/**
* Computes the cube of bit sets.
*
* <p>For example, <code>rollup({0}, {1})</code> returns <code>({0, 1}, {0}, {})</code>.
*
* <p>Bit sets are not necessarily singletons: <code>rollup({0, 2}, {3, 5})</code> returns <code>
* ({0, 2, 3, 5}, {0, 2}, {})</code>.
*/
@VisibleForTesting
public static ImmutableList<ImmutableBitSet> cube(List<ImmutableBitSet> bitSets) {
// Given the bit sets [{1}, {2, 3}, {5}],
// form the lists [[{1}, {}], [{2, 3}, {}], [{5}, {}]].
final Set<List<ImmutableBitSet>> builder = Sets.newLinkedHashSet();
for (ImmutableBitSet bitSet : bitSets) {
builder.add(Arrays.asList(bitSet, ImmutableBitSet.of()));
}
Set<ImmutableBitSet> flattenedBitSets = Sets.newLinkedHashSet();
for (List<ImmutableBitSet> o : Linq4j.product(builder)) {
flattenedBitSets.add(ImmutableBitSet.union(o));
}
return ImmutableList.copyOf(flattenedBitSets);
}
/** Analyzes a component of a tuple in a GROUPING SETS clause. */
private static ImmutableBitSet analyzeGroupExpr(
SqlValidatorScope scope,
List<SqlNode> groupExprs,
Map<Integer, Integer> groupExprProjection,
SqlNode groupExpr) {
final SqlNode expandedGroupExpr = scope.getValidator().expand(groupExpr, scope);
switch (expandedGroupExpr.getKind()) {
case ROW:
return ImmutableBitSet.union(
analyzeGroupTuple(
scope,
groupExprs,
groupExprProjection,
((SqlCall) expandedGroupExpr).getOperandList()));
case OTHER:
if (expandedGroupExpr instanceof SqlNodeList
&& ((SqlNodeList) expandedGroupExpr).size() == 0) {
return ImmutableBitSet.of();
}
}
final int ref = lookupGroupExpr(groupExprs, groupExpr);
if (expandedGroupExpr instanceof SqlIdentifier) {
// SQL 2003 does not allow expressions of column references
SqlIdentifier expr = (SqlIdentifier) expandedGroupExpr;
// column references should be fully qualified.
assert expr.names.size() == 2;
String originalRelName = expr.names.get(0);
String originalFieldName = expr.names.get(1);
final SqlValidatorScope.ResolvedImpl resolved = new SqlValidatorScope.ResolvedImpl();
scope.resolve(ImmutableList.of(originalRelName), false, resolved);
assert resolved.count() == 1;
final SqlValidatorScope.Resolve resolve = resolved.only();
final SqlValidatorNamespace foundNs = resolve.namespace;
final int childNamespaceIndex = resolve.path.steps().get(0).i;
int namespaceOffset = 0;
if (childNamespaceIndex > 0) {
// If not the first child, need to figure out the width of
// output types from all the preceding namespaces
final SqlValidatorScope ancestorScope = resolve.scope;
assert ancestorScope instanceof ListScope;
List<SqlValidatorNamespace> children = ((ListScope) ancestorScope).getChildren();
for (int j = 0; j < childNamespaceIndex; j++) {
namespaceOffset += children.get(j).getRowType().getFieldCount();
}
}
RelDataTypeField field =
scope.getValidator().getCatalogReader().field(foundNs.getRowType(), originalFieldName);
int origPos = namespaceOffset + field.getIndex();
groupExprProjection.put(origPos, ref);
}
return ImmutableBitSet.of(ref);
}
