File	Doc	Category	Size	Date	Package
IndexWriter.java	API Doc	Apache Lucene 2.2.0	79249	Sat Jun 16 22:20:36 BST 2007	org.apache.lucene.index

IndexWriter

• java.lang.Object

Fields Summary
public static long	WRITE_LOCK_TIMEOUT Default value for the write lock timeout (1,000).
private long	writeLockTimeout
public static final String	WRITE_LOCK_NAME Name of the write lock in the index.
public static final int	DEFAULT_MERGE_FACTOR Default value is 10. Change using {@link #setMergeFactor(int)}.
public static final int	DEFAULT_MAX_BUFFERED_DOCS Default value is 10. Change using {@link #setMaxBufferedDocs(int)}.
public static final int	DEFAULT_MAX_BUFFERED_DELETE_TERMS Default value is 1000. Change using {@link #setMaxBufferedDeleteTerms(int)}.
public static final int	DEFAULT_MAX_MERGE_DOCS Default value is {@link Integer#MAX_VALUE}. Change using {@link #setMaxMergeDocs(int)}.
public static final int	DEFAULT_MAX_FIELD_LENGTH Default value is 10,000. Change using {@link #setMaxFieldLength(int)}.
public static final int	DEFAULT_TERM_INDEX_INTERVAL Default value is 128. Change using {@link #setTermIndexInterval(int)}.
private static final int	MERGE_READ_BUFFER_SIZE
private Directory	directory
private Analyzer	analyzer
private Similarity	similarity
private boolean	commitPending
private SegmentInfos	rollbackSegmentInfos
private SegmentInfos	localRollbackSegmentInfos
private boolean	localAutoCommit
private boolean	autoCommit
SegmentInfos	segmentInfos
SegmentInfos	ramSegmentInfos
private final RAMDirectory	ramDirectory
private IndexFileDeleter	deleter
private Lock	writeLock
private int	termIndexInterval
private int	maxBufferedDeleteTerms
private HashMap	bufferedDeleteTerms
private int	numBufferedDeleteTerms
private boolean	useCompoundFile Use compound file setting. Defaults to true, minimizing the number of files used. Setting this to false may improve indexing performance, but may also cause file handle problems.
private boolean	closeDir
private boolean	closed
private int	maxFieldLength The maximum number of terms that will be indexed for a single field in a document. This limits the amount of memory required for indexing, so that collections with very large files will not crash the indexing process by running out of memory. Note that this effectively truncates large documents, excluding from the index terms that occur further in the document. If you know your source documents are large, be sure to set this value high enough to accomodate the expected size. If you set it to Integer.MAX_VALUE, then the only limit is your memory, but you should anticipate an OutOfMemoryError. By default, no more than 10,000 terms will be indexed for a field.
private int	mergeFactor Determines how often segment indices are merged by addDocument(). With smaller values, less RAM is used while indexing, and searches on unoptimized indices are faster, but indexing speed is slower. With larger values, more RAM is used during indexing, and while searches on unoptimized indices are slower, indexing is faster. Thus larger values (> 10) are best for batch index creation, and smaller values (< 10) for indices that are interactively maintained. This must never be less than 2. The default value is {@link #DEFAULT_MERGE_FACTOR}.
private int	minMergeDocs Determines the minimal number of documents required before the buffered in-memory documents are merging and a new Segment is created. Since Documents are merged in a {@link org.apache.lucene.store.RAMDirectory}, large value gives faster indexing. At the same time, mergeFactor limits the number of files open in a FSDirectory. The default value is {@link #DEFAULT_MAX_BUFFERED_DOCS}.
private int	maxMergeDocs Determines the largest number of documents ever merged by addDocument(). Small values (e.g., less than 10,000) are best for interactive indexing, as this limits the length of pauses while indexing to a few seconds. Larger values are best for batched indexing and speedier searches. The default value is {@link #DEFAULT_MAX_MERGE_DOCS}.
private PrintStream	infoStream If non-null, information about merges will be printed to this.
private static PrintStream	defaultInfoStream

Constructors Summary
public IndexWriter(Directory d, Analyzer a, boolean create) Constructs an IndexWriter for the index in d. Text will be analyzed with a. If create is true, then a new, empty index will be created in d, replacing the index already there, if any. param d the index directory param a the analyzer to use param create true to create the index or overwrite the existing one; false to append to the existing index throws CorruptIndexException if the index is corrupt throws LockObtainFailedException if another writer has this index open (write.lock could not be obtained) throws IOException if the directory cannot be read/written to, or if it does not exist and create is false or if there is any other low-level IO error init(d, a, create, false, null, true);
public IndexWriter(String path, Analyzer a) Constructs an IndexWriter for the index in path, first creating it if it does not already exist. Text will be analyzed with a. param path the path to the index directory param a the analyzer to use throws CorruptIndexException if the index is corrupt throws LockObtainFailedException if another writer has this index open (write.lock could not be obtained) throws IOException if the directory cannot be read/written to or if there is any other low-level IO error init(FSDirectory.getDirectory(path), a, true, null, true);
public IndexWriter(File path, Analyzer a) Constructs an IndexWriter for the index in path, first creating it if it does not already exist. Text will be analyzed with a. param path the path to the index directory param a the analyzer to use throws CorruptIndexException if the index is corrupt throws LockObtainFailedException if another writer has this index open (write.lock could not be obtained) throws IOException if the directory cannot be read/written to or if there is any other low-level IO error init(FSDirectory.getDirectory(path), a, true, null, true);
public IndexWriter(Directory d, Analyzer a) Constructs an IndexWriter for the index in d, first creating it if it does not already exist. Text will be analyzed with a. param d the index directory param a the analyzer to use throws CorruptIndexException if the index is corrupt throws LockObtainFailedException if another writer has this index open (write.lock could not be obtained) throws IOException if the directory cannot be read/written to or if there is any other low-level IO error init(d, a, false, null, true);
