The SegmentReader type exposes the following members.

Constructors

  NameDescription
Public methodSegmentReader
Initializes a new instance of the SegmentReader class

Methods

  NameDescription
Protected methodAcquireWriteLock
Does nothing by default. Subclasses that require a write lock for index modifications must implement this method.
(Inherited from IndexReader.)
Public methodClone()()()() (Overrides IndexReader..::..Clone()()()().)
Public methodClone(Boolean) (Overrides IndexReader..::..Clone(Boolean).)
Protected methodCloneDeletedDocs
Clones the deleteDocs BitVector. May be overridden by subclasses. New and experimental.
Protected methodCloneNormBytes
Clones the norm bytes. May be overridden by subclasses. New and experimental.
Public methodClose
Closes files associated with this index. Also saves any new deletions to disk. No other methods should be called after this has been called.
(Inherited from IndexReader.)
Public methodCommit()()()()
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).
(Inherited from IndexReader.)
Public methodCommit(IDictionary<(Of <<'(String, String>)>>))
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).
(Inherited from IndexReader.)
Public methodDecRef
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.
(Inherited from IndexReader.)
Public methodDeleteDocument
Deletes the document numbered
CopyC#
docNum
. Once a document is deleted it will not appear in TermDocs or TermPostitions enumerations. Attempts to read its field with the {@link #document} method will result in an error. The presence of this document may still be reflected in the {@link #docFreq} statistic, though this will be corrected eventually as the index is further modified.
(Inherited from IndexReader.)
Public methodDeleteDocuments
Deletes all documents that have a given
CopyC#
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 {@link #DeleteDocument(int)} for information about when this deletion will become effective.
(Inherited from IndexReader.)
Public methodDirectory
Returns the directory this index resides in.
(Overrides IndexReader..::..Directory()()()().)
Public methodDispose
.NET
(Inherited from IndexReader.)
Public methodDocFreq (Overrides IndexReader..::..DocFreq(Term).)
Protected methodDoClose (Overrides IndexReader..::..DoClose()()()().)
Protected methodDoCommit()()()() Obsolete. (Overrides IndexReader..::..DoCommit()()()().)
Protected methodDoCommit(IDictionary<(Of <<'(String, String>)>>)) (Overrides IndexReader..::..DoCommit(IDictionary<(Of <<'(String, String>)>>)).)
Public methodDocument(Int32)
Returns the stored fields of the
CopyC#
n
th
CopyC#
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 {@link #IsDeleted(int)} with the requested document ID to verify the document is not deleted.

(Inherited from IndexReader.)
Public methodDocument(Int32, FieldSelector) (Overrides IndexReader..::..Document(Int32, FieldSelector).)
Protected methodDoDelete (Overrides IndexReader..::..DoDelete(Int32).)
Protected methodDoSetNorm (Overrides IndexReader..::..DoSetNorm(Int32, String, Byte).)
Protected methodDoUndeleteAll (Overrides IndexReader..::..DoUndeleteAll()()()().)
Protected methodEnsureOpen (Inherited from IndexReader.)
Public methodEquals
Determines whether the specified Object is equal to the current Object.
(Inherited from Object.)
Public methodFieldInfos
Protected methodFinalize
Allows an Object to attempt to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection.
(Inherited from Object.)
Public methodFlush()()()()
(Inherited from IndexReader.)
Public methodFlush(IDictionary<(Of <<'(String, String>)>>)) (Inherited from IndexReader.)
Public methodStatic memberGet(SegmentInfo) Obsolete.
Public methodStatic memberGet(Boolean, SegmentInfo, Int32)
Public methodStatic memberGet(Boolean, Directory, SegmentInfo, Int32, Boolean, Int32)
Public methodGetCommitUserData()()()()
Retrieve the String userData optionally passed to IndexWriter#commit. This will return null if {@link IndexWriter#Commit(Map)} has never been called for this index.
(Inherited from IndexReader.)
Public methodGetDeletesCacheKey (Overrides IndexReader..::..GetDeletesCacheKey()()()().)
Public methodGetDisableFakeNorms Obsolete.
Expert: Return the state of the flag that disables fakes norms in favor of representing the absence of field norms with null.
(Inherited from IndexReader.)
Public methodGetFieldCacheKey Obsolete. (Overrides IndexReader..::..GetFieldCacheKey()()()().)
Public methodGetFieldNames (Overrides IndexReader..::..GetFieldNames(IndexReader..::..FieldOption).)
Public methodGetHashCode
Serves as a hash function for a particular type.
(Inherited from Object.)
Public methodGetIndexCommit
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.

(Inherited from IndexReader.)
Protected methodGetNorms
Public methodStatic memberGetOnlySegmentReader(Directory)
Lotsa tests did hacks like:
SegmentReader reader = (SegmentReader) IndexReader.open(dir);
They broke. This method serves as a hack to keep hacks working
Public methodStatic memberGetOnlySegmentReader(IndexReader)
Public methodGetRefCount
Expert: returns the current refCount for this reader
(Inherited from IndexReader.)
Public methodGetSegmentName
Return the name of the segment this reader is reading.
Public methodGetSequentialSubReaders
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 {@link #open}. Use the parent reader directly.

