com.hazelcast.jet.sql.impl.validate.operators.json.HazelcastJsonValueFunction Maven / Gradle / Ivy
/*
* Copyright 2021 Hazelcast Inc.
*
* Licensed under the Hazelcast Community License (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://hazelcast.com/hazelcast-community-license
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.hazelcast.jet.sql.impl.validate.operators.json;
import com.hazelcast.jet.sql.impl.validate.HazelcastCallBinding;
import com.hazelcast.jet.sql.impl.validate.operand.MultiTypeOperandChecker;
import com.hazelcast.jet.sql.impl.validate.operand.OperandCheckerProgram;
import com.hazelcast.jet.sql.impl.validate.operand.TypedOperandChecker;
import com.hazelcast.jet.sql.impl.validate.operators.common.HazelcastFunction;
import com.hazelcast.jet.sql.impl.validate.operators.typeinference.JsonFunctionOperandTypeInference;
import com.hazelcast.org.apache.calcite.rel.type.RelDataType;
import com.hazelcast.org.apache.calcite.sql.SqlCall;
import com.hazelcast.org.apache.calcite.sql.SqlCallBinding;
import com.hazelcast.org.apache.calcite.sql.SqlFunctionCategory;
import com.hazelcast.org.apache.calcite.sql.SqlJsonValueReturning;
import com.hazelcast.org.apache.calcite.sql.SqlKind;
import com.hazelcast.org.apache.calcite.sql.SqlLiteral;
import com.hazelcast.org.apache.calcite.sql.SqlOperandCountRange;
import com.hazelcast.org.apache.calcite.sql.SqlOperatorBinding;
import com.hazelcast.org.apache.calcite.sql.SqlWriter;
import com.hazelcast.org.apache.calcite.sql.type.SqlOperandCountRanges;
import com.hazelcast.org.apache.calcite.sql.type.SqlReturnTypeInference;
import com.hazelcast.org.apache.calcite.sql.type.SqlTypeName;
@SuppressWarnings("checkstyle:MagicNumber")
public class HazelcastJsonValueFunction extends HazelcastFunction {
public static final HazelcastJsonValueFunction INSTANCE = new HazelcastJsonValueFunction();
public HazelcastJsonValueFunction() {
super(
"JSON_VALUE",
SqlKind.OTHER_FUNCTION,
new JsonValueFunctionReturnTypeInference(),
new JsonFunctionOperandTypeInference(),
SqlFunctionCategory.SYSTEM
);
}
@Override
protected boolean checkOperandTypes(final HazelcastCallBinding callBinding, final boolean throwOnFailure) {
return new OperandCheckerProgram(
MultiTypeOperandChecker.JSON_OR_VARCHAR,
TypedOperandChecker.VARCHAR
).check(callBinding, throwOnFailure);
}
@Override
public SqlOperandCountRange getOperandCountRange() {
return SqlOperandCountRanges.from(2);
}
@Override
public void unparse(final SqlWriter writer, final SqlCall call, final int leftPrec, final int rightPrec) {
final SqlWriter.Frame frame = writer.startFunCall(this.getName());
call.operand(0).unparse(writer, leftPrec, rightPrec);
writer.sep(",", true);
call.operand(1).unparse(writer, leftPrec, rightPrec);
for (int i = 2; i < call.operandCount(); i++) {
call.operand(i).unparse(writer, leftPrec, rightPrec);
}
writer.endFunCall(frame);
}
private static final class JsonValueFunctionReturnTypeInference implements SqlReturnTypeInference {
@Override
public RelDataType inferReturnType(final SqlOperatorBinding binding) {
// the returning clause is always the 3rd argument, if it's there
if (binding.getOperandCount() >= 4
&& binding.getOperandType(2).getSqlTypeName() == SqlTypeName.SYMBOL) {
final Object value = ((SqlLiteral) ((SqlCallBinding) binding).getCall().operand(2)).getValue();
if (value == SqlJsonValueReturning.RETURNING) {
// the next operand contains the data type
return binding.getOperandType(3);
}
}
return binding.getTypeFactory().createSqlType(SqlTypeName.VARCHAR);
}
}
}