internal override DocumentsWriter.DocWriter processDocument()
        {
            consumer.startDocument();
            Document doc = docState.doc;

            System.Diagnostics.Debug.Assert(docFieldProcessor.docWriter.writer.TestPoint("DocumentsWriter.ThreadState.init start"));

            fieldCount = 0;

            int thisFieldGen = fieldGen++;

            System.Collections.IList docFields = doc.GetFields();
            int numDocFields = docFields.Count;

            // Absorb any new fields first seen in this document.
            // Also absorb any changes to fields we had already
            // seen before (eg suddenly turning on norms or
            // vectors, etc.):

            for (int i = 0; i < numDocFields; i++)
            {
                Fieldable field     = (Fieldable)docFields[i];
                string    fieldName = field.Name();

                // Make sure we have a PerField allocated
                int hashPos = fieldName.GetHashCode() & hashMask;
                DocFieldProcessorPerField fp = fieldHash[hashPos];
                while (fp != null && !fp.fieldInfo.name.Equals(fieldName))
                {
                    fp = fp.next;
                }

                if (fp == null)
                {
                    // TODO FI: we need to genericize the "flags" that a
                    // field holds, and, how these flags are merged; it
                    // needs to be more "pluggable" such that if I want
                    // to have a new "thing" my Fields can do, I can
                    // easily add it
                    FieldInfo fi = fieldInfos.Add(fieldName, field.IsIndexed(), field.IsTermVectorStored(),
                                                  field.IsStorePositionWithTermVector(), field.IsStoreOffsetWithTermVector(),
                                                  field.GetOmitNorms(), false, field.GetOmitTf());

                    fp                 = new DocFieldProcessorPerField(this, fi);
                    fp.next            = fieldHash[hashPos];
                    fieldHash[hashPos] = fp;
                    totalFieldCount++;

                    if (totalFieldCount >= fieldHash.Length / 2)
                    {
                        rehash();
                    }
                }
                else
                {
                    fp.fieldInfo.update(field.IsIndexed(), field.IsTermVectorStored(),
                                        field.IsStorePositionWithTermVector(), field.IsStoreOffsetWithTermVector(),
                                        field.GetOmitNorms(), false, field.GetOmitTf());
                }

                if (thisFieldGen != fp.lastGen)
                {
                    // First time we're seeing this field for this doc
                    fp.fieldCount = 0;

                    if (fieldCount == fields.Length)
                    {
                        int newSize = fields.Length * 2;
                        DocFieldProcessorPerField[] newArray = new DocFieldProcessorPerField[newSize];
                        System.Array.Copy(fields, 0, newArray, 0, fieldCount);
                        fields = newArray;
                    }

                    fields[fieldCount++] = fp;
                    fp.lastGen           = thisFieldGen;
                }

                if (fp.fieldCount == fp.fields.Length)
                {
                    Fieldable[] newArray = new Fieldable[fp.fields.Length * 2];
                    System.Array.Copy(fp.fields, 0, newArray, 0, fp.fieldCount);
                    fp.fields = newArray;
                }

                fp.fields[fp.fieldCount++] = field;
            }

            // If we are writing vectors then we must visit
            // fields in sorted order so they are written in
            // sorted order.  TODO: we actually only need to
            // sort the subset of fields that have vectors
            // enabled; we could save [small amount of] CPU
            // here.
            quickSort(fields, 0, fieldCount - 1);

            for (int i = 0; i < fieldCount; i++)
            {
                fields[i].consumer.processFields(fields[i].fields, fields[i].fieldCount);
            }

            if (docState.maxTermPrefix != null && docState.infoStream != null)
            {
                docState.infoStream.WriteLine("WARNING: document contains at least one immense term (longer than the max length " + DocumentsWriter.MAX_TERM_LENGTH + "), all of which were skipped.  Please correct the analyzer to not produce such terms.  The prefix of the first immense term is: '" + docState.maxTermPrefix + "...'");
            }

            return(consumer.finishDocument());
        }