com.hazelcast.jet.sql.impl.aggregate.MaxSqlAggregation Maven / Gradle / Ivy
/*
* Copyright 2024 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.aggregate;
import com.hazelcast.nio.ObjectDataInput;
import com.hazelcast.nio.ObjectDataOutput;
import com.hazelcast.sql.impl.QueryException;
import javax.annotation.concurrent.NotThreadSafe;
import java.io.IOException;
@NotThreadSafe
public class MaxSqlAggregation implements SqlAggregation {
private Object value;
@Override
public void accumulate(Object value) {
if (value == null) {
return;
}
if (this.value == null || compare(this.value, value) < 0) {
this.value = value;
}
}
@Override
public void combine(SqlAggregation other0) {
MaxSqlAggregation other = (MaxSqlAggregation) other0;
Object value = other.value;
if (this.value == null || (value != null && compare(this.value, value) < 0)) {
this.value = value;
}
}
@SuppressWarnings({"rawtypes", "unchecked"})
private int compare(Object left, Object right) {
assert left != null;
assert right != null;
Comparable leftComparable = asComparable(left);
Comparable rightComparable = asComparable(right);
return leftComparable.compareTo(rightComparable);
}
private static Comparable> asComparable(Object value) {
if (value instanceof Comparable) {
return (Comparable>) value;
} else {
throw QueryException.error("MAX not supported for " + value.getClass() + ": not comparable");
}
}
@Override
public Object collect() {
return value;
}
@Override
public void writeData(ObjectDataOutput out) throws IOException {
out.writeObject(value);
}
@Override
public void readData(ObjectDataInput in) throws IOException {
value = in.readObject();
}
}
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