public IndexWriter(Directory d, boolean autoCommit, Analyzer a) Constructs an IndexWriter for the index in d, first creating it if it does not already exist. Text will be analyzed with a. param d the index directory param autoCommit see above param a the analyzer to use throws CorruptIndexException if the index is corrupt throws LockObtainFailedException if another writer has this index open (write.lock could not be obtained) throws IOException if the directory cannot be read/written to or if there is any other low-level IO error init(d, a, false, null, autoCommit);
public IndexWriter(Directory d, boolean autoCommit, Analyzer a, boolean create) Constructs an IndexWriter for the index in d. Text will be analyzed with a. If create is true, then a new, empty index will be created in d, replacing the index already there, if any. param d the index directory param autoCommit see above param a the analyzer to use param create true to create the index or overwrite the existing one; false to append to the existing index throws CorruptIndexException if the index is corrupt throws LockObtainFailedException if another writer has this index open (write.lock could not be obtained) throws IOException if the directory cannot be read/written to, or if it does not exist and create is false or if there is any other low-level IO error init(d, a, create, false, null, autoCommit);
public IndexWriter(Directory d, boolean autoCommit, Analyzer a, IndexDeletionPolicy deletionPolicy) Expert: constructs an IndexWriter with a custom {@link IndexDeletionPolicy}, for the index in d, first creating it if it does not already exist. Text will be analyzed with a. param d the index directory param autoCommit see above param a the analyzer to use param deletionPolicy see above throws CorruptIndexException if the index is corrupt throws LockObtainFailedException if another writer has this index open (write.lock could not be obtained) throws IOException if the directory cannot be read/written to or if there is any other low-level IO error init(d, a, false, deletionPolicy, autoCommit);
public IndexWriter(Directory d, boolean autoCommit, Analyzer a, boolean create, IndexDeletionPolicy deletionPolicy) Expert: constructs an IndexWriter with a custom {@link IndexDeletionPolicy}, for the index in d. Text will be analyzed with a. If create is true, then a new, empty index will be created in d, replacing the index already there, if any. param d the index directory param autoCommit see above param a the analyzer to use param create true to create the index or overwrite the existing one; false to append to the existing index param deletionPolicy see above throws CorruptIndexException if the index is corrupt throws LockObtainFailedException if another writer has this index open (write.lock could not be obtained) throws IOException if the directory cannot be read/written to, or if it does not exist and create is false or if there is any other low-level IO error init(d, a, create, false, deletionPolicy, autoCommit);
public IndexWriter(String path, Analyzer a, boolean create) Constructs an IndexWriter for the index in path. Text will be analyzed with a. If create is true, then a new, empty index will be created in path, replacing the index already there, if any. param path the path to the index directory param a the analyzer to use param create true to create the index or overwrite the existing one; false to append to the existing index throws CorruptIndexException if the index is corrupt throws LockObtainFailedException if another writer has this index open (write.lock could not be obtained) throws IOException if the directory cannot be read/written to, or if it does not exist and create is false or if there is any other low-level IO error init(FSDirectory.getDirectory(path), a, create, true, null, true);
public IndexWriter(File path, Analyzer a, boolean create) Constructs an IndexWriter for the index in path. Text will be analyzed with a. If create is true, then a new, empty index will be created in path, replacing the index already there, if any. param path the path to the index directory param a the analyzer to use param create true to create the index or overwrite the existing one; false to append to the existing index throws CorruptIndexException if the index is corrupt throws LockObtainFailedException if another writer has this index open (write.lock could not be obtained) throws IOException if the directory cannot be read/written to, or if it does not exist and create is false or if there is any other low-level IO error init(FSDirectory.getDirectory(path), a, create, true, null, true);

Methods Summary
public synchronized void	abort() Close the IndexWriter without committing any of the changes that have occurred since it was opened. This removes any temporary files that had been created, after which the state of the index will be the same as it was when this writer was first opened. This can only be called when this IndexWriter was opened with autoCommit=false. throws IllegalStateException if this is called when the writer was opened with autoCommit=true. throws IOException if there is a low-level IO error ensureOpen(); if (!autoCommit) { // Keep the same segmentInfos instance but replace all // of its SegmentInfo instances. This is so the next // attempt to commit using this instance of IndexWriter // will always write to a new generation ("write once"). segmentInfos.clear(); segmentInfos.addAll(rollbackSegmentInfos); // Ask deleter to locate unreferenced files & remove // them: deleter.checkpoint(segmentInfos, false); deleter.refresh(); ramSegmentInfos = new SegmentInfos(); bufferedDeleteTerms.clear(); numBufferedDeleteTerms = 0; commitPending = false; close(); } else { throw new IllegalStateException("abort() can only be called when IndexWriter was opened with autoCommit=false"); }
