internal override void closeDocStore(DocumentsWriter.FlushState state)
        {
            lock (this)
            {
                int inc = state.numDocsInStore - lastDocID;
                if (inc > 0)
                {
                    initFieldsWriter();
                    fill(state.numDocsInStore - docWriter.GetDocStoreOffset());
                }

                if (fieldsWriter != null)
                {
                    fieldsWriter.Close();
                    fieldsWriter = null;
                    lastDocID = 0;
                    System.Diagnostics.Debug.Assert(state.docStoreSegmentName != null);

                    string fdtFile = state.docStoreSegmentName + "." + IndexFileNames.FIELDS_EXTENSION;
                    string fdxFile = state.docStoreSegmentName + "." + IndexFileNames.FIELDS_INDEX_EXTENSION;

                    state.flushedFiles[fdtFile] = fdtFile;
                    state.flushedFiles[fdxFile] = fdxFile;

                    state.docWriter.RemoveOpenFile(fdtFile);
                    state.docWriter.RemoveOpenFile(fdxFile);

                    if (4 + state.numDocsInStore * 8 != state.directory.FileLength(fdxFile))
                        throw new System.SystemException("after flush: fdx size mismatch: " + state.numDocsInStore + " docs vs " + state.directory.FileLength(fdxFile) + " length in bytes of " + fdxFile);
                }
            }
        }

 public DocFieldProcessor(DocumentsWriter docWriter, DocFieldConsumer consumer)
 {
     this.docWriter = docWriter;
     this.consumer = consumer;
     consumer.SetFieldInfos(fieldInfos);
     fieldsWriter = new StoredFieldsWriter(docWriter, fieldInfos);
 }

        public override ThreadState GetAndLock(Thread requestingThread, DocumentsWriter documentsWriter)
        {
            ThreadState threadState = null;
            if (ActiveThreadState == 0)
            {
                lock (this)
                {
                    if (ActiveThreadState == 0)
                    {
                        threadState = States[0] = NewThreadState();
                        return threadState;
                    }
                }
            }
            Debug.Assert(ActiveThreadState > 0);
            for (int i = 0; i < MaxRetry; i++)
            {
                int ord = Random.Next(ActiveThreadState);
                lock (this)
                {
                    threadState = States[ord];
                    Debug.Assert(threadState != null);
                }

                if (threadState.TryLock())
                {
                    return threadState;
                }
                if (Random.Next(20) == 0)
                {
                    break;
                }
            }
            /*
             * only try to create a new threadstate if we can not lock the randomly
             * selected state. this is important since some tests rely on a single
             * threadstate in the single threaded case. Eventually it would be nice if
             * we would not have this limitation but for now we just make sure we only
             * allocate one threadstate if indexing is single threaded
             */

            lock (this)
            {
                ThreadState newThreadState = NewThreadState();
                if (newThreadState != null) // did we get a new state?
                {
                    threadState = States[ActiveThreadState - 1] = newThreadState;
                    //Debug.Assert(threadState.HeldByCurrentThread);
                    return threadState;
                }
                // if no new state is available lock the random one
            }
            Debug.Assert(threadState != null);
            [email protected]();
            return threadState;
        }

        internal int numThreads = 1; // Number of threads that share this instance

        #endregion Fields

        #region Constructors

        public DocumentsWriterThreadState(DocumentsWriter docWriter)
        {
            this.docWriter = docWriter;
            docState = new DocumentsWriter.DocState();
            docState.maxFieldLength = docWriter.maxFieldLength;
            docState.infoStream = docWriter.infoStream;
            docState.similarity = docWriter.similarity;
            docState.docWriter = docWriter;
            consumer = docWriter.consumer.AddThread(this);
        }

 internal override void closeDocStore(DocumentsWriter.FlushState state)
 {
     try
     {
         one.closeDocStore(state);
     }
     finally
     {
         two.closeDocStore(state);
     }
 }

