IndexReader is an abstract class, providing an interface for accessing an index. Search of an index is done entirely through this abstract interface, so that any subclass which implements it is searchable. Concrete subclasses of IndexReader are usually constructed with a call to one of the static open() methods, e.g. Open(Lucene.Net.Store.Directory, bool) For efficiency, in this API documents are often referred to via document numbers, non-negative integers which each name a unique document in the index. These document numbers are ephemeral–they may change as documents are added to and deleted from an index. Clients should thus not rely on a given document having the same number between sessions. An IndexReader can be opened on a directory for which an IndexWriter is opened already, but it cannot be used to delete documents from the index then. NOTE: for backwards API compatibility, several methods are not listed as abstract, but have no useful implementations in this base class and instead always throw UnsupportedOperationException. Subclasses are strongly encouraged to override these methods, but in many cases may not need to. NOTE: as of 2.4, it's possible to open a read-only IndexReader using the static open methods that accepts the boolean readOnly parameter. Such a reader has better better concurrency as it's not necessary to synchronize on the isDeleted method. You must explicitly specify false if you want to make changes with the resulting IndexReader. NOTE: IndexReader instances are completely thread safe, meaning multiple threads can call any of its methods, concurrently. If your application requires external synchronization, you should not synchronize on the IndexReader instance; use your own (non-Lucene) objects instead. More...

Inherits ICloneable, and IDisposable.

Inherited by Lucene.Net.Index.DirectoryReader, Lucene.Net.Index.FilterIndexReader, Lucene.Net.Index.Memory.MemoryIndex.MemoryIndexReader, Lucene.Net.Index.MultiReader, Lucene.Net.Index.ParallelReader, and Lucene.Net.Index.SegmentReader.

Classes
class	FieldOption
	Constants describing field properties, for example used for IndexReader.GetFieldNames(FieldOption). More...

Public Member Functions
virtual void	IncRef ()
	Expert: increments the refCount of this IndexReader instance. RefCounts are used to determine when a reader can be closed safely, i.e. as soon as there are no more references. Be sure to always call a corresponding DecRef, in a finally clause; otherwise the reader may never be closed. Note that Close simply calls decRef(), which means that the IndexReader will not really be closed until DecRef has been called for all outstanding references.

virtual void	DecRef ()
	Expert: decreases the refCount of this IndexReader instance. If the refCount drops to 0, then pending changes (if any) are committed to the index and this reader is closed.

virtual IndexReader	Reopen ()
	Refreshes an IndexReader if the index has changed since this instance was (re)opened. 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:

virtual IndexReader	Reopen (bool openReadOnly)
	Just like 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.

virtual IndexReader	Reopen (IndexCommit commit)
	Expert: reopen this reader on a specific commit point. This always returns a readOnly reader. If the specified commit point matches what this reader is already on, and this reader is already readOnly, then this same instance is returned; if it is not already readOnly, a readOnly clone is returned.

virtual System.Object	Clone ()
	Efficiently clones the IndexReader (sharing most internal state). 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 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.

virtual IndexReader	Clone (bool openReadOnly)
	Clones the IndexReader and optionally changes readOnly. A readOnly reader cannot open a writeable reader.

virtual Directory	Directory ()
	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.

virtual bool	IsCurrent ()
	Check whether any new changes have occurred to the index since this reader was opened.

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

abstract ITermFreqVector[]	GetTermFreqVectors (int docNumber)
	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 ITermFreqVector or of type TermPositionVector if positions or offsets have been stored.

abstract ITermFreqVector	GetTermFreqVector (int docNumber, String field)
	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.

abstract 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 ITermFreqVector.

abstract void	GetTermFreqVector (int docNumber, TermVectorMapper mapper)
	Map all the term vectors for all fields in a Document

abstract int	NumDocs ()
	Returns the number of documents in this index.

virtual Document	Document (int n)
	Returns the stored fields of the `n`^th `Document` in this index. 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 IsDeleted(int) with the requested document ID to verify the document is not deleted.

abstract Document	Document (int n, FieldSelector fieldSelector)
	Get the Lucene.Net.Documents.Document at the `n` ^th position. The FieldSelector may be used to determine what Lucene.Net.Documents.Fields to load and how they should be loaded. NOTE: If this Reader (more specifically, the underlying `FieldsReader`) is closed before the lazy Lucene.Net.Documents.Field is loaded an exception may be thrown. If you want the value of a lazy Lucene.Net.Documents.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 IsDeleted(int) with the requested document ID to verify the document is not deleted.

abstract bool	IsDeleted (int n)
	Returns true if document n has been deleted

virtual bool	HasNorms (System.String field)
	Returns true if there are norms stored for this field.

abstract byte[]	Norms (System.String field)
	Returns the byte-encoded normalization factor for the named field of every document. This is used by the search code to score documents.

abstract void	Norms (System.String field, byte[] bytes, int offset)
	Reads the byte-encoded normalization factor for the named field of every document. This is used by the search code to score documents.

virtual void	SetNorm (int doc, String field, byte value)
	Expert: Resets the normalization factor for the named field of the named document. The norm represents the product of the field's boost and its length normalization. Thus, to preserve the length normalization values when resetting this, one should base the new value upon the old.

virtual void	SetNorm (int doc, System.String field, float value)
	Expert: Resets the normalization factor for the named field of the named document.

abstract TermEnum	Terms ()
	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.

abstract TermEnum	Terms (Term t)
	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.

abstract int	DocFreq (Term t)
	Returns the number of documents containing the term `t`.

virtual TermDocs	TermDocs (Term term)
	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:    =>    <docNum, freq>^* The enumeration is ordered by document number. Each document number is greater than all that precede it in the enumeration.

abstract TermDocs	TermDocs ()
	Returns an unpositioned Lucene.Net.Index.TermDocs enumerator.

