A problem about additonal info(after some modification for lucene)

[王建新]

I modified some lucene's code to make lucene have the new use like:

    doc=new Document();
    byte[] additionalInfo=new byte[]{'x','x','x'};
    doc.add(new Field("field1","aa 
aa",Field.Store.YES,Field.Index.TOKENIZED,Field.TermVector.NO,additionalInfo));

I change the *.frp file as:
        if (1 == termDocFreq) {
          freqOut.writeVInt(newDocCode|1);
        } else {
          freqOut.writeVInt(newDocCode);
          freqOut.writeVInt(termDocFreq);
        }
        Iterator<Integer> it=minState.fieldnos.iterator();//fieldnos is a set 
containing all filed no about the term in a specified field.
        while(it.hasNext()) 
        {
         int fieldno=it.next();
         freqOut.writeVInt(fieldno);//##
        }
        freqOut.writeVInt(0);
I use 0 to mark the end of filednos.for example:

doc.add(new Field("field1","aa 
aa",Field.Store.YES,Field.Index.TOKENIZED,Field.TermVector.NO,additionalInfo));
doc.add(new Field("field1","aa 
aa",Field.Store.YES,Field.Index.TOKENIZED,Field.TermVector.NO,additionalInfo));

the *.frq file is(one record):
     docid(?)    4(freq)    1,2

1,2 : the first(1) and second(2) fields has  term "aa".

It works correctly, if count<480000 as the following code. but if count>=48000, 
error occurs.
int count=480000;
for(int i=0;i<count;i++)
  {
  doc=new Document();
  byte[] additionalInfo=new byte[]{'x','x','x'};
  doc.add(new Field("field1","aa 
aa",Field.Store.YES,Field.Index.TOKENIZED,Field.TermVector.NO,additionalInfo));
  additionalInfo=new byte[]{'y','y','y'};
  doc.add(new Field("field1","aa  
aa",Field.Store.YES,Field.Index.TOKENIZED,Field.TermVector.NO,additionalInfo));
  doc.add(new Field("field2","bb 
cc",Field.Store.YES,Field.Index.TOKENIZED,Field.TermVector.NO,additionalInfo));
  writer.addDocument(doc);
  
  doc=new Document();
  additionalInfo=new byte[]{'c','c','c','c'};
  doc.add(new Field("field1","aa 
bb",Field.Store.YES,Field.Index.TOKENIZED,Field.TermVector.NO,additionalInfo));
  additionalInfo=new byte[]{'b','b','b','b'};
  doc.add(new 
Field("field1","bb",Field.Store.YES,Field.Index.TOKENIZED,Field.TermVector.NO,additionalInfo));
  doc.add(new Field("field1","cc 
bb",Field.Store.YES,Field.Index.TOKENIZED,Field.TermVector.NO,additionalInfo));
  writer.addDocument(doc);
}

I think it will merge index if count>=480000. the error may be in  class 
SegmentMerger.
private final int mergeTermInfo(SegmentMergeInfo[] smis, int n)
          throws CorruptIndexException, IOException {
    long freqPointer = freqOutput.getFilePointer();
    long proxPointer = proxOutput.getFilePointer();

    int df = appendPostings(smis, n);    // append posting data

    long skipPointer = skipListWriter.writeSkip(freqOutput);
    System.err.println("long skipPointer = 
skipListWriter.writeSkip(freqOutput);");

    if (df > 0) {
      // add an entry to the dictionary with pointers to prox and freq files
      termInfo.set(df, freqPointer, proxPointer, (int) (skipPointer - 
freqPointer));
      termInfosWriter.add(smis[0].term, termInfo);
    }

    return df;
  }

I cannot understand the process of here.
Could you give me any help?
Thanks.