private SetIndexWriter ( |
||
writer | ||
리턴 |
internal readonly Codec Codec; // for writing new segments /// <summary> /// Constructs a new IndexWriter per the settings given in <code>conf</code>. /// If you want to make "live" changes to this writer instance, use /// <seealso cref="#getConfig()"/>. /// /// <p> /// <b>NOTE:</b> after ths writer is created, the given configuration instance /// cannot be passed to another writer. If you intend to do so, you should /// <seealso cref="IndexWriterConfig#clone() clone"/> it beforehand. /// </summary> /// <param name="d"> /// the index directory. The index is either created or appended /// according <code>conf.getOpenMode()</code>. </param> /// <param name="conf"> /// the configuration settings according to which IndexWriter should /// be initialized. </param> /// <exception cref="IOException"> /// if the directory cannot be read/written to, or if it does not /// exist and <code>conf.getOpenMode()</code> is /// <code>OpenMode.APPEND</code> or if there is any other low-level /// IO error </exception> public IndexWriter(Directory d, IndexWriterConfig conf) { /*if (!InstanceFieldsInitialized) { InitializeInstanceFields(); InstanceFieldsInitialized = true; }*/ readerPool = new ReaderPool(this); conf.SetIndexWriter(this); // prevent reuse by other instances Config_Renamed = new LiveIndexWriterConfig(conf); directory = d; analyzer = Config_Renamed.Analyzer; infoStream = Config_Renamed.InfoStream; mergePolicy = Config_Renamed.MergePolicy; mergePolicy.IndexWriter = this; mergeScheduler = Config_Renamed.MergeScheduler; Codec = Config_Renamed.Codec; BufferedUpdatesStream = new BufferedUpdatesStream(infoStream); PoolReaders = Config_Renamed.ReaderPooling; WriteLock = directory.MakeLock(WRITE_LOCK_NAME); if (!WriteLock.Obtain(Config_Renamed.WriteLockTimeout)) // obtain write lock { throw new LockObtainFailedException("Index locked for write: " + WriteLock); } bool success = false; try { OpenMode_e? mode = Config_Renamed.OpenMode; bool create; if (mode == OpenMode_e.CREATE) { create = true; } else if (mode == OpenMode_e.APPEND) { create = false; } else { // CREATE_OR_APPEND - create only if an index does not exist create = !DirectoryReader.IndexExists(directory); } // If index is too old, reading the segments will throw // IndexFormatTooOldException. segmentInfos = new SegmentInfos(); bool initialIndexExists = true; 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) { // Likely this means it's a fresh directory initialIndexExists = false; } // Record that we have a change (zero out all // segments) pending: Changed(); } else { segmentInfos.Read(directory); IndexCommit commit = Config_Renamed.IndexCommit; if (commit != null) { // Swap out all segments, but, keep metadata in // SegmentInfos, like version & generation, to // preserve write-once. this is important if // readers are open against the future commit // points. if (commit.Directory != directory) { throw new System.ArgumentException("IndexCommit's directory doesn't match my directory"); } SegmentInfos oldInfos = new SegmentInfos(); oldInfos.Read(directory, commit.SegmentsFileName); segmentInfos.Replace(oldInfos); Changed(); if (infoStream.IsEnabled("IW")) { infoStream.Message("IW", "init: loaded commit \"" + commit.SegmentsFileName + "\""); } } } RollbackSegments = segmentInfos.CreateBackupSegmentInfos(); // start with previous field numbers, but new FieldInfos GlobalFieldNumberMap = FieldNumberMap; Config_Renamed.FlushPolicy.Init(Config_Renamed); DocWriter = new DocumentsWriter(this, Config_Renamed, directory); eventQueue = DocWriter.EventQueue(); // Default deleter (for backwards compatibility) is // KeepOnlyLastCommitDeleter: lock (this) { Deleter = new IndexFileDeleter(directory, Config_Renamed.DelPolicy, segmentInfos, infoStream, this, initialIndexExists); } if (Deleter.StartingCommitDeleted) { // Deletion policy deleted the "head" commit point. // We have to mark ourself as changed so that if we // are closed w/o any further changes we write a new // segments_N file. Changed(); } if (infoStream.IsEnabled("IW")) { infoStream.Message("IW", "init: create=" + create); MessageState(); } success = true; } finally { if (!success) { if (infoStream.IsEnabled("IW")) { infoStream.Message("IW", "init: hit exception on init; releasing write lock"); } WriteLock.Release(); IOUtils.CloseWhileHandlingException(WriteLock); WriteLock = null; } } }