virtual TermPositions	TermPositions (Term term)
	Returns an enumeration of all the documents which contain `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:

abstract TermPositions	TermPositions ()
	Returns an unpositioned Lucene.Net.Index.TermPositions enumerator.

virtual void	DeleteDocument (int docNum)
	Deletes the document numbered `docNum`. Once a document is deleted it will not appear in TermDocs or TermPostitions enumerations. Attempts to read its field with the Document(int) method will result in an error. The presence of this document may still be reflected in the DocFreq statistic, though this will be corrected eventually as the index is further modified.

virtual int	DeleteDocuments (Term term)
	Deletes all documents that have a given `term` indexed. This is useful if one uses a document field to hold a unique ID string for the document. Then to delete such a document, one merely constructs a term with the appropriate field and the unique ID string as its text and passes it to this method. See DeleteDocument(int) for information about when this deletion will become effective.

virtual void	UndeleteAll ()
	Undeletes all documents currently marked as deleted in this index.

void	Flush ()


void	Flush (IDictionary< string, string > commitUserData)

void	Commit ()
	Commit changes resulting from delete, undeleteAll, or setNorm operations

void	Commit (IDictionary< string, string > commitUserData)
	Commit changes resulting from delete, undeleteAll, or setNorm operations

void	Close ()

void	Dispose ()
	Closes files associated with this index. Also saves any new deletions to disk. No other methods should be called after this has been called.

abstract ICollection< string >	GetFieldNames (FieldOption fldOption)
	Get a list of unique field names that exist in this index and have the specified field option information.

virtual IndexReader[]	GetSequentialSubReaders ()
	Expert: returns the sequential sub readers that this reader is logically composed of. For example, IndexSearcher uses this API to drive searching by one sub reader at a time. If this reader is not composed of sequential child readers, it should return null. If this method returns an empty array, that means this reader is a null reader (for example a MultiReader that has no sub readers). NOTE: You should not try using sub-readers returned by this method to make any changes (setNorm, deleteDocument, etc.). While this might succeed for one composite reader (like MultiReader), it will most likely lead to index corruption for other readers (like DirectoryReader obtained through IndexReader.Open(Lucene.Net.Store.Directory,bool). Use the parent reader directly.

Static Public Member Functions
static IndexReader	Open (Directory directory, bool readOnly)
	Returns an IndexReader reading the index in the given Directory. You should pass readOnly=true, since it gives much better concurrent performance, unless you intend to do write operations (delete documents or change norms) with the reader.

static IndexReader	Open (IndexCommit commit, bool readOnly)
	Expert: returns an IndexReader reading the index in the given IndexCommit. You should pass readOnly=true, since it gives much better concurrent performance, unless you intend to do write operations (delete documents or change norms) with the reader.

static IndexReader	Open (Directory directory, IndexDeletionPolicy deletionPolicy, bool readOnly)
	Expert: returns an IndexReader reading the index in the given Directory, with a custom IndexDeletionPolicy . You should pass readOnly=true, since it gives much better concurrent performance, unless you intend to do write operations (delete documents or change norms) with the reader.

static IndexReader	Open (Directory directory, IndexDeletionPolicy deletionPolicy, bool readOnly, int termInfosIndexDivisor)
	Expert: returns an IndexReader reading the index in the given Directory, with a custom IndexDeletionPolicy . You should pass readOnly=true, since it gives much better concurrent performance, unless you intend to do write operations (delete documents or change norms) with the reader.

static IndexReader	Open (IndexCommit commit, IndexDeletionPolicy deletionPolicy, bool readOnly)
	Expert: returns an IndexReader reading the index in the given Directory, using a specific commit and with a custom IndexDeletionPolicy. You should pass readOnly=true, since it gives much better concurrent performance, unless you intend to do write operations (delete documents or change norms) with the reader.

static IndexReader	Open (IndexCommit commit, IndexDeletionPolicy deletionPolicy, bool readOnly, int termInfosIndexDivisor)
	Expert: returns an IndexReader reading the index in the given Directory, using a specific commit and with a custom IndexDeletionPolicy. You should pass readOnly=true, since it gives much better concurrent performance, unless you intend to do write operations (delete documents or change norms) with the reader.

static long	LastModified (Directory directory2)
	Returns the time the index in the named directory was last modified. Do not use this to check whether the reader is still up-to-date, use IsCurrent() instead.

static long	GetCurrentVersion (Directory directory)
	Reads version number from segments files. The version number is initialized with a timestamp and then increased by one for each change of the index.

static System.Collections.Generic.IDictionary < string, string >	GetCommitUserData (Directory directory)
	Reads commitUserData, previously passed to IndexWriter.Commit(System.Collections.Generic.IDictionary{string, string}), from current index segments file. This will return null if IndexWriter.Commit(System.Collections.Generic.IDictionary{string, string}) has never been called for this index.

static bool	IndexExists (Directory directory)
	Returns `true` if an index exists at the specified directory. If the directory does not exist or if there is no index in it.

static void	Main (String[] args)
	Prints the filename and size of each file within a given compound file. Add the -extract flag to extract files to the current working directory. In order to make the extracted version of the index work, you have to copy the segments file from the compound index into the directory where the extracted files are stored.

static System.Collections.Generic.ICollection < IndexCommit >	ListCommits (Directory dir)
	Returns all commit points that exist in the Directory. Normally, because the default is KeepOnlyLastCommitDeletionPolicy , there would be only one commit point. But if you're using a custom IndexDeletionPolicy then there could be many commits. Once you have a given commit, you can open a reader on it by calling IndexReader.Open(IndexCommit,bool) There must be at least one commit in the Directory, else this method throws System.IO.IOException. Note that if a commit is in progress while this method is running, that commit may or may not be returned array.