public void	addDocument(org.apache.lucene.document.Document doc) Adds a document to this index. If the document contains more than {@link #setMaxFieldLength(int)} terms for a given field, the remainder are discarded. 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 (every {@link #setMaxBufferedDocs}), and also periodically merges segments in the index (every {@link #setMergeFactor} flushes). When this occurs, the method will take more time to run (possibly a long time if the index is large), and will require free temporary space in the Directory to do the merging. The amount of free space required when a merge is triggered 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 {@link #optimize()} for details). Most merges are small (merging the smallest segments together), but whenever a full merge occurs (all segments in the index, which is the worst case for temporary space usage) then the maximum free disk space required is the same as {@link #optimize}. throws CorruptIndexException if the index is corrupt throws IOException if there is a low-level IO error addDocument(doc, analyzer);
public void	addDocument(org.apache.lucene.document.Document doc, org.apache.lucene.analysis.Analyzer analyzer) Adds a document to this index, using the provided analyzer instead of the value of {@link #getAnalyzer()}. If the document contains more than {@link #setMaxFieldLength(int)} terms for a given field, the remainder are discarded. See {@link #addDocument(Document)} for details on index and IndexWriter state after an Exception, and flushing/merging temporary free space requirements. throws CorruptIndexException if the index is corrupt throws IOException if there is a low-level IO error ensureOpen(); SegmentInfo newSegmentInfo = buildSingleDocSegment(doc, analyzer); synchronized (this) { ramSegmentInfos.addElement(newSegmentInfo); maybeFlushRamSegments(); }
public synchronized void	addIndexes(org.apache.lucene.store.Directory[] dirs) Merges 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. After this completes, the index is optimized. 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. If an Exception is hit, it's still possible that all indexes were successfully added. This happens when the Exception is hit when trying to build a CFS file. In this case, one segment in the index will be in non-CFS format, even when using compound file format. Also note that on an Exception, the index may still have been partially or fully optimized even though none of the input indexes were added. 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 {@link #optimize()} for details). Once this completes, the final size of the index will be less than the sum of all input index sizes (including the starting index). It could be quite a bit smaller (if there were many pending deletes) or just slightly smaller. See LUCENE-702 for details. throws CorruptIndexException if the index is corrupt throws IOException if there is a low-level IO error ensureOpen(); optimize(); // start with zero or 1 seg int start = segmentInfos.size(); boolean success = false; startTransaction(); try { for (int i = 0; i < dirs.length; i++) { SegmentInfos sis = new SegmentInfos(); // read infos from dir sis.read(dirs[i]); for (int j = 0; j < sis.size(); j++) { segmentInfos.addElement(sis.info(j)); // add each info } } // merge newly added segments in log(n) passes while (segmentInfos.size() > start+mergeFactor) { for (int base = start; base < segmentInfos.size(); base++) { int end = Math.min(segmentInfos.size(), base+mergeFactor); if (end-base > 1) { mergeSegments(segmentInfos, base, end); } } } success = true; } finally { if (success) { commitTransaction(); } else { rollbackTransaction(); } } optimize(); // final cleanup
public synchronized void	addIndexes(org.apache.lucene.index.IndexReader[] readers) Merges the provided indexes into this index. After this completes, the index is optimized. The provided IndexReaders are not closed. See {@link #addIndexes(Directory[])} for details on transactional semantics, temporary free space required in the Directory, and non-CFS segments on an Exception. throws CorruptIndexException if the index is corrupt throws IOException if there is a low-level IO error ensureOpen(); optimize(); // start with zero or 1 seg final String mergedName = newSegmentName(); SegmentMerger merger = new SegmentMerger(this, mergedName); SegmentInfo info; IndexReader sReader = null; try { if (segmentInfos.size() == 1){ // add existing index, if any sReader = SegmentReader.get(segmentInfos.info(0)); merger.add(sReader); } for (int i = 0; i < readers.length; i++) // add new indexes merger.add(readers[i]); boolean success = false; startTransaction(); try { int docCount = merger.merge(); // merge 'em if(sReader != null) { sReader.close(); sReader = null; } segmentInfos.setSize(0); // pop old infos & add new info = new SegmentInfo(mergedName, docCount, directory, false, true); segmentInfos.addElement(info); success = true; } finally { if (!success) { rollbackTransaction(); } else { commitTransaction(); } } } finally { if (sReader != null) { sReader.close(); } } if (useCompoundFile) { boolean success = false; startTransaction(); try { merger.createCompoundFile(mergedName + ".cfs"); info.setUseCompoundFile(true); } finally { if (!success) { rollbackTransaction(); } else { commitTransaction(); } } }
public synchronized void	addIndexesNoOptimize(org.apache.lucene.store.Directory[] dirs) Merges all segments from an array of indexes into this index. This is similar to addIndexes(Directory[]). However, no optimize() is called either at the beginning or at the end. Instead, merges are carried out as necessary. This requires this index not be among those to be added, and the upper bound* of those segment doc counts not exceed maxMergeDocs. See {@link #addIndexes(Directory[])} for details on transactional semantics, temporary free space required in the Directory, and non-CFS segments on an Exception. throws CorruptIndexException if the index is corrupt throws IOException if there is a low-level IO error // Adding indexes can be viewed as adding a sequence of segments S to // a sequence of segments T. Segments in T follow the invariants but // segments in S may not since they could come from multiple indexes. // Here is the merge algorithm for addIndexesNoOptimize(): // // 1 Flush ram segments. // 2 Consider a combined sequence with segments from T followed // by segments from S (same as current addIndexes(Directory[])). // 3 Assume the highest level for segments in S is h. Call // maybeMergeSegments(), but instead of starting w/ lowerBound = -1 // and upperBound = maxBufferedDocs, start w/ lowerBound = -1 and // upperBound = upperBound of level h. After this, the invariants // are guaranteed except for the last < M segments whose