public DuplicateFilter(String fieldName) 
{
	
		this(fieldName, KM_USE_LAST_OCCURRENCE,PM_FULL_VALIDATION);
}

 public DuplicateFilter(String fieldName,
    int keepMode,
    int processingMode) 
{
		this.fieldName = fieldName;
		this.keepMode = keepMode;
		this.processingMode = processingMode;
}

 public BitSet bits(IndexReader reader) throws IOException 
{
		if(processingMode==PM_FAST_INVALIDATION)
		{
			return fastBits(reader);
		}
		else
		{
			return correctBits(reader);
		}
}

 public boolean equals(Object obj) 
{
		if(this == obj)
			return true;
		if((obj == null) || (obj.getClass() != this.getClass()))
			return false;
		DuplicateFilter other = (DuplicateFilter)obj;
		return keepMode == other.keepMode &&
		processingMode == other.processingMode &&
			(fieldName == other.fieldName || (fieldName != null && fieldName.equals(other.fieldName)));
}

 public String getFieldName() 
{
		return fieldName;
}

 public int getKeepMode() 
{
		return keepMode;
}

 public int getProcessingMode() 
{
		return processingMode;
}

 public int hashCode() 
{
		int hash = 217;
		hash = 31 * hash + keepMode;
		hash = 31 * hash + processingMode;
		hash = 31 * hash + fieldName.hashCode();
		return hash;
}

 public static  void main(String[] args) throws Exception 
{
		IndexReader r=IndexReader.open("/indexes/personCentricAnon");
//		IndexReader r=IndexReader.open("/indexes/enron");
		long start=System.currentTimeMillis();
//		DuplicateFilter df = new DuplicateFilter("threadId",KM_USE_FIRST_OCCURRENCE, PM_FAST_INVALIDATION);
//		DuplicateFilter df = new DuplicateFilter("threadId",KM_USE_LAST_OCCURRENCE, PM_FAST_INVALIDATION);
		DuplicateFilter df = new DuplicateFilter("vehicle.vrm",KM_USE_LAST_OCCURRENCE, PM_FAST_INVALIDATION);
//		DuplicateFilter df = new DuplicateFilter("title",USE_LAST_OCCURRENCE);
//		df.setProcessingMode(PM_SLOW_VALIDATION);
		BitSet b = df.bits(r);
		long end=System.currentTimeMillis()-start;
		System.out.println(b.cardinality()+" in "+end+" ms ");
}

 public  void setFieldName(String fieldName) 
{
		this.fieldName = fieldName;
}

 public  void setKeepMode(int keepMode) 
{
		this.keepMode = keepMode;
}

 public  void setProcessingMode(int processingMode) 
{
		this.processingMode = processingMode;
}