/** Returns the path of a schema, appending the name of a table if not null. */
public static List<String> path(Schema schema, String name) {
final List<String> list = new ArrayList<String>();
if (name != null) {
list.add(name);
}
for (Schema s = schema; s != null; s = s.getParentSchema()) {
if (s.getParentSchema() != null || !s.getName().equals("")) {
// Omit the root schema's name from the path if it's the empty string,
// which it usually is.
list.add(s.getName());
}
}
return ImmutableList.copyOf(Lists.reverse(list));
}
public static TableFunction methodMember(final Method method, final JavaTypeFactory typeFactory) {
final List<Parameter> parameters = new ArrayList<Parameter>();
for (final Class<?> parameterType : method.getParameterTypes()) {
parameters.add(
new Parameter() {
final int ordinal = parameters.size();
final RelDataType type = typeFactory.createType(parameterType);
public int getOrdinal() {
return ordinal;
}
public String getName() {
return "a" + ordinal;
}
public RelDataType getType(RelDataTypeFactory typeFactory) {
return type;
}
});
}
return new TableFunction() {
public List<Parameter> getParameters() {
return parameters;
}
public Table apply(List<Object> arguments) {
try {
//noinspection unchecked
return (Table) method.invoke(null, arguments.toArray());
} catch (IllegalAccessException e) {
throw new RuntimeException(e);
} catch (InvocationTargetException e) {
throw new RuntimeException(e);
}
}
public RelDataType getRowType(RelDataTypeFactory typeFactory) {
final Class<?> returnType = method.getReturnType();
return ((JavaTypeFactory) typeFactory).createType(returnType);
}
};
}
public static OptiqSchema.TableFunctionEntry resolve(
RelDataTypeFactory typeFactory,
String name,
Collection<OptiqSchema.TableFunctionEntry> tableFunctions,
List<RelDataType> argumentTypes) {
final List<OptiqSchema.TableFunctionEntry> matches =
new ArrayList<OptiqSchema.TableFunctionEntry>();
for (OptiqSchema.TableFunctionEntry member : tableFunctions) {
if (matches(typeFactory, member.getTableFunction(), argumentTypes)) {
matches.add(member);
}
}
switch (matches.size()) {
case 0:
return null;
case 1:
return matches.get(0);
default:
throw new RuntimeException(
"More than one match for " + name + " with arguments " + argumentTypes);
}
}
private static boolean matches(
RelDataTypeFactory typeFactory, TableFunction member, List<RelDataType> argumentTypes) {
List<Parameter> parameters = member.getParameters();
if (parameters.size() != argumentTypes.size()) {
return false;
}
for (int i = 0; i < argumentTypes.size(); i++) {
RelDataType argumentType = argumentTypes.get(i);
Parameter parameter = parameters.get(i);
if (!canConvert(argumentType, parameter.getType(typeFactory))) {
return false;
}
}
return true;
}
