| java.lang.Object org.apache.lucene.index.IndexWriter
IndexWriter | public class IndexWriter (Code) | | An IndexWriter creates and maintains an index.
The create argument to the
constructor
determines whether a new index is created, or whether an existing index is
opened. Note that you
can open an index with create=true 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. There are
also constructors
with no create argument which
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.
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.
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
buffered deletes (see
IndexWriter.setMaxBufferedDeleteTerms )
or enough added documents since the last flush, whichever
is sooner. For the added documents, flushing is triggered
either by RAM usage of the documents (see
IndexWriter.setRAMBufferSizeMB ) or the number of added documents.
The default is to flush when RAM usage hits 16 MB. For
best indexing speed you should flush by RAM usage with a
large RAM buffer. You can also force a flush by calling
IndexWriter.flush . When a flush occurs, both pending deletes
and added documents are flushed to the index. 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 ).
The optional autoCommit argument to the
constructors
controls visibility of the changes to
IndexReader instances reading the same index.
When this is false , changes are not
visible until
IndexWriter.close() is called.
Note that changes will still be flushed to the
org.apache.lucene.store.Directory as new files,
but are not committed (no new segments_N file
is written referencing the new files) until
IndexWriter.close is
called. If something goes terribly wrong (for example the
JVM crashes) before
IndexWriter.close() , then
the index will reflect none of the changes made (it will
remain in its starting state).
You can also call
IndexWriter.abort() , which closes the writer without committing any
changes, and removes any index
files that had been flushed but are now unreferenced.
This mode is useful for preventing readers from refreshing
at a bad time (for example after you've done all your
deletes but before you've done your adds).
It can also be used to implement simple single-writer
transactional semantics ("all or none").
When autoCommit is true then
every flush is also a commit (
IndexReader instances will see each flush as changes to the index).
This is the default, to match the behavior before 2.2.
When running in this mode, be careful not to refresh your
readers while optimize or segment merges are taking place
as this can tie up substantial disk space.
Regardless of autoCommit , an
IndexReader or
org.apache.lucene.search.IndexSearcher will only see the
index as of the "point in time" that it was opened. Any
changes committed to the index after the reader was opened
are not visible until the reader is re-opened.
If an index will not have more documents added for a while and optimal search
performance is desired, then the optimize
method should be called before the index is closed.
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 . The
LockObtainFailedException is also thrown if an IndexReader on the same directory is used to delete documents
from the index.
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 (this matches
behavior before 2.2). Creating your own policy can allow
you to explicitly keep previous "point in time" commits
alive in the index for some time, to allow readers to
refresh to the new commit without having the old commit
deleted out from under them. This is necessary on
filesystems like NFS that do not support "delete on last
close" semantics, which Lucene's "point in time" search
normally relies on.
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. It
also selects merges to do for optimize(). (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 .
|
Constructor Summary | |
public | IndexWriter(String path, Analyzer a, boolean create) Constructs an IndexWriter for the index in path .
Text will be analyzed with a . | public | IndexWriter(File path, Analyzer a, boolean create) Constructs an IndexWriter for the index in path .
Text will be analyzed with a . | public | IndexWriter(Directory d, Analyzer a, boolean create) Constructs an IndexWriter for the index in d .
Text will be analyzed with a . | public | IndexWriter(String path, Analyzer a) Constructs an IndexWriter for the index in
path , first creating it if it does not
already exist. | public | IndexWriter(File path, Analyzer a) Constructs an IndexWriter for the index in
path , first creating it if it does not
already exist. | public | IndexWriter(Directory d, Analyzer a) Constructs an IndexWriter for the index in
d , first creating it if it does not
already exist. | 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. | public | IndexWriter(Directory d, boolean autoCommit, Analyzer a, boolean create) Constructs an IndexWriter for the index in d .
Text will be analyzed with a . | public | IndexWriter(Directory d, boolean autoCommit, Analyzer a, IndexDeletionPolicy deletionPolicy) Expert: constructs an IndexWriter with a custom
IndexDeletionPolicy , for the index in d ,
first creating it if it does not already exist. | public | IndexWriter(Directory d, boolean autoCommit, Analyzer a, boolean create, IndexDeletionPolicy deletionPolicy) Expert: constructs an IndexWriter with a custom
IndexDeletionPolicy , for the index in d .