levels <= h. // 4 If the invariants hold for the last < M segments whose levels <= h, // if some of those < M segments are from S (not merged in step 3), // properly copy them over*, otherwise done. // Otherwise, simply merge those segments. If the merge results in // a segment of level <= h, done. Otherwise, it's of level h+1 and call // maybeMergeSegments() starting w/ upperBound = upperBound of level h+1. // // * Ideally, we want to simply copy a segment. However, directory does // not support copy yet. In addition, source may use compound file or not // and target may use compound file or not. So we use mergeSegments() to // copy a segment, which may cause doc count to change because deleted // docs are garbage collected. // 1 flush ram segments ensureOpen(); flushRamSegments(); // 2 copy segment infos and find the highest level from dirs int startUpperBound = minMergeDocs; boolean success = false; startTransaction(); try { for (int i = 0; i < dirs.length; i++) { if (directory == dirs[i]) { // cannot add this index: segments may be deleted in merge before added throw new IllegalArgumentException("Cannot add this index to itself"); } SegmentInfos sis = new SegmentInfos(); // read infos from dir sis.read(dirs[i]); for (int j = 0; j < sis.size(); j++) { SegmentInfo info = sis.info(j); segmentInfos.addElement(info); // add each info while (startUpperBound < info.docCount) { startUpperBound *= mergeFactor; // find the highest level from dirs if (startUpperBound > maxMergeDocs) { // upper bound cannot exceed maxMergeDocs throw new IllegalArgumentException("Upper bound cannot exceed maxMergeDocs"); } } } } // 3 maybe merge segments starting from the highest level from dirs maybeMergeSegments(startUpperBound); // get the tail segments whose levels <= h int segmentCount = segmentInfos.size(); int numTailSegments = 0; while (numTailSegments < segmentCount && startUpperBound >= segmentInfos.info(segmentCount - 1 - numTailSegments).docCount) { numTailSegments++; } if (numTailSegments == 0) { success = true; return; } // 4 make sure invariants hold for the tail segments whose levels <= h if (checkNonDecreasingLevels(segmentCount - numTailSegments)) { // identify the segments from S to be copied (not merged in 3) int numSegmentsToCopy = 0; while (numSegmentsToCopy < segmentCount && directory != segmentInfos.info(segmentCount - 1 - numSegmentsToCopy).dir) { numSegmentsToCopy++; } if (numSegmentsToCopy == 0) { success = true; return; } // copy those segments from S for (int i = segmentCount - numSegmentsToCopy; i < segmentCount; i++) { mergeSegments(segmentInfos, i, i + 1); } if (checkNonDecreasingLevels(segmentCount - numSegmentsToCopy)) { success = true; return; } } // invariants do not hold, simply merge those segments mergeSegments(segmentInfos, segmentCount - numTailSegments, segmentCount); // maybe merge segments again if necessary if (segmentInfos.info(segmentInfos.size() - 1).docCount > startUpperBound) { maybeMergeSegments(startUpperBound * mergeFactor); } success = true; } finally { if (success) { commitTransaction(); } else { rollbackTransaction(); } }
private final void	applyDeletes(java.util.HashMap deleteTerms, org.apache.lucene.index.IndexReader reader) Iterator iter = deleteTerms.entrySet().iterator(); while (iter.hasNext()) { Entry entry = (Entry) iter.next(); reader.deleteDocuments((Term) entry.getKey()); }
private final void	applyDeletesSelectively(java.util.HashMap deleteTerms, org.apache.lucene.index.IndexReader reader) Iterator iter = deleteTerms.entrySet().iterator(); while (iter.hasNext()) { Entry entry = (Entry) iter.next(); Term term = (Term) entry.getKey(); TermDocs docs = reader.termDocs(term); if (docs != null) { int num = ((Num) entry.getValue()).getNum(); try { while (docs.next()) { int doc = docs.doc(); if (doc >= num) { break; } reader.deleteDocument(doc); } } finally { docs.close(); } } }
private void	bufferDeleteTerm(org.apache.lucene.index.Term term) Num num = (Num) bufferedDeleteTerms.get(term); if (num == null) { bufferedDeleteTerms.put(term, new Num(ramSegmentInfos.size())); } else { num.setNum(ramSegmentInfos.size()); } numBufferedDeleteTerms++;
org.apache.lucene.index.SegmentInfo	buildSingleDocSegment(org.apache.lucene.document.Document doc, org.apache.lucene.analysis.Analyzer analyzer) DocumentWriter dw = new DocumentWriter(ramDirectory, analyzer, this); dw.setInfoStream(infoStream); String segmentName = newRamSegmentName(); dw.addDocument(segmentName, doc); SegmentInfo si = new SegmentInfo(segmentName, 1, ramDirectory, false, false); si.setNumFields(dw.getNumFields()); return si;
private final boolean	checkNonDecreasingLevels(int start) int lowerBound = -1; int upperBound = minMergeDocs; for (int i = segmentInfos.size() - 1; i >= start; i--) { int docCount = segmentInfos.info(i).docCount; if (docCount <= lowerBound) { return false; } while (docCount > upperBound) { lowerBound = upperBound; upperBound *= mergeFactor; } } return true;
private void	checkpoint() if (autoCommit) { segmentInfos.write(directory); } else { commitPending = true; }
public synchronized void	close() Flushes all changes to an index and closes all associated files. If an Exception is hit during close, eg due to disk full or some other reason, then both the on-disk index and the internal state of the IndexWriter instance will be consistent. However, the close will not be complete even though part of it (flushing buffered documents) may have succeeded, so the write lock will still be held. If you can correct the underlying cause (eg free up some disk space) then you can call close() again. Failing that, if you want to force the write lock to be released (dangerous, because you may then lose buffered docs in the IndexWriter instance) then you can do something like this: try { writer.close(); } finally { if (IndexReader.isLocked(directory)) { IndexReader.unlock(directory); } } after which, you must be certain not to use the writer instance anymore. throws CorruptIndexException if the index is corrupt throws IOException if there is a low-level IO error if (!closed) { flushRamSegments(); if (commitPending) { segmentInfos.write(directory); // now commit changes deleter.checkpoint(segmentInfos, true); commitPending = false; rollbackSegmentInfos = null; } ramDirectory.close(); if (writeLock != null) { writeLock.release(); // release write lock writeLock = null; } closed = true; if(closeDir) directory.close(); }
