Module org.apache.lucene.core
Package org.apache.lucene.index

Class IndexWriter

java.lang.Object
org.apache.lucene.index.IndexWriter
All Implemented Interfaces:
Closeable, AutoCloseable, MergePolicy.MergeContext, TwoPhaseCommit, Accountable
public class IndexWriter extends Object implements Closeable, TwoPhaseCommit, Accountable, MergePolicy.MergeContext
An IndexWriter creates and maintains an index.

The IndexWriterConfig.OpenMode option on IndexWriterConfig.setOpenMode(OpenMode) determines whether a new index is created, or whether an existing index is opened. Note that you can open an index with IndexWriterConfig.OpenMode.CREATE even while readers are using the index. The old readers will continue to search the "point in time" snapshot they had opened, and won't see the newly created index until they re-open. If IndexWriterConfig.OpenMode.CREATE_OR_APPEND is used IndexWriter will create a new index if there is not already an index at the provided path and otherwise open the existing index.

In either case, documents are added with addDocument and removed with deleteDocuments(Term...) or deleteDocuments(Query...). A document can be updated with updateDocument (which just deletes and then adds the entire document). When finished adding, deleting and updating documents, close should be called.

Each method that changes the index returns a long sequence number, which expresses the effective order in which each change was applied. commit() also returns a sequence number, describing which changes are in the commit point and which are not. Sequence numbers are transient (not saved into the index in any way) and only valid within a single IndexWriter instance.

These changes are buffered in memory and periodically flushed to the Directory (during the above method calls). A flush is triggered when there are enough added documents since the last flush. Flushing is triggered either by RAM usage of the documents (see IndexWriterConfig.setRAMBufferSizeMB(double)) or the number of added documents (see IndexWriterConfig.setMaxBufferedDocs(int)). The default is to flush when RAM usage hits IndexWriterConfig.DEFAULT_RAM_BUFFER_SIZE_MB MB. For best indexing speed you should flush by RAM usage with a large RAM buffer. In contrast to the other flush options IndexWriterConfig.setRAMBufferSizeMB(double) and IndexWriterConfig.setMaxBufferedDocs(int), deleted terms won't trigger a segment flush. Note that flushing just moves the internal buffered state in IndexWriter into the index, but these changes are not visible to IndexReader until either commit() or close() is called. A flush may also trigger one or more segment merges which by default run with a background thread so as not to block the addDocument calls (see below for changing the MergeScheduler).

Opening an IndexWriter creates a lock file for the directory in use. Trying to open another IndexWriter on the same directory will lead to a LockObtainFailedException.

Expert: IndexWriter allows an optional IndexDeletionPolicy implementation to be specified. You can use this to control when prior commits are deleted from the index. The default policy is KeepOnlyLastCommitDeletionPolicy which removes all prior commits as soon as a new commit is done. Creating your own policy can allow you to explicitly keep previous "point in time" commits alive in the index for some time, either because this is useful for your application, or to give readers enough time to refresh to the new commit without having the old commit deleted out from under them. The latter is necessary when multiple computers take turns opening their own IndexWriter and IndexReaders against a single shared index mounted via remote filesystems like NFS which do not support "delete on last close" semantics. A single computer accessing an index via NFS is fine with the default deletion policy since NFS clients emulate "delete on last close" locally. That said, accessing an index via NFS will likely result in poor performance compared to a local IO device.

Expert: IndexWriter allows you to separately change the MergePolicy and the MergeScheduler. The MergePolicy is invoked whenever there are changes to the segments in the index. Its role is to select which merges to do, if any, and return a MergePolicy.MergeSpecification describing the merges. The default is LogByteSizeMergePolicy. Then, the MergeScheduler is invoked with the requested merges and it decides when and how to run the merges. The default is ConcurrentMergeScheduler.

NOTE: if you hit a VirtualMachineError, or disaster strikes during a checkpoint then IndexWriter will close itself. This is a defensive measure in case any internal state (buffered documents, deletions, reference counts) were corrupted. Any subsequent calls will throw an AlreadyClosedException.

NOTE: IndexWriter 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 IndexWriter instance as this may cause deadlock; use your own (non-Lucene) objects instead.

NOTE: If you call Thread.interrupt() on a thread that's within IndexWriter, IndexWriter will try to catch this (eg, if it's in a wait() or Thread.sleep()), and will then throw the unchecked exception ThreadInterruptedException and clear the interrupt status on the thread.

  • Field Details

    • MAX_DOCS

      public static final int MAX_DOCS
      Hard limit on maximum number of documents that may be added to the index. If you try to add more than this you'll hit IllegalArgumentException.
      See Also:

    • MAX_POSITION

      public static final int MAX_POSITION
      Maximum value of the token position in an indexed field.
      See Also:

    • actualMaxDocs

      private static int actualMaxDocs

    • enableTestPoints

      private final boolean enableTestPoints
      Used only for testing.

    • UNBOUNDED_MAX_MERGE_SEGMENTS

      private static final int UNBOUNDED_MAX_MERGE_SEGMENTS
      See Also:

    • WRITE_LOCK_NAME

      public static final String WRITE_LOCK_NAME
      Name of the write lock in the index.
      See Also:

    • SOURCE

      public static final String SOURCE
      Key for the source of a segment in the diagnostics.
      See Also:

    • SOURCE_MERGE

      public static final String SOURCE_MERGE
      Source of a segment which results from a merge of other segments.
      See Also:

    • SOURCE_FLUSH

      public static final String SOURCE_FLUSH
      Source of a segment which results from a flush.
      See Also:

    • SOURCE_ADDINDEXES_READERS

      public static final String SOURCE_ADDINDEXES_READERS
      Source of a segment which results from a call to addIndexes(CodecReader...).
      See Also:

    • MAX_TERM_LENGTH

      public static final int MAX_TERM_LENGTH
      Absolute hard maximum length for a term, in bytes once encoded as UTF8. If a term arrives from the analyzer longer than this length, an IllegalArgumentException is thrown and a message is printed to infoStream, if set (see IndexWriterConfig.setInfoStream(InfoStream)).
      See Also:

    • MAX_STORED_STRING_LENGTH

      public static final int MAX_STORED_STRING_LENGTH
      Maximum length string for a stored field.

