|
||||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | |||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
java.lang.Object org.apache.lucene.index.IndexReader org.apache.lucene.index.SegmentReader
public class SegmentReader
Nested Class Summary |
---|
Nested classes/interfaces inherited from class org.apache.lucene.index.IndexReader |
---|
IndexReader.FieldOption, IndexReader.ReaderFinishedListener |
Field Summary | |
---|---|
protected boolean |
readOnly
|
Fields inherited from class org.apache.lucene.index.IndexReader |
---|
hasChanges, readerFinishedListeners |
Constructor Summary | |
---|---|
SegmentReader()
|
Method Summary | |
---|---|
Object |
clone()
Efficiently clones the IndexReader (sharing most internal state). |
IndexReader |
clone(boolean openReadOnly)
Clones the IndexReader and optionally changes readOnly. |
protected BitVector |
cloneDeletedDocs(BitVector bv)
Clones the deleteDocs BitVector. |
protected byte[] |
cloneNormBytes(byte[] bytes)
Clones the norm bytes. |
Directory |
directory()
Returns the directory this index resides in. |
int |
docFreq(Term t)
Returns the number of documents containing the term t . |
protected void |
doClose()
Implements close. |
protected void |
doCommit(Map<String,String> commitUserData)
Implements commit. |
Document |
document(int n,
FieldSelector fieldSelector)
Get the Document at the n
th 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. |
static SegmentReader |
get(boolean readOnly,
Directory dir,
SegmentInfo si,
int readBufferSize,
boolean doOpenStores,
int termInfosIndexDivisor)
|
static SegmentReader |
get(boolean readOnly,
SegmentInfo si,
int termInfosIndexDivisor)
|
Object |
getCoreCacheKey()
Expert |
Object |
getDeletesCacheKey()
Expert. |
Collection<String> |
getFieldNames(IndexReader.FieldOption fieldOption)
Get a list of unique field names that exist in this index and have the specified field option information. |
protected byte[] |
getNorms(String field)
|
String |
getSegmentName()
Return the name of the segment this reader is reading. |
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. |
int |
getTermInfosIndexDivisor()
For IndexReader implementations that use TermInfosReader to read terms, this returns the current indexDivisor as specified when the reader was opened. |
long |
getUniqueTermCount()
Returns the number of unique terms (across all fields) in this reader. |
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[] bytes,
int offset)
Read norms into a pre-allocated array. |
int |
numDocs()
Returns the number of documents in this index. |
protected void |
readerFinished()
|
IndexReader |
reopen()
Refreshes an IndexReader if the index has changed since this instance was (re)opened. |
IndexReader |
reopen(boolean openReadOnly)
Just like IndexReader.reopen() , except you can change the
readOnly of the original reader. |
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. |
String |
toString()
|
Methods inherited from class org.apache.lucene.index.IndexReader |
---|
acquireWriteLock, addReaderFinishedListener, close, commit, commit, decRef, deleteDocument, deleteDocuments, document, ensureOpen, flush, flush, getCommitUserData, getCommitUserData, getCurrentVersion, getIndexCommit, getRefCount, getSequentialSubReaders, getVersion, incRef, indexExists, isCurrent, isOptimized, lastModified, listCommits, main, notifyReaderFinishedListeners, numDeletedDocs, open, open, open, open, open, open, open, open, removeReaderFinishedListener, reopen, reopen, setNorm, setNorm, termPositions, undeleteAll |
Methods inherited from class java.lang.Object |
---|
equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait |
Field Detail |
---|
protected boolean readOnly
Constructor Detail |
---|
public SegmentReader()
Method Detail |
---|
public static SegmentReader get(boolean readOnly, SegmentInfo si, int termInfosIndexDivisor) throws CorruptIndexException, IOException
CorruptIndexException
- if the index is corrupt
IOException
- if there is a low-level IO errorpublic static SegmentReader get(boolean readOnly, Directory dir, SegmentInfo si, int readBufferSize, boolean doOpenStores, int termInfosIndexDivisor) throws CorruptIndexException, IOException
CorruptIndexException
- if the index is corrupt
IOException
- if there is a low-level IO errorprotected byte[] cloneNormBytes(byte[] bytes)
bytes
- Byte array to clone
protected BitVector cloneDeletedDocs(BitVector bv)
bv
- BitVector to clone
public final Object clone()
IndexReader
On cloning a reader with pending changes (deletions, norms), the original reader transfers its write lock to the cloned reader. This means only the cloned reader may make further changes to the index, and commit the changes to the index on close, but the old reader still reflects all changes made up until it was cloned.