Text will be analyzed with a . |
Method Summary | |
public void | abort() Close the IndexWriter without committing
any of the changes that have occurred since it was
opened. | public void | addDocument(Document doc) Adds a document to this index. | public void | addDocument(Document doc, Analyzer analyzer) Adds a document to this index, using the provided analyzer instead of the
value of
IndexWriter.getAnalyzer() . | public synchronized void | addIndexes(Directory[] dirs) Merges all segments from an array of indexes into this index.
This may be used to parallelize batch indexing. | public synchronized void | addIndexes(IndexReader[] readers) Merges the provided indexes into this index.
After this completes, the index is optimized. | public synchronized void | addIndexesNoOptimize(Directory[] dirs) Merges all segments from an array of indexes into this index.
This is similar to addIndexes(Directory[]). | synchronized void | addMergeException(MergePolicy.OneMerge merge) | public 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. | public void | close(boolean waitForMerges) Closes the index with or without waiting for currently
running merges to finish. | public void | deleteDocuments(Term term) Deletes the document(s) containing term . | public void | deleteDocuments(Term[] terms) Deletes the document(s) containing any of the
terms. | void | doAfterFlush() | public synchronized int | docCount() Returns the number of documents currently in this index. | final protected void | ensureOpen() Used internally to throw an
AlreadyClosedException if this IndexWriter has been
closed. | protected void | finalize() Release the write lock, if needed. | final public void | flush() Flush all in-memory buffered updates (adds and deletes)
to the Directory. | final protected void | flush(boolean triggerMerge, boolean flushDocStores) Flush all in-memory buffered udpates (adds and deletes)
to the Directory. | public Analyzer | getAnalyzer() Returns the analyzer used by this index. | final synchronized int | getBufferedDeleteTermsSize() | public static PrintStream | getDefaultInfoStream() Returns the current default infoStream for newly
instantiated IndexWriters. | public static long | getDefaultWriteLockTimeout() Returns default write lock timeout for newly
instantiated IndexWriters. | public Directory | getDirectory() Returns the Directory used by this index. | final synchronized int | getDocCount(int i) | public PrintStream | getInfoStream() Returns the current infoStream in use by this writer. | public int | getMaxBufferedDeleteTerms() Returns the number of buffered deleted terms that will
trigger a flush if enabled. | public int | getMaxBufferedDocs() Returns the number of buffered added documents that will
trigger a flush if enabled. | public int | getMaxFieldLength() Returns the maximum number of terms that will be
indexed for a single field in a document. | public int | getMaxMergeDocs() Returns the largest segment (measured by document
count) that may be merged with other segments.
Note that this method is a convenience method: it
just calls mergePolicy.getMaxMergeDocs as long as
mergePolicy is an instance of
LogMergePolicy . | 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.
Note that this method is a convenience method: it
just calls mergePolicy.getMergeFactor as long as
mergePolicy is an instance of
LogMergePolicy . | public MergePolicy | getMergePolicy() Expert: returns the current MergePolicy in use by this writer. | public MergeScheduler | getMergeScheduler() Expert: returns the current MergePolicy in use by this
writer. | synchronized MergePolicy.OneMerge | getNextMerge() | final synchronized int | getNumBufferedDeleteTerms() | final synchronized int | getNumBufferedDocuments() | public double | getRAMBufferSizeMB() Returns the value set by
IndexWriter.setRAMBufferSizeMB if enabled. | final synchronized int | getSegmentCount() | public Similarity | getSimilarity() Expert: Return the Similarity implementation used by this IndexWriter. | public int | getTermIndexInterval() Expert: Return the interval between indexed terms. | public boolean | getUseCompoundFile() Get the current setting of whether newly flushed
segments will use the compound file format. | public long | getWriteLockTimeout() Returns allowed timeout when acquiring the write lock. | final public void | maybeMerge() 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. | final void | merge(MergePolicy.OneMerge merge) Merges the indicated segments, replacing them in the stack with a
single segment. | final synchronized void | mergeFinish(MergePolicy.OneMerge merge) Does fininishing for a merge, which is fast but holds
the synchronized lock on IndexWriter instance. | final synchronized void | mergeInit(MergePolicy.OneMerge merge) Does initial setup for a merge, which is fast but holds
the synchronized lock on IndexWriter instance. | public void | message(String message) Prints a message to the infoStream (if non-null),
prefixed with the identifying information for this
