GetMergedFiles() private method

private GetMergedFiles ( ) : ICollection
return ICollection
コード例 #1
0
ファイル: IndexWriter.cs プロジェクト: Mpdreamz/lucene.net
		/// <summary>Does the actual (time-consuming) work of the merge,
		/// but without holding synchronized lock on IndexWriter
		/// instance 
		/// </summary>
		private int MergeMiddle(MergePolicy.OneMerge merge)
		{
			
			merge.CheckAborted(directory);
			
			System.String mergedName = merge.info.name;
			
			SegmentMerger merger = null;
			
			int mergedDocCount = 0;
			
			SegmentInfos sourceSegments = merge.segments;
			int numSegments = sourceSegments.Count;
			
			if (infoStream != null)
				Message("merging " + merge.SegString(directory));
			
			merger = new SegmentMerger(this, mergedName, merge);
			
			merge.readers = new SegmentReader[numSegments];
			merge.readersClone = new SegmentReader[numSegments];
			
			bool mergeDocStores = false;

            System.Collections.Hashtable dss = new System.Collections.Hashtable();
			
            String currentDocStoreSegment;
            lock(this) {
                currentDocStoreSegment = docWriter.GetDocStoreSegment();
            }
            bool currentDSSMerged = false;

			// This is try/finally to make sure merger's readers are
			// closed:
			bool success = false;
            try
            {
                int totDocCount = 0;

                for (int i = 0; i < numSegments; i++)
                {

                    SegmentInfo info = sourceSegments.Info(i);

                    // Hold onto the "live" reader; we will use this to
                    // commit merged deletes
                    SegmentReader reader = merge.readers[i] = readerPool.Get(info, merge.mergeDocStores, MERGE_READ_BUFFER_SIZE, -1);

                    // We clone the segment readers because other
                    // deletes may come in while we're merging so we
                    // need readers that will not change
                    SegmentReader clone = merge.readersClone[i] = (SegmentReader)reader.Clone(true);
                    merger.Add(clone);

                    if (clone.HasDeletions())
                    {
                        mergeDocStores = true;
                    }

                    if (info.GetDocStoreOffset() != -1 && currentDocStoreSegment != null)
                    {
                        currentDSSMerged |= currentDocStoreSegment.Equals(info.GetDocStoreSegment());
                    }

                    totDocCount += clone.NumDocs();
                }

                if (infoStream != null)
                {
                    Message("merge: total " + totDocCount + " docs");
                }

                merge.CheckAborted(directory);

                // If deletions have arrived and it has now become
                // necessary to merge doc stores, go and open them:
                if (mergeDocStores && !merge.mergeDocStores)
                {
                    merge.mergeDocStores = true;
                    lock (this)
                    {
                        if (currentDSSMerged)
                        {
                            if (infoStream != null)
                            {
                                Message("now flush at mergeMiddle");
                            }
                            DoFlush(true, false);
                        }
                    }

                    for (int i = 0; i < numSegments; i++)
                    {
                        merge.readersClone[i].OpenDocStores();
                    }

                    // Clear DSS
                    merge.info.SetDocStore(-1, null, false);

                }

                // This is where all the work happens:
                mergedDocCount = merge.info.docCount = merger.Merge(merge.mergeDocStores);

                System.Diagnostics.Debug.Assert(mergedDocCount == totDocCount);

                if (merge.useCompoundFile)
                {

                    success = false;
                    string compoundFileName = IndexFileNames.SegmentFileName(mergedName, IndexFileNames.COMPOUND_FILE_EXTENSION);

                    try
                    {
                        if (infoStream != null)
                        {
                            Message("create compound file " + compoundFileName);
                        }
                        merger.CreateCompoundFile(compoundFileName);
                        success = true;
                    }
                    catch (System.IO.IOException ioe)
                    {
                        lock (this)
                        {
                            if (merge.IsAborted())
                            {
                                // This can happen if rollback or close(false)
                                // is called -- fall through to logic below to
                                // remove the partially created CFS:
                            }
                            else
                            {
                                HandleMergeException(ioe, merge);
                            }
                        }
                    }
                    catch (Exception t)
                    {
                        HandleMergeException(t, merge);
                    }
                    finally
                    {
                        if (!success)
                        {
                            if (infoStream != null)
                            {
                                Message("hit exception creating compound file during merge");
                            }

                            lock (this)
                            {
                                deleter.DeleteFile(compoundFileName);
                                deleter.DeleteNewFiles(merger.GetMergedFiles());
                            }
                        }
                    }

                    success = false;

                    lock (this)
                    {

                        // delete new non cfs files directly: they were never
                        // registered with IFD
                        deleter.DeleteNewFiles(merger.GetMergedFiles());

                        if (merge.IsAborted())
                        {
                            if (infoStream != null)
                            {
                                Message("abort merge after building CFS");
                            }
                            deleter.DeleteFile(compoundFileName);
                            return 0;
                        }
                    }

                    merge.info.SetUseCompoundFile(true);
                }

                int termsIndexDivisor;
                bool loadDocStores;

                // if the merged segment warmer was not installed when
                // this merge was started, causing us to not force
                // the docStores to close, we can't warm it now
                bool canWarm = merge.info.GetDocStoreSegment() == null || currentDocStoreSegment == null || !merge.info.GetDocStoreSegment().Equals(currentDocStoreSegment);

                if (poolReaders && mergedSegmentWarmer != null && canWarm)
                {
                    // Load terms index & doc stores so the segment
                    // warmer can run searches, load documents/term
                    // vectors
                    termsIndexDivisor = readerTermsIndexDivisor;
                    loadDocStores = true;
                }
                else
                {
                    termsIndexDivisor = -1;
                    loadDocStores = false;
                }

                // TODO: in the non-realtime case, we may want to only
                // keep deletes (it's costly to open entire reader
                // when we just need deletes)

                SegmentReader mergedReader = readerPool.Get(merge.info, loadDocStores, BufferedIndexInput.BUFFER_SIZE, termsIndexDivisor);
                try
                {
                    if (poolReaders && mergedSegmentWarmer != null)
                    {
                        mergedSegmentWarmer.Warm(mergedReader);
                    }
                    if (!CommitMerge(merge, merger, mergedDocCount, mergedReader))
                    {
                        // commitMerge will return false if this merge was aborted
                        return 0;
                    }
                }
                finally
                {
                    lock (this)
                    {
                        readerPool.Release(mergedReader);
                    }
                }

                success = true;
            }
            finally
            {
                // Readers are already closed in commitMerge if we didn't hit
                // an exc:
                if (!success)
                {
                    CloseMergeReaders(merge, true);
                }
            }

            merge.mergeDone = true;

            lock (mergeScheduler)
            {
                System.Threading.Monitor.PulseAll(mergeScheduler); 
            }

			// Force a sync after commiting the merge.  Once this
			// sync completes then all index files referenced by the
			// current segmentInfos are on stable storage so if the
			// OS/machine crashes, or power cord is yanked, the
			// index will be intact.  Note that this is just one
			// (somewhat arbitrary) policy; we could try other
			// policies like only sync if it's been > X minutes or
			// more than Y bytes have been written, etc.
			if (autoCommit)
			{
				long size;
				lock (this)
				{
					size = merge.info.SizeInBytes();
				}
				Commit(size);
			}
			
			return mergedDocCount;
		}