    • tragedy

      private final AtomicReference<Throwable> tragedy

    • directoryOrig

      private final Directory directoryOrig

    • directory

      private final Directory directory

    • changeCount

      private final AtomicLong changeCount

    • lastCommitChangeCount

      private volatile long lastCommitChangeCount

    • rollbackSegments

      private List<SegmentCommitInfo> rollbackSegments

    • pendingCommit

      private volatile SegmentInfos pendingCommit

    • pendingSeqNo

      private volatile long pendingSeqNo

    • pendingCommitChangeCount

      private volatile long pendingCommitChangeCount

    • filesToCommit

      private Collection<String> filesToCommit

    • segmentInfos

      private final SegmentInfos segmentInfos

    • globalFieldNumberMap

      final FieldInfos.FieldNumbers globalFieldNumberMap

    • docWriter

      final DocumentsWriter docWriter

    • eventQueue

      private final IndexWriter.EventQueue eventQueue

    • mergeSource

      private final MergeScheduler.MergeSource mergeSource

    • addIndexesMergeSource

      private final IndexWriter.AddIndexesMergeSource addIndexesMergeSource

    • writeDocValuesLock

      private final ReentrantLock writeDocValuesLock

    • deleter

      private final IndexFileDeleter deleter

    • segmentsToMerge

      private final Map<SegmentCommitInfo,Boolean> segmentsToMerge

    • mergeMaxNumSegments

      private int mergeMaxNumSegments

    • writeLock

      private Lock writeLock

    • closed

      private volatile boolean closed

    • closing

      private volatile boolean closing

    • maybeMerge

      private final AtomicBoolean maybeMerge

    • commitUserData

      private Iterable<Map.Entry<String,String>> commitUserData

    • mergingSegments

      private final HashSet<SegmentCommitInfo> mergingSegments

    • mergeScheduler

      private final MergeScheduler mergeScheduler

    • runningAddIndexesMerges

      private final Set<SegmentMerger> runningAddIndexesMerges

    • pendingMerges

      private final Deque<MergePolicy.OneMerge> pendingMerges

    • runningMerges

      private final Set<MergePolicy.OneMerge> runningMerges

    • mergeExceptions

      private final List<MergePolicy.OneMerge> mergeExceptions

    • mergeGen

      private long mergeGen

    • merges

      private IndexWriter.Merges merges

    • didMessageState

      private boolean didMessageState

    • flushCount

      private final AtomicInteger flushCount

    • flushDeletesCount

      private final AtomicInteger flushDeletesCount

    • readerPool

      private final ReaderPool readerPool

    • bufferedUpdatesStream

      private final BufferedUpdatesStream bufferedUpdatesStream

    • eventListener

      private final IndexWriterEventListener eventListener

    • mergeFinishedGen

      private final AtomicLong mergeFinishedGen
      Counts how many merges have completed; this is used by forceApply(FrozenBufferedUpdates) to handle concurrently apply deletes/updates with merges completing.

    • config

      private final LiveIndexWriterConfig config

    • startCommitTime

      private long startCommitTime
      System.nanoTime() when commit started; used to write an infoStream message about how long commit took.

    • pendingNumDocs

      private final AtomicLong pendingNumDocs
      How many documents are in the index, or are in the process of being added (reserved). E.g., operations like addIndexes will first reserve the right to add N docs, before they actually change the index, much like how hotels place an "authorization hold" on your credit card to make sure they can later charge you when you check out.

    • softDeletesEnabled

      private final boolean softDeletesEnabled

    • flushNotifications

      private final DocumentsWriter.FlushNotifications flushNotifications

    • infoStream

      private final InfoStream infoStream
      If enabled, information about merges will be printed to this.

    • commitLock

      private final Object commitLock

    • fullFlushLock

      private final Object fullFlushLock

  • Constructor Details

    • IndexWriter

      public IndexWriter(Directory d, IndexWriterConfig conf) throws IOException
      Constructs a new IndexWriter per the settings given in conf. If you want to make "live" changes to this writer instance, use getConfig().

      NOTE: after ths writer is created, the given configuration instance cannot be passed to another writer.

      Parameters:
      d - the index directory. The index is either created or appended according conf.getOpenMode().
      conf - the configuration settings according to which IndexWriter should be initialized.
      Throws:
      IOException - if the directory cannot be read/written to, or if it does not exist and conf.getOpenMode() is OpenMode.APPEND or if there is any other low-level IO error

  • Method Details

    • setMaxDocs

      static void setMaxDocs(int maxDocs)
      Used only for testing.

    • getActualMaxDocs

      static int getActualMaxDocs()

    • getReader

      DirectoryReader getReader(boolean applyAllDeletes, boolean writeAllDeletes) throws IOException
      Expert: returns a readonly reader, covering all committed as well as un-committed changes to the index. This provides "near real-time" searching, in that changes made during an IndexWriter session can be quickly made available for searching without closing the writer nor calling commit().

      Note that this is functionally equivalent to calling {#flush} and then opening a new reader. But the turnaround time of this method should be faster since it avoids the potentially costly commit().

      You must close the IndexReader returned by this method once you are done using it.

      It's near real-time because there is no hard guarantee on how quickly you can get a new reader after making changes with IndexWriter. You'll have to experiment in your situation to determine if it's fast enough. As this is a new and experimental feature, please report back on your findings so we can learn, improve and iterate.

      The resulting reader supports DirectoryReader.openIfChanged(org.apache.lucene.index.DirectoryReader), but that call will simply forward back to this method (though this may change in the future).

      The very first time this method is called, this writer instance will make every effort to pool the readers that it opens for doing merges, applying deletes, etc. This means additional resources (RAM, file descriptors, CPU time) will be consumed.

      For lower latency on reopening a reader, you should call IndexWriterConfig.setMergedSegmentWarmer(org.apache.lucene.index.IndexWriter.IndexReaderWarmer) to pre-warm a newly merged segment before it's committed to the index. This is important for minimizing index-to-search delay after a large merge.

      If an addIndexes* call is running in another thread, then this reader will only search those segments from the foreign index that have been successfully copied over, so far.

      NOTE: Once the writer is closed, any outstanding readers may continue to be used. However, if you attempt to reopen any of those readers, you'll hit an AlreadyClosedException.

      Returns:
      IndexReader that covers entire index plus all changes made so far by this IndexWriter instance
      Throws:
      IOException - If there is a low-level I/O error

    • finishGetReaderMerge

      private StandardDirectoryReader finishGetReaderMerge(AtomicBoolean stopCollectingMergedReaders, Map<String,SegmentReader> mergedReaders, Map<String,SegmentReader> openedReadOnlyClones, SegmentInfos openingSegmentInfos, boolean applyAllDeletes, boolean writeAllDeletes, MergePolicy.MergeSpecification pointInTimeMerges, long maxCommitMergeWaitMillis) throws IOException
      Throws:
      IOException

    • maybeReopenMergedNRTReader

      private StandardDirectoryReader maybeReopenMergedNRTReader(Map<String,SegmentReader> mergedReaders, Map<String,SegmentReader> openedReadOnlyClones, SegmentInfos openingSegmentInfos, boolean applyAllDeletes, boolean writeAllDeletes) throws IOException
      Throws:
      IOException

    • ramBytesUsed

      public final long ramBytesUsed()
      Description copied from interface: Accountable
      Return the memory usage of this object in bytes. Negative values are illegal.
      Specified by:
      ramBytesUsed in interface Accountable

    • getFlushingBytes

      public final long getFlushingBytes()
      Returns the number of bytes currently being flushed

    • writeSomeDocValuesUpdates

      final void writeSomeDocValuesUpdates() throws IOException
      Throws:
      IOException

    • numDeletedDocs

      public int numDeletedDocs(SegmentCommitInfo info)
      Obtain the number of deleted docs for a pooled reader. If the reader isn't being pooled, the segmentInfo's delCount is returned.
      Specified by:
      numDeletedDocs in interface MergePolicy.MergeContext

    • ensureOpen

      protected final void ensureOpen(boolean failIfClosing) throws AlreadyClosedException
      Used internally to throw an AlreadyClosedException if this IndexWriter has been closed or is in the process of closing.
      Parameters:
      failIfClosing - if true, also fail when IndexWriter is in the process of closing (closing=true) but not yet done closing ( closed=false)
      Throws:
      AlreadyClosedException - if this IndexWriter is closed or in the process of closing

    • ensureOpen

      protected final void ensureOpen() throws AlreadyClosedException
      Used internally to throw an AlreadyClosedException if this IndexWriter has been closed (closed=true) or is in the process of closing (closing=true).