writer and the thread that's calling it. | final String | newSegmentName() | SegmentInfo | newestSegment() | final public synchronized int | numRamDocs() Expert: Return the number of documents whose segments are currently cached in memory. | public void | optimize() Requests an "optimize" operation on an index, priming the index
for the fastest available search. | public void | optimize(int maxNumSegments) Optimize the index down to <= maxNumSegments. | public void | optimize(boolean doWait) Just like
IndexWriter.optimize() , except you can specify
whether the call should block until the optimize
completes. | public void | optimize(int maxNumSegments, boolean doWait) Just like
IndexWriter.optimize(int) , except you can
specify whether the call should block until the
optimize completes. | final public long | ramSizeInBytes() Expert: Return the total size of all index files currently cached in memory. | final synchronized boolean | registerMerge(MergePolicy.OneMerge merge) Checks whether this merge involves any segments
already participating in a merge. | public synchronized String | segString() | public static void | setDefaultInfoStream(PrintStream infoStream) If non-null, this will be the default infoStream used
by a newly instantiated IndexWriter. | public static void | setDefaultWriteLockTimeout(long writeLockTimeout) Sets the default (for any instance of IndexWriter) maximum time to wait for a write lock (in
milliseconds). | public void | setInfoStream(PrintStream infoStream) If non-null, information about merges, deletes and a
message when maxFieldLength is reached will be printed
to this. | public void | setMaxBufferedDeleteTerms(int maxBufferedDeleteTerms) Determines the minimal number of delete terms required before the buffered
in-memory delete terms are applied and flushed. | public void | setMaxBufferedDocs(int maxBufferedDocs) Determines the minimal number of documents required
before the buffered in-memory documents are flushed as
a new Segment. | public void | setMaxFieldLength(int maxFieldLength) The maximum number of terms that will be indexed for a single field in a
document. | public void | setMaxMergeDocs(int maxMergeDocs) Determines the largest segment (measured by
document count) that may be merged with other segments.
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. | public void | setMergeFactor(int mergeFactor) Determines how often segment indices are merged by addDocument(). | public void | setMergePolicy(MergePolicy mp) Expert: set the merge policy used by this writer. | public void | setMergeScheduler(MergeScheduler mergeScheduler) Expert: set the merge scheduler used by this writer. | public void | setRAMBufferSizeMB(double mb) Determines the amount of RAM that may be used for
buffering added documents before they are flushed as a
new Segment. | public void | setSimilarity(Similarity similarity) Expert: Set the Similarity implementation used by this IndexWriter. | public void | setTermIndexInterval(int interval) Expert: Set the interval between indexed terms. | public void | setUseCompoundFile(boolean value) Setting to turn on usage of a compound file. | public void | setWriteLockTimeout(long writeLockTimeout) Sets the maximum time to wait for a write lock (in milliseconds) for this instance of IndexWriter. | public void | updateDocument(Term term, Document doc) Updates a document by first deleting the document(s)
containing term and then adding the new
document. | public void | updateDocument(Term term, Document doc, Analyzer analyzer) Updates a document by first deleting the document(s)
containing term and then adding the new
document. |
DEFAULT_MAX_BUFFERED_DOCS | final public static int DEFAULT_MAX_BUFFERED_DOCS(Code) | | Disabled by default (because IndexWriter flushes by RAM usage
by default). Change using
IndexWriter.setMaxBufferedDocs(int) .
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DEFAULT_RAM_BUFFER_SIZE_MB | final public static double DEFAULT_RAM_BUFFER_SIZE_MB(Code) | | Default value is 16 MB (which means flush when buffered
docs consume 16 MB RAM). Change using
IndexWriter.setRAMBufferSizeMB .
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DISABLE_AUTO_FLUSH | final public static int DISABLE_AUTO_FLUSH(Code) | | Value to denote a flush trigger is disabled
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MAX_TERM_LENGTH | final public static int MAX_TERM_LENGTH(Code) | | Absolute hard maximum length for a term. If a term
arrives from the analyzer longer than this length, it
is skipped and a message is printed to infoStream, if
set (see
IndexWriter.setInfoStream ).
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WRITE_LOCK_NAME | final public static String WRITE_LOCK_NAME(Code) | | Name of the write lock in the index.
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IndexWriter | public IndexWriter(String path, Analyzer a, boolean create) throws CorruptIndexException, LockObtainFailedException, IOException(Code) | | 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.