Like IndexReader.reopen()
, it's safe to make changes to
either the original or the cloned reader: all shared
mutable state obeys "copy on write" semantics to ensure
the changes are not seen by other readers.
clone
in class IndexReader
public final IndexReader clone(boolean openReadOnly) throws CorruptIndexException, IOException
IndexReader
clone
in class IndexReader
CorruptIndexException
- if the index is corrupt
IOException
- if there is a low-level IO errorpublic IndexReader reopen() throws CorruptIndexException, IOException
IndexReader
Opening an IndexReader is an expensive operation. This method can be used to refresh an existing IndexReader to reduce these costs. This method tries to only load segments that have changed or were created after the IndexReader was (re)opened.
If the index has not changed since this instance was (re)opened, then this
call is a NOOP and returns this instance. Otherwise, a new instance is
returned. The old instance is not closed and remains usable.
If the reader is reopened, even though they share resources internally, it's safe to make changes (deletions, norms) with the new reader. All shared mutable state obeys "copy on write" semantics to ensure the changes are not seen by other readers.
You can determine whether a reader was actually reopened by comparing the old instance with the instance returned by this method:
IndexReader reader = ... ... IndexReader newReader = r.reopen(); if (newReader != reader) { ... // reader was reopened reader.close(); } reader = newReader; ...Be sure to synchronize that code so that other threads, if present, can never use reader after it has been closed and before it's switched to newReader.
NOTE: If this reader is a near real-time
reader (obtained from IndexWriter.getReader()
,
reopen() will simply call writer.getReader() again for
you, though this may change in the future.
reopen
in class IndexReader
CorruptIndexException
- if the index is corrupt
IOException
- if there is a low-level IO errorpublic IndexReader reopen(boolean openReadOnly) throws CorruptIndexException, IOException
IndexReader
IndexReader.reopen()
, except you can change the
readOnly of the original reader. If the index is
unchanged but readOnly is different then a new reader
will be returned.
reopen
in class IndexReader
CorruptIndexException
IOException
protected void doCommit(Map<String,String> commitUserData) throws IOException
IndexReader
doCommit
in class IndexReader
IOException
protected void doClose() throws IOException
IndexReader
doClose
in class IndexReader
IOException
public boolean hasDeletions()
IndexReader
hasDeletions
in class IndexReader
protected void doDelete(int docNum)
IndexReader
docNum
.
Applications should call IndexReader.deleteDocument(int)
or IndexReader.deleteDocuments(Term)
.
doDelete
in class IndexReader
protected void doUndeleteAll()
IndexReader
doUndeleteAll
in class IndexReader
public TermEnum terms()
IndexReader
TermEnum.next()
must be called
on the resulting enumeration before calling other methods such as
TermEnum.term()
.
terms
in class IndexReader
public TermEnum terms(Term t) throws IOException
IndexReader
terms
in class IndexReader
IOException
- if there is a low-level IO errorpublic Document document(int n, FieldSelector fieldSelector) throws CorruptIndexException, 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.
NOTE: for performance reasons, this method does not check if the
requested document is deleted, and therefore asking for a deleted document
may yield unspecified results. Usually this is not required, however you
can call IndexReader.isDeleted(int)
with the requested document ID to verify
the document is not deleted.