      Calls ensureOpen(true).

      Throws:
      AlreadyClosedException - if this IndexWriter is closed

    • validateIndexSort

      private void validateIndexSort()
      Confirms that the incoming index sort (if any) matches the existing index sort (if any).

    • isCongruentSort

      static boolean isCongruentSort(Sort indexSort, Sort otherSort)
      Returns true if indexSort is a prefix of otherSort.

    • readFieldInfos

      static FieldInfos readFieldInfos(SegmentCommitInfo si) throws IOException
      Throws:
      IOException

    • getFieldNumberMap

      private FieldInfos.FieldNumbers getFieldNumberMap() throws IOException
      Loads or returns the already loaded the global field number map for this SegmentInfos. If this SegmentInfos has no global field number map the returned instance is empty
      Throws:
      IOException

    • getConfig

      public LiveIndexWriterConfig getConfig()
      Returns a LiveIndexWriterConfig, which can be used to query the IndexWriter current settings, as well as modify "live" ones.

    • messageState

      private void messageState()

    • shutdown

      private void shutdown() throws IOException
      Gracefully closes (commits, waits for merges), but calls rollback if there's an exc so the IndexWriter is always closed. This is called from close() when LiveIndexWriterConfig.commitOnClose is true.
      Throws:
      IOException

    • close

      public void close() throws IOException
      Closes all open resources and releases the write lock.

      If LiveIndexWriterConfig.commitOnClose is true, this will attempt to gracefully shut down by writing any changes, waiting for any running merges, committing, and closing. In this case, note that:

      • If you called prepareCommit but failed to call commit, this method will throw IllegalStateException and the IndexWriter will not be closed.
      • If this method throws any other exception, the IndexWriter will be closed, but changes may have been lost.

      Note that this may be a costly operation, so, try to re-use a single writer instead of closing and opening a new one. See commit() for caveats about write caching done by some IO devices.

      NOTE: You must ensure no other threads are still making changes at the same time that this method is invoked.

      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Throws:
      IOException

    • shouldClose

      private boolean shouldClose(boolean waitForClose)

    • getDirectory

      public Directory getDirectory()
      Returns the Directory used by this index.

    • getInfoStream

      public InfoStream getInfoStream()
      Description copied from interface: MergePolicy.MergeContext
      Returns the info stream that can be used to log messages
      Specified by:
      getInfoStream in interface MergePolicy.MergeContext

    • getAnalyzer

      public Analyzer getAnalyzer()
      Returns the analyzer used by this index.

    • advanceSegmentInfosVersion

      public void advanceSegmentInfosVersion(long newVersion)
      If SegmentInfos.getVersion() is below newVersion then update it to this value.

    • hasDeletions

      public boolean hasDeletions()
      Returns true if this index has deletions (including buffered deletions). Note that this will return true if there are buffered Term/Query deletions, even if it turns out those buffered deletions don't match any documents.

    • addDocument

      public long addDocument(Iterable<? extends IndexableField> doc) throws IOException
      Adds a document to this index.

      Note that if an Exception is hit (for example disk full) then the index will be consistent, but this document may not have been added. Furthermore, it's possible the index will have one segment in non-compound format even when using compound files (when a merge has partially succeeded).

      This method periodically flushes pending documents to the Directory (see above), and also periodically triggers segment merges in the index according to the MergePolicy in use.

      Merges temporarily consume space in the directory. The amount of space required is up to 1X the size of all segments being merged, when no readers/searchers are open against the index, and up to 2X the size of all segments being merged when readers/searchers are open against the index (see forceMerge(int) for details). The sequence of primitive merge operations performed is governed by the merge policy.

      Note that each term in the document can be no longer than MAX_TERM_LENGTH in bytes, otherwise an IllegalArgumentException will be thrown.

      Note that it's possible to create an invalid Unicode string in java if a UTF16 surrogate pair is malformed. In this case, the invalid characters are silently replaced with the Unicode replacement character U+FFFD.

      Returns:
      The sequence number for this operation
      Throws:
      CorruptIndexException - if the index is corrupt
      IOException - if there is a low-level IO error

    • addDocuments

      public long addDocuments(Iterable<? extends Iterable<? extends IndexableField>> docs) throws IOException
      Atomically adds a block of documents with sequentially assigned document IDs, such that an external reader will see all or none of the documents.

      WARNING: the index does not currently record which documents were added as a block. Today this is fine, because merging will preserve a block. The order of documents within a segment will be preserved, even when child documents within a block are deleted. Most search features (like result grouping and block joining) require you to mark documents; when these documents are deleted these search features will not work as expected. Obviously adding documents to an existing block will require you the reindex the entire block.

      However it's possible that in the future Lucene may merge more aggressively re-order documents (for example, perhaps to obtain better index compression), in which case you may need to fully re-index your documents at that time.

      See addDocument(Iterable) for details on index and IndexWriter state after an Exception, and flushing/merging temporary free space requirements.

      NOTE: tools that do offline splitting of an index (for example, IndexSplitter in contrib) or re-sorting of documents (for example, IndexSorter in contrib) are not aware of these atomically added documents and will likely break them up. Use such tools at your own risk!

      Returns:
      The sequence number for this operation
      Throws:
      CorruptIndexException - if the index is corrupt
      IOException - if there is a low-level IO error

    • updateDocuments

      public long updateDocuments(Term delTerm, Iterable<? extends Iterable<? extends IndexableField>> docs) throws IOException
      Atomically deletes documents matching the provided delTerm and adds a block of documents with sequentially assigned document IDs, such that an external reader will see all or none of the documents.

      See addDocuments(Iterable).

      Returns:
      The sequence number for this operation
      Throws:
      CorruptIndexException - if the index is corrupt
      IOException - if there is a low-level IO error

    • updateDocuments

      public long updateDocuments(Query delQuery, Iterable<? extends Iterable<? extends IndexableField>> docs) throws IOException
      Similar to updateDocuments(Term, Iterable), but take a query instead of a term to identify the documents to be updated
      Throws:
      IOException

    • updateDocuments

      private long updateDocuments(DocumentsWriterDeleteQueue.Node<?> delNode, Iterable<? extends Iterable<? extends IndexableField>> docs) throws IOException
      Throws:
      IOException

    • softUpdateDocuments

      public long softUpdateDocuments(Term term, Iterable<? extends Iterable<? extends IndexableField>> docs, Field... softDeletes) throws IOException
      Expert: Atomically updates documents matching the provided term with the given doc-values fields and adds a block of documents with sequentially assigned document IDs, such that an external reader will see all or none of the documents.

      One use of this API is to retain older versions of documents instead of replacing them. The existing documents can be updated to reflect they are no longer current while atomically adding new documents at the same time.

      In contrast to updateDocuments(Term, Iterable) this method will not delete documents in the index matching the given term but instead update them with the given doc-values fields which can be used as a soft-delete mechanism.

      See addDocuments(Iterable) and updateDocuments(Term, Iterable).

      Returns:
      The sequence number for this operation
      Throws:
      CorruptIndexException - if the index is corrupt
      IOException - if there is a low-level IO error

    • tryDeleteDocument

      public long tryDeleteDocument(IndexReader readerIn, int docID) throws IOException
      Expert: attempts to delete by document ID, as long as the provided reader is a near-real-time reader (from DirectoryReader.open(IndexWriter)). If the provided reader is an NRT reader obtained from this writer, and its segment has not been merged away, then the delete succeeds and this method returns a valid (> 0) sequence number; else, it returns -1 and the caller must then separately delete by Term or Query.