Parameters: path - the path to the index directory Parameters: a - the analyzer to use Parameters: create - true to create the index or overwritethe existing one; false to append to the existingindex throws: CorruptIndexException - if the index is corrupt throws: LockObtainFailedException - if another writerhas this index open (write.lock could notbe obtained) throws: IOException - if the directory cannot be read/written to, orif it does not exist and create isfalse or if there is any other low-levelIO error |
IndexWriter | public IndexWriter(File path, Analyzer a, boolean create) throws CorruptIndexException, LockObtainFailedException, IOException(Code) | | 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.
Parameters: path - the path to the index directory Parameters: a - the analyzer to use Parameters: create - true to create the index or overwritethe existing one; false to append to the existingindex throws: CorruptIndexException - if the index is corrupt throws: LockObtainFailedException - if another writerhas this index open (write.lock could notbe obtained) throws: IOException - if the directory cannot be read/written to, orif it does not exist and create isfalse or if there is any other low-levelIO error |
IndexWriter | public IndexWriter(Directory d, Analyzer a, boolean create) throws CorruptIndexException, LockObtainFailedException, IOException(Code) | | 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.
Parameters: d - the index directory Parameters: a - the analyzer to use Parameters: create - true to create the index or overwritethe existing one; false to append to the existingindex throws: CorruptIndexException - if the index is corrupt throws: LockObtainFailedException - if another writerhas this index open (write.lock could notbe obtained) throws: IOException - if the directory cannot be read/written to, orif it does not exist and create isfalse or if there is any other low-levelIO error |
IndexWriter | public IndexWriter(Directory d, boolean autoCommit, Analyzer a, boolean create) throws CorruptIndexException, LockObtainFailedException, IOException(Code) | | 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.
Parameters: d - the index directory Parameters: autoCommit - see above Parameters: a - the analyzer to use Parameters: create - true to create the index or overwritethe existing one; false to append to the existingindex throws: CorruptIndexException - if the index is corrupt throws: LockObtainFailedException - if another writerhas this index open (write.lock could notbe obtained) throws: IOException - if the directory cannot be read/written to, orif it does not exist and create isfalse or if there is any other low-levelIO error |
IndexWriter | public IndexWriter(Directory d, boolean autoCommit, Analyzer a, boolean create, IndexDeletionPolicy deletionPolicy) throws CorruptIndexException, LockObtainFailedException, IOException(Code) | | Expert: constructs an IndexWriter with a custom
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.
Parameters: d - the index directory Parameters: autoCommit - see above Parameters: a - the analyzer to use Parameters: create - true to create the index or overwritethe existing one; false to append to the existingindex Parameters: deletionPolicy - see above throws: CorruptIndexException - if the index is corrupt throws: LockObtainFailedException - if another writerhas this index open (write.lock could notbe obtained) throws: IOException - if the directory cannot be read/written to, orif it does not exist and create isfalse or if there is any other low-levelIO error |
abort | public void abort() throws IOException(Code) | | 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 whenthe writer was opened with autoCommit=true . throws: IOException - if there is a low-level IO error |
addDocument | public void addDocument(Document doc) throws CorruptIndexException, IOException(Code) | | Adds a document to this index. If the document contains more than
IndexWriter.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
IndexWriter.setMaxBufferedDocs ),
and also periodically merges segments in the index
(every
IndexWriter.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
IndexWriter.optimize() 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 16383 characters, otherwise an
IllegalArgumentException will be thrown.
throws: CorruptIndexException - if the index is corrupt throws: IOException - if there is a low-level IO error |
addIndexes | public synchronized void addIndexes(Directory[] dirs) throws CorruptIndexException, IOException(Code) | | 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.
NOTE: the index in each Directory must not be
changed (opened by a writer) while this method is
running. This method does not acquire a write lock in
each input Directory, so it is up to the caller to
enforce this.
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
IndexWriter.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 |
addIndexesNoOptimize | public synchronized void addIndexesNoOptimize(Directory[] dirs) throws CorruptIndexException, IOException(Code) | | 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.
NOTE: the index in each Directory must not be
changed (opened by a writer) while this method is
running. This method does not acquire a write lock in
each input Directory, so it is up to the caller to
enforce this.
This requires this index not be among those to be added, and the
upper bound* of those segment doc counts not exceed maxMergeDocs.
See
IndexWriter.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 |
close | public void close() throws CorruptIndexException, IOException(Code) | | 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 |
close | public void close(boolean waitForMerges) throws CorruptIndexException, IOException(Code) | | Closes the index with or without waiting for currently
running merges to finish. This is only meaningful when
using a MergeScheduler that runs merges in background
threads.