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
CorruptIndexException
- if the index is corrupt
IOException
- if there is a low-level IO errorFieldable
,
FieldSelector
,
SetBasedFieldSelector
,
LoadFirstFieldSelector
public boolean isDeleted(int n)
IndexReader
isDeleted
in class IndexReader
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. If term is null, then all non-deleted
docs are returned with freq=1.
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
- if there is a low-level IO errorpublic TermDocs termDocs() throws IOException
IndexReader
TermDocs
enumerator.
Note: the TermDocs returned is unpositioned. Before using it, ensure
that you first position it with TermDocs.seek(Term)
or
TermDocs.seek(TermEnum)
.
termDocs
in class IndexReader
IOException
- if there is a low-level IO errorpublic TermPositions termPositions() throws IOException
IndexReader
TermPositions
enumerator.
termPositions
in class IndexReader
IOException
- if there is a low-level IO errorpublic int docFreq(Term t) throws IOException
IndexReader
t
.
docFreq
in class IndexReader
IOException
- if there is a low-level IO errorpublic int numDocs()
IndexReader
numDocs
in class IndexReader
public int maxDoc()
IndexReader
maxDoc
in class IndexReader
public Collection<String> getFieldNames(IndexReader.FieldOption fieldOption)
IndexReader
getFieldNames
in class IndexReader
fieldOption
- specifies which field option should be available for the returned fields
IndexReader.getFieldNames(org.apache.lucene.index.IndexReader.FieldOption)
public boolean hasNorms(String field)
IndexReader
hasNorms
in class IndexReader
protected byte[] getNorms(String field) throws IOException
IOException
public byte[] norms(String field) throws IOException
IndexReader
norms
in class IndexReader
IOException
AbstractField.setBoost(float)
protected void doSetNorm(int doc, String field, byte value) throws IOException
IndexReader
doSetNorm
in class IndexReader
IOException
public void norms(String field, byte[] bytes, int offset) throws IOException
norms
in class IndexReader
IOException
AbstractField.setBoost(float)
public TermFreqVector getTermFreqVector(int docNumber, String field) throws IOException
getTermFreqVector
in class IndexReader
docNumber
- document for which the term frequency vector is returnedfield
- field for which the term frequency vector is returned.
IOException
Field.TermVector
public void getTermFreqVector(int docNumber, String field, TermVectorMapper mapper) throws IOException
IndexReader
TermFreqVector
.
getTermFreqVector
in class IndexReader
docNumber
- The number of the document to load the vector forfield
- The name of the field to loadmapper
- The TermVectorMapper
to process the vector. Must not be null
IOException
- if term vectors cannot be accessed or if they do not exist on the field and doc. specified.public void getTermFreqVector(int docNumber, TermVectorMapper mapper) throws IOException
IndexReader
getTermFreqVector
in class IndexReader
docNumber
- The number of the document to load the vector formapper
- The TermVectorMapper
to process the vector. Must not be null
IOException
- if term vectors cannot be accessed or if they do not exist on the field and doc. specified.public TermFreqVector[] getTermFreqVectors(int docNumber) throws IOException
getTermFreqVectors
in class IndexReader
docNumber
- document for which term frequency vectors are returned
IOException
Field.TermVector
public String toString()
toString
in class IndexReader
public String getSegmentName()
public Directory directory()
directory
in class IndexReader
public final Object getCoreCacheKey()
IndexReader
getCoreCacheKey
in class IndexReader
public Object getDeletesCacheKey()
IndexReader
getDeletesCacheKey
in class IndexReader
public long getUniqueTermCount()
IndexReader
getUniqueTermCount
in class IndexReader
public int getTermInfosIndexDivisor()
IndexReader
getTermInfosIndexDivisor
in class IndexReader
protected void readerFinished()
readerFinished
in class IndexReader
|
||||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | |||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |