/**
* 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.texpressions;
import com.foundationdb.ais.model.Sequence;
import com.foundationdb.qp.operator.QueryBindings;
import com.foundationdb.qp.operator.QueryContext;
import com.foundationdb.qp.row.Row;
import com.foundationdb.server.explain.Attributes;
import com.foundationdb.server.explain.CompoundExplainer;
import com.foundationdb.server.explain.ExplainContext;
import com.foundationdb.server.explain.Label;
import com.foundationdb.server.explain.PrimitiveExplainer;
import com.foundationdb.server.explain.Type;
import com.foundationdb.server.types.TInstance;
import com.foundationdb.server.types.TPreptimeValue;
import com.foundationdb.server.types.value.Value;
import com.foundationdb.server.types.value.ValueSource;
import com.foundationdb.server.types.value.ValueSources;
public class TSequenceNextValueExpression implements TPreparedExpression
{
private final TInstance resultType;
private final Sequence sequence;
public TSequenceNextValueExpression(TInstance resultType, Sequence sequence) {
assert resultType != null;
assert sequence != null;
this.resultType = resultType;
this.sequence = sequence;
}
@Override
public TPreptimeValue evaluateConstant(QueryContext queryContext) {
// Never constant
return null;
}
@Override
public TInstance resultType() {
return resultType;
}
@Override
public TEvaluatableExpression build() {
return new InnerEvaluation();
}
@Override
public CompoundExplainer getExplainer(ExplainContext context) {
Attributes states = new Attributes();
states.put(Label.NAME, PrimitiveExplainer.getInstance("_SEQ_NEXT"));
states.put(Label.OPERAND, PrimitiveExplainer.getInstance(sequence.getSequenceName().getSchemaName()));
states.put(Label.OPERAND, PrimitiveExplainer.getInstance(sequence.getSequenceName().getTableName()));
return new CompoundExplainer(Type.FUNCTION, states);
}
private class InnerEvaluation implements TEvaluatableExpression
{
private QueryContext context;
private Value value;
@Override
public ValueSource resultValue() {
return value;
}
@Override
public void evaluate() {
long next = context.getStore().sequenceNextValue(sequence);
value = new Value(resultType);
ValueSources.valueFromLong(next, value);
}
@Override
public void with(Row row) {
}
@Override
public void with(QueryContext context) {
this.context = context;
this.value = null;
}
@Override
public void with(QueryBindings bindings) {
}
}
}