Protected Member Functions
virtual void	Dispose (bool disposing)

Properties
virtual int	RefCount `[get]`
	Expert: returns the current refCount for this reader

virtual long	Version `[get]`
	Version number when this IndexReader was opened. Not implemented in the IndexReader base class.

virtual IDictionary< string, string >	CommitUserData `[get]`
	Retrieve the String userData optionally passed to IndexWriter.Commit(System.Collections.Generic.IDictionary{string, string}). This will return null if IndexWriter.Commit(System.Collections.Generic.IDictionary{string, string}) has never been called for this index.

abstract int	MaxDoc `[get]`
	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.

virtual int	NumDeletedDocs `[get]`
	Returns the number of deleted documents.

Document	this[int doc] `[get]`
	Returns the stored fields of the `n`^th `Document` in this index. 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 IsDeleted(int) with the requested document ID to verify the document is not deleted.

abstract bool	HasDeletions `[get]`
	Returns true if any documents have been deleted

virtual IndexCommit	IndexCommit `[get]`
	Expert: return the IndexCommit that this reader has opened. This method is only implemented by those readers that correspond to a Directory with its own segments_N file.

virtual object	FieldCacheKey `[get]`
	Expert

virtual object	DeletesCacheKey `[get]`

virtual long	UniqueTermCount `[get]`
	Returns the number of unique terms (across all fields) in this reader.

virtual int	TermInfosIndexDivisor `[get]`
	For IndexReader implementations that use TermInfosReader to read terms, this returns the current indexDivisor as specified when the reader was opened.

Detailed Description

IndexReader is an abstract class, providing an interface for accessing an index. Search of an index is done entirely through this abstract interface, so that any subclass which implements it is searchable.

Concrete subclasses of IndexReader are usually constructed with a call to one of the static open() methods, e.g. Open(Lucene.Net.Store.Directory, bool)

For efficiency, in this API documents are often referred to via document numbers, non-negative integers which each name a unique document in the index. These document numbers are ephemeral–they may change as documents are added to and deleted from an index. Clients should thus not rely on a given document having the same number between sessions.

An IndexReader can be opened on a directory for which an IndexWriter is opened already, but it cannot be used to delete documents from the index then.

NOTE: for backwards API compatibility, several methods are not listed as abstract, but have no useful implementations in this base class and instead always throw UnsupportedOperationException. Subclasses are strongly encouraged to override these methods, but in many cases may not need to.

NOTE: as of 2.4, it's possible to open a read-only IndexReader using the static open methods that accepts the boolean readOnly parameter. Such a reader has better better concurrency as it's not necessary to synchronize on the isDeleted method. You must explicitly specify false if you want to make changes with the resulting IndexReader.

NOTE: IndexReader instances are completely thread safe, meaning multiple threads can call any of its methods, concurrently. If your application requires external synchronization, you should not synchronize on the IndexReader instance; use your own (non-Lucene) objects instead.

Definition at line 65 of file IndexReader.cs.

Member Function Documentation

virtual System.Object Lucene.Net.Index.IndexReader.Clone ( )

virtual

Efficiently clones the IndexReader (sharing most internal state). 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 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.

<throws> CorruptIndexException if the index is corrupt </throws>

Exceptions

System.IO.IOException If there is a low-level IO error

Reimplemented in Lucene.Net.Index.SegmentReader, Lucene.Net.Index.DirectoryReader, Lucene.Net.Index.FilterIndexReader, Lucene.Net.Index.MultiReader, and Lucene.Net.Index.ParallelReader.

Definition at line 460 of file IndexReader.cs.

virtual IndexReader Lucene.Net.Index.IndexReader.Clone ( bool openReadOnly )

virtual

Clones the IndexReader and optionally changes readOnly. A readOnly reader cannot open a writeable reader.

<throws> CorruptIndexException if the index is corrupt </throws>

Exceptions

System.IO.IOException If there is a low-level IO error

Reimplemented in Lucene.Net.Index.SegmentReader, and Lucene.Net.Index.DirectoryReader.

Definition at line 470 of file IndexReader.cs.

void Lucene.Net.Index.IndexReader.Close ( )

Definition at line 1138 of file IndexReader.cs.

void Lucene.Net.Index.IndexReader.Commit ( )

Commit changes resulting from delete, undeleteAll, or setNorm operations

If an exception is hit, then either no changes or all changes will have been committed to the index (transactional semantics).

Exceptions

System.IO.IOException If there is a low-level IO error

Definition at line 1106 of file IndexReader.cs.

void Lucene.Net.Index.IndexReader.Commit ( IDictionary< string, string > commitUserData )

Commit changes resulting from delete, undeleteAll, or setNorm operations

If an exception is hit, then either no changes or all changes will have been committed to the index (transactional semantics).

Exceptions

System.IO.IOException If there is a low-level IO error

Definition at line 1122 of file IndexReader.cs.

virtual void Lucene.Net.Index.IndexReader.DecRef ( )

virtual

Expert: decreases the refCount of this IndexReader instance. If the refCount drops to 0, then pending changes (if any) are committed to the index and this reader is closed.

<throws> IOException in case an IOException occurs in commit() or doClose() </throws>

See Also: IncRef

Definition at line 179 of file IndexReader.cs.

virtual void Lucene.Net.Index.IndexReader.DeleteDocument ( int docNum )

virtual

Deletes the document numbered docNum. Once a document is deleted it will not appear in TermDocs or TermPostitions enumerations. Attempts to read its field with the Document(int) method will result in an error. The presence of this document may still be reflected in the DocFreq statistic, though this will be corrected eventually as the index is further modified.

