Examples with ListTupleList mondrian.calc.impl.ListTupleList used on opensource projects

Example 1 with ListTupleList

use of mondrian.calc.impl.ListTupleList in project mondrian by pentaho.

the class SqlTupleReader method readTuples.

public TupleList readTuples(DataSource jdbcConnection, TupleList partialResult, List<List<RolapMember>> newPartialResult) {
    // The following algorithm will first group targets based on the cubes
    // that are applicable to each.  This allows loading the tuple data
    // in groups that join correctly to the associated fact table.
    // Once each group has been loaded, results of each are
    // brought together in a crossjoin, and then projected into a new
    // tuple list based on the ordering originally specified by the
    // targets list.
    // For non-virtual cube queries there is only a single
    // targetGroup.
    List<List<TargetBase>> targetGroups = groupTargets(targets, constraint.getEvaluator().getQuery());
    List<TupleList> tupleLists = new ArrayList<>();
    for (List<TargetBase> targetGroup : targetGroups) {
        prepareTuples(jdbcConnection, partialResult, newPartialResult, targetGroup);
        int size = targetGroup.size();
        final Iterator<Member>[] iter = new Iterator[size];
        for (int i = 0; i < size; i++) {
            TargetBase t = targetGroup.get(i);
            iter[i] = t.close().iterator();
        }
        List<Member> members = new ArrayList<>();
        while (iter[0].hasNext()) {
            for (int i = 0; i < size; i++) {
                members.add(iter[i].next());
            }
        }
        tupleLists.add(size + emptySets == 1 ? new UnaryTupleList(members) : new ListTupleList(size + emptySets, members));
    }
    if (tupleLists.isEmpty()) {
        return TupleCollections.emptyList(targets.size());
    }
    TupleList tupleList = CrossJoinFunDef.mutableCrossJoin(tupleLists);
    if (!tupleList.isEmpty() && targetGroups.size() > 1) {
        tupleList = projectTupleList(tupleList);
    }
    // need to hierarchize the columns from the enumerated targets
    // since we didn't necessarily add them in the order in which
    // they originally appeared in the cross product
    int enumTargetCount = getEnumTargetCount();
    if (enumTargetCount > 0) {
        tupleList = FunUtil.hierarchizeTupleList(tupleList, false);
    }
    return tupleList;
}