Ejemplo n.º 1
0
 @Override
 public GroupBy optimize(final QueryContext qc, final VarScope scp) throws QueryException {
   final int pl = preExpr.length;
   for (int p = 0; p < pl; p++) {
     final SeqType it = preExpr[p].seqType();
     post[p].refineType(it.withOcc(it.mayBeZero() ? Occ.ZERO_MORE : Occ.ONE_MORE), qc);
   }
   return this;
 }
Ejemplo n.º 2
0
 @Override
 public Expr optimize(final QueryContext qc, final VarScope scp) throws QueryException {
   // number of predicates may change in loop
   for (int p = 0; p < preds.length; p++) {
     final Expr pred = preds[p];
     if (pred instanceof CmpG || pred instanceof CmpV) {
       final Cmp cmp = (Cmp) pred;
       if (cmp.exprs[0].isFunction(Function.POSITION)) {
         final Expr e2 = cmp.exprs[1];
         final SeqType st2 = e2.seqType();
         // position() = last() -> last()
         // position() = $n (numeric) -> $n
         if (e2.isFunction(Function.LAST) || st2.one() && st2.type.isNumber()) {
           if (cmp instanceof CmpG && ((CmpG) cmp).op == OpG.EQ
               || cmp instanceof CmpV && ((CmpV) cmp).op == OpV.EQ) {
             qc.compInfo(OPTWRITE, pred);
             preds[p] = e2;
           }
         }
       }
     } else if (pred instanceof And) {
       if (!pred.has(Flag.FCS)) {
         // replace AND expression with predicates (don't swap position tests)
         qc.compInfo(OPTPRED, pred);
         final Expr[] and = ((Arr) pred).exprs;
         final int m = and.length - 1;
         final ExprList el = new ExprList(preds.length + m);
         for (final Expr e : Arrays.asList(preds).subList(0, p)) el.add(e);
         for (final Expr a : and) {
           // wrap test with boolean() if the result is numeric
           el.add(Function.BOOLEAN.get(null, info, a).optimizeEbv(qc, scp));
         }
         for (final Expr e : Arrays.asList(preds).subList(p + 1, preds.length)) el.add(e);
         preds = el.finish();
       }
     } else if (pred instanceof ANum) {
       final ANum it = (ANum) pred;
       final long i = it.itr();
       if (i == it.dbl()) {
         preds[p] = Pos.get(i, info);
       } else {
         qc.compInfo(OPTREMOVE, this, pred);
         return Empty.SEQ;
       }
     } else if (pred.isValue()) {
       if (pred.ebv(qc, info).bool(info)) {
         qc.compInfo(OPTREMOVE, this, pred);
         preds = Array.delete(preds, p--);
       } else {
         // handle statically known predicates
         qc.compInfo(OPTREMOVE, this, pred);
         return Empty.SEQ;
       }
     }
   }
   return this;
 }
Ejemplo n.º 3
0
  @Override
  public final Expr optimize(final QueryContext qc, final VarScope scp) throws QueryException {
    final Value v = initial(qc);
    if (v != null && v.isEmpty() || emptyPath(v)) return optPre(qc);

    // merge descendant steps
    Expr e = mergeSteps(qc);
    if (e == this && v != null && v.type == NodeType.DOC) {
      // check index access
      e = index(qc, v);
      // rewrite descendant to child steps
      if (e == this) e = children(qc, v);
    }
    // recompile path if it has changed
    if (e != this) return e.compile(qc, scp);

    // set atomic type for single attribute steps to speed up predicate tests
    if (root == null && steps.length == 1 && steps[0] instanceof Step) {
      final Step curr = (Step) steps[0];
      if (curr.axis == ATTR && curr.test.kind == Kind.URI_NAME) curr.seqType(SeqType.NOD_ZO);
    }

    // choose best path implementation and set type information
    final Path path = get(info, root, steps);
    path.size = path.size(qc);
    path.seqType = SeqType.get(steps[steps.length - 1].seqType().type, size);
    return path;
  }
Ejemplo n.º 4
0
  /**
   * Returns an instance of a with the specified name and number of arguments, or {@code null}.
   *
   * @param name name of the function
   * @param args optional arguments
   * @param dyn compile-/run-time flag
   * @param ctx query context
   * @param ii input info
   * @return function instance
   * @throws QueryException query exception
   */
  public static TypedFunc get(
      final QNm name,
      final Expr[] args,
      final boolean dyn,
      final QueryContext ctx,
      final InputInfo ii)
      throws QueryException {

    // get namespace and local name
    // parse data type constructors
    if (eq(name.uri(), XSURI)) {
      final byte[] ln = name.local();
      final AtomType type = AtomType.find(name, false);
      if (type == null) {
        final Levenshtein ls = new Levenshtein();
        for (final AtomType t : AtomType.values()) {
          if (t.par != null
              && t != AtomType.NOT
              && t != AtomType.AAT
              && t != AtomType.BIN
              && ls.similar(lc(ln), lc(t.string()), 0))
            FUNSIMILAR.thrw(ii, name.string(), t.string());
        }
      }
      // no constructor function found, or abstract type specified
      if (type == null || type == AtomType.NOT || type == AtomType.AAT) {
        FUNCUNKNOWN.thrw(ii, name.string());
      }

      if (args.length != 1) FUNCTYPE.thrw(ii, name.string());
      final SeqType to = SeqType.get(type, Occ.ZERO_ONE);
      return TypedFunc.constr(new Cast(ii, args[0], to), to);
    }

    // pre-defined functions
    final StandardFunc fun = Functions.get().get(name, args, ii);
    if (fun != null) {
      if (!ctx.sc.xquery3 && fun.xquery3()) FEATURE30.thrw(ii);
      for (final Function f : Function.UPDATING) {
        if (fun.sig == f) {
          ctx.updating(true);
          break;
        }
      }
      return new TypedFunc(fun, fun.sig.type(args.length));
    }

    // user-defined function
    final TypedFunc tf = ctx.funcs.get(name, args, ii);
    if (tf != null) return tf;

    // Java function (only allowed with administrator permissions)
    final JavaMapping jf = JavaMapping.get(name, args, ctx, ii);
    if (jf != null) return TypedFunc.java(jf);

    // add user-defined function that has not been declared yet
    if (!dyn && FuncType.find(name) == null) return ctx.funcs.add(name, args, ii, ctx);

    // no function found
    return null;
  }