private void	commitTransaction() // First restore autoCommit in case we hit an exception below: autoCommit = localAutoCommit; boolean success = false; try { checkpoint(); success = true; } finally { if (!success) { rollbackTransaction(); } } if (!autoCommit) // Remove the incRef we did in startTransaction. deleter.decRef(localRollbackSegmentInfos); localRollbackSegmentInfos = null; // Give deleter a chance to remove files now: deleter.checkpoint(segmentInfos, autoCommit);
public synchronized void	deleteDocuments(org.apache.lucene.index.Term term) Deletes the document(s) containing term. param term the term to identify the documents to be deleted throws CorruptIndexException if the index is corrupt throws IOException if there is a low-level IO error ensureOpen(); bufferDeleteTerm(term); maybeFlushRamSegments();
public synchronized void	deleteDocuments(org.apache.lucene.index.Term[] terms) Deletes the document(s) containing any of the terms. All deletes are flushed at the same time. param terms array of terms to identify the documents to be deleted throws CorruptIndexException if the index is corrupt throws IOException if there is a low-level IO error ensureOpen(); for (int i = 0; i < terms.length; i++) { bufferDeleteTerm(terms[i]); } maybeFlushRamSegments();
void	doAfterFlush()
public synchronized int	docCount() Returns the number of documents currently in this index. ensureOpen(); int count = ramSegmentInfos.size(); for (int i = 0; i < segmentInfos.size(); i++) { SegmentInfo si = segmentInfos.info(i); count += si.docCount; } return count;
protected final void	ensureOpen() Used internally to throw an {@link AlreadyClosedException} if this IndexWriter has been closed. throws AlreadyClosedException if this IndexWriter is if (closed) { throw new AlreadyClosedException("this IndexWriter is closed"); }
protected void	finalize() Release the write lock, if needed. try { if (writeLock != null) { writeLock.release(); // release write lock writeLock = null; } } finally { super.finalize(); }
public final synchronized void	flush() Flush all in-memory buffered updates (adds and deletes) to the Directory. Note: if autoCommit=false, flushed data would still not be visible to readers, until {@link #close} is called. throws CorruptIndexException if the index is corrupt throws IOException if there is a low-level IO error ensureOpen(); flushRamSegments();
private final synchronized void	flushRamSegments() Expert: Flushes all RAM-resident segments (buffered documents), then may merge segments. flushRamSegments(true);
protected final synchronized void	flushRamSegments(boolean triggerMerge) Expert: Flushes all RAM-resident segments (buffered documents), then may merge segments if triggerMerge==true. if (ramSegmentInfos.size() > 0 || bufferedDeleteTerms.size() > 0) { mergeSegments(ramSegmentInfos, 0, ramSegmentInfos.size()); if (triggerMerge) maybeMergeSegments(minMergeDocs); }
public org.apache.lucene.analysis.Analyzer	getAnalyzer() Returns the analyzer used by this index. ensureOpen(); return analyzer;
final synchronized int	getBufferedDeleteTermsSize() return bufferedDeleteTerms.size();
public static java.io.PrintStream	getDefaultInfoStream() Returns the current default infoStream for newly instantiated IndexWriters. see #setDefaultInfoStream return IndexWriter.defaultInfoStream;
public static long	getDefaultWriteLockTimeout() Returns default write lock timeout for newly instantiated IndexWriters. see #setDefaultWriteLockTimeout return IndexWriter.WRITE_LOCK_TIMEOUT;
public org.apache.lucene.store.Directory	getDirectory() Returns the Directory used by this index. ensureOpen(); return directory;
final synchronized int	getDocCount(int i) if (i >= 0 && i < segmentInfos.size()) { return segmentInfos.info(i).docCount; } else { return -1; }
public java.io.PrintStream	getInfoStream() Returns the current infoStream in use by this writer. see #setInfoStream ensureOpen(); return infoStream;
public int	getMaxBufferedDeleteTerms() Returns the number of buffered deleted terms that will trigger a flush. see #setMaxBufferedDeleteTerms ensureOpen(); return maxBufferedDeleteTerms;
public int	getMaxBufferedDocs() Returns the number of buffered added documents that will trigger a flush. see #setMaxBufferedDocs ensureOpen(); return minMergeDocs;
public int	getMaxFieldLength() Returns the maximum number of terms that will be indexed for a single field in a document. see #setMaxFieldLength ensureOpen(); return maxFieldLength;
public int	getMaxMergeDocs() Returns the largest number of documents allowed in a single segment. see #setMaxMergeDocs ensureOpen(); return maxMergeDocs;
public int	getMergeFactor() Returns the number of segments that are merged at once and also controls the total number of segments allowed to accumulate in the index. see #setMergeFactor ensureOpen(); return mergeFactor;
final synchronized int	getNumBufferedDeleteTerms() return numBufferedDeleteTerms;
final synchronized int	getRamSegmentCount() return ramSegmentInfos.size();
final synchronized int	getSegmentCount() return segmentInfos.size();
public org.apache.lucene.search.Similarity	getSimilarity() Expert: Return the Similarity implementation used by this IndexWriter. This defaults to the current value of {@link Similarity#getDefault()}. ensureOpen(); return this.similarity;
public int	getTermIndexInterval() Expert: Return the interval between indexed terms. see #setTermIndexInterval(int) ensureOpen(); return termIndexInterval;
public boolean	getUseCompoundFile() Get the current setting of whether to use the compound file format. Note that this just returns the value you set with setUseCompoundFile(boolean) or the default. You cannot use this to query the status of an existing index. see #setUseCompoundFile(boolean) ensureOpen(); return useCompoundFile;
public long	getWriteLockTimeout() Returns allowed timeout when acquiring the write lock. see #setWriteLockTimeout ensureOpen(); return writeLockTimeout;
private void	init(org.apache.lucene.store.Directory d, org.apache.lucene.analysis.Analyzer a, boolean closeDir, org.apache.lucene.index.IndexDeletionPolicy deletionPolicy, boolean autoCommit) if (IndexReader.indexExists(d)) { init(d, a, false, closeDir, deletionPolicy, autoCommit); } else { init(d, a, true, closeDir, deletionPolicy, autoCommit); }
