/// <summary>
/// Retrieve suggestions, specifying whether all terms
/// must match (<paramref name="allTermsRequired"/>) and whether the hits
/// should be highlighted (<paramref name="doHighlight"/>).
/// </summary>
public virtual IList <LookupResult> DoLookup(string key, IEnumerable <BytesRef> contexts, int num, bool allTermsRequired, bool doHighlight)
{
if (m_searcherMgr == null)
{
throw new InvalidOperationException("suggester was not built");
}
Occur occur;
if (allTermsRequired)
{
occur = Occur.MUST;
}
else
{
occur = Occur.SHOULD;
}
TokenStream ts = null;
BooleanQuery query;
var matchedTokens = new HashSet <string>();
string prefixToken = null;
try
{
ts = m_queryAnalyzer.GetTokenStream("", new StringReader(key));
//long t0 = System.currentTimeMillis();
ts.Reset();
var termAtt = ts.AddAttribute <ICharTermAttribute>();
var offsetAtt = ts.AddAttribute <IOffsetAttribute>();
string lastToken = null;
query = new BooleanQuery();
int maxEndOffset = -1;
matchedTokens = new HashSet <string>();
while (ts.IncrementToken())
{
if (lastToken != null)
{
matchedTokens.Add(lastToken);
query.Add(new TermQuery(new Term(TEXT_FIELD_NAME, lastToken)), occur);
}
lastToken = termAtt.ToString();
if (lastToken != null)
{
maxEndOffset = Math.Max(maxEndOffset, offsetAtt.EndOffset);
}
}
ts.End();
if (lastToken != null)
{
Query lastQuery;
if (maxEndOffset == offsetAtt.EndOffset)
{
// Use PrefixQuery (or the ngram equivalent) when
// there was no trailing discarded chars in the
// string (e.g. whitespace), so that if query does
// not end with a space we show prefix matches for
// that token:
lastQuery = GetLastTokenQuery(lastToken);
prefixToken = lastToken;
}
else
{
// Use TermQuery for an exact match if there were
// trailing discarded chars (e.g. whitespace), so
// that if query ends with a space we only show
// exact matches for that term:
matchedTokens.Add(lastToken);
lastQuery = new TermQuery(new Term(TEXT_FIELD_NAME, lastToken));
}
if (lastQuery != null)
{
query.Add(lastQuery, occur);
}
}
if (contexts != null)
{
BooleanQuery sub = new BooleanQuery();
query.Add(sub, Occur.MUST);
foreach (BytesRef context in contexts)
{
// NOTE: we "should" wrap this in
// ConstantScoreQuery, or maybe send this as a
// Filter instead to search, but since all of
// these are MUST'd, the change to the score won't
// affect the overall ranking. Since we indexed
// as DOCS_ONLY, the perf should be the same
// either way (no freq int[] blocks to decode):
// TODO: if we had a BinaryTermField we could fix
// this "must be valid ut8f" limitation:
sub.Add(new TermQuery(new Term(CONTEXTS_FIELD_NAME, context.Utf8ToString())), Occur.SHOULD);
}
}
}
finally
{
IOUtils.CloseWhileHandlingException(ts);
}
// TODO: we could allow blended sort here, combining
// weight w/ score. Now we ignore score and sort only
// by weight:
Query finalQuery = FinishQuery(query, allTermsRequired);
//System.out.println("finalQuery=" + query);
// Sort by weight, descending:
TopFieldCollector c = TopFieldCollector.Create(SORT, num, true, false, false, false);
// We sorted postings by weight during indexing, so we
// only retrieve the first num hits now:
ICollector c2 = new EarlyTerminatingSortingCollector(c, SORT, num);
IndexSearcher searcher = m_searcherMgr.Acquire();
IList <LookupResult> results = null;
try
{
//System.out.println("got searcher=" + searcher);
searcher.Search(finalQuery, c2);
TopFieldDocs hits = (TopFieldDocs)c.GetTopDocs();
// Slower way if postings are not pre-sorted by weight:
// hits = searcher.search(query, null, num, SORT);
results = CreateResults(searcher, hits, num, key, doHighlight, matchedTokens, prefixToken);
}
finally
{
m_searcherMgr.Release(searcher);
}
//System.out.println((System.currentTimeMillis() - t0) + " msec for infix suggest");
//System.out.println(results);
return(results);
}
/// <summary>
/// Retrieve suggestions, specifying whether all terms
/// must match ({@code allTermsRequired}) and whether the hits
/// should be highlighted ({@code doHighlight}).