        internal int numThreads = 1; // Number of threads that share this instance

        #endregion Fields

        #region Constructors

        public DocumentsWriterThreadState(DocumentsWriter docWriter)
        {
            this.docWriter = docWriter;
            docState = new DocumentsWriter.DocState();
            docState.maxFieldLength = docWriter.maxFieldLength;
            docState.infoStream = docWriter.infoStream;
            docState.similarity = docWriter.similarity;
            docState.docWriter = docWriter;
            docState.allowMinus1Position = docWriter.writer.GetAllowMinus1Position();
            consumer = docWriter.consumer.AddThread(this);
        }

		public SegmentWriteState(DocumentsWriter docWriter, Directory directory, System.String segmentName, System.String docStoreSegmentName, int numDocs, int numDocsInStore, int termIndexInterval)
		{
			this.docWriter = docWriter;
			this.directory = directory;
			this.segmentName = segmentName;
			this.docStoreSegmentName = docStoreSegmentName;
			this.numDocs = numDocs;
			this.numDocsInStore = numDocsInStore;
			this.termIndexInterval = termIndexInterval;
            flushedFiles = new Support.Set<string>();
		}

        //internal override void flush(/*IDictionary*/ IDictionary<DocFieldConsumerPerThread, ICollection<DocFieldConsumerPerField>> threadsAndFields, DocumentsWriter.FlushState state)
        internal override void flush(/*IDictionary*/ IDictionary<object, ICollection<object>> threadsAndFields, DocumentsWriter.FlushState state)
        {
            //IDictionary oneThreadsAndFields = new Dictionary();
            //IDictionary twoThreadsAndFields = new Dictionary();
            //IDictionary<DocFieldConsumerPerThread, ICollection<DocFieldConsumerPerField>> oneThreadsAndFields = new Dictionary<DocFieldConsumerPerThread, ICollection<DocFieldConsumerPerField>>();
            //IDictionary<DocFieldConsumerPerThread, ICollection<DocFieldConsumerPerField>> twoThreadsAndFields = new Dictionary<DocFieldConsumerPerThread, ICollection<DocFieldConsumerPerField>>();
            IDictionary<object, ICollection<object>> oneThreadsAndFields = new Dictionary<object, ICollection<object>>();
            IDictionary<object, ICollection<object>> twoThreadsAndFields = new Dictionary<object, ICollection<object>>();

            //IEnumerator it = threadsAndFields.GetEnumerator();
            //IEnumerator<KeyValuePair<DocFieldConsumerPerThread, ICollection<DocFieldConsumerPerField>>> it = threadsAndFields.GetEnumerator();
            IEnumerator<KeyValuePair<object, ICollection<object>>> it = threadsAndFields.GetEnumerator();
            while (it.MoveNext())
            {
                //KeyValuePair entry = it.Current;
                //KeyValuePair<DocFieldConsumerPerThread, ICollection<DocFieldConsumerPerField>> entry = it.Current;
                KeyValuePair<object, ICollection<object>> entry = it.Current;

                //DocFieldConsumersPerThread perThread = (DocFieldConsumersPerThread)entry.Key;
                DocFieldConsumersPerThread perThread = (DocFieldConsumersPerThread)entry.Key;

                //ICollection fields = (ICollection)entry.Value;
                //ICollection<DocFieldConsumerPerField> fields = entry.Value;
                ICollection<object> fields = entry.Value;

                //IEnumerator fieldsIt = fields.GetEnumerator();
                //IEnumerator<DocFieldConsumerPerField> fieldsIt = fields.GetEnumerator();
                IEnumerator<object> fieldsIt = fields.GetEnumerator();

