import org.apache.lucene.codecs.FieldInfosFormat; //导入依赖的package包/类
private Set<String> writeFieldInfosGen(FieldInfos fieldInfos, Directory dir, DocValuesFormat dvFormat, 
    FieldInfosFormat infosFormat) throws IOException {
  final long nextFieldInfosGen = info.getNextFieldInfosGen();
  final String segmentSuffix = Long.toString(nextFieldInfosGen, Character.MAX_RADIX);
  // we write approximately that many bytes (based on Lucene46DVF):
  // HEADER + FOOTER: 40
  // 90 bytes per-field (over estimating long name and attributes map)
  final long estInfosSize = 40 + 90 * fieldInfos.size();
  final IOContext infosContext = new IOContext(new FlushInfo(info.info.getDocCount(), estInfosSize));
  // separately also track which files were created for this gen
  final TrackingDirectoryWrapper trackingDir = new TrackingDirectoryWrapper(dir);
  infosFormat.getFieldInfosWriter().write(trackingDir, info.info.name, segmentSuffix, fieldInfos, infosContext);
  info.advanceFieldInfosGen();
  return trackingDir.getCreatedFiles();
}
 

import org.apache.lucene.codecs.FieldInfosFormat; //导入依赖的package包/类
@Override
public FieldInfosFormat fieldInfosFormat() {
  if (LuceneTestCase.OLD_FORMAT_IMPERSONATION_IS_ACTIVE) {
    return fieldInfos;
  } else {
    return super.fieldInfosFormat();
  }
}
 

import org.apache.lucene.codecs.FieldInfosFormat; //导入依赖的package包/类
@Override
public FieldInfosFormat fieldInfosFormat() {
  if (LuceneTestCase.PREFLEX_IMPERSONATION_IS_ACTIVE) {
    return fieldInfos;
  } else {
    return super.fieldInfosFormat();
  }
}
 

import org.apache.lucene.codecs.FieldInfosFormat; //导入依赖的package包/类
@Override
public FieldInfosFormat fieldInfosFormat() {
  return fieldInfosFormat;
}
 

import org.apache.lucene.codecs.FieldInfosFormat; //导入依赖的package包/类
@Override
public final FieldInfosFormat fieldInfosFormat() {
  return fieldInfosFormat;
}
 

import org.apache.lucene.codecs.FieldInfosFormat; //导入依赖的package包/类
@Override
public FieldInfosFormat fieldInfosFormat() {
  return fieldInfos;
}
 

import org.apache.lucene.codecs.FieldInfosFormat; //导入依赖的package包/类
@Override
public FieldInfosFormat fieldInfosFormat() {
  return new CrankyFieldInfosFormat(delegate.fieldInfosFormat(), random);
}
 

import org.apache.lucene.codecs.FieldInfosFormat; //导入依赖的package包/类
CrankyFieldInfosFormat(FieldInfosFormat delegate, Random random) {
  this.delegate = delegate;
  this.random = random;
}