/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.drill.exec.planner.sql;
import org.apache.calcite.sql.SqlCallBinding;
import org.apache.calcite.sql.SqlFunction;
import org.apache.calcite.sql.SqlFunctionCategory;
import org.apache.calcite.sql.SqlIdentifier;
import org.apache.calcite.sql.SqlOperandCountRange;
import org.apache.calcite.sql.SqlOperator;
import org.apache.calcite.sql.parser.SqlParserPos;
import org.apache.calcite.sql.type.SqlOperandCountRanges;
import org.apache.calcite.sql.type.SqlOperandTypeChecker;
import org.apache.calcite.sql.type.SqlReturnTypeInference;
public class HiveUDFOperator extends SqlFunction {
public HiveUDFOperator(String name, SqlReturnTypeInference sqlReturnTypeInference) {
super(new SqlIdentifier(name, SqlParserPos.ZERO), sqlReturnTypeInference, null, ArgChecker.INSTANCE, null,
SqlFunctionCategory.USER_DEFINED_FUNCTION);
}
// Consider Hive functions to be non-deterministic so they are not folded at
// planning time. The expression interpreter used to evaluate constant expressions
// currently does not support anything but simple DrillFuncs.
@Override
public boolean isDeterministic() {
return false;
}
/** Argument Checker for variable number of arguments */
public static class ArgChecker implements SqlOperandTypeChecker {
public static ArgChecker INSTANCE = new ArgChecker();
private SqlOperandCountRange range = SqlOperandCountRanges.any();
@Override
public boolean checkOperandTypes(SqlCallBinding callBinding, boolean throwOnFailure) {
return true;
}
@Override
public Consistency getConsistency() {
return Consistency.NONE;
}
@Override
public SqlOperandCountRange getOperandCountRange() {
return range;
}
@Override
public String getAllowedSignatures(SqlOperator op, String opName) {
return opName + "(HiveUDF - Opaque)";
}
@Override
public boolean isOptional(int arg) {
return false;
}
}
}