                //IDictionary oneFields = new Dictionary();
                //IDictionary twoFields = new Dictionary();
                //IDictionary<DocFieldConsumerPerField, DocFieldConsumerPerField> oneFields = new Dictionary<DocFieldConsumerPerField, DocFieldConsumerPerField>();
                //IDictionary<DocFieldConsumerPerField, DocFieldConsumerPerField> twoFields = new Dictionary<DocFieldConsumerPerField, DocFieldConsumerPerField>();
                IDictionary<object, object> oneFields = new Dictionary<object, object>();
                IDictionary<object, object> twoFields = new Dictionary<object, object>();

                while (fieldsIt.MoveNext())
                {
                    DocFieldConsumersPerField perField = (DocFieldConsumersPerField)fieldsIt.Current;
                    oneFields[perField.one] = perField.one;
                    twoFields[perField.two] = perField.two;
                }

                oneThreadsAndFields[perThread.one] = oneFields.Keys;
                twoThreadsAndFields[perThread.two] = twoFields.Keys;
            }

            one.flush(oneThreadsAndFields, state);
            two.flush(twoThreadsAndFields, state);
        }

		public TermsHash(DocumentsWriter docWriter, bool trackAllocations, TermsHashConsumer consumer, TermsHash nextTermsHash)
		{
			this.docWriter = docWriter;
			this.consumer = consumer;
			this.nextTermsHash = nextTermsHash;
			this.trackAllocations = trackAllocations;
			
			// Why + 4*POINTER_NUM_BYTE below?
			//   +1: Posting is referenced by postingsFreeList array
			//   +3: Posting is referenced by hash, which
			//       targets 25-50% fill factor; approximate this
			//       as 3X # pointers
			bytesPerPosting = consumer.BytesPerPosting() + 4 * DocumentsWriter.POINTER_NUM_BYTE;
			postingsFreeChunk = (int) (DocumentsWriter.BYTE_BLOCK_SIZE / bytesPerPosting);
		}

        internal override void Flush(ICollection<object> threads, DocumentsWriter.FlushState state)
        {
            IDictionary<object, ICollection<object>> childThreadsAndFields = new Dictionary<object, ICollection<object>>();
            IEnumerator<object> it = threads.GetEnumerator();
            while (it.MoveNext())
            {
                DocFieldProcessorPerThread perThread = (DocFieldProcessorPerThread)it.Current;
                childThreadsAndFields[perThread.consumer] = perThread.Fields();
                perThread.trimFields(state);
            }

            consumer.flush(childThreadsAndFields, state);

            // Important to save after asking consumer to flush so
            // consumer can alter the FieldInfo* if necessary.  EG,
            // FreqProxTermsWriter does this with
            // FieldInfo.storePayload.
            fieldInfos.Write(state.directory, state.segmentName + ".fnm");
        }

        //internal override void flush(IDictionary<DocFieldConsumerPerThread, ICollection<DocFieldConsumerPerField>> threadsAndFields, DocumentsWriter.FlushState state)
        internal override void flush(IDictionary<object, ICollection<object>> threadsAndFields, DocumentsWriter.FlushState state)
        {
            //IDictionary<DocFieldConsumerPerThread, ICollection<DocFieldConsumerPerField>> childThreadsAndFields = new Dictionary<DocFieldConsumerPerThread, ICollection<DocFieldConsumerPerField>>();
            //IDictionary<DocFieldConsumerPerThread, ICollection<DocFieldConsumerPerField>> endChildThreadsAndFields = new Dictionary<DocFieldConsumerPerThread, ICollection<DocFieldConsumerPerField>>();
            IDictionary<object, ICollection<object>> childThreadsAndFields = new Dictionary<object, ICollection<object>>();
            IDictionary<object, ICollection<object>> endChildThreadsAndFields = new Dictionary<object, ICollection<object>>();

            //IEnumerator<KeyValuePair<DocFieldConsumerPerThread, ICollection<DocFieldConsumerPerField>>> it = threadsAndFields.GetEnumerator();
            IEnumerator<KeyValuePair<object, ICollection<object>>> it = threadsAndFields.GetEnumerator();
            while (it.MoveNext())
            {
                //KeyValuePair<DocFieldConsumerPerThread, ICollection<DocFieldConsumerPerField>> entry = it.Current;
                KeyValuePair<object, ICollection<object>> entry = it.Current;

                DocInverterPerThread perThread = (DocInverterPerThread)entry.Key;