Parameters: waitForMerges - if true, this call will blockuntil all merges complete; else, it will ask allrunning merges to abort, wait until those merges havefinished (which should be at most a few seconds), andthen return. |
deleteDocuments | public void deleteDocuments(Term[] terms) throws CorruptIndexException, IOException(Code) | | Deletes the document(s) containing any of the
terms. All deletes are flushed at the same time.
Parameters: terms - array of terms to identify the documentsto be deleted throws: CorruptIndexException - if the index is corrupt throws: IOException - if there is a low-level IO error |
docCount | public synchronized int docCount()(Code) | | Returns the number of documents currently in this index.
|
finalize | protected void finalize() throws Throwable(Code) | | Release the write lock, if needed.
|
flush | final protected void flush(boolean triggerMerge, boolean flushDocStores) throws CorruptIndexException, IOException(Code) | | Flush all in-memory buffered udpates (adds and deletes)
to the Directory.
Parameters: triggerMerge - if true, we may merge segments (ifdeletes or docs were flushed) if necessary Parameters: flushDocStores - if false we are allowed to keepdoc stores open to share with the next segment |
getAnalyzer | public Analyzer getAnalyzer()(Code) | | Returns the analyzer used by this index.
|
getBufferedDeleteTermsSize | final synchronized int getBufferedDeleteTermsSize()(Code) | | |
getDirectory | public Directory getDirectory()(Code) | | Returns the Directory used by this index.
|
getDocCount | final synchronized int getDocCount(int i)(Code) | | |
getMaxBufferedDocs | public int getMaxBufferedDocs()(Code) | | Returns the number of buffered added documents that will
trigger a flush if enabled.
See Also: IndexWriter.setMaxBufferedDocs |
getMaxFieldLength | public int getMaxFieldLength()(Code) | | Returns the maximum number of terms that will be
indexed for a single field in a document.
See Also: IndexWriter.setMaxFieldLength |
getMaxMergeDocs | public int getMaxMergeDocs()(Code) | | Returns the largest segment (measured by document
count) that may be merged with other segments.
Note that this method is a convenience method: it
just calls mergePolicy.getMaxMergeDocs as long as
mergePolicy is an instance of
LogMergePolicy .
Otherwise an IllegalArgumentException is thrown.
See Also: IndexWriter.setMaxMergeDocs |
getMergeFactor | public int getMergeFactor()(Code) | | Returns the number of segments that are merged at
once and also controls the total number of segments
allowed to accumulate in the index.
Note that this method is a convenience method: it
just calls mergePolicy.getMergeFactor as long as
mergePolicy is an instance of
LogMergePolicy .
Otherwise an IllegalArgumentException is thrown.
See Also: IndexWriter.setMergeFactor |
getNumBufferedDeleteTerms | final synchronized int getNumBufferedDeleteTerms()(Code) | | |
getNumBufferedDocuments | final synchronized int getNumBufferedDocuments()(Code) | | |
getSegmentCount | final synchronized int getSegmentCount()(Code) | | |
getSimilarity | public Similarity getSimilarity()(Code) | | Expert: Return the Similarity implementation used by this IndexWriter.
This defaults to the current value of
Similarity.getDefault .
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getUseCompoundFile | public boolean getUseCompoundFile()(Code) | | Get the current setting of whether newly flushed
segments will use the compound file format. Note that
this just returns the value previously set with
setUseCompoundFile(boolean), or the default value
(true). You cannot use this to query the status of
previously flushed segments.
Note that this method is a convenience method: it
just calls mergePolicy.getUseCompoundFile as long as
mergePolicy is an instance of
LogMergePolicy .
Otherwise an IllegalArgumentException is thrown.
See Also: IndexWriter.setUseCompoundFile(boolean) |
maybeMerge | final public void maybeMerge() throws CorruptIndexException, IOException(Code) | | 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.
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mergeFinish | final synchronized void mergeFinish(MergePolicy.OneMerge merge) throws IOException(Code) | | Does fininishing for a merge, which is fast but holds
the synchronized lock on IndexWriter instance.
|
mergeInit | final synchronized void mergeInit(MergePolicy.OneMerge merge) throws IOException(Code) | | Does initial setup for a merge, which is fast but holds
the synchronized lock on IndexWriter instance.
