/**
* Search for pages matching a query, eliminating excessive hits with matching values for a named
* field. Hits after the first <code>maxHitsPerDup</code> are removed from results. The remaining
* hits have {@link Hit#moreFromDupExcluded()} set.
*
* <p>If maxHitsPerDup is zero then all hits are returned.
*
* @param query query
* @param numHits number of requested hits
* @param maxHitsPerDup the maximum hits returned with matching values, or zero
* @param dedupField field name to check for duplicates
* @param sortField Field to sort on (or null if no sorting).
* @param reverse True if we are to reverse sort by <code>sortField</code>.
* @return Hits the matching hits
* @throws IOException
*/
public Hits search(
Query query,
int numHits,
int maxHitsPerDup,
String dedupField,
String sortField,
boolean reverse)
throws IOException {
if (maxHitsPerDup <= 0) // disable dup checking
return search(query, numHits, dedupField, sortField, reverse);
final float rawHitsFactor = this.conf.getFloat("searcher.hostgrouping.rawhits.factor", 2.0f);
int numHitsRaw = (int) (numHits * rawHitsFactor);
if (LOG.isInfoEnabled()) {
LOG.info("searching for " + numHitsRaw + " raw hits");
}
Hits hits = searchBean.search(query, numHitsRaw, dedupField, sortField, reverse);
final long total = hits.getTotal();
final Map<String, DupHits> dupToHits = new HashMap<String, DupHits>();
final List<Hit> resultList = new ArrayList<Hit>();
final Set<Hit> seen = new HashSet<Hit>();
final List<String> excludedValues = new ArrayList<String>();
boolean totalIsExact = true;
for (int rawHitNum = 0; rawHitNum < hits.getTotal(); rawHitNum++) {
// get the next raw hit
if (rawHitNum >= hits.getLength()) {
// optimize query by prohibiting more matches on some excluded values
final Query optQuery = (Query) query.clone();
for (int i = 0; i < excludedValues.size(); i++) {
if (i == MAX_PROHIBITED_TERMS) break;
optQuery.addProhibitedTerm(excludedValues.get(i), dedupField);
}
numHitsRaw = (int) (numHitsRaw * rawHitsFactor);
if (LOG.isInfoEnabled()) {
LOG.info("re-searching for " + numHitsRaw + " raw hits, query: " + optQuery);
}
hits = searchBean.search(optQuery, numHitsRaw, dedupField, sortField, reverse);
if (LOG.isInfoEnabled()) {
LOG.info("found " + hits.getTotal() + " raw hits");
}
rawHitNum = -1;
continue;
}
final Hit hit = hits.getHit(rawHitNum);
if (seen.contains(hit)) continue;
seen.add(hit);
// get dup hits for its value
final String value = hit.getDedupValue();
DupHits dupHits = dupToHits.get(value);
if (dupHits == null) dupToHits.put(value, dupHits = new DupHits());
// does this hit exceed maxHitsPerDup?
if (dupHits.size() == maxHitsPerDup) { // yes -- ignore the hit
if (!dupHits.maxSizeExceeded) {
// mark prior hits with moreFromDupExcluded
for (int i = 0; i < dupHits.size(); i++) {
dupHits.get(i).setMoreFromDupExcluded(true);
}
dupHits.maxSizeExceeded = true;
excludedValues.add(value); // exclude dup
}
totalIsExact = false;
} else { // no -- collect the hit
resultList.add(hit);
dupHits.add(hit);
// are we done?
// we need to find one more than asked for, so that we can tell if
// there are more hits to be shown
if (resultList.size() > numHits) break;
}
}
final Hits results = new Hits(total, resultList.toArray(new Hit[resultList.size()]));
results.setTotalIsExact(totalIsExact);
return results;
}
/**
* 从已匹配的Hit中直接取出DictSegment，继续向下匹配
*
* @return Hit
*/
public Hit matchWithHit(char[] charArray, int currentIndex, Hit matchedHit) {
DictSegment ds = matchedHit.getMatchedDictSegment();
return ds.match(charArray, currentIndex, 1, matchedHit);
}