/**
* 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.mfuncs;
import com.foundationdb.server.types.*;
import com.foundationdb.server.types.common.BigDecimalWrapper;
import com.foundationdb.server.types.common.types.DecimalAttribute;
import com.foundationdb.server.types.common.types.TBigDecimal;
import com.foundationdb.server.types.mcompat.mtypes.MNumeric;
import com.foundationdb.server.types.value.ValueSource;
import com.foundationdb.server.types.value.ValueTarget;
import com.foundationdb.server.types.texpressions.TInputSetBuilder;
import com.foundationdb.server.types.texpressions.TScalarBase;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
public class MRoundTruncateDecimal extends TScalarBase {
public static final Collection<TScalar> overloads = createAll();
private static final int DEC_INDEX = 0;
private enum RoundingStrategy {
ROUND {
@Override
protected void apply(BigDecimalWrapper io, int scale) {
io.round(scale);
}
},
TRUNCATE {
@Override
protected void apply(BigDecimalWrapper io, int scale) {
io.truncate(scale);
}
};
protected abstract void apply(BigDecimalWrapper io, int scale);
}
@Override
protected void doEvaluate(TExecutionContext context, LazyList<? extends ValueSource> inputs, ValueTarget output) {
BigDecimalWrapper result = TBigDecimal.getWrapper(context, DEC_INDEX);
result.set(TBigDecimal.getWrapper(inputs.get(0), context.inputTypeAt(0)));
int scale = signatureStrategy.roundToScale(inputs);
roundingStrategy.apply(result, scale);
output.putObject(result);
}
@Override
public TOverloadResult resultType() {
return TOverloadResult.custom(new TCustomOverloadResult() {
@Override
public TInstance resultInstance(List<TPreptimeValue> inputs, TPreptimeContext context) {
TPreptimeValue valueToRound = inputs.get(0);
ValueSource roundToPVal = signatureStrategy.getScaleOperand(inputs);
int precision, scale;
if ((roundToPVal == null) || roundToPVal.isNull()) {
precision = 17;
int incomingScale = valueToRound.type().attribute(DecimalAttribute.SCALE);
if (incomingScale > 1)
precision += (incomingScale - 1);
scale = incomingScale;
} else {
scale = roundToPVal.getInt32();
TInstance incomingInstance = valueToRound.type();
int incomingPrecision = incomingInstance.attribute(DecimalAttribute.PRECISION);
int incomingScale = incomingInstance.attribute(DecimalAttribute.SCALE);
precision = incomingPrecision;
if (incomingScale > 1)
precision -= (incomingScale - 1);
precision += scale;
}
return MNumeric.DECIMAL.instance(precision, scale, anyContaminatingNulls(inputs));
}
});
}
@Override
protected void buildInputSets(TInputSetBuilder builder) {
signatureStrategy.buildInputSets(MNumeric.DECIMAL, builder);
}
@Override
public String displayName() {
return roundingStrategy.name();
}
protected MRoundTruncateDecimal(RoundingOverloadSignature signatureStrategy,
RoundingStrategy roundingStrategy)
{
this.signatureStrategy = signatureStrategy;
this.roundingStrategy = roundingStrategy;
}
private static Collection<TScalar> createAll() {
List<TScalar> results = new ArrayList<>();
for (RoundingOverloadSignature signature : RoundingOverloadSignature.values()) {
for (RoundingStrategy rounding : RoundingStrategy.values()) {
results.add(new MRoundTruncateDecimal(signature, rounding));
}
}
return Collections.unmodifiableCollection(results);
}
private final RoundingOverloadSignature signatureStrategy;
private final RoundingStrategy roundingStrategy;
}