final class DocFieldProcessor extends DocConsumer {  final DocFieldConsumer consumer;  final StoredFieldsConsumer storedConsumer;  final Codec codec;  // 存储doc里所有的DocFieldProcessorPerField（这个类里面会存放多个fieldinfo相同的field），位置按顺序存储，一个位置里面放一个  DocFieldProcessorPerField[] fields = new DocFieldProcessorPerField[1];  int fieldCount;  // 存储doc里所有的DocFieldProcessorPerField（这个类里面会存放多个fieldinfo相同的field），位置按fieldname的hash来存放，一个位置可能匹配多个，以链表结构存放  DocFieldProcessorPerField[] fieldHash = new DocFieldProcessorPerField[2];  int hashMask = 1;  int totalFieldCount;  int fieldGen;//浅拷贝 要分析的doument  final DocumentsWriterPerThread.DocState docState;  final Counter bytesUsed;

  public void processDocument(FieldInfos.Builder fieldInfos) throws IOException {    consumer.startDocument();    storedConsumer.startDocument();    fieldCount = 0;    final int thisFieldGen = fieldGen++;//循环doc里的field，合并同fieldinfo的field进入一个DocFieldProcessorPerField，并且如果此轮循环有新创建的DocFieldProcessorPerField对象，则加入到顺序数组和hash数组里面    for(IndexableField field : docState.doc) {      final String fieldName = field.name();      //计算fieldname在hash数组里对应的位置      final int hashPos = fieldName.hashCode() & hashMask;      DocFieldProcessorPerField fp = fieldHash[hashPos];     //查找对应位置下fieldname符合当前field的DocFieldProcessorPerField对象      while(fp != null && !fp.fieldInfo.name.equals(fieldName)) {        fp = fp.next;      }      if (fp == null) {        //表示该fieldinfo是第一次出现，把field的info信息添加到fieldinfos里面，并且创建对应的fieldinfo对象        FieldInfo fi = fieldInfos.addOrUpdate(fieldName, field.fieldType());        //创建一个DocFieldProcessorPerField        fp = new DocFieldProcessorPerField(this, fi);               //加入到hash链表里面        fp.next = fieldHash[hashPos];        fieldHash[hashPos] = fp;        totalFieldCount++;        //hash表快满了，重新做hash        if (totalFieldCount >= fieldHash.length/2) {          rehash();        }      } else {      //更新fieldinfo对象        FieldInfo fi = fieldInfos.addOrUpdate(fieldName, field.fieldType());        assert fi == fp.fieldInfo : "should only have updated an existing FieldInfo instance";      }      if (thisFieldGen != fp.lastGen) {      //说明这个fieldinfo是第一次出现，即本次循环new了DocFieldProcessorPerField        fp.fieldCount = 0;        //判断顺序数组是不是满了        if (fieldCount == fields.length) {          final int newSize = fields.length*2;          DocFieldProcessorPerField newArray[] = new DocFieldProcessorPerField[newSize];          System.arraycopy(fields, 0, newArray, 0, fieldCount);          fields = newArray;        }        fields[fieldCount++] = fp;        fp.lastGen = thisFieldGen;      }     //把field加入到fp中，同fieldinfo的field会加入到同一个fp里面      fp.addField(field);           storedConsumer.addField(docState.docID, field, fp.fieldInfo);    }    //遍历顺序数组里的DocFieldProcessorPerField，调用DocInverterPerField对其里面的field进行分词建立索引之类的操作    ArrayUtil.introSort(fields, 0, fieldCount, fieldsComp);    for(int i=0;i<fieldCount;i++) {      final DocFieldProcessorPerField perField = fields[i];      perField.consumer.processFields(perField.fields, perField.fieldCount);    }  }