(Inherited from IndexReader.)
Public methodGetTermFreqVector(Int32, TermVectorMapper) (Overrides IndexReader..::..GetTermFreqVector(Int32, TermVectorMapper).)
Public methodGetTermFreqVector(Int32, String)
Return a term frequency vector for the specified document and field. The vector returned contains term numbers and frequencies for all terms in the specified field of this document, if the field had storeTermVector flag set. If the flag was not set, the method returns null.
(Overrides IndexReader..::..GetTermFreqVector(Int32, String).)
Public methodGetTermFreqVector(Int32, String, TermVectorMapper) (Overrides IndexReader..::..GetTermFreqVector(Int32, String, TermVectorMapper).)
Public methodGetTermFreqVectors
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 vector contains term numbers and frequencies for all terms in a given vectorized field. If no such fields existed, the method returns null.
(Overrides IndexReader..::..GetTermFreqVectors(Int32).)
Public methodGetTermInfosIndexDivisor (Overrides IndexReader..::..GetTermInfosIndexDivisor()()()().)
Public methodGetType
Gets the Type of the current instance.
(Inherited from Object.)
Public methodGetUniqueTermCount (Overrides IndexReader..::..GetUniqueTermCount()()()().)
Public methodGetVersion
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 {@link #Open}, or {@link #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 {@link IndexWriter#Commit} is called.

If instead this reader is a near real-time reader (ie, obtained by a call to {@link IndexWriter#GetReader}, or by calling {@link #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 {@link #IsCurrent} instead.

(Inherited from IndexReader.)
Public methodHasDeletions (Overrides IndexReader..::..HasDeletions()()()().)
Public methodHasNorms (Overrides IndexReader..::..HasNorms(String).)
Public methodIncRef
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 {@link #decRef}, in a finally clause; otherwise the reader may never be closed. Note that {@link #close} simply calls decRef(), which means that the IndexReader will not really be closed until {@link #decRef} has been called for all outstanding references.
(Inherited from IndexReader.)
Public methodIsCurrent
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 {@link #open}, or {@link #reopen} on a reader based on a Directory), then this method checks if any further commits (see {@link IndexWriter#commit} have occurred in that directory).

If instead this reader is a near real-time reader (ie, obtained by a call to {@link IndexWriter#getReader}, or by calling {@link #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 {@link #reopen} to get a new reader that sees the changes.

(Inherited from IndexReader.)
Public methodIsDeleted (Overrides IndexReader..::..IsDeleted(Int32).)
Public methodIsOptimized
Checks is the index is optimized (if it has a single segment and no deletions). Not implemented in the IndexReader base class.
(Inherited from IndexReader.)
Public methodMaxDoc (Overrides IndexReader..::..MaxDoc()()()().)
Protected methodMemberwiseClone
Creates a shallow copy of the current Object.
(Inherited from Object.)
Public methodNorms(String) (Overrides IndexReader..::..Norms(String).)
Public methodNorms(String, array<Byte>[]()[][], Int32)
Read norms into a pre-allocated array.
(Overrides IndexReader..::..Norms(String, array<Byte>[]()[][], Int32).)
Public methodNormsClosed()()()()
Public methodNormsClosed(String)
Public methodNumDeletedDocs
Returns the number of deleted documents.
(Inherited from IndexReader.)
Public methodNumDocs (Overrides IndexReader..::..NumDocs()()()().)
Public methodReopen()()()()
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 {@link IndexWriter#GetReader()}, reopen() will simply call writer.getReader() again for you, though this may change in the future.

(Inherited from IndexReader.)
Public methodReopen(Boolean)
Just like {@link #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.
(Inherited from IndexReader.)
Public methodReopen(IndexCommit)
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.
(Inherited from IndexReader.)
Public methodSetDisableFakeNorms Obsolete.
Expert: Set the state of the flag that disables fakes norms in favor of representing the absence of field norms with null.
(Inherited from IndexReader.)
Public methodSetNorm(Int32, String, Byte)
Expert: Resets the normalization factor for the named field of the named document. The norm represents the product of the field's {@link Lucene.Net.Documents.Fieldable#SetBoost(float) boost} and its {@link Similarity#LengthNorm(String, int) 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.
(Inherited from IndexReader.)
Public methodSetNorm(Int32, String, Single)
Expert: Resets the normalization factor for the named field of the named document.
(Inherited from IndexReader.)
Public methodSetTermInfosIndexDivisor Obsolete.

For IndexReader implementations that use TermInfosReader to read terms, this sets the indexDivisor to subsample the number of indexed terms loaded into memory. This has the same effect as {@link IndexWriter#setTermIndexInterval} 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.

NOTE: you must call this before the term index is loaded. If the index is already loaded, an IllegalStateException is thrown.

(Inherited from IndexReader.)
Public methodTermDocs()()()() (Overrides IndexReader..::..TermDocs()()()().)
Public methodTermDocs(Term) (Overrides IndexReader..::..TermDocs(Term).)
Public methodTermPositions()()()() (Overrides IndexReader..::..TermPositions()()()().)
Public methodTermPositions(Term)
Returns an enumeration of all the documents which contain
CopyC#
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:

    Term    =>    <docNum, freq, <pos1, pos2, ... posfreq-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.

(Inherited from IndexReader.)
Public methodTerms()()()() (Overrides IndexReader..::..Terms()()()().)
Public methodTerms(Term) (Overrides IndexReader..::..Terms(Term).)
Public methodTermsIndexLoaded
Public methodToString
Returns a String that represents the current Object.
(Inherited from Object.)
Public methodUndeleteAll
Undeletes all documents currently marked as deleted in this index.
(Inherited from IndexReader.)

Fields

  NameDescription
Protected fieldhasChanges (Inherited from IndexReader.)
Protected fieldreadOnly

Properties

See Also