      NOTE: this method can only delete documents visible to the currently open NRT reader. If you need to delete documents indexed after opening the NRT reader you must use deleteDocuments(Term...)).

      Throws:
      IOException

    • tryUpdateDocValue

      public long tryUpdateDocValue(IndexReader readerIn, int docID, Field... fields) throws IOException
      Expert: attempts to update doc values by document ID, as long as the provided reader is a near-real-time reader (from DirectoryReader.open(IndexWriter)). If the provided reader is an NRT reader obtained from this writer, and its segment has not been merged away, then the update succeeds and this method returns a valid (> 0) sequence number; else, it returns -1 and the caller must then either retry the update and resolve the document again. If a doc values fields data is null the existing value is removed from all documents matching the term. This can be used to un-delete a soft-deleted document since this method will apply the field update even if the document is marked as deleted.

      NOTE: this method can only updates documents visible to the currently open NRT reader. If you need to update documents indexed after opening the NRT reader you must use updateDocValues(Term, Field...).

      Throws:
      IOException

    • tryModifyDocument

      private long tryModifyDocument(IndexReader readerIn, int docID, IndexWriter.DocModifier toApply) throws IOException
      Throws:
      IOException

    • dropDeletedSegment

      private void dropDeletedSegment(SegmentCommitInfo info) throws IOException
      Drops a segment that has 100% deleted documents.
      Throws:
      IOException

    • deleteDocuments

      public long deleteDocuments(Term... terms) throws IOException
      Deletes the document(s) containing any of the terms. All given deletes are applied and flushed atomically at the same time.
      Parameters:
      terms - array of terms to identify the documents to be deleted
      Returns:
      The sequence number for this operation
      Throws:
      CorruptIndexException - if the index is corrupt
      IOException - if there is a low-level IO error

    • deleteDocuments

      public long deleteDocuments(Query... queries) throws IOException
      Deletes the document(s) matching any of the provided queries. All given deletes are applied and flushed atomically at the same time.
      Parameters:
      queries - array of queries to identify the documents to be deleted
      Returns:
      The sequence number for this operation
      Throws:
      CorruptIndexException - if the index is corrupt
      IOException - if there is a low-level IO error

    • updateDocument

      public long updateDocument(Term term, Iterable<? extends IndexableField> doc) throws IOException
      Updates a document by first deleting the document(s) containing term and then adding the new document. The delete and then add are atomic as seen by a reader on the same index (flush may happen only after the add).
      Parameters:
      term - the term to identify the document(s) to be deleted
      doc - the document to be added
      Returns:
      The sequence number for this operation
      Throws:
      CorruptIndexException - if the index is corrupt
      IOException - if there is a low-level IO error

    • softUpdateDocument

      public long softUpdateDocument(Term term, Iterable<? extends IndexableField> doc, Field... softDeletes) throws IOException
      Expert: Updates a document by first updating the document(s) containing term with the given doc-values fields and then adding the new document. The doc-values update and then add are atomic as seen by a reader on the same index (flush may happen only after the add).

      One use of this API is to retain older versions of documents instead of replacing them. The existing documents can be updated to reflect they are no longer current while atomically adding new documents at the same time.

      In contrast to updateDocument(Term, Iterable) this method will not delete documents in the index matching the given term but instead update them with the given doc-values fields which can be used as a soft-delete mechanism.

      See addDocuments(Iterable) and updateDocuments(Term, Iterable).

      Returns:
      The sequence number for this operation
      Throws:
      CorruptIndexException - if the index is corrupt
      IOException - if there is a low-level IO error

    • updateNumericDocValue

      public long updateNumericDocValue(Term term, String field, long value) throws IOException
      Updates a document's NumericDocValues for field to the given value . You can only update fields that already exist in the index, not add new fields through this method. You can only update fields that were indexed with doc values only.
      Parameters:
      term - the term to identify the document(s) to be updated
      field - field name of the NumericDocValues field
      value - new value for the field
      Returns:
      The sequence number for this operation
      Throws:
      CorruptIndexException - if the index is corrupt
      IOException - if there is a low-level IO error

    • updateBinaryDocValue

      public long updateBinaryDocValue(Term term, String field, BytesRef value) throws IOException
      Updates a document's BinaryDocValues for field to the given value . You can only update fields that already exist in the index, not add new fields through this method. You can only update fields that were indexed only with doc values.

      NOTE: this method currently replaces the existing value of all affected documents with the new value.

      Parameters:
      term - the term to identify the document(s) to be updated
      field - field name of the BinaryDocValues field
      value - new value for the field
      Returns:
      The sequence number for this operation
      Throws:
      CorruptIndexException - if the index is corrupt
      IOException - if there is a low-level IO error

    • updateDocValues

      public long updateDocValues(Term term, Field... updates) throws IOException
      Updates documents' DocValues fields to the given values. Each field update is applied to the set of documents that are associated with the Term to the same value. All updates are atomically applied and flushed together. If a doc values fields data is null the existing value is removed from all documents matching the term.
      Parameters:
      updates - the updates to apply
      Returns:
      The sequence number for this operation
      Throws:
      CorruptIndexException - if the index is corrupt
      IOException - if there is a low-level IO error

    • buildDocValuesUpdate

      private DocValuesUpdate[] buildDocValuesUpdate(Term term, Field[] updates)

    • getFieldNames

      public Set<String> getFieldNames()
      Return an unmodifiable set of all field names as visible from this IndexWriter, across all segments of the index.

    • getSegmentCount

      final int getSegmentCount()

    • getNumBufferedDocuments

      final int getNumBufferedDocuments()

    • maxDoc

      final int maxDoc(int i)

    • getFlushCount

      final int getFlushCount()

    • getFlushDeletesCount

      final int getFlushDeletesCount()

    • newSegmentName

      private final String newSegmentName()

    • forceMerge

      public void forceMerge(int maxNumSegments) throws IOException
      Forces merge policy to merge segments until there are <= maxNumSegments. The actual merges to be executed are determined by the MergePolicy.

      This is a horribly costly operation, especially when you pass a small maxNumSegments; usually you should only call this if the index is static (will no longer be changed).

      Note that this requires free space that is proportional to the size of the index in your Directory: 2X if you are not using compound file format, and 3X if you are. For example, if your index size is 10 MB then you need an additional 20 MB free for this to complete (30 MB if you're using compound file format). This is also affected by the Codec that is used to execute the merge, and may result in even a bigger index. Also, it's best to call commit() afterwards, to allow IndexWriter to free up disk space.

      If some but not all readers re-open while merging is underway, this will cause > 2X temporary space to be consumed as those new readers will then hold open the temporary segments at that time. It is best not to re-open readers while merging is running.

      The actual temporary usage could be much less than these figures (it depends on many factors).

      In general, once this completes, the total size of the index will be less than the size of the starting index. It could be quite a bit smaller (if there were many pending deletes) or just slightly smaller.

      If an Exception is hit, for example due to disk full, the index will not be corrupted and no documents will be lost. However, it may have been partially merged (some segments were merged but not all), and it's possible that one of the segments in the index will be in non-compound format even when using compound file format. This will occur when the Exception is hit during conversion of the segment into compound format.