                //ICollection<DocFieldConsumerPerField> fields = entry.Value;
                ICollection<object> fields = entry.Value;
                //IEnumerator<DocFieldConsumerPerField> fieldsIt = fields.GetEnumerator();
                IEnumerator<object> fieldsIt = fields.GetEnumerator();

                //IDictionary<DocFieldConsumerPerField, DocFieldConsumerPerField> childFields = new Dictionary<DocFieldConsumerPerField, DocFieldConsumerPerField>();
                //IDictionary<DocFieldConsumerPerField, DocFieldConsumerPerField> endChildFields = new Dictionary<DocFieldConsumerPerField, DocFieldConsumerPerField>();
                IDictionary<object, object> childFields = new Dictionary<object, object>();
                IDictionary<object, object> endChildFields = new Dictionary<object, object>();

                while (fieldsIt.MoveNext())
                {
                    DocInverterPerField perField = (DocInverterPerField)fieldsIt.Current;
                    childFields[perField.consumer] = perField.consumer;
                    endChildFields[perField.endConsumer] = perField.endConsumer;
                }

                childThreadsAndFields[perThread.consumer] = childFields.Keys;
                // create new collection to provide for deletions in NormsWriter
                endChildThreadsAndFields[perThread.endConsumer] = new List<object>(endChildFields.Keys);
            }

            consumer.flush(childThreadsAndFields, state);
            endConsumer.flush(endChildThreadsAndFields, state);
        }

        public override ThreadState GetAndLock(Thread requestingThread, DocumentsWriter documentsWriter)
        {
            ThreadState threadState;
            ThreadBindings.TryGetValue(requestingThread, out threadState);
            if (threadState != null && threadState.TryLock())
            {
                return threadState;
            }
            ThreadState minThreadState = null;

            /* TODO -- another thread could lock the minThreadState we just got while
             we should somehow prevent this. */
            // Find the state that has minimum number of threads waiting
            minThreadState = MinContendedThreadState();
            if (minThreadState == null || minThreadState.HasQueuedThreads)
            {
                ThreadState newState = NewThreadState(); // state is already locked if non-null
                if (newState != null)
                {
                    //Debug.Assert(newState.HeldByCurrentThread);
                    ThreadBindings[requestingThread] = newState;
                    return newState;
                }
                else if (minThreadState == null)
                {
                    /*
                     * no new threadState available we just take the minContented one
                     * this must return a valid thread state since we accessed the
                     * synced context in newThreadState() above.
                     */
                    minThreadState = MinContendedThreadState();
                }
            }
            Debug.Assert(minThreadState != null, "ThreadState is null");

            [email protected]();
            return minThreadState;
        }

 internal ByteBlockAllocator(DocumentsWriter enclosing_instance)
 {
     this.enclosing_instance = enclosing_instance;
 }

		public StoredFieldsWriterPerThread(DocumentsWriter.DocState docState, StoredFieldsWriter storedFieldsWriter)
		{
			this.storedFieldsWriter = storedFieldsWriter;
			this.docState = docState;
			localFieldsWriter = new FieldsWriter((IndexOutput) null, (IndexOutput) null, storedFieldsWriter.fieldInfos);
		}

		public TermVectorsTermsWriter(DocumentsWriter docWriter)
		{
			InitBlock();
			this.docWriter = docWriter;
		}

		public StoredFieldsWriter(DocumentsWriter docWriter, FieldInfos fieldInfos)
		{
			InitBlock();
			this.docWriter = docWriter;
			this.fieldInfos = fieldInfos;
		}

			internal abstract DocConsumer GetChain(DocumentsWriter documentsWriter);

			private void  InitBlock(DocumentsWriter enclosingInstance)
			{
				this.enclosingInstance = enclosingInstance;
			}

 public PerDocBuffer(DocumentsWriter enclosingInstance)
 {
     this.enclosingInstance = enclosingInstance;
 }

			public ByteBlockAllocator(DocumentsWriter enclosingInstance)
			{
				InitBlock(enclosingInstance);
			}