com.hazelcast.org.apache.calcite.sql.SqlSessionTableFunction Maven / Gradle / Ivy
/*
* 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 com.hazelcast.org.apache.calcite.sql;
import com.hazelcast.org.apache.calcite.rel.type.RelDataType;
import com.hazelcast.org.apache.calcite.sql.type.SqlTypeUtil;
import com.hazelcast.org.apache.calcite.sql.validate.SqlValidator;
import com.hazelcast.com.google.common.collect.ImmutableList;
/**
* SqlSessionTableFunction implements an operator for per-key sessionization. It allows
* four parameters:
*
*
* - table as data source
* - a descriptor to provide a watermarked column name from the input table
* - a descriptor to provide a column as key, on which sessionization will be applied,
* optional
* - an interval parameter to specify a inactive activity gap to break sessions
*
*/
public class SqlSessionTableFunction extends SqlWindowTableFunction {
public SqlSessionTableFunction() {
super(SqlKind.SESSION.name(), new OperandMetadataImpl());
}
/** Operand type checker for SESSION. */
private static class OperandMetadataImpl extends AbstractOperandMetadata {
OperandMetadataImpl() {
super(ImmutableList.of(PARAM_DATA, PARAM_TIMECOL, PARAM_KEY, PARAM_SIZE),
3);
}
@Override public boolean checkOperandTypes(SqlCallBinding callBinding,
boolean throwOnFailure) {
if (!checkTableAndDescriptorOperands(callBinding, 1)) {
return throwValidationSignatureErrorOrReturnFalse(callBinding, throwOnFailure);
}
if (!checkTimeColumnDescriptorOperand(callBinding, 1)) {
return throwValidationSignatureErrorOrReturnFalse(callBinding, throwOnFailure);
}
final SqlValidator validator = callBinding.getValidator();
final SqlNode operand2 = callBinding.operand(2);
final RelDataType type2 = validator.getValidatedNodeType(operand2);
if (operand2.getKind() == SqlKind.DESCRIPTOR) {
final SqlNode operand0 = callBinding.operand(0);
final RelDataType type = validator.getValidatedNodeType(operand0);
validateColumnNames(
validator, type.getFieldNames(), ((SqlCall) operand2).getOperandList());
} else if (!SqlTypeUtil.isInterval(type2)) {
return throwValidationSignatureErrorOrReturnFalse(callBinding, throwOnFailure);
}
if (callBinding.getOperandCount() > 3) {
final RelDataType type3 = validator.getValidatedNodeType(callBinding.operand(3));
if (!SqlTypeUtil.isInterval(type3)) {
return throwValidationSignatureErrorOrReturnFalse(callBinding, throwOnFailure);
}
}
return true;
}
@Override public String getAllowedSignatures(SqlOperator op, String opName) {
return opName + "(TABLE table_name, DESCRIPTOR(timecol), "
+ "DESCRIPTOR(key) optional, datetime interval)";
}
}
}
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