      This call will merge those segments present in the index when the call started. If other threads are still adding documents and flushing segments, those newly created segments will not be merged unless you call forceMerge again.

      Parameters:
      maxNumSegments - maximum number of segments left in the index after merging finishes
      Throws:
      CorruptIndexException - if the index is corrupt
      IOException - if there is a low-level IO error
      See Also:

    • forceMerge

      public void forceMerge(int maxNumSegments, boolean doWait) throws IOException
      Just like forceMerge(int), except you can specify whether the call should block until all merging completes. This is only meaningful with a MergeScheduler that is able to run merges in background threads.
      Throws:
      IOException

    • maxNumSegmentsMergesPending

      private boolean maxNumSegmentsMergesPending()
      Returns true if any merges in pendingMerges or runningMerges are maxNumSegments merges.

    • forceMergeDeletes

      public void forceMergeDeletes(boolean doWait) throws IOException
      Just like forceMergeDeletes(), except you can specify whether the call should block until the operation completes. This is only meaningful with a MergeScheduler that is able to run merges in background threads.
      Throws:
      IOException

    • forceMergeDeletes

      public void forceMergeDeletes() throws IOException
      Forces merging of all segments that have deleted documents. The actual merges to be executed are determined by the MergePolicy. For example, the default TieredMergePolicy will only pick a segment if the percentage of deleted docs is over 10%.

      This is often a horribly costly operation; rarely is it warranted.

      To see how many deletions you have pending in your index, call IndexReader.numDeletedDocs().

      NOTE: this method first flushes a new segment (if there are indexed documents), and applies all buffered deletes.

      Throws:
      IOException

    • maybeMerge

      public final void maybeMerge() throws IOException
      Expert: asks the mergePolicy whether any merges are necessary now and if so, runs the requested merges and then iterate (test again if merges are needed) until no more merges are returned by the mergePolicy.

      Explicit calls to maybeMerge() are usually not necessary. The most common case is when merge policy parameters have changed.

      This method will call the MergePolicy with MergeTrigger.EXPLICIT.

      Throws:
      IOException

    • maybeMerge

      private final void maybeMerge(MergePolicy mergePolicy, MergeTrigger trigger, int maxNumSegments) throws IOException
      Throws:
      IOException

    • executeMerge

      final void executeMerge(MergeTrigger trigger) throws IOException
      Throws:
      IOException

    • updatePendingMerges

      private MergePolicy.MergeSpecification updatePendingMerges(MergePolicy mergePolicy, MergeTrigger trigger, int maxNumSegments) throws IOException
      Throws:
      IOException

    • getMergingSegments

      public Set<SegmentCommitInfo> getMergingSegments()
      Expert: to be used by a MergePolicy to avoid selecting merges for segments already being merged. The returned collection is not cloned, and thus is only safe to access if you hold IndexWriter's lock (which you do when IndexWriter invokes the MergePolicy).

      The Set is unmodifiable.

      Specified by:
      getMergingSegments in interface MergePolicy.MergeContext

    • getNextMerge

      private MergePolicy.OneMerge getNextMerge()
      Expert: the MergeScheduler calls this method to retrieve the next merge requested by the MergePolicy

    • hasPendingMerges

      public boolean hasPendingMerges()
      Expert: returns true if there are merges waiting to be scheduled.

    • rollback

      public void rollback() throws IOException
      Close the IndexWriter without committing any changes that have occurred since the last commit (or since it was opened, if commit hasn't been called). This removes any temporary files that had been created, after which the state of the index will be the same as it was when commit() was last called or when this writer was first opened. This also clears a previous call to prepareCommit().
      Specified by:
      rollback in interface TwoPhaseCommit
      Throws:
      IOException - if there is a low-level IO error

    • rollbackInternal

      private void rollbackInternal() throws IOException
      Throws:
      IOException

    • rollbackInternalNoCommit

      private void rollbackInternalNoCommit() throws IOException
      Throws:
      IOException

    • deleteAll

      public long deleteAll() throws IOException
      Delete all documents in the index.

      This method will drop all buffered documents and will remove all segments from the index. This change will not be visible until a commit() has been called. This method can be rolled back using rollback().

      NOTE: this method is much faster than using deleteDocuments( new MatchAllDocsQuery() ). Yet, this method also has different semantics compared to deleteDocuments(Query...) since internal data-structures are cleared as well as all segment information is forcefully dropped anti-viral semantics like omitting norms are reset or doc value types are cleared. Essentially a call to deleteAll() is equivalent to creating a new IndexWriter with IndexWriterConfig.OpenMode.CREATE which a delete query only marks documents as deleted.

      NOTE: this method will forcefully abort all merges in progress. If other threads are running forceMerge(int), addIndexes(CodecReader[]) or forceMergeDeletes(boolean) methods, they may receive MergePolicy.MergeAbortedExceptions.

      Returns:
      The sequence number for this operation
      Throws:
      IOException

    • abortMerges

      private void abortMerges() throws IOException
      Aborts running merges. Be careful when using this method: when you abort a long-running merge, you lose a lot of work that must later be redone.
      Throws:
      IOException

    • waitForMerges

      void waitForMerges() throws IOException
      Wait for any currently outstanding merges to finish.

      It is guaranteed that any merges started prior to calling this method will have completed once this method completes.

      Throws:
      IOException

    • checkpoint

      private void checkpoint() throws IOException
      Called whenever the SegmentInfos has been updated and the index files referenced exist (correctly) in the index directory.
      Throws:
      IOException

    • checkpointNoSIS

      private void checkpointNoSIS() throws IOException
      Checkpoints with IndexFileDeleter, so it's aware of new files, and increments changeCount, so on close/commit we will write a new segments file, but does NOT bump segmentInfos.version.
      Throws:
      IOException

    • changed

      private void changed()
      Called internally if any index state has changed.

    • publishFrozenUpdates

      private long publishFrozenUpdates(FrozenBufferedUpdates packet)

    • publishFlushedSegment

      private void publishFlushedSegment(SegmentCommitInfo newSegment, FieldInfos fieldInfos, FrozenBufferedUpdates packet, FrozenBufferedUpdates globalPacket, Sorter.DocMap sortMap) throws IOException
      Atomically adds the segment private delete packet and publishes the flushed segments SegmentInfo to the index writer.
      Throws:
      IOException

    • resetMergeExceptions

      private void resetMergeExceptions()

    • noDupDirs

      private void noDupDirs(Directory... dirs)

    • acquireWriteLocks

      private List<Lock> acquireWriteLocks(Directory... dirs) throws IOException
      Acquires write locks on all the directories; be sure to match with a call to IOUtils.close(java.io.Closeable...) in a finally clause.
      Throws:
      IOException

    • addIndexes

      public long addIndexes(Directory... dirs) throws IOException
      Adds all segments from an array of indexes into this index.

      This may be used to parallelize batch indexing. A large document collection can be broken into sub-collections. Each sub-collection can be indexed in parallel, on a different thread, process or machine. The complete index can then be created by merging sub-collection indexes with this method.

      NOTE: this method acquires the write lock in each directory, to ensure that no IndexWriter is currently open or tries to open while this is running.

      This method is transactional in how Exceptions are handled: it does not commit a new segments_N file until all indexes are added. This means if an Exception occurs (for example disk full), then either no indexes will have been added or they all will have been.