private void	init(org.apache.lucene.store.Directory d, org.apache.lucene.analysis.Analyzer a, boolean create, boolean closeDir, org.apache.lucene.index.IndexDeletionPolicy deletionPolicy, boolean autoCommit) this.closeDir = closeDir; directory = d; analyzer = a; this.infoStream = defaultInfoStream; if (create) { // Clear the write lock in case it's leftover: directory.clearLock(IndexWriter.WRITE_LOCK_NAME); } Lock writeLock = directory.makeLock(IndexWriter.WRITE_LOCK_NAME); if (!writeLock.obtain(writeLockTimeout)) // obtain write lock throw new LockObtainFailedException("Index locked for write: " + writeLock); this.writeLock = writeLock; // save it try { if (create) { // Try to read first. This is to allow create // against an index that's currently open for // searching. In this case we write the next // segments_N file with no segments: try { segmentInfos.read(directory); segmentInfos.clear(); } catch (IOException e) { // Likely this means it's a fresh directory } segmentInfos.write(directory); } else { segmentInfos.read(directory); } this.autoCommit = autoCommit; if (!autoCommit) { rollbackSegmentInfos = (SegmentInfos) segmentInfos.clone(); } // Default deleter (for backwards compatibility) is // KeepOnlyLastCommitDeleter: deleter = new IndexFileDeleter(directory, deletionPolicy == null ? new KeepOnlyLastCommitDeletionPolicy() : deletionPolicy, segmentInfos, infoStream); } catch (IOException e) { this.writeLock.release(); this.writeLock = null; throw e; }
private final void	maybeApplyDeletes(boolean doMerge) if (bufferedDeleteTerms.size() > 0) { if (infoStream != null) infoStream.println("flush " + numBufferedDeleteTerms + " buffered deleted terms on " + segmentInfos.size() + " segments."); if (doMerge) { IndexReader reader = null; try { reader = SegmentReader.get(segmentInfos.info(segmentInfos.size() - 1)); // Apply delete terms to the segment just flushed from ram // apply appropriately so that a delete term is only applied to // the documents buffered before it, not those buffered after it. applyDeletesSelectively(bufferedDeleteTerms, reader); } finally { if (reader != null) { try { reader.doCommit(); } finally { reader.doClose(); } } } } int infosEnd = segmentInfos.size(); if (doMerge) { infosEnd--; } for (int i = 0; i < infosEnd; i++) { IndexReader reader = null; try { reader = SegmentReader.get(segmentInfos.info(i)); // Apply delete terms to disk segments // except the one just flushed from ram. applyDeletes(bufferedDeleteTerms, reader); } finally { if (reader != null) { try { reader.doCommit(); } finally { reader.doClose(); } } } } // Clean up bufferedDeleteTerms. bufferedDeleteTerms.clear(); numBufferedDeleteTerms = 0; }
protected final void	maybeFlushRamSegments() Used internally to trigger a flush if the number of buffered added documents or buffered deleted terms are large enough. // A flush is triggered if enough new documents are buffered or // if enough delete terms are buffered if (ramSegmentInfos.size() >= minMergeDocs || numBufferedDeleteTerms >= maxBufferedDeleteTerms) { flushRamSegments(); }
private final void	maybeMergeSegments(int startUpperBound) Incremental segment merger. long lowerBound = -1; long upperBound = startUpperBound; while (upperBound < maxMergeDocs) { int minSegment = segmentInfos.size(); int maxSegment = -1; // find merge-worthy segments while (--minSegment >= 0) { SegmentInfo si = segmentInfos.info(minSegment); if (maxSegment == -1 && si.docCount > lowerBound && si.docCount <= upperBound) { // start from the rightmost* segment whose doc count is in bounds maxSegment = minSegment; } else if (si.docCount > upperBound) { // until the segment whose doc count exceeds upperBound break; } } minSegment++; maxSegment++; int numSegments = maxSegment - minSegment; if (numSegments < mergeFactor) { break; } else { boolean exceedsUpperLimit = false; // number of merge-worthy segments may exceed mergeFactor when // mergeFactor and/or maxBufferedDocs change(s) while (numSegments >= mergeFactor) { // merge the leftmost* mergeFactor segments int docCount = mergeSegments(segmentInfos, minSegment, minSegment + mergeFactor); numSegments -= mergeFactor; if (docCount > upperBound) { // continue to merge the rest of the worthy segments on this level minSegment++; exceedsUpperLimit = true; } else { // if the merged segment does not exceed upperBound, consider // this segment for further merges on this same level numSegments++; } } if (!exceedsUpperLimit) { // if none of the merged segments exceed upperBound, done break; } } lowerBound = upperBound; upperBound *= mergeFactor; }
private final int	mergeSegments(org.apache.lucene.index.SegmentInfos sourceSegments, int minSegment, int end) Merges the named range of segments, replacing them in the stack with a single segment. // We may be called solely because there are deletes // pending, in which case doMerge is false: boolean doMerge = end > 0; final String mergedName = newSegmentName(); SegmentMerger merger = null; final List ramSegmentsToDelete = new ArrayList(); SegmentInfo newSegment = null; int mergedDocCount = 0; boolean anyDeletes = (bufferedDeleteTerms.size() != 0); // This is try/finally to make sure merger's readers are closed: try { if (doMerge) { if (infoStream != null) infoStream.print("merging segments"); merger = new SegmentMerger(this, mergedName); for (int i = minSegment; i < end; i++) { SegmentInfo si = sourceSegments.info(i); if (infoStream != null) infoStream.print(" " + si.name + " (" + si.docCount + " docs)"); IndexReader reader = SegmentReader.get(si, MERGE_READ_BUFFER_SIZE); // no need to set deleter (yet) merger.add(reader); if (reader.directory() == this.ramDirectory) { ramSegmentsToDelete.add(si); } } } SegmentInfos rollback = null; boolean success = false; // This is try/finally to rollback our internal state // if we hit exception when doing the merge: try { if (doMerge) { mergedDocCount = merger.merge(); if (infoStream != null) { infoStream.println(" into "+mergedName+" ("+mergedDocCount+" docs)"); } newSegment = new SegmentInfo(mergedName, mergedDocCount, directory, false, true); } if (sourceSegments != ramSegmentInfos || anyDeletes) { // Now save the SegmentInfo instances that // we are replacing: rollback = (SegmentInfos) segmentInfos.clone(); } if (doMerge) { if (sourceSegments == ramSegmentInfos) { segmentInfos.addElement(newSegment); } else { for (int i = end-1; i > minSegment; i--) // remove old infos & add new sourceSegments.remove(i); segmentInfos.set(minSegment, newSegment); } } if (sourceSegments == ramSegmentInfos) { maybeApplyDeletes(doMerge); doAfterFlush(); } checkpoint(); success = true; } finally { if (success) { // The non-ram-segments case is already committed // (above), so all the remains for ram segments case // is to clear the ram segments: if (sourceSegments == ramSegmentInfos) { ramSegmentInfos.removeAllElements(); } } else { // Must rollback so our state matches index: if (sourceSegments == ramSegmentInfos && !anyDeletes) { // Simple case: newSegment may or may not have // been added to the end of our segment infos, // so just check & remove if so: if (newSegment != null && segmentInfos.size() > 0 && segmentInfos.info(segmentInfos.size()-1) == newSegment) { segmentInfos.remove(segmentInfos.size()-1); } } else if (rollback != null) { // Rollback the individual SegmentInfo // instances, but keep original SegmentInfos // instance (so we don't try to write again the // same segments_N file -- write once): segmentInfos.clear(); segmentInfos.addAll(rollback); } // Delete any partially created and now unreferenced files: deleter.refresh(); } } } finally { // close readers before we attempt to delete now-obsolete segments if (doMerge) merger.closeReaders(); } // Delete the RAM segments deleter.deleteDirect(ramDirectory, ramSegmentsToDelete); // Give deleter a chance to remove files now. deleter.checkpoint(segmentInfos, autoCommit); if (useCompoundFile && doMerge) { boolean success = false; try { merger.createCompoundFile(mergedName + ".cfs"); newSegment.setUseCompoundFile(true); checkpoint(); success = true; } finally { if (!success) { // Must rollback: newSegment.setUseCompoundFile(false); deleter.refresh(); } } // Give deleter a chance to remove files now. deleter.checkpoint(segmentInfos, autoCommit); } return mergedDocCount;
final synchronized java.lang.String	newRamSegmentName() return "_ram_" + Integer.toString(ramSegmentInfos.counter++, Character.MAX_RADIX);
final synchronized java.lang.String	newSegmentName() return "_" + Integer.toString(segmentInfos.counter++, Character.MAX_RADIX);
public final synchronized int	numRamDocs() Expert: Return the number of documents whose segments are currently cached in memory. Useful when calling flushRamSegments() ensureOpen(); return ramSegmentInfos.size();
public synchronized void	optimize() Merges all segments together into a single segment, optimizing an index for search. It is recommended that this method be called upon completion of indexing. In environments with frequent updates, optimize is best done during low volume times, if at all. See http://www.gossamer-threads.com/lists/lucene/java-dev/47895 for more discussion. Note that this requires substantial temporary free space in the Directory (see LUCENE-764 for details): If no readers/searchers are open against the index, then free space required is up to 1X the total size of the starting index. For example, if the starting index is 10 GB, then you must have up to 10 GB of free space before calling optimize. If readers/searchers are using the index, then free space required is up to 2X the size of the starting index. This is because in addition to the 1X used by optimize, the original 1X of the starting index is still consuming space in the Directory as the readers are holding the segments files open. Even on Unix, where it will appear as if the files are gone ("ls" won't list them), they still consume storage due to "delete on last close" semantics. Furthermore, if some but not all readers re-open while the optimize is underway, this will cause > 2X temporary space to be consumed as those new readers will then hold open the partially optimized segments at that time. It is best not to re-open readers while optimize is running. The actual temporary usage could be much less than these figures (it depends on many factors). Once the optimize 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 during optimize(), for example due to disk full, the index will not be corrupt and no documents will have been lost. However, it may have been partially optimized (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. throws CorruptIndexException if the index is corrupt throws IOException if there is a low-level IO error ensureOpen(); flushRamSegments(); while (segmentInfos.size() > 1 || (segmentInfos.size() == 1 && (SegmentReader.hasDeletions(segmentInfos.info(0)) || SegmentReader.hasSeparateNorms(segmentInfos.info(0)) || segmentInfos.info(0).dir != directory || (useCompoundFile && (!SegmentReader.usesCompoundFile(segmentInfos.info(0))))))) { int minSegment = segmentInfos.size() - mergeFactor; mergeSegments(segmentInfos, minSegment < 0 ? 0 : minSegment, segmentInfos.size()); }
public final long	ramSizeInBytes() Expert: Return the total size of all index files currently cached in memory. Useful for size management with flushRamDocs() ensureOpen(); return ramDirectory.sizeInBytes();
private void	rollbackTransaction() // First restore autoCommit in case we hit an exception below: autoCommit = localAutoCommit; // Keep the same segmentInfos instance but replace all // of its SegmentInfo instances. This is so the next // attempt to commit using this instance of IndexWriter // will always write to a new generation ("write once"). segmentInfos.clear(); segmentInfos.addAll(localRollbackSegmentInfos); localRollbackSegmentInfos = null; // Ask deleter to locate unreferenced files we had // created & remove them: deleter.checkpoint(segmentInfos, false); if (!autoCommit) // Remove the incRef we did in startTransaction: deleter.decRef(segmentInfos); deleter.refresh();
public static void	setDefaultInfoStream(java.io.PrintStream infoStream) If non-null, this will be the default infoStream used by a newly instantiated IndexWriter. see #setInfoStream IndexWriter.defaultInfoStream = infoStream;
public static void	setDefaultWriteLockTimeout(long writeLockTimeout) Sets the default (for any instance of IndexWriter) maximum time to wait for a write lock (in milliseconds). IndexWriter.WRITE_LOCK_TIMEOUT = writeLockTimeout;
public void	setInfoStream(java.io.PrintStream infoStream) If non-null, information about merges, deletes and a message when maxFieldLength is reached will be printed to this. ensureOpen(); this.infoStream = infoStream; deleter.setInfoStream(infoStream);
