exactphrasescorer.java

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package org.apache.lucene.search;

/* ====================================================================
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 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
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import java.io.IOException;
import java.util.Vector;
import org.apache.lucene.util.*;
import org.apache.lucene.index.*;

final class ExactPhraseScorer extends PhraseScorer {

  ExactPhraseScorer(TermPositions[] tps, byte[] n, float w)
       throws IOException {
    super(tps, n, w);
  }

  protected final float phraseFreq() throws IOException {
    // sort list with pq
    for (PhrasePositions pp = first; pp != null; pp = pp.next) {
      pp.firstPosition();
      pq.put(pp);				  // build pq from list
    }
    pqToList();					  // rebuild list from pq

    int freq = 0;
    do {					  // find position w/ all terms
      while (first.position < last.position) {	  // scan forward in first
	do {
	  if (!first.nextPosition())
	    return (float)freq;
	} while (first.position < last.position);
	firstToLast();
      }
      freq++;					  // all equal: a match
    } while (last.nextPosition());
  
    return (float)freq;
  }
}