      Note that this requires temporary free space in the Directory up to 2X the sum of all input indexes (including the starting index). If readers/searchers are open against the starting index, then temporary free space required will be higher by the size of the starting index (see forceMerge(int) for details).

      This requires this index not be among those to be added.

      All added indexes must have been created by the same Lucene version as this index.

      Returns:
      The sequence number for this operation
      Throws:
      CorruptIndexException - if the index is corrupt
      IOException - if there is a low-level IO error
      IllegalArgumentException - if addIndexes would cause the index to exceed MAX_DOCS, or if the indoming index sort does not match this index's index sort

    • validateMergeReader

      private void validateMergeReader(CodecReader leaf)

    • addIndexes

      public long addIndexes(CodecReader... readers) throws IOException
      Merges the provided indexes into this index.

      The provided IndexReaders are not closed.

      See addIndexes(org.apache.lucene.store.Directory...) for details on transactional semantics, temporary free space required in the Directory, and non-CFS segments on an Exception.

      NOTE: empty segments are dropped by this method and not added to this index.

      NOTE: provided LeafReaders are merged as specified by the MergePolicy.findMerges(CodecReader...) API. Default behavior is to merge all provided readers into a single segment. You can modify this by overriding the findMerge API in your custom merge policy.

      Returns:
      The sequence number for this operation
      Throws:
      CorruptIndexException - if the index is corrupt
      IOException - if there is a low-level IO error
      IllegalArgumentException - if addIndexes would cause the index to exceed MAX_DOCS

    • addIndexesReaderMerge

      public void addIndexesReaderMerge(MergePolicy.OneMerge merge) throws IOException
      Runs a single merge operation for addIndexes(CodecReader...).

      Merges and creates a SegmentInfo, for the readers grouped together in provided OneMerge.

      Parameters:
      merge - OneMerge object initialized from readers.
      Throws:
      IOException - if there is a low-level IO error

    • copySegmentAsIs

      private SegmentCommitInfo copySegmentAsIs(SegmentCommitInfo info, String segName, IOContext context) throws IOException
      Copies the segment files as-is into the IndexWriter's directory.
      Throws:
      IOException

    • doAfterFlush

      protected void doAfterFlush() throws IOException
      A hook for extending classes to execute operations after pending added and deleted documents have been flushed to the Directory but before the change is committed (new segments_N file written).
      Throws:
      IOException

    • doBeforeFlush

      protected void doBeforeFlush() throws IOException
      A hook for extending classes to execute operations before pending added and deleted documents are flushed to the Directory.
      Throws:
      IOException

    • prepareCommit

      public final long prepareCommit() throws IOException
      Expert: prepare for commit. This does the first phase of 2-phase commit. This method does all steps necessary to commit changes since this writer was opened: flushes pending added and deleted docs, syncs the index files, writes most of next segments_N file. After calling this you must call either commit() to finish the commit, or rollback() to revert the commit and undo all changes done since the writer was opened.

      You can also just call commit() directly without prepareCommit first in which case that method will internally call prepareCommit.

      Specified by:
      prepareCommit in interface TwoPhaseCommit
      Returns:
      The sequence number of the last operation in the commit. All sequence numbers <= this value will be reflected in the commit, and all others will not.
      Throws:
      IOException

    • flushNextBuffer

      public final boolean flushNextBuffer() throws IOException
      Expert: Flushes the next pending writer per thread buffer if available or the largest active non-pending writer per thread buffer in the calling thread. This can be used to flush documents to disk outside of an indexing thread. In contrast to flush() this won't mark all currently active indexing buffers as flush-pending.

      Note: this method is best-effort and might not flush any segments to disk. If there is a full flush happening concurrently multiple segments might have been flushed. Users of this API can access the IndexWriters current memory consumption via ramBytesUsed()

      Returns:
      true iff this method flushed at least on segment to disk.
      Throws:
      IOException

    • prepareCommitInternal

      private long prepareCommitInternal() throws IOException
      Throws:
      IOException

    • preparePointInTimeMerge

      private MergePolicy.MergeSpecification preparePointInTimeMerge(SegmentInfos mergingSegmentInfos, BooleanSupplier stopCollectingMergeResults, MergeTrigger trigger, IOConsumer<SegmentCommitInfo> mergeFinished) throws IOException
      This optimization allows a commit/getReader to wait for merges on smallish segments to reduce the eventual number of tiny segments in the commit point / NRT Reader. We wrap a OneMerge to update the mergingSegmentInfos once the merge has finished. We replace the source segments in the SIS that we are going to commit / open the reader on with the freshly merged segment, but ignore all deletions and updates that are made to documents in the merged segment while it was merging. The updates that are made do not belong to the point-in-time commit point / NRT READER and should therefore not be included. See the clone call in onMergeComplete below. We also ensure that we pull the merge readers while holding IndexWriter's lock. Otherwise we could see concurrent deletions/updates applied that do not belong to the segment.
      Throws:
      IOException

    • writeReaderPool

      private void writeReaderPool(boolean writeDeletes) throws IOException
      Ensures that all changes in the reader-pool are written to disk.
      Parameters:
      writeDeletes - if true if deletes should be written to disk too.
      Throws:
      IOException

    • setLiveCommitData

      public final void setLiveCommitData(Iterable<Map.Entry<String,String>> commitUserData)
      Sets the iterator to provide the commit user data map at commit time. Calling this method is considered a committable change and will be committed even if there are no other changes this writer. Note that you must call this method before prepareCommit(). Otherwise it won't be included in the follow-on commit().

      NOTE: the iterator is late-binding: it is only visited once all documents for the commit have been written to their segments, before the next segments_N file is written

    • setLiveCommitData

      public final void setLiveCommitData(Iterable<Map.Entry<String,String>> commitUserData, boolean doIncrementVersion)
      Sets the commit user data iterator, controlling whether to advance the SegmentInfos.getVersion().
      See Also:

    • getLiveCommitData

      public final Iterable<Map.Entry<String,String>> getLiveCommitData()
      Returns the commit user data iterable previously set with setLiveCommitData(Iterable), or null if nothing has been set yet.

    • commit

      public final long commit() throws IOException
      Commits all pending changes (added and deleted documents, segment merges, added indexes, etc.) to the index, and syncs all referenced index files, such that a reader will see the changes and the index updates will survive an OS or machine crash or power loss. Note that this does not wait for any running background merges to finish. This may be a costly operation, so you should test the cost in your application and do it only when really necessary.

      Note that this operation calls Directory.sync on the index files. That call should not return until the file contents and metadata are on stable storage. For FSDirectory, this calls the OS's fsync. But, beware: some hardware devices may in fact cache writes even during fsync, and return before the bits are actually on stable storage, to give the appearance of faster performance. If you have such a device, and it does not have a battery backup (for example) then on power loss it may still lose data. Lucene cannot guarantee consistency on such devices.

      If nothing was committed, because there were no pending changes, this returns -1. Otherwise, it returns the sequence number such that all indexing operations prior to this sequence will be included in the commit point, and all other operations will not.

      Specified by:
      commit in interface TwoPhaseCommit
      Returns:
      The sequence number of the last operation in the commit. All sequence numbers <= this value will be reflected in the commit, and all others will not.
      Throws:
      IOException
      See Also:

    • hasUncommittedChanges

      public final boolean hasUncommittedChanges()
      Returns true if there may be changes that have not been committed. There are cases where this may return true when there are no actual "real" changes to the index, for example if you've deleted by Term or Query but that Term or Query does not match any documents. Also, if a merge kicked off as a result of flushing a new segment during commit(), or a concurrent merged finished, this method may return true right after you had just called commit().

