/**
* Evaluates the full-text match.
*
* @param qc query context
* @return number of tokens, used for scoring
* @throws QueryException query exception
*/
private int contains(final QueryContext qc) throws QueryException {
first = true;
final FTLexer lexer = ftt.lexer(qc.ftToken);
// use faster evaluation for default options
int num = 0;
if (fast) {
for (final byte[] t : tokens) {
final FTTokens qtok = ftt.cache(t);
num = Math.max(num, ftt.contains(qtok, lexer) * qtok.length());
}
return num;
}
// find and count all occurrences
final boolean all = mode == FTMode.ALL || mode == FTMode.ALL_WORDS;
int oc = 0;
for (final byte[] w : unique(tokens(qc))) {
final FTTokens qtok = ftt.cache(w);
final int o = ftt.contains(qtok, lexer);
if (all && o == 0) return 0;
num = Math.max(num, o * qtok.length());
oc += o;
}
// check if occurrences are in valid range. if yes, return number of tokens
final long mn = occ != null ? toLong(occ[0], qc) : 1;
final long mx = occ != null ? toLong(occ[1], qc) : Long.MAX_VALUE;
if (mn == 0 && oc == 0) matches = FTNot.not(matches);
return oc >= mn && oc <= mx ? Math.max(1, num) : 0;
}
@Override
public boolean indexAccessible(final IndexInfo ii) {
/* If the following conditions yield true, the index is accessed:
* - all query terms are statically available
* - no FTTimes option is specified
* - explicitly set case, diacritics and stemming match options do not
* conflict with index options. */
data = ii.ic.data;
final MetaData md = data.meta;
final FTOpt fto = ftt.opt;
/* Index will be applied if no explicit match options have been set
* that conflict with the index options. As a consequence, though, index-
* based querying might yield other results than sequential scanning. */
if (occ != null
|| fto.cs != null && md.casesens == (fto.cs == FTCase.INSENSITIVE)
|| fto.isSet(DC) && md.diacritics != fto.is(DC)
|| fto.isSet(ST) && md.stemming != fto.is(ST)
|| fto.ln != null && !fto.ln.equals(md.language)) return false;
// adopt database options to tokenizer
fto.copy(md);
// estimate costs if text is not known at compile time
if (tokens == null) {
ii.costs = Math.max(2, data.meta.size / 30);
return true;
}
// summarize number of hits; break loop if no hits are expected
final FTLexer ft = new FTLexer(fto);
ii.costs = 0;
for (byte[] t : tokens) {
ft.init(t);
while (ft.hasNext()) {
final byte[] tok = ft.nextToken();
if (fto.sw != null && fto.sw.contains(tok)) continue;
if (fto.is(WC)) {
// don't use index if one of the terms starts with a wildcard
t = ft.get();
if (t[0] == '.') return false;
// don't use index if certain characters or more than 1 dot are found
int d = 0;
for (final byte w : t) {
if (w == '{' || w == '\\' || w == '.' && ++d > 1) return false;
}
}
// favor full-text index requests over exact queries
final int costs = data.costs(ft);
if (costs != 0) ii.costs += Math.max(2, costs / 100);
}
}
return true;
}
@Override
public Value value(final QueryContext qc) throws QueryException {
final FItem getKey = checkArity(exprs[1], 1, qc);
final long k = Math.min(toLong(exprs[2], qc), Integer.MAX_VALUE);
if (k < 1) return Empty.SEQ;
final Iter iter = exprs[0].iter(qc);
final MinHeap<Item, Item> heap =
new MinHeap<>(
new Comparator<Item>() {
@Override
public int compare(final Item it1, final Item it2) {
try {
return OpV.LT.eval(it1, it2, sc.collation, sc, info) ? -1 : 1;
} catch (final QueryException qe) {
throw new QueryRTException(qe);
}
}
});
try {
for (Item it; (it = iter.next()) != null; ) {
heap.insert(checkNoEmpty(getKey.invokeItem(qc, info, it)), it);
if (heap.size() > k) heap.removeMin();
}
} catch (final QueryRTException ex) {
throw ex.getCause();
}
final ValueBuilder vb = new ValueBuilder();
while (!heap.isEmpty()) vb.addFront(heap.removeMin());
return vb.value();
}
/**
* Merges two matches.
*
* @param i1 first item
* @param i2 second item
*/
private static void and(final FTNode i1, final FTNode i2) {
final FTMatches all = new FTMatches((byte) Math.max(i1.matches().pos, i2.matches().pos));
for (final FTMatch s1 : i1.matches()) {
for (final FTMatch s2 : i2.matches()) {
all.add(new FTMatch(s1.size() + s2.size()).add(s1).add(s2));
}
}
i1.score(Scoring.avg(i1.score() + i2.score(), 2));
i1.matches(all);
}
/**
* Rounds values.
*
* @param qc query context
* @param even half-to-even flag
* @return number
* @throws QueryException query exception
*/
ANum round(final QueryContext qc, final boolean even) throws QueryException {
final ANum num = toNumber(exprs[0], qc);
final long p = exprs.length == 1 ? 0 : Math.max(Integer.MIN_VALUE, toLong(exprs[1], qc));
return num == null ? null : p > Integer.MAX_VALUE ? num : num.round((int) p, even);
}
/**
* Evaluates the specified query.
*
* @param query query
* @return success flag
*/
final boolean query(final String query) {
final Performance p = new Performance();
String error;
if (exception != null) {
error = Util.message(exception);
} else {
try {
long hits = 0;
final boolean run = options.get(MainOptions.RUNQUERY);
final boolean serial = options.get(MainOptions.SERIALIZE);
final int runs = Math.max(1, options.get(MainOptions.RUNS));
for (int r = 0; r < runs; ++r) {
// reuse existing processor instance
if (r != 0) qp = null;
qp(query, context);
parse(p);
if (r == 0) plan(false);
qp.compile();
info.compiling += p.time();
if (r == 0) plan(true);
if (!run) continue;
final PrintOutput po = r == 0 && serial ? out : new NullOutput();
try (final Serializer ser = qp.getSerializer(po)) {
if (maxResults >= 0) {
result = qp.cache(maxResults);
info.evaluating += p.time();
result.serialize(ser);
hits = result.size();
} else {
hits = 0;
final Iter ir = qp.iter();
info.evaluating += p.time();
for (Item it; (it = ir.next()) != null; ) {
ser.serialize(it);
++hits;
checkStop();
}
}
}
qp.close();
info.serializing += p.time();
}
// dump some query info
// out.flush();
// remove string list if global locking is used and if query is updating
if (soptions.get(StaticOptions.GLOBALLOCK) && qp.updating) {
info.readLocked = null;
info.writeLocked = null;
}
return info(info.toString(qp, out.size(), hits, options.get(MainOptions.QUERYINFO)));
} catch (final QueryException | IOException ex) {
exception = ex;
error = Util.message(ex);
} catch (final ProcException ex) {
error = INTERRUPTED;
} catch (final StackOverflowError ex) {
Util.debug(ex);
error = BASX_STACKOVERFLOW.desc;
} catch (final RuntimeException ex) {
extError("");
Util.debug(info());
throw ex;
} finally {
// close processor after exceptions
if (qp != null) qp.close();
}
}
return extError(error);
}