/// <summary> /// Merges the provided indexes into this index. /// /// <p> /// The provided IndexReaders are not closed. /// /// <p> /// See <seealso cref="#addIndexes"/> for details on transactional semantics, temporary /// free space required in the Directory, and non-CFS segments on an Exception. /// /// <p> /// <b>NOTE</b>: if this method hits an OutOfMemoryError you should immediately /// close the writer. See <a href="#OOME">above</a> for details. /// /// <p> /// <b>NOTE:</b> empty segments are dropped by this method and not added to this /// index. /// /// <p> /// <b>NOTE:</b> this method merges all given <seealso cref="IndexReader"/>s in one /// merge. If you intend to merge a large number of readers, it may be better /// to call this method multiple times, each time with a small set of readers. /// In principle, if you use a merge policy with a {@code mergeFactor} or /// {@code maxMergeAtOnce} parameter, you should pass that many readers in one /// call. Also, if the given readers are <seealso cref="DirectoryReader"/>s, they can be /// opened with {@code termIndexInterval=-1} to save RAM, since during merge /// the in-memory structure is not used. See /// <seealso cref="DirectoryReader#open(Directory, int)"/>. /// /// <p> /// <b>NOTE</b>: if you call <seealso cref="#close(boolean)"/> with <tt>false</tt>, which /// aborts all running merges, then any thread still running this method might /// hit a <seealso cref="MergePolicy.MergeAbortedException"/>. /// </summary> /// <exception cref="CorruptIndexException"> /// if the index is corrupt </exception> /// <exception cref="IOException"> /// if there is a low-level IO error </exception> public virtual void AddIndexes(params IndexReader[] readers) { EnsureOpen(); int numDocs = 0; try { if (infoStream.IsEnabled("IW")) { infoStream.Message("IW", "flush at addIndexes(IndexReader...)"); } Flush(false, true); string mergedName = NewSegmentName(); IList<AtomicReader> mergeReaders = new List<AtomicReader>(); foreach (IndexReader indexReader in readers) { numDocs += indexReader.NumDocs(); foreach (AtomicReaderContext ctx in indexReader.Leaves()) { mergeReaders.Add(ctx.AtomicReader); } } IOContext context = new IOContext(new MergeInfo(numDocs, -1, true, -1)); // TODO: somehow we should fix this merge so it's // abortable so that IW.close(false) is able to stop it TrackingDirectoryWrapper trackingDir = new TrackingDirectoryWrapper(directory); SegmentInfo info = new SegmentInfo(directory, Constants.LUCENE_MAIN_VERSION, mergedName, -1, false, Codec, null); SegmentMerger merger = new SegmentMerger(mergeReaders, info, infoStream, trackingDir, Config_Renamed.TermIndexInterval, MergeState.CheckAbort.NONE, GlobalFieldNumberMap, context, Config_Renamed.CheckIntegrityAtMerge); if (!merger.ShouldMerge()) { return; } MergeState mergeState; bool success = false; try { mergeState = merger.Merge(); // merge 'em success = true; } finally { if (!success) { lock (this) { Deleter.Refresh(info.Name); } } } SegmentCommitInfo infoPerCommit = new SegmentCommitInfo(info, 0, -1L, -1L); info.Files = new HashSet<string>(trackingDir.CreatedFiles); trackingDir.CreatedFiles.Clear(); SetDiagnostics(info, SOURCE_ADDINDEXES_READERS); bool useCompoundFile; lock (this) // Guard segmentInfos { if (StopMerges) { Deleter.DeleteNewFiles(infoPerCommit.Files()); return; } EnsureOpen(); useCompoundFile = mergePolicy.UseCompoundFile(segmentInfos, infoPerCommit); } // Now create the compound file if needed if (useCompoundFile) { ICollection<string> filesToDelete = infoPerCommit.Files(); try { CreateCompoundFile(infoStream, directory, MergeState.CheckAbort.NONE, info, context); } finally { // delete new non cfs files directly: they were never // registered with IFD lock (this) { Deleter.DeleteNewFiles(filesToDelete); } } info.UseCompoundFile = true; } // Have codec write SegmentInfo. Must do this after // creating CFS so that 1) .si isn't slurped into CFS, // and 2) .si reflects useCompoundFile=true change // above: success = false; try { Codec.SegmentInfoFormat().SegmentInfoWriter.Write(trackingDir, info, mergeState.FieldInfos, context); success = true; } finally { if (!success) { lock (this) { Deleter.Refresh(info.Name); } } } info.AddFiles(trackingDir.CreatedFiles); // Register the new segment lock (this) { if (StopMerges) { Deleter.DeleteNewFiles(info.Files); return; } EnsureOpen(); segmentInfos.Add(infoPerCommit); Checkpoint(); } } catch (System.OutOfMemoryException oom) { HandleOOM(oom, "addIndexes(IndexReader...)"); } }