/** * Returns all summary path nodes for the specified location step or {@code null} if nodes cannot * be retrieved or are found on different levels. * * @param data data reference * @param l last step to be checked * @return path nodes */ ArrayList<PathNode> pathNodes(final Data data, final int l) { // skip request if no path index exists or might be out-of-date if (!data.meta.uptodate) return null; ArrayList<PathNode> in = data.paths.root(); for (int s = 0; s <= l; ++s) { final Step curr = axisStep(s); if (curr == null) return null; final boolean desc = curr.axis == DESC; if (!desc && curr.axis != CHILD || curr.test.mode != Mode.LN) return null; final int name = data.tagindex.id(curr.test.name.local()); final ArrayList<PathNode> al = new ArrayList<>(); for (final PathNode pn : PathSummary.desc(in, desc)) { if (pn.kind == Data.ELEM && name == pn.name) { // skip test if a tag is found on different levels if (!al.isEmpty() && al.get(0).level() != pn.level()) return null; al.add(pn); } } if (al.isEmpty()) return null; in = al; } return in; }
/** * Returns all summary path nodes for the specified location step or {@code null} if nodes cannot * be retrieved or are found on different levels. * * @param data data reference * @param last last step to be checked * @return path nodes */ private ArrayList<PathNode> pathNodes(final Data data, final int last) { // skip request if no path index exists or might be out-of-date if (!data.meta.uptodate) return null; ArrayList<PathNode> nodes = data.paths.root(); for (int s = 0; s <= last; s++) { // only follow axis steps final Step curr = axisStep(s); if (curr == null) return null; final boolean desc = curr.axis == DESC; if (!desc && curr.axis != CHILD || curr.test.kind != Kind.NAME) return null; final int name = data.elemNames.id(curr.test.name.local()); final ArrayList<PathNode> tmp = new ArrayList<>(); for (final PathNode node : PathSummary.desc(nodes, desc)) { if (node.kind == Data.ELEM && name == node.name) { // skip test if an element name occurs on different levels if (!tmp.isEmpty() && tmp.get(0).level() != node.level()) return null; tmp.add(node); } } if (tmp.isEmpty()) return null; nodes = tmp; } return nodes; }
/** * Converts descendant to child steps. * * @param ctx query context * @param data data reference * @return path */ Expr children(final QueryContext ctx, final Data data) { // skip path check if no path index exists, or if it is out-of-date if (!data.meta.uptodate || data.nspaces.globalNS() == null) return this; Path path = this; for (int s = 0; s < steps.length; ++s) { // don't allow predicates in preceding location steps final Step prev = s > 0 ? axisStep(s - 1) : null; if (prev != null && prev.preds.length != 0) break; // ignore axes other than descendant, or numeric predicates final Step curr = axisStep(s); if (curr == null || curr.axis != DESC || curr.has(Flag.FCS)) continue; // check if child steps can be retrieved for current step ArrayList<PathNode> pn = pathNodes(data, s); if (pn == null) continue; // cache child steps final ArrayList<QNm> qnm = new ArrayList<>(); while (pn.get(0).par != null) { QNm nm = new QNm(data.tagindex.key(pn.get(0).name)); // skip children with prefixes if (nm.hasPrefix()) return this; for (final PathNode p : pn) { if (pn.get(0).name != p.name) nm = null; } qnm.add(nm); pn = PathSummary.parent(pn); } ctx.compInfo(OPTCHILD, steps[s]); // build new steps int ts = qnm.size(); final Expr[] stps = new Expr[ts + steps.length - s - 1]; for (int t = 0; t < ts; ++t) { final Expr[] preds = t == ts - 1 ? ((Preds) steps[s]).preds : new Expr[0]; final QNm nm = qnm.get(ts - t - 1); final NameTest nt = nm == null ? new NameTest(false) : new NameTest(nm, Mode.LN, false, null); stps[t] = Step.get(info, CHILD, nt, preds); } while (++s < steps.length) stps[ts++] = steps[s]; path = get(info, root, stps); break; } // check if the all children in the path exist; don't test with namespaces if (data.nspaces.size() == 0) { LOOP: for (int s = 0; s < path.steps.length; ++s) { // only verify child steps; ignore namespaces final Step st = path.axisStep(s); if (st == null || st.axis != CHILD) break; if (st.test.mode == Mode.ALL || st.test.mode == null) continue; if (st.test.mode != Mode.LN) break; // check if one of the addressed nodes is on the correct level final int name = data.tagindex.id(st.test.name.local()); for (final PathNode pn : data.paths.desc(name, Data.ELEM)) { if (pn.level() == s + 1) continue LOOP; } ctx.compInfo(OPTPATH, path); return Empty.SEQ; } } return path; }