/**
* Copyright (C) 2009-2013 FoundationDB, LLC
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package com.foundationdb.server.types.mcompat.aggr;
import com.foundationdb.server.types.TAggregator;
import com.foundationdb.server.types.TAggregatorBase;
import com.foundationdb.server.types.TClass;
import com.foundationdb.server.types.TInstance;
import com.foundationdb.server.types.TOverloadResult;
import com.foundationdb.server.types.value.Value;
import com.foundationdb.server.types.value.ValueSource;
import com.foundationdb.server.types.value.ValueTarget;
import com.foundationdb.server.types.value.ValueTargets;
public class MMinMaxAggregation extends TAggregatorBase {
private final MType mType;
private enum MType {
MIN() {
@Override
boolean condition(int a) {
return a < 0;
}
},
MAX() {
@Override
boolean condition(int a) {
return a > 0;
}
};
abstract boolean condition (int a);
}
public static final TAggregator MIN = new MMinMaxAggregation(MType.MIN);
public static final TAggregator MAX = new MMinMaxAggregation(MType.MAX);
private MMinMaxAggregation(MType mType) {
super(mType.name(), null);
this.mType = mType;
}
@Override
public void input(TInstance type, ValueSource source, TInstance stateType, Value state, Object o) {
if (source.isNull())
return;
if (!state.hasAnyValue()) {
ValueTargets.copyFrom(source, state);
return;
}
TClass tClass = type.typeClass();
assert stateType.typeClass().equals(tClass) : "incompatible types " + type + " and " + stateType;
int comparison = TClass.compare(type, source, stateType, state);
if (mType.condition(comparison))
ValueTargets.copyFrom(source, state);
}
@Override
public void emptyValue(ValueTarget state) {
state.putNull();
}
@Override
public TOverloadResult resultType() {
return TOverloadResult.picking();
}
}