/**
* 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.tajo.engine.function.builtin;
import org.apache.tajo.catalog.CatalogUtil;
import org.apache.tajo.catalog.Column;
import org.apache.tajo.engine.function.AggFunction;
import org.apache.tajo.engine.function.FunctionContext;
import org.apache.tajo.common.TajoDataTypes.DataType;
import org.apache.tajo.common.TajoDataTypes.Type;
import org.apache.tajo.datum.Datum;
import org.apache.tajo.datum.DatumFactory;
import org.apache.tajo.datum.Int8Datum;
import org.apache.tajo.storage.Tuple;
public class MaxLong extends AggFunction<Int8Datum> {
public MaxLong() {
super(new Column[] {
new Column("val", Type.INT8)
});
}
@Override
public FunctionContext newContext() {
return new MaxContext();
}
@Override
public void eval(FunctionContext ctx, Tuple params) {
MaxContext maxCtx = (MaxContext) ctx;
maxCtx.max = Math.max(maxCtx.max, params.get(0).asInt8());
}
@Override
public Datum getPartialResult(FunctionContext ctx) {
return DatumFactory.createInt8(((MaxContext) ctx).max);
}
@Override
public DataType getPartialResultType() {
return CatalogUtil.newSimpleDataType(Type.INT8);
}
@Override
public Int8Datum terminate(FunctionContext ctx) {
return DatumFactory.createInt8(((MaxContext) ctx).max);
}
private class MaxContext implements FunctionContext {
long max;
}
}