    • hasChangesInRam

      boolean hasChangesInRam()
      Returns true if there are any changes or deletes that are not flushed or applied.

    • commitInternal

      private long commitInternal(MergePolicy mergePolicy) throws IOException
      Throws:
      IOException

    • finishCommit

      private void finishCommit() throws IOException
      Throws:
      IOException

    • flush

      public final void flush() throws IOException
      Moves all in-memory segments to the Directory, but does not commit (fsync) them (call commit() for that).
      Throws:
      IOException

    • flush

      final void flush(boolean triggerMerge, boolean applyAllDeletes) throws IOException
      Flush all in-memory buffered updates (adds and deletes) to the Directory.
      Parameters:
      triggerMerge - if true, we may merge segments (if deletes or docs were flushed) if necessary
      applyAllDeletes - whether pending deletes should also
      Throws:
      IOException

    • doFlush

      private boolean doFlush(boolean applyAllDeletes) throws IOException
      Returns true a segment was flushed or deletes were applied.
      Throws:
      IOException

    • applyAllDeletesAndUpdates

      private void applyAllDeletesAndUpdates() throws IOException
      Throws:
      IOException

    • getDocsWriter

      DocumentsWriter getDocsWriter()

    • numRamDocs

      public final int numRamDocs()
      Expert: Return the number of documents currently buffered in RAM.

    • ensureValidMerge

      private void ensureValidMerge(MergePolicy.OneMerge merge)

    • commitMergedDeletesAndUpdates

      private ReadersAndUpdates commitMergedDeletesAndUpdates(MergePolicy.OneMerge merge, MergeState.DocMap[] docMaps) throws IOException
      Carefully merges deletes and updates for the segments we just merged. This is tricky because, although merging will clear all deletes (compacts the documents) and compact all the updates, new deletes and updates may have been flushed to the segments since the merge was started. This method "carries over" such new deletes and updates onto the newly merged segment, and saves the resulting deletes and updates files (incrementing the delete and DV generations for merge.info). If no deletes were flushed, no new deletes file is saved.
      Throws:
      IOException

    • carryOverHardDeletes

      private static void carryOverHardDeletes(ReadersAndUpdates mergedReadersAndUpdates, int maxDoc, Bits prevHardLiveDocs, Bits currentHardLiveDocs, MergeState.DocMap segDocMap) throws IOException
      This method carries over hard-deleted documents that are applied to the source segment during a merge.
      Throws:
      IOException

    • commitMerge

      private boolean commitMerge(MergePolicy.OneMerge merge, MergeState.DocMap[] docMaps) throws IOException
      Throws:
      IOException

    • handleMergeException

      private void handleMergeException(Throwable t, MergePolicy.OneMerge merge) throws IOException
      Throws:
      IOException

    • merge

      protected void merge(MergePolicy.OneMerge merge) throws IOException
      Merges the indicated segments, replacing them in the stack with a single segment.
      Throws:
      IOException

    • mergeSuccess

      protected void mergeSuccess(MergePolicy.OneMerge merge)
      Hook that's called when the specified merge is complete.

    • abortOneMerge

      private void abortOneMerge(MergePolicy.OneMerge merge) throws IOException
      Throws:
      IOException

    • registerMerge

      private boolean registerMerge(MergePolicy.OneMerge merge) throws IOException
      Checks whether this merge involves any segments already participating in a merge. If not, this merge is "registered", meaning we record that its segments are now participating in a merge, and true is returned. Else (the merge conflicts) false is returned.
      Throws:
      IOException

    • mergeInit

      final void mergeInit(MergePolicy.OneMerge merge) throws IOException
      Does initial setup for a merge, which is fast but holds the synchronized lock on IndexWriter instance.
      Throws:
      IOException

    • _mergeInit

      private void _mergeInit(MergePolicy.OneMerge merge) throws IOException
      Throws:
      IOException

    • setDiagnostics

      static void setDiagnostics(SegmentInfo info, String source)

    • setDiagnostics

      private static void setDiagnostics(SegmentInfo info, String source, Map<String,String> details)

    • mergeFinish

      private void mergeFinish(MergePolicy.OneMerge merge)
      Does finishing for a merge, which is fast but holds the synchronized lock on IndexWriter instance.

    • closeMergeReaders

      private void closeMergeReaders(MergePolicy.OneMerge merge, boolean suppressExceptions, boolean droppedSegment) throws IOException
      Throws:
      IOException

    • countSoftDeletes

      private void countSoftDeletes(CodecReader reader, Bits wrappedLiveDocs, Bits hardLiveDocs, Counter softDeleteCounter, Counter hardDeleteCounter) throws IOException
      Throws:
      IOException

    • assertSoftDeletesCount

      private boolean assertSoftDeletesCount(CodecReader reader, int expectedCount) throws IOException
      Throws:
      IOException

    • mergeMiddle

      private int mergeMiddle(MergePolicy.OneMerge merge, MergePolicy mergePolicy) throws IOException
      Does the actual (time-consuming) work of the merge, but without holding synchronized lock on IndexWriter instance
      Throws:
      IOException

    • addMergeException

      private void addMergeException(MergePolicy.OneMerge merge)

    • getBufferedDeleteTermsSize

      final int getBufferedDeleteTermsSize()

    • newestSegment

      SegmentCommitInfo newestSegment()

    • segString

      String segString()
      Returns a string description of all segments, for debugging.

    • segString

      String segString(Iterable<SegmentCommitInfo> infos)

    • segString

      private String segString(SegmentCommitInfo info)
      Returns a string description of the specified segment, for debugging.

    • doWait

      private void doWait()

    • filesExist

      private boolean filesExist(SegmentInfos toSync) throws IOException
      Throws:
      IOException

    • toLiveInfos

      SegmentInfos toLiveInfos(SegmentInfos sis)

    • startCommit

      private void startCommit(SegmentInfos toSync) throws IOException
      Walk through all files referenced by the current segmentInfos and ask the Directory to sync each file, if it wasn't already. If that succeeds, then we prepare a new segments_N file but do not fully commit it.
      Throws:
      IOException

    • onTragicEvent

      public void onTragicEvent(Throwable tragedy, String location)
      This method should be called on a tragic event ie. if a downstream class of the writer hits an unrecoverable exception. This method does not rethrow the tragic event exception.

      Note: This method will not close the writer but can be called from any location without respecting any lock order

    • tragicEvent

      private void tragicEvent(Throwable tragedy, String location) throws IOException
      This method set the tragic exception unless it's already set and closes the writer if necessary. Note this method will not rethrow the throwable passed to it.
      Throws:
      IOException

    • maybeCloseOnTragicEvent

      private void maybeCloseOnTragicEvent() throws IOException
      Throws:
      IOException

    • getTragicException

      public Throwable getTragicException()
      If this IndexWriter was closed as a side-effect of a tragic exception, e.g. disk full while flushing a new segment, this returns the root cause exception. Otherwise (no tragic exception has occurred) it returns null.

    • isOpen

      public boolean isOpen()
      Returns true if this IndexWriter is still open.

