import org.apache.lucene.store.FlushInfo; //导入依赖的package包/类
private void initTermVectorsWriter() throws IOException {
  if (writer == null) {
    IOContext context = new IOContext(new FlushInfo(docWriter.getNumDocsInRAM(), docWriter.bytesUsed()));
    writer = docWriter.codec.termVectorsFormat().vectorsWriter(docWriter.directory, docWriter.getSegmentInfo(), context);
    lastDocID = 0;
  }
}
 

import org.apache.lucene.store.FlushInfo; //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.store.FlushInfo; //导入依赖的package包/类
/** TODO: javadoc */
public static IOContext newIOContext(Random random, IOContext oldContext) {
  final int randomNumDocs = random.nextInt(4192);
  final int size = random.nextInt(512) * randomNumDocs;
  if (oldContext.flushInfo != null) {
    // Always return at least the estimatedSegmentSize of
    // the incoming IOContext:
    return new IOContext(new FlushInfo(randomNumDocs, Math.max(oldContext.flushInfo.estimatedSegmentSize, size)));
  } else if (oldContext.mergeInfo != null) {
    // Always return at least the estimatedMergeBytes of
    // the incoming IOContext:
    return new IOContext(new MergeInfo(randomNumDocs, Math.max(oldContext.mergeInfo.estimatedMergeBytes, size), random.nextBoolean(), TestUtil.nextInt(random, 1, 100)));
  } else {
    // Make a totally random IOContext:
    final IOContext context;
    switch (random.nextInt(5)) {
    case 0:
      context = IOContext.DEFAULT;
      break;
    case 1:
      context = IOContext.READ;
      break;
    case 2:
      context = IOContext.READONCE;
      break;
    case 3:
      context = new IOContext(new MergeInfo(randomNumDocs, size, true, -1));
      break;
    case 4:
      context = new IOContext(new FlushInfo(randomNumDocs, size));
      break;
    default:
      context = IOContext.DEFAULT;
    }
    return context;
  }
}
 

import org.apache.lucene.store.FlushInfo; //导入依赖的package包/类
private final void initTermVectorsWriter() throws IOException {
  if (writer == null) {
    IOContext context = new IOContext(new FlushInfo(docWriter.getNumDocsInRAM(), docWriter.bytesUsed()));
    writer = docWriter.codec.termVectorsFormat().vectorsWriter(docWriter.directory, docWriter.getSegmentInfo(), context);
    lastDocID = 0;
  }
}