Exceptions

StaleReaderException	If the index has changed since this reader was opened
CorruptIndexException	If the index is corrupt
LockObtainFailedException	If another writer has this index open (`write.lock` could not be obtained)
System.IO.IOException	If there is a low-level IO error

Definition at line 978 of file IndexReader.cs.

virtual int Lucene.Net.Index.IndexReader.DeleteDocuments ( Term term )

virtual

Deletes all documents that have a given term indexed. This is useful if one uses a document field to hold a unique ID string for the document. Then to delete such a document, one merely constructs a term with the appropriate field and the unique ID string as its text and passes it to this method. See DeleteDocument(int) for information about when this deletion will become effective.

Returns: The number of documents deleted

Exceptions

StaleReaderException	If the index has changed since this reader was opened
CorruptIndexException	If the index is corrupt
LockObtainFailedException	If another writer has this index open (`write.lock` could not be obtained)
System.IO.IOException	If there is a low-level IO error

Definition at line 1014 of file IndexReader.cs.

virtual Directory Lucene.Net.Index.IndexReader.Directory ( )

virtual

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.

<throws> UnsupportedOperationException if no directory </throws>

Reimplemented in Lucene.Net.Index.SegmentReader, Lucene.Net.Index.DirectoryReader, and Lucene.Net.Index.FilterIndexReader.

Definition at line 484 of file IndexReader.cs.

void Lucene.Net.Index.IndexReader.Dispose ( )

Closes files associated with this index. Also saves any new deletions to disk. No other methods should be called after this has been called.

Exceptions

System.IO.IOException If there is a low-level IO error

Definition at line 1148 of file IndexReader.cs.

virtual void Lucene.Net.Index.IndexReader.Dispose ( bool disposing )

protectedvirtual

Definition at line 1153 of file IndexReader.cs.

abstract int Lucene.Net.Index.IndexReader.DocFreq ( Term t )

pure virtual

Returns the number of documents containing the term t.

Exceptions

System.IO.IOException If there is a low-level IO error

Implemented in Lucene.Net.Index.SegmentReader, Lucene.Net.Index.DirectoryReader, Lucene.Net.Index.ParallelReader, Lucene.Net.Index.MultiReader, and Lucene.Net.Index.FilterIndexReader.

virtual Document Lucene.Net.Index.IndexReader.Document ( int n )

virtual

Returns the stored fields of the n^th Document in this index. 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 IsDeleted(int) with the requested document ID to verify the document is not deleted.

<throws> CorruptIndexException if the index is corrupt </throws>

Exceptions

System.IO.IOException If there is a low-level IO error

Definition at line 729 of file IndexReader.cs.

abstract Document Lucene.Net.Index.IndexReader.Document	(	int	n,
		FieldSelector	fieldSelector
	)

pure virtual

Get the Lucene.Net.Documents.Document at the n ^th position. The FieldSelector may be used to determine what Lucene.Net.Documents.Fields to load and how they should be loaded. NOTE: If this Reader (more specifically, the underlying FieldsReader) is closed before the lazy Lucene.Net.Documents.Field is loaded an exception may be thrown. If you want the value of a lazy Lucene.Net.Documents.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 IsDeleted(int) with the requested document ID to verify the document is not deleted.

Parameters

n	Get the document at the `n`^th position
fieldSelector	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.

Returns: The stored fields of the Lucene.Net.Documents.Document at the nth position

<throws> CorruptIndexException if the index is corrupt </throws>

Exceptions

System.IO.IOException If there is a low-level IO error

See Also: IFieldable

See Also: Lucene.Net.Documents.FieldSelector

See Also: Lucene.Net.Documents.SetBasedFieldSelector

See Also: Lucene.Net.Documents.LoadFirstFieldSelector

Implemented in Lucene.Net.Index.SegmentReader, Lucene.Net.Index.DirectoryReader, Lucene.Net.Index.ParallelReader, Lucene.Net.Index.MultiReader, and Lucene.Net.Index.FilterIndexReader.

void Lucene.Net.Index.IndexReader.Flush ( )

Exceptions

System.IO.IOException

Definition at line 1075 of file IndexReader.cs.

void Lucene.Net.Index.IndexReader.Flush ( IDictionary< string, string > commitUserData )

Parameters

commitUserData Opaque Map (String -> String) that's recorded into the segments file in the index, and retrievable by IndexReader.GetCommitUserData

Exceptions

System.IO.IOException

Definition at line 1089 of file IndexReader.cs.

static System.Collections.Generic.IDictionary<string, string> Lucene.Net.Index.IndexReader.GetCommitUserData ( Directory directory )

static

Reads commitUserData, previously passed to IndexWriter.Commit(System.Collections.Generic.IDictionary{string, string}), from current index segments file. This will return null if IndexWriter.Commit(System.Collections.Generic.IDictionary{string, string}) has never been called for this index.

Parameters

directory where the index resides.

Returns: commit userData.

<throws> CorruptIndexException if the index is corrupt </throws>

Exceptions

System.IO.IOException If there is a low-level IO error

See Also: GetCommitUserData(Store.Directory)

Definition at line 533 of file IndexReader.cs.

static long Lucene.Net.Index.IndexReader.GetCurrentVersion ( Directory directory )

static

Reads version number from segments files. The version number is initialized with a timestamp and then increased by one for each change of the index.

Parameters

directory where the index resides.

Returns: version number.

<throws> CorruptIndexException if the index is corrupt </throws>

Exceptions

System.IO.IOException If there is a low-level IO error

Definition at line 512 of file IndexReader.cs.

abstract ICollection<string> Lucene.Net.Index.IndexReader.GetFieldNames ( FieldOption fldOption )

pure virtual

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

Parameters

fldOption 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

virtual IndexReader [] Lucene.Net.Index.IndexReader.GetSequentialSubReaders ( )

virtual

Expert: returns the sequential sub readers that this reader is logically composed of. For example, IndexSearcher uses this API to drive searching by one sub reader at a time. If this reader is not composed of sequential child readers, it should return null. If this method returns an empty array, that means this reader is a null reader (for example a MultiReader that has no sub readers). NOTE: You should not try using sub-readers returned by this method to make any changes (setNorm, deleteDocument, etc.). While this might succeed for one composite reader (like MultiReader), it will most likely lead to index corruption for other readers (like DirectoryReader obtained through IndexReader.Open(Lucene.Net.Store.Directory,bool). Use the parent reader directly.

