/**
* Writes full-text data for a single token to disk.<br>
* Format: {@code score? pre1 pos1 pre2 pos2 ... (0 score)? pre...}
*
* @param out DataOutput for disk access
* @param vpre compressed pre values
* @param vpos compressed pos values
* @throws IOException IOException
*/
final void writeFTData(final DataOutput out, final byte[] vpre, final byte[] vpos)
throws IOException {
int np = 4, pp = 4, lp = -1, lu = -1;
final int ns = Num.size(vpre);
while (np < ns) {
if (scm > 0) {
final int p = Num.get(vpre, np);
if (lp != p) {
// new pre value: find document root
int u = unit.sortedIndexOf(p);
if (u < 0) u = -u - 1;
if (lu != u) {
// new unit: store scoring
final int s = Scoring.tfIDF(freq.get(fc++), maxfreq[u], unit.size(), ntoken[token]);
if (max < s) max = s;
if (min > s) min = s;
if (np != 4) out.write(0);
out.writeNum(s);
lu = u;
}
lp = p;
}
}
// full-text data is stored here, with -scoreU, pre1, pos1, ...,
// -scoreU, preU, posU
for (final int l = np + Num.length(vpre, np); np < l; ++np) out.write(vpre[np]);
for (final int l = pp + Num.length(vpos, pp); pp < l; ++pp) out.write(vpos[pp]);
}
++token;
}
/**
* Checks if the predicates are successful for the specified item.
*
* @param it item to be checked
* @param qc query context
* @return result of check
* @throws QueryException query exception
*/
protected final boolean preds(final Item it, final QueryContext qc) throws QueryException {
if (preds.length == 0) return true;
// set context value and position
final Value cv = qc.value;
try {
if (qc.scoring) {
double s = 0;
for (final Expr p : preds) {
qc.value = it;
final Item i = p.test(qc, info);
if (i == null) return false;
s += i.score();
}
it.score(Scoring.avg(s, preds.length));
} else {
for (final Expr p : preds) {
qc.value = it;
if (p.test(qc, info) == null) return false;
}
}
return true;
} finally {
qc.value = cv;
}
}
/**
* 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);
}
@Override
public FTNode item(final QueryContext qc, final InputInfo ii) throws QueryException {
if (pos == 0) pos = ++qc.ftPos;
matches.reset(pos);
final int c = contains(qc);
if (c == 0) matches.size(0);
// scoring: include number of tokens for calculations
return new FTNode(matches, c == 0 ? 0 : Scoring.word(c, qc.ftToken.count()));
}
@Override
public Item item(final QueryContext qc, final InputInfo ii) throws QueryException {
// compute scoring
if (qc.scoring) {
double s = 0;
boolean f = false;
for (final Expr expr : exprs) {
final Item it = expr.ebv(qc, info);
f |= it.bool(ii);
s += it.score();
}
return Bln.get(f, Scoring.avg(s, exprs.length));
}
// standard evaluation
for (final Expr expr : exprs) {
if (expr.ebv(qc, info).bool(ii)) return Bln.TRUE;
}
return Bln.FALSE;
}