public void	setMaxBufferedDeleteTerms(int maxBufferedDeleteTerms) Determines the minimal number of delete terms required before the buffered in-memory delete terms are applied and flushed. If there are documents buffered in memory at the time, they are merged and a new segment is created. The default value is {@link #DEFAULT_MAX_BUFFERED_DELETE_TERMS}. throws IllegalArgumentException if maxBufferedDeleteTerms is smaller than 1 ensureOpen(); if (maxBufferedDeleteTerms < 1) throw new IllegalArgumentException("maxBufferedDeleteTerms must at least be 1"); this.maxBufferedDeleteTerms = maxBufferedDeleteTerms;
public void	setMaxBufferedDocs(int maxBufferedDocs) Determines the minimal number of documents required before the buffered in-memory documents are merged and a new Segment is created. Since Documents are merged in a {@link org.apache.lucene.store.RAMDirectory}, large value gives faster indexing. At the same time, mergeFactor limits the number of files open in a FSDirectory. The default value is 10. throws IllegalArgumentException if maxBufferedDocs is smaller than 2 ensureOpen(); if (maxBufferedDocs < 2) throw new IllegalArgumentException("maxBufferedDocs must at least be 2"); this.minMergeDocs = maxBufferedDocs;
public void	setMaxFieldLength(int maxFieldLength) The maximum number of terms that will be indexed for a single field in a document. This limits the amount of memory required for indexing, so that collections with very large files will not crash the indexing process by running out of memory. Note that this effectively truncates large documents, excluding from the index terms that occur further in the document. If you know your source documents are large, be sure to set this value high enough to accomodate the expected size. If you set it to Integer.MAX_VALUE, then the only limit is your memory, but you should anticipate an OutOfMemoryError. By default, no more than 10,000 terms will be indexed for a field. ensureOpen(); this.maxFieldLength = maxFieldLength;
public void	setMaxMergeDocs(int maxMergeDocs) Determines the largest number of documents ever merged by addDocument(). Small values (e.g., less than 10,000) are best for interactive indexing, as this limits the length of pauses while indexing to a few seconds. Larger values are best for batched indexing and speedier searches. The default value is {@link Integer#MAX_VALUE}. ensureOpen(); this.maxMergeDocs = maxMergeDocs;
public void	setMergeFactor(int mergeFactor) Determines how often segment indices are merged by addDocument(). With smaller values, less RAM is used while indexing, and searches on unoptimized indices are faster, but indexing speed is slower. With larger values, more RAM is used during indexing, and while searches on unoptimized indices are slower, indexing is faster. Thus larger values (> 10) are best for batch index creation, and smaller values (< 10) for indices that are interactively maintained. This must never be less than 2. The default value is 10. ensureOpen(); if (mergeFactor < 2) throw new IllegalArgumentException("mergeFactor cannot be less than 2"); this.mergeFactor = mergeFactor;
public void	setSimilarity(org.apache.lucene.search.Similarity similarity) Expert: Set the Similarity implementation used by this IndexWriter. see Similarity#setDefault(Similarity) ensureOpen(); this.similarity = similarity;
public void	setTermIndexInterval(int interval) Expert: Set the interval between indexed terms. Large values cause less memory to be used by IndexReader, but slow random-access to terms. Small values cause more memory to be used by an IndexReader, and speed random-access to terms. This parameter determines the amount of computation required per query term, regardless of the number of documents that contain that term. In particular, it is the maximum number of other terms that must be scanned before a term is located and its frequency and position information may be processed. In a large index with user-entered query terms, query processing time is likely to be dominated not by term lookup but rather by the processing of frequency and positional data. In a small index or when many uncommon query terms are generated (e.g., by wildcard queries) term lookup may become a dominant cost. In particular, numUniqueTerms/interval terms are read into memory by an IndexReader, and, on average, interval/2 terms must be scanned for each random term access. see #DEFAULT_TERM_INDEX_INTERVAL ensureOpen(); this.termIndexInterval = interval;
public void	setUseCompoundFile(boolean value) Setting to turn on usage of a compound file. When on, multiple files for each segment are merged into a single file once the segment creation is finished. This is done regardless of what directory is in use. ensureOpen(); useCompoundFile = value;
public void	setWriteLockTimeout(long writeLockTimeout) Sets the maximum time to wait for a write lock (in milliseconds) for this instance of IndexWriter. @see see #setDefaultWriteLockTimeout to change the default value for all instances of IndexWriter. ensureOpen(); this.writeLockTimeout = writeLockTimeout;
private void	startTransaction() localRollbackSegmentInfos = (SegmentInfos) segmentInfos.clone(); localAutoCommit = autoCommit; if (localAutoCommit) { flushRamSegments(); // Turn off auto-commit during our local transaction: autoCommit = false; } else // We must "protect" our files at this point from // deletion in case we need to rollback: deleter.incRef(segmentInfos, false);
public void	updateDocument(org.apache.lucene.index.Term term, org.apache.lucene.document.Document doc) 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). param term the term to identify the document(s) to be deleted param doc the document to be added throws CorruptIndexException if the index is corrupt throws IOException if there is a low-level IO error ensureOpen(); updateDocument(term, doc, getAnalyzer());
public void	updateDocument(org.apache.lucene.index.Term term, org.apache.lucene.document.Document doc, org.apache.lucene.analysis.Analyzer analyzer) 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). param term the term to identify the document(s) to be deleted param doc the document to be added param analyzer the analyzer to use when analyzing the document throws CorruptIndexException if the index is corrupt throws IOException if there is a low-level IO error ensureOpen(); SegmentInfo newSegmentInfo = buildSingleDocSegment(doc, analyzer); synchronized (this) { bufferDeleteTerm(term); ramSegmentInfos.addElement(newSegmentInfo); maybeFlushRamSegments(); }