Reimplemented in Lucene.Net.Index.DirectoryReader, Lucene.Net.Index.MultiReader, and Lucene.Net.Index.FilterIndexReader.

Definition at line 1324 of file IndexReader.cs.

abstract ITermFreqVector Lucene.Net.Index.IndexReader.GetTermFreqVector	(	int	docNumber,
		String	field
	)

pure virtual

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.

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 </throws>

See Also: Lucene.Net.Documents.Field.TermVector

abstract void Lucene.Net.Index.IndexReader.GetTermFreqVector	(	int	docNumber,
		String	field,
		TermVectorMapper	mapper
	)

pure virtual

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

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. </throws>

abstract void Lucene.Net.Index.IndexReader.GetTermFreqVector	(	int	docNumber,
		TermVectorMapper	mapper
	)

pure virtual

Map all the term vectors for all fields in a Document

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. </throws>

Implemented in Lucene.Net.Index.SegmentReader, Lucene.Net.Index.DirectoryReader, Lucene.Net.Index.ParallelReader, Lucene.Net.Index.MultiReader, and Lucene.Net.Index.FilterIndexReader.

abstract ITermFreqVector [] Lucene.Net.Index.IndexReader.GetTermFreqVectors ( int docNumber )

pure virtual

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 ITermFreqVector or of type TermPositionVector if positions or offsets have been stored.

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 </throws>

See Also: Lucene.Net.Documents.Field.TermVector

Implemented in Lucene.Net.Index.SegmentReader, Lucene.Net.Index.DirectoryReader, Lucene.Net.Index.ParallelReader, Lucene.Net.Index.MultiReader, and Lucene.Net.Index.FilterIndexReader.

virtual bool Lucene.Net.Index.IndexReader.HasNorms ( System.String field )

virtual

Returns true if there are norms stored for this field.

Reimplemented in Lucene.Net.Index.SegmentReader, Lucene.Net.Index.DirectoryReader, Lucene.Net.Index.ParallelReader, Lucene.Net.Index.MultiReader, and Lucene.Net.Index.FilterIndexReader.

Definition at line 798 of file IndexReader.cs.

virtual void Lucene.Net.Index.IndexReader.IncRef ( )

virtual

Expert: increments the refCount of this IndexReader instance. RefCounts are used to determine when a reader can be closed safely, i.e. as soon as there are no more references. Be sure to always call a corresponding DecRef, in a finally clause; otherwise the reader may never be closed. Note that Close simply calls decRef(), which means that the IndexReader will not really be closed until DecRef has been called for all outstanding references.

See Also: DecRef

Definition at line 158 of file IndexReader.cs.

static bool Lucene.Net.Index.IndexReader.IndexExists ( Directory directory )

static

Returns true if an index exists at the specified directory. If the directory does not exist or if there is no index in it.

Parameters

directory the directory to check for an index

Returns: true if an index exists; false otherwise

<throws> IOException if there is a problem with accessing the index </throws>

Definition at line 696 of file IndexReader.cs.

virtual bool Lucene.Net.Index.IndexReader.IsCurrent ( )

virtual

Check whether any new changes have occurred to the index since this reader was opened.

If this reader is based on a Directory (ie, was created by calling <cref>Open(Store.Directory)</cref>

, or Reopen() on a reader based on a Directory), then this method checks if any further commits (see IndexWriter.Commit() have occurred in that directory).

If instead this reader is a near real-time reader (ie, obtained by a call to IndexWriter.GetReader(), or by calling Reopen() on a near real-time reader), then this method checks if either a new commmit has occurred, or any new uncommitted changes have taken place via the writer. Note that even if the writer has only performed merging, this method will still return false.

In any event, if this returns false, you should call Reopen() to get a new reader that sees the changes.

<throws> CorruptIndexException if the index is corrupt </throws>

Exceptions

System.IO.IOException If there is a low-level IO error

<throws> UnsupportedOperationException unless overridden in subclass </throws>

Reimplemented in Lucene.Net.Index.DirectoryReader, Lucene.Net.Index.MultiReader, Lucene.Net.Index.ParallelReader, and Lucene.Net.Index.FilterIndexReader.

Definition at line 612 of file IndexReader.cs.

abstract bool Lucene.Net.Index.IndexReader.IsDeleted ( int n )

pure virtual

Returns true if document n has been deleted

Implemented in Lucene.Net.Index.SegmentReader, Lucene.Net.Index.DirectoryReader, Lucene.Net.Index.MultiReader, Lucene.Net.Index.ParallelReader, Lucene.Net.Index.FilterIndexReader, and Lucene.Net.Index.ReadOnlySegmentReader.

virtual bool Lucene.Net.Index.IndexReader.IsOptimized ( )

virtual

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

Returns: <c>true</c> if the index is optimized; <c>false</c> otherwise

<throws> UnsupportedOperationException unless overridden in subclass </throws>

Reimplemented in Lucene.Net.Index.DirectoryReader, Lucene.Net.Index.ParallelReader, Lucene.Net.Index.FilterIndexReader, and Lucene.Net.Index.MultiReader.

Definition at line 622 of file IndexReader.cs.

static long Lucene.Net.Index.IndexReader.LastModified ( Directory directory2 )

static

Returns the time the index in the named directory was last modified. Do not use this to check whether the reader is still up-to-date, use IsCurrent() instead.