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message | public void message(String message)(Code) | | Prints a message to the infoStream (if non-null),
prefixed with the identifying information for this
writer and the thread that's calling it.
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numRamDocs | final public synchronized int numRamDocs()(Code) | | Expert: Return the number of documents whose segments are currently cached in memory.
Useful when calling flush()
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optimize | public void optimize() throws CorruptIndexException, IOException(Code) | | Requests an "optimize" operation on an index, priming the index
for the fastest available search. Traditionally this has meant
merging all segments into a single segment as is done in the
default merge policy, but individaul merge policies may implement
optimize in different ways.
See Also: LogMergePolicy.findMergesForOptimize See Also: It is recommended that this method be called upon completion of indexing. In See Also: environments with frequent updates, optimize is best done during low volume times, if at all. See Also: See Also: See http://www.gossamer-threads.com/lists/lucene/java-dev/47895 for more discussion. See Also: Note that this can require substantial temporary free See Also: space in the Directory (see See Also: href="http://issues.apache.org/jira/browse/LUCENE-764">LUCENE-764 See Also: for details): See Also: See Also: See Also: If no readers/searchers are open against the index, See Also: then free space required is up to 1X the total size of See Also: the starting index. For example, if the starting See Also: index is 10 GB, then you must have up to 10 GB of free See Also: space before calling optimize. See Also: See Also: If readers/searchers are using the index, then free See Also: space required is up to 2X the size of the starting See Also: index. This is because in addition to the 1X used by See Also: optimize, the original 1X of the starting index is See Also: still consuming space in the Directory as the readers See Also: are holding the segments files open. Even on Unix, See Also: where it will appear as if the files are gone ("ls" See Also: won't list them), they still consume storage due to See Also: "delete on last close" semantics. See Also: Furthermore, if some but not all readers re-open See Also: while the optimize is underway, this will cause > 2X See Also: temporary space to be consumed as those new readers See Also: will then hold open the partially optimized segments at See Also: that time. It is best not to re-open readers while See Also: optimize is running. See Also:
See Also: The actual temporary usage could be much less than See Also: these figures (it depends on many factors). See Also: In general, once the optimize completes, the total size of the See Also: index will be less than the size of the starting index. See Also: It could be quite a bit smaller (if there were many See Also: pending deletes) or just slightly smaller. See Also: If an Exception is hit during optimize(), for example See Also: due to disk full, the index will not be corrupt and no See Also: documents will have been lost. However, it may have See Also: been partially optimized (some segments were merged but See Also: not all), and it's possible that one of the segments in See Also: the index will be in non-compound format even when See Also: using compound file format. This will occur when the See Also: Exception is hit during conversion of the segment into See Also: compound format. See Also: This call will optimize those segments present in See Also: the index when the call started. If other threads are See Also: still adding documents and flushing segments, those See Also: newly created segments will not be optimized unless you See Also: call optimize again. throws: CorruptIndexException - if the index is corrupt throws: IOException - if there is a low-level IO error |
optimize | public void optimize(int maxNumSegments) throws CorruptIndexException, IOException(Code) | | Optimize the index down to <= maxNumSegments. If
maxNumSegments==1 then this is the same as
IndexWriter.optimize() .
Parameters: maxNumSegments - maximum number of segments leftin the index after optimization finishes |
ramSizeInBytes | final public long ramSizeInBytes()(Code) | | Expert: Return the total size of all index files currently cached in memory.
Useful for size management with flushRamDocs()
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registerMerge | final synchronized boolean registerMerge(MergePolicy.OneMerge merge)(Code) | | 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.
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setDefaultInfoStream | public static void setDefaultInfoStream(PrintStream infoStream)(Code) | | If non-null, this will be the default infoStream used
by a newly instantiated IndexWriter.
See Also: IndexWriter.setInfoStream |
setDefaultWriteLockTimeout | public static void setDefaultWriteLockTimeout(long writeLockTimeout)(Code) | | Sets the default (for any instance of IndexWriter) maximum time to wait for a write lock (in
milliseconds).
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setInfoStream | public void setInfoStream(PrintStream infoStream)(Code) | | If non-null, information about merges, deletes and a
message when maxFieldLength is reached will be printed
to this.
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setMaxBufferedDeleteTerms | public void setMaxBufferedDeleteTerms(int maxBufferedDeleteTerms)(Code) | | 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.