    • testPoint

      private void testPoint(String message)

    • nrtIsCurrent

      boolean nrtIsCurrent(SegmentInfos infos)

    • isClosed

      boolean isClosed()

    • isDeleterClosed

      boolean isDeleterClosed()

    • deleteUnusedFiles

      public void deleteUnusedFiles() throws IOException
      Expert: remove any index files that are no longer used.

      IndexWriter normally deletes unused files itself, during indexing. However, on Windows, which disallows deletion of open files, if there is a reader open on the index then those files cannot be deleted. This is fine, because IndexWriter will periodically retry the deletion.

      However, IndexWriter doesn't try that often: only on open, close, flushing a new segment, and finishing a merge. If you don't do any of these actions with your IndexWriter, you'll see the unused files linger. If that's a problem, call this method to delete them (once you've closed the open readers that were preventing their deletion).

      In addition, you can call this method to delete unreferenced index commits. This might be useful if you are using an IndexDeletionPolicy which holds onto index commits until some criteria are met, but those commits are no longer needed. Otherwise, those commits will be deleted the next time commit() is called.

      Throws:
      IOException

    • createCompoundFile

      static void createCompoundFile(InfoStream infoStream, TrackingDirectoryWrapper directory, SegmentInfo info, IOContext context, IOConsumer<Collection<String>> deleteFiles) throws IOException
      NOTE: this method creates a compound file for all files returned by info.files(). While, generally, this may include separate norms and deletion files, this SegmentInfo must not reference such files when this method is called, because they are not allowed within a compound file.
      Throws:
      IOException

    • deleteNewFiles

      private void deleteNewFiles(Collection<String> files) throws IOException
      Tries to delete the given files if unreferenced
      Parameters:
      files - the files to delete
      Throws:
      IOException - if an IOException occurs
      See Also:

    • flushFailed

      private void flushFailed(SegmentInfo info) throws IOException
      Cleans up residuals from a segment that could not be entirely flushed due to an error
      Throws:
      IOException

    • publishFlushedSegments

      private void publishFlushedSegments(boolean forced) throws IOException
      Publishes the flushed segment, segment-private deletes (if any) and its associated global delete (if present) to IndexWriter. The actual publishing operation is synced on IW -> BDS so that the SegmentInfo's delete generation is always GlobalPacket_deleteGeneration + 1
      Parameters:
      forced - if true this call will block on the ticket queue if the lock is held by another thread. if false the call will try to acquire the queue lock and exits if it's held by another thread.
      Throws:
      IOException

    • incRefDeleter

      public void incRefDeleter(SegmentInfos segmentInfos) throws IOException
      Record that the files referenced by this SegmentInfos are still in use.
      Throws:
      IOException

    • decRefDeleter

      public void decRefDeleter(SegmentInfos segmentInfos) throws IOException
      Record that the files referenced by this SegmentInfos are no longer in use. Only call this if you are sure you previously called incRefDeleter(org.apache.lucene.index.SegmentInfos).
      Throws:
      IOException

    • maybeProcessEvents

      private long maybeProcessEvents(long seqNo) throws IOException
      Processes all events and might trigger a merge if the given seqNo is negative
      Parameters:
      seqNo - if the seqNo is less than 0 this method will process events otherwise it's a no-op.
      Returns:
      the given seqId inverted if negative.
      Throws:
      IOException

    • processEvents

      private void processEvents(boolean triggerMerge) throws IOException
      Throws:
      IOException

    • reserveDocs

      private void reserveDocs(long addedNumDocs)
      Anything that will add N docs to the index should reserve first to make sure it's allowed. This will throw IllegalArgumentException if it's not allowed.

    • testReserveDocs

      private void testReserveDocs(long addedNumDocs)
      Does a best-effort check, that the current index would accept this many additional docs, but does not actually reserve them.
      Throws:
      IllegalArgumentException - if there would be too many docs

    • tooManyDocs

      private void tooManyDocs(long addedNumDocs)

    • getPendingNumDocs

      public long getPendingNumDocs()
      Returns the number of documents in the index including documents are being added (i.e., reserved).

    • getMaxCompletedSequenceNumber

      public long getMaxCompletedSequenceNumber()
      Returns the highest sequence number across all completed operations, or 0 if no operations have finished yet. Still in-flight operations (in other threads) are not counted until they finish.

    • adjustPendingNumDocs

      private long adjustPendingNumDocs(long numDocs)

    • isFullyDeleted

      final boolean isFullyDeleted(ReadersAndUpdates readersAndUpdates) throws IOException
      Throws:
      IOException

    • numDeletesToMerge

      public final int numDeletesToMerge(SegmentCommitInfo info) throws IOException
      Returns the number of deletes a merge would claim back if the given segment is merged.
      Specified by:
      numDeletesToMerge in interface MergePolicy.MergeContext
      Parameters:
      info - the segment to get the number of deletes for
      Throws:
      IOException
      See Also:

    • release

      void release(ReadersAndUpdates readersAndUpdates) throws IOException
      Throws:
      IOException

    • release

      private void release(ReadersAndUpdates readersAndUpdates, boolean assertLiveInfo) throws IOException
      Throws:
      IOException

    • getPooledInstance

      ReadersAndUpdates getPooledInstance(SegmentCommitInfo info, boolean create)

    • tryApply

      final boolean tryApply(FrozenBufferedUpdates updates) throws IOException
      Translates a frozen packet of delete term/query, or doc values updates, into their actual docIDs in the index, and applies the change. This is a heavy operation and is done concurrently by incoming indexing threads. This method will return immediately without blocking if another thread is currently applying the package. In order to ensure the packet has been applied, forceApply(FrozenBufferedUpdates) must be called.
      Throws:
      IOException

    • forceApply

      final void forceApply(FrozenBufferedUpdates updates) throws IOException
      Translates a frozen packet of delete term/query, or doc values updates, into their actual docIDs in the index, and applies the change. This is a heavy operation and is done concurrently by incoming indexing threads.
      Throws:
      IOException

    • getInfosToApply

      private List<SegmentCommitInfo> getInfosToApply(FrozenBufferedUpdates updates)
      Returns the SegmentCommitInfo that this packet is supposed to apply its deletes to, or null if the private segment was already merged away.

    • finishApply

      private void finishApply(BufferedUpdatesStream.SegmentState[] segStates, boolean success, Set<String> delFiles) throws IOException
      Throws:
      IOException

    • closeSegmentStates

      private BufferedUpdatesStream.ApplyDeletesResult closeSegmentStates(BufferedUpdatesStream.SegmentState[] segStates, boolean success) throws IOException
      Close segment states previously opened with openSegmentStates.
      Throws:
      IOException

    • openSegmentStates

      private BufferedUpdatesStream.SegmentState[] openSegmentStates(List<SegmentCommitInfo> infos, Set<SegmentCommitInfo> alreadySeenSegments, long delGen) throws IOException
      Opens SegmentReader and inits SegmentState for each segment.
      Throws:
      IOException

    • isEnableTestPoints

      protected boolean isEnableTestPoints()
      Tests should override this to enable test points. Default is false.

    • validate

      private void validate(SegmentCommitInfo info)

    • cloneSegmentInfos

      final SegmentInfos cloneSegmentInfos()
      Tests should use this method to snapshot the current segmentInfos to have a consistent view

    • getDocStats

      public IndexWriter.DocStats getDocStats()
      Returns accurate IndexWriter.DocStats for this writer. The numDoc for instance can change after maxDoc is fetched that causes numDocs to be greater than maxDoc which makes it hard to get accurate document stats from IndexWriter.