<throws> CorruptIndexException if the index is corrupt </throws>

Exceptions

System.IO.IOException If there is a low-level IO error

Definition at line 496 of file IndexReader.cs.

static System.Collections.Generic.ICollection<IndexCommit> Lucene.Net.Index.IndexReader.ListCommits ( Directory dir )

static

Returns all commit points that exist in the Directory. Normally, because the default is KeepOnlyLastCommitDeletionPolicy , there would be only one commit point. But if you're using a custom IndexDeletionPolicy then there could be many commits. Once you have a given commit, you can open a reader on it by calling IndexReader.Open(IndexCommit,bool) There must be at least one commit in the Directory, else this method throws System.IO.IOException. Note that if a commit is in progress while this method is running, that commit may or may not be returned array.

Definition at line 1303 of file IndexReader.cs.

static void Lucene.Net.Index.IndexReader.Main ( String[] args )

static

Prints the filename and size of each file within a given compound file. Add the -extract flag to extract files to the current working directory. In order to make the extracted version of the index work, you have to copy the segments file from the compound index into the directory where the extracted files are stored.

Parameters

args	Usage: Lucene.Net.Index.IndexReader [-extract] <cfsfile>

Definition at line 1204 of file IndexReader.cs.

abstract byte [] Lucene.Net.Index.IndexReader.Norms ( System.String field )

pure virtual

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

See Also: Lucene.Net.Documents.AbstractField.Boost

Implemented in Lucene.Net.Index.SegmentReader, Lucene.Net.Index.DirectoryReader, Lucene.Net.Index.ParallelReader, Lucene.Net.Index.MultiReader, and Lucene.Net.Index.FilterIndexReader.

abstract void Lucene.Net.Index.IndexReader.Norms	(	System.String	field,
		byte[]	bytes,
		int	offset
	)

pure virtual

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

See Also: Lucene.Net.Documents.AbstractField.Boost

Implemented in Lucene.Net.Index.SegmentReader, Lucene.Net.Index.DirectoryReader, Lucene.Net.Index.ParallelReader, Lucene.Net.Index.MultiReader, and Lucene.Net.Index.FilterIndexReader.

abstract int Lucene.Net.Index.IndexReader.NumDocs ( )

pure virtual

Returns the number of documents in this index.

Implemented in Lucene.Net.Index.SegmentReader, Lucene.Net.Index.DirectoryReader, Lucene.Net.Index.ParallelReader, Lucene.Net.Index.MultiReader, and Lucene.Net.Index.FilterIndexReader.

static IndexReader Lucene.Net.Index.IndexReader.Open	(	Directory	directory,
		bool	readOnly
	)

static

Returns an IndexReader reading the index in the given Directory. You should pass readOnly=true, since it gives much better concurrent performance, unless you intend to do write operations (delete documents or change norms) with the reader.

Parameters

directory	the index directory
readOnly	true if no changes (deletions, norms) will be made with this IndexReader

Exceptions

CorruptIndexException	CorruptIndexException if the index is corrupt
System.IO.IOException	IOException if there is a low-level IO error

Definition at line 218 of file IndexReader.cs.

static IndexReader Lucene.Net.Index.IndexReader.Open	(	IndexCommit	commit,
		bool	readOnly
	)

static

Expert: returns an IndexReader reading the index in the given IndexCommit. You should pass readOnly=true, since it gives much better concurrent performance, unless you intend to do write operations (delete documents or change norms) with the reader.

Parameters

commit	the commit point to open
readOnly	true if no changes (deletions, norms) will be made with this IndexReader

<throws> CorruptIndexException if the index is corrupt </throws>

Exceptions

System.IO.IOException If there is a low-level IO error

Definition at line 235 of file IndexReader.cs.

static IndexReader Lucene.Net.Index.IndexReader.Open	(	Directory	directory,
		IndexDeletionPolicy	deletionPolicy,
		bool	readOnly
	)

static

Expert: returns an IndexReader reading the index in the given Directory, with a custom IndexDeletionPolicy . You should pass readOnly=true, since it gives much better concurrent performance, unless you intend to do write operations (delete documents or change norms) with the reader.

Parameters

directory	the index directory
deletionPolicy	a custom deletion policy (only used if you use this reader to perform deletes or to set norms); see IndexWriter for details.
readOnly	true if no changes (deletions, norms) will be made with this IndexReader

<throws> CorruptIndexException if the index is corrupt </throws>

Exceptions

System.IO.IOException If there is a low-level IO error

Definition at line 257 of file IndexReader.cs.

static IndexReader Lucene.Net.Index.IndexReader.Open	(	Directory	directory,
		IndexDeletionPolicy	deletionPolicy,
		bool	readOnly,
		int	termInfosIndexDivisor
	)

static

Expert: returns an IndexReader reading the index in the given Directory, with a custom IndexDeletionPolicy . You should pass readOnly=true, since it gives much better concurrent performance, unless you intend to do write operations (delete documents or change norms) with the reader.

Parameters

directory	the index directory
deletionPolicy	a custom deletion policy (only used if you use this reader to perform deletes or to set norms); see IndexWriter for details.
readOnly	true if no changes (deletions, norms) will be made with this IndexReader
termInfosIndexDivisor	Subsamples which indexed terms are loaded into RAM. This has the same effect as <cref>IndexWriter.SetTermIndexInterval</cref> except that setting must be done at indexing time while this setting can be set per reader. When set to N, then one in every N*termIndexInterval terms in the index is loaded into memory. By setting this to a value > 1 you can reduce memory usage, at the expense of higher latency when loading a TermInfo. The default value is 1. Set this to -1 to skip loading the terms index entirely.

<throws> CorruptIndexException if the index is corrupt </throws>

Exceptions

System.IO.IOException If there is a low-level IO error

Definition at line 291 of file IndexReader.cs.

static IndexReader Lucene.Net.Index.IndexReader.Open	(	IndexCommit	commit,
		IndexDeletionPolicy	deletionPolicy,
		bool	readOnly
	)

static

Expert: returns an IndexReader reading the index in the given Directory, using a specific commit and with a custom IndexDeletionPolicy. You should pass readOnly=true, since it gives much better concurrent performance, unless you intend to do write operations (delete documents or change norms) with the reader.