Disabled by default (writer flushes by RAM usage).
throws: IllegalArgumentException - if maxBufferedDeleteTermsis enabled but smaller than 1 See Also: IndexWriter.setRAMBufferSizeMB |
setMaxBufferedDocs | public void setMaxBufferedDocs(int maxBufferedDocs)(Code) | | Determines the minimal number of documents required
before the buffered in-memory documents are flushed as
a new Segment. Large values generally gives faster
indexing.
When this is set, the writer will flush every
maxBufferedDocs added documents. Pass in
IndexWriter.DISABLE_AUTO_FLUSH to prevent triggering a flush due
to number of buffered documents. Note that if flushing
by RAM usage is also enabled, then the flush will be
triggered by whichever comes first.
Disabled by default (writer flushes by RAM usage).
throws: IllegalArgumentException - if maxBufferedDocs isenabled but smaller than 2, or it disables maxBufferedDocswhen ramBufferSize is already disabled See Also: IndexWriter.setRAMBufferSizeMB |
setMaxFieldLength | public void setMaxFieldLength(int maxFieldLength)(Code) | | 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. This setting refers to the number of running terms,
not to the number of different terms.
Note: this silently truncates large documents, excluding from the
index all 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.
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setMaxMergeDocs | public void setMaxMergeDocs(int maxMergeDocs)(Code) | | Determines the largest segment (measured by
document count) that may be merged with other segments.
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
Integer.MAX_VALUE .
Note that this method is a convenience method: it
just calls mergePolicy.setMaxMergeDocs as long as
mergePolicy is an instance of
LogMergePolicy .
Otherwise an IllegalArgumentException is thrown.
The default merge policy (
LogByteSizeMergePolicy ) also allows you to set this
limit by net size (in MB) of the segment, using
LogByteSizeMergePolicy.setMaxMergeMB .
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setMergeFactor | public void setMergeFactor(int mergeFactor)(Code) | | 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.
Note that this method is a convenience method: it
just calls mergePolicy.setMergeFactor as long as
mergePolicy is an instance of
LogMergePolicy .
Otherwise an IllegalArgumentException is thrown.
This must never be less than 2. The default value is 10.
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setMergePolicy | public void setMergePolicy(MergePolicy mp)(Code) | | Expert: set the merge policy used by this writer.
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setRAMBufferSizeMB | public void setRAMBufferSizeMB(double mb)(Code) | | Determines the amount of RAM that may be used for
buffering added documents before they are flushed as a
new Segment. Generally for faster indexing performance
it's best to flush by RAM usage instead of document
count and use as large a RAM buffer as you can.
When this is set, the writer will flush whenever
buffered documents use this much RAM. Pass in
IndexWriter.DISABLE_AUTO_FLUSH to prevent triggering a flush due
to RAM usage. Note that if flushing by document count
is also enabled, then the flush will be triggered by
whichever comes first.
The default value is
IndexWriter.DEFAULT_RAM_BUFFER_SIZE_MB .
throws: IllegalArgumentException - if ramBufferSize isenabled but non-positive, or it disables ramBufferSizewhen maxBufferedDocs is already disabled |
setTermIndexInterval | public void setTermIndexInterval(int interval)(Code) | | 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 Also: IndexWriter.DEFAULT_TERM_INDEX_INTERVAL |
setUseCompoundFile | public void setUseCompoundFile(boolean value)(Code) | | Setting to turn on usage of a compound file. When on,
multiple files for each segment are merged into a
single file when a new segment is flushed.
Note that this method is a convenience method: it
just calls mergePolicy.setUseCompoundFile as long as
mergePolicy is an instance of
LogMergePolicy .
Otherwise an IllegalArgumentException is thrown.
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setWriteLockTimeout | public void setWriteLockTimeout(long writeLockTimeout)(Code) | | Sets the maximum time to wait for a write lock (in milliseconds) for this instance of IndexWriter. @see
See Also: IndexWriter.setDefaultWriteLockTimeout See Also: to change the default value for all instances of IndexWriter. |
updateDocument | public void updateDocument(Term term, Document doc) throws CorruptIndexException, IOException(Code) | | 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 bedeleted Parameters: doc - the document to be added throws: CorruptIndexException - if the index is corrupt throws: IOException - if there is a low-level IO error |
updateDocument | public void updateDocument(Term term, Document doc, Analyzer analyzer) throws CorruptIndexException, IOException(Code) | | 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 bedeleted Parameters: doc - the document to be added Parameters: 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 |
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