOException
IndexReader
term
. For each document, in addition to the document number
and frequency of the term in that document, a list of all of the ordinal
positions of the term in the document is available. Thus, this method
implements the mapping:
This positional information faciliates phrase and proximity searching.
The enumeration is ordered by document number. Each document number is greater than all that precede it in the enumeration.
termPositions
in class IndexReader
IOException
public TermPositions termPositions() throws IOException
IndexReader
TermPositions
enumerator.
termPositions
in class IndexReader
IOException
protected void doCommit() throws IOException
IndexReader
doCommit
in class IndexReader
IOException
protected void doClose() throws IOException
IndexReader
doClose
in class IndexReader
IOException
public Collection getFieldNames(IndexReader.FieldOption fieldNames)
IndexReader
getFieldNames
in class IndexReader
fieldNames
- specifies which field option should be available for the returned fields
IndexReader.FieldOption
|
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