Parameters

commit	the specific IndexCommit to open; see IndexReader.ListCommits to list all commits in a directory
deletionPolicy	a custom deletion policy (only used if you use this reader to perform deletes or to set norms); see IndexWriter for details.
readOnly	true if no changes (deletions, norms) will be made with this IndexReader

<throws> CorruptIndexException if the index is corrupt </throws>

Exceptions

System.IO.IOException If there is a low-level IO error

Definition at line 315 of file IndexReader.cs.

static IndexReader Lucene.Net.Index.IndexReader.Open	(	IndexCommit	commit,
		IndexDeletionPolicy	deletionPolicy,
		bool	readOnly,
		int	termInfosIndexDivisor
	)

static

Expert: returns an IndexReader reading the index in the given Directory, using a specific commit and with a custom IndexDeletionPolicy. You should pass readOnly=true, since it gives much better concurrent performance, unless you intend to do write operations (delete documents or change norms) with the reader.

Parameters

commit	the specific IndexCommit to open; see IndexReader.ListCommits to list all commits in a directory
deletionPolicy	a custom deletion policy (only used if you use this reader to perform deletes or to set norms); see IndexWriter for details.
readOnly	true if no changes (deletions, norms) will be made with this IndexReader
termInfosIndexDivisor	Subsambles which indexed terms are loaded into RAM. This has the same effect as <cref>IndexWriter.SetTermIndexInterval</cref> except that setting must be done at indexing time while this setting can be set per reader. When set to N, then one in every N*termIndexInterval terms in the index is loaded into memory. By setting this to a value > 1 you can reduce memory usage, at the expense of higher latency when loading a TermInfo. The default value is 1. Set this to -1 to skip loading the terms index entirely.

<throws> CorruptIndexException if the index is corrupt </throws>

Exceptions

System.IO.IOException If there is a low-level IO error

Definition at line 351 of file IndexReader.cs.

virtual IndexReader Lucene.Net.Index.IndexReader.Reopen ( )

virtual

Refreshes an IndexReader if the index has changed since this instance was (re)opened. 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.

<throws> CorruptIndexException if the index is corrupt </throws>

Exceptions

System.IO.IOException If there is a low-level IO error

Reimplemented in Lucene.Net.Index.DirectoryReader, Lucene.Net.Index.ParallelReader, and Lucene.Net.Index.MultiReader.

Definition at line 405 of file IndexReader.cs.

virtual IndexReader Lucene.Net.Index.IndexReader.Reopen ( bool openReadOnly )

virtual

Just like 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.

Reimplemented in Lucene.Net.Index.DirectoryReader.

Definition at line 419 of file IndexReader.cs.

virtual IndexReader Lucene.Net.Index.IndexReader.Reopen ( IndexCommit commit )

virtual

Expert: reopen this reader on a specific commit point. This always returns a readOnly reader. If the specified commit point matches what this reader is already on, and this reader is already readOnly, then this same instance is returned; if it is not already readOnly, a readOnly clone is returned.

Reimplemented in Lucene.Net.Index.DirectoryReader.

Definition at line 434 of file IndexReader.cs.

virtual void Lucene.Net.Index.IndexReader.SetNorm	(	int	doc,
		String	field,
		byte	value
	)

virtual

Expert: Resets the normalization factor for the named field of the named document. The norm represents the product of the field's boost and its length normalization. Thus, to preserve the length normalization values when resetting this, one should base the new value upon the old.

NOTE: If this field does not store norms, then this method call will silently do nothing.

See Also: Norms(String), Similarity.DecodeNorm(byte)

Exceptions

StaleReaderException	If the index has changed since this reader was opened
CorruptIndexException	If the index is corrupt
LockObtainFailedException	If another writer has this index open (`write.lock` could not be obtained)
System.IO.IOException	If there is a low-level IO error

Definition at line 842 of file IndexReader.cs.

virtual void Lucene.Net.Index.IndexReader.SetNorm	(	int	doc,
		System.String	field,
		float	value
	)

virtual

Expert: Resets the normalization factor for the named field of the named document.

See Also: Norms(String), Similarity.DecodeNorm(byte)

Exceptions

StaleReaderException	If the index has changed since this reader was opened
CorruptIndexException	If the index is corrupt
LockObtainFailedException	If another writer has this index open (`write.lock` could not be obtained)
System.IO.IOException	If there is a low-level IO error

Definition at line 873 of file IndexReader.cs.

virtual TermDocs Lucene.Net.Index.IndexReader.TermDocs ( Term term )

virtual

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:

   =>    <docNum, freq>^* The enumeration is ordered by document number. Each document number is greater than all that precede it in the enumeration.

Exceptions

System.IO.IOException If there is a low-level IO error

Reimplemented in Lucene.Net.Index.SegmentReader, Lucene.Net.Index.ParallelReader, and Lucene.Net.Index.FilterIndexReader.

Definition at line 919 of file IndexReader.cs.

abstract TermDocs Lucene.Net.Index.IndexReader.TermDocs ( )

pure virtual

Returns an unpositioned Lucene.Net.Index.TermDocs enumerator.

Exceptions

System.IO.IOException If there is a low-level IO error

Implemented in Lucene.Net.Index.SegmentReader, Lucene.Net.Index.DirectoryReader, Lucene.Net.Index.ParallelReader, Lucene.Net.Index.MultiReader, and Lucene.Net.Index.FilterIndexReader.

virtual TermPositions Lucene.Net.Index.IndexReader.TermPositions ( Term term )

virtual

Returns an enumeration of all the documents which contain 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:

   =>    <docNum, freq, <pos₁, pos₂, ... pos_freq-1> >^*

This positional information facilitates phrase and proximity searching.