/// </summary>
public virtual IList<LookupResult> Lookup(string key, HashSet<BytesRef> contexts, int num, bool allTermsRequired, bool doHighlight)
{
if (searcherMgr == null)
{
throw new InvalidOperationException("suggester was not built");
}
BooleanClause.Occur occur;
if (allTermsRequired)
{
occur = BooleanClause.Occur.MUST;
}
else
{
occur = BooleanClause.Occur.SHOULD;
}
TokenStream ts = null;
BooleanQuery query;
var matchedTokens = new HashSet<string>();
string prefixToken = null;
try
{
ts = queryAnalyzer.TokenStream("", new StringReader(key));
//long t0 = System.currentTimeMillis();
ts.Reset();
var termAtt = ts.AddAttribute<CharTermAttribute>();
var offsetAtt = ts.AddAttribute<OffsetAttribute>();
string lastToken = null;
query = new BooleanQuery();
int maxEndOffset = -1;
matchedTokens = new HashSet<string>();
while (ts.IncrementToken())
{
if (lastToken != null)
{
matchedTokens.Add(lastToken);
query.Add(new TermQuery(new Term(TEXT_FIELD_NAME, lastToken)), occur);
}
lastToken = termAtt.ToString();
if (lastToken != null)
{
maxEndOffset = Math.Max(maxEndOffset, offsetAtt.EndOffset());
}
}
ts.End();
if (lastToken != null)
{
Query lastQuery;
if (maxEndOffset == offsetAtt.EndOffset())
{
// Use PrefixQuery (or the ngram equivalent) when
// there was no trailing discarded chars in the
// string (e.g. whitespace), so that if query does
// not end with a space we show prefix matches for
// that token:
lastQuery = GetLastTokenQuery(lastToken);
prefixToken = lastToken;
}
else
{
// Use TermQuery for an exact match if there were
// trailing discarded chars (e.g. whitespace), so
// that if query ends with a space we only show
// exact matches for that term:
matchedTokens.Add(lastToken);
lastQuery = new TermQuery(new Term(TEXT_FIELD_NAME, lastToken));
}
if (lastQuery != null)
{
query.Add(lastQuery, occur);
}
}
if (contexts != null)
{
BooleanQuery sub = new BooleanQuery();
query.Add(sub, BooleanClause.Occur.MUST);
foreach (BytesRef context in contexts)
{
// NOTE: we "should" wrap this in
// ConstantScoreQuery, or maybe send this as a
// Filter instead to search, but since all of
// these are MUST'd, the change to the score won't
// affect the overall ranking. Since we indexed
// as DOCS_ONLY, the perf should be the same
// either way (no freq int[] blocks to decode):
// TODO: if we had a BinaryTermField we could fix
// this "must be valid ut8f" limitation:
sub.Add(new TermQuery(new Term(CONTEXTS_FIELD_NAME, context.Utf8ToString())), BooleanClause.Occur.SHOULD);
}
}
}
finally
{
IOUtils.CloseWhileHandlingException(ts);
}
// TODO: we could allow blended sort here, combining
// weight w/ score. Now we ignore score and sort only
// by weight:
Query finalQuery = FinishQuery(query, allTermsRequired);
//System.out.println("finalQuery=" + query);
// Sort by weight, descending:
TopFieldCollector c = TopFieldCollector.Create(SORT, num, true, false, false, false);
// We sorted postings by weight during indexing, so we
// only retrieve the first num hits now:
Collector c2 = new EarlyTerminatingSortingCollector(c, SORT, num);
IndexSearcher searcher = searcherMgr.Acquire();
IList<LookupResult> results = null;
try
{
//System.out.println("got searcher=" + searcher);
searcher.Search(finalQuery, c2);
TopFieldDocs hits = (TopFieldDocs)c.TopDocs();
// Slower way if postings are not pre-sorted by weight:
// hits = searcher.search(query, null, num, SORT);
results = createResults(searcher, hits, num, key, doHighlight, matchedTokens, prefixToken);
}
finally
{
searcherMgr.Release(searcher);
}
//System.out.println((System.currentTimeMillis() - t0) + " msec for infix suggest");
//System.out.println(results);
return results;
}
