package org.basex.query.ft;
import static org.basex.query.QueryText.*;
import java.io.IOException;
import org.basex.io.serial.Serializer;
import org.basex.query.QueryContext;
import org.basex.query.QueryException;
import org.basex.query.expr.CmpG;
import org.basex.query.expr.Context;
import org.basex.query.expr.Expr;
import org.basex.query.expr.ParseExpr;
import org.basex.query.item.Bln;
import org.basex.query.item.DBNode;
import org.basex.query.item.FTNode;
import org.basex.query.item.Item;
import org.basex.query.item.NodeType;
import org.basex.query.item.SeqType;
import org.basex.query.iter.Iter;
import org.basex.query.path.AxisPath;
import org.basex.query.path.AxisStep;
import org.basex.query.util.IndexContext;
import org.basex.query.util.Var;
import org.basex.util.InputInfo;
import org.basex.util.ft.FTLexer;
import org.basex.util.ft.FTOpt;
import org.basex.util.ft.Scoring;
/**
* FTContains expression.
*
* @author BaseX Team 2005-12, BSD License
* @author Christian Gruen
*/
public class FTContains extends ParseExpr {
/** Expression. */
Expr expr;
/** Full-text expression. */
FTExpr ftexpr;
/** Full-text parser. */
FTLexer lex;
/**
* Constructor.
* @param e expression
* @param fte full-text expression
* @param ii input info
*/
public FTContains(final Expr e, final FTExpr fte, final InputInfo ii) {
super(ii);
expr = e;
ftexpr = fte;
type = SeqType.BLN;
}
@Override
public final Expr comp(final QueryContext ctx) throws QueryException {
expr = checkUp(expr, ctx).comp(ctx).addText(ctx);
lex = new FTLexer(new FTOpt());
ftexpr = ftexpr.comp(ctx);
return expr.isEmpty() ? optPre(Bln.FALSE, ctx) : this;
}
@Override
public Bln item(final QueryContext ctx, final InputInfo ii)
throws QueryException {
final Iter iter = expr.iter(ctx);
final FTLexer tmp = ctx.fttoken;
double s = 0;
ctx.fttoken = lex;
for(Item it; (it = iter.next()) != null;) {
lex.init(it.string(input));
final FTNode item = ftexpr.item(ctx, input);
double d = 0;
if(item.all.matches()) {
d = item.score();
// no scoring found - use default value
if(d == 0) d = 1;
}
s = Scoring.and(s, d);
// add entry to visualization
if(d > 0 && ctx.ftpos != null && it instanceof DBNode) {
final DBNode node = (DBNode) it;
ctx.ftpos.add(node.data, node.pre, item.all);
}
}
ctx.fttoken = tmp;
return Bln.get(s);
}
@Override
public final boolean indexAccessible(final IndexContext ic)
throws QueryException {
// return if step is no text node, or if no index is available
final AxisStep s = expr instanceof Context ? ic.step : CmpG.indexStep(expr);
final boolean ok = s != null && ic.data.meta.ftxtindex &&
s.test.type == NodeType.TXT && ftexpr.indexAccessible(ic);
ic.seq |= ic.not;
return ok;
}
@Override
public final Expr indexEquivalent(final IndexContext ic)
throws QueryException {
ic.ctx.compInfo(OPTFTXINDEX);
// sequential evaluation with index access
final FTExpr ie = ftexpr.indexEquivalent(ic);
if(ic.seq) return new FTContainsIndex(input, expr, ie, ic);
// standard index evaluation; first expression will always be an axis path
final FTIndexAccess root = new FTIndexAccess(input, ie, ic);
return expr instanceof Context ? root :
((AxisPath) expr).invertPath(root, ic.step);
}
@Override
public final boolean uses(final Use u) {
return expr.uses(u) || ftexpr.uses(u);
}
@Override
public final int count(final Var v) {
return expr.count(v) + ftexpr.count(v);
}
@Override
public final boolean removable(final Var v) {
return expr.removable(v) && ftexpr.removable(v);
}
@Override
public final Expr remove(final Var v) {
expr = expr.remove(v);
ftexpr = ftexpr.remove(v);
return this;
}
@Override
public final void plan(final Serializer ser) throws IOException {
ser.openElement(this);
expr.plan(ser);
ftexpr.plan(ser);
ser.closeElement();
}
@Override
public String toString() {
return expr + " " + CONTAINS + ' ' + TEXT + ' ' + ftexpr;
}
}