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

Exceptions

System.IO.IOException If there is a low-level IO error

Reimplemented in Lucene.Net.Index.ParallelReader.

Definition at line 948 of file IndexReader.cs.

abstract TermPositions Lucene.Net.Index.IndexReader.TermPositions ( )

pure virtual

Returns an unpositioned Lucene.Net.Index.TermPositions enumerator.

Exceptions

System.IO.IOException If there is a low-level IO error

Implemented in Lucene.Net.Index.SegmentReader, Lucene.Net.Index.DirectoryReader, Lucene.Net.Index.ParallelReader, Lucene.Net.Index.MultiReader, and Lucene.Net.Index.FilterIndexReader.

abstract TermEnum Lucene.Net.Index.IndexReader.Terms ( )

pure virtual

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.

Exceptions

System.IO.IOException If there is a low-level IO error

Implemented in Lucene.Net.Index.SegmentReader, Lucene.Net.Index.DirectoryReader, Lucene.Net.Index.ParallelReader, Lucene.Net.Index.MultiReader, and Lucene.Net.Index.FilterIndexReader.

abstract TermEnum Lucene.Net.Index.IndexReader.Terms ( Term t )

pure virtual

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.

Exceptions

System.IO.IOException If there is a low-level IO error

Implemented in Lucene.Net.Index.SegmentReader, Lucene.Net.Index.DirectoryReader, Lucene.Net.Index.ParallelReader, Lucene.Net.Index.MultiReader, and Lucene.Net.Index.FilterIndexReader.

virtual void Lucene.Net.Index.IndexReader.UndeleteAll ( )

virtual

Undeletes all documents currently marked as deleted in this index.

Exceptions

StaleReaderException	If the index has changed since this reader was opened
CorruptIndexException	If the index is corrupt
LockObtainFailedException	If another writer has this index open (`write.lock` could not be obtained)
System.IO.IOException	If there is a low-level IO error

Definition at line 1047 of file IndexReader.cs.

Property Documentation

virtual IDictionary<string, string> Lucene.Net.Index.IndexReader.CommitUserData

get

Retrieve the String userData optionally passed to IndexWriter.Commit(System.Collections.Generic.IDictionary{string, string}). This will return null if IndexWriter.Commit(System.Collections.Generic.IDictionary{string, string}) has never been called for this index.

See Also: GetCommitUserData(Store.Directory)

Definition at line 578 of file IndexReader.cs.

virtual object Lucene.Net.Index.IndexReader.DeletesCacheKey

get

Definition at line 1340 of file IndexReader.cs.

virtual object Lucene.Net.Index.IndexReader.FieldCacheKey

get

Expert

Definition at line 1331 of file IndexReader.cs.

abstract bool Lucene.Net.Index.IndexReader.HasDeletions

get

Returns true if any documents have been deleted

Definition at line 795 of file IndexReader.cs.

virtual IndexCommit Lucene.Net.Index.IndexReader.IndexCommit

get

Expert: return the IndexCommit that this reader has opened. This method is only implemented by those readers that correspond to a Directory with its own segments_N file.

WARNING: this API is new and experimental and may suddenly change.

Definition at line 1192 of file IndexReader.cs.

abstract int Lucene.Net.Index.IndexReader.MaxDoc

get

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.

Definition at line 709 of file IndexReader.cs.

virtual int Lucene.Net.Index.IndexReader.NumDeletedDocs

get

Returns the number of deleted documents.

Definition at line 713 of file IndexReader.cs.

virtual int Lucene.Net.Index.IndexReader.RefCount

get

Expert: returns the current refCount for this reader

Definition at line 134 of file IndexReader.cs.

virtual int Lucene.Net.Index.IndexReader.TermInfosIndexDivisor

get

For IndexReader implementations that use TermInfosReader to read terms, this returns the current indexDivisor as specified when the reader was opened.

Definition at line 1370 of file IndexReader.cs.

Document Lucene.Net.Index.IndexReader.this[int doc]

get

Returns the stored fields of the n^th Document in this index. 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 IsDeleted(int) with the requested document ID to verify the document is not deleted.

<throws> CorruptIndexException if the index is corrupt </throws>

Exceptions

System.IO.IOException If there is a low-level IO error

Definition at line 748 of file IndexReader.cs.

virtual long Lucene.Net.Index.IndexReader.UniqueTermCount

get

Returns the number of unique terms (across all fields) in this reader.

This method returns long, even though internally Lucene cannot handle more than 2^31 unique terms, for a possible future when this limitation is removed.

<throws> UnsupportedOperationException if this count </throws>

cannot be easily determined (eg Multi*Readers). Instead, you should call GetSequentialSubReaders and ask each sub reader for its unique term count.

Definition at line 1359 of file IndexReader.cs.

virtual long Lucene.Net.Index.IndexReader.Version

get

Version number when this IndexReader was opened. Not implemented in the IndexReader base class.

If this reader is based on a Directory (ie, was created by calling Open(Lucene.Net.Store.Directory, bool), or Reopen() on a reader based on a Directory), then this method returns the version recorded in the commit that the reader opened. This version is advanced every time IndexWriter.Commit() is called.

If instead this reader is a near real-time reader (ie, obtained by a call to IndexWriter.GetReader(), or by calling Reopen() on a near real-time reader), then this method returns the version of the last commit done by the writer. Note that even as further changes are made with the writer, the version will not changed until a commit is completed. Thus, you should not rely on this method to determine when a near real-time reader should be opened. Use IsCurrent instead.

<throws> UnsupportedOperationException </throws>

unless overridden in subclass

Definition at line 565 of file IndexReader.cs.

The documentation for this class was generated from the following file:

core/Index/IndexReader.cs

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