/*
* Licensed 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 com.facebook.presto.metadata;
import com.facebook.presto.operator.aggregation.AggregationCompiler;
import com.facebook.presto.operator.aggregation.InternalAggregationFunction;
import com.facebook.presto.spi.type.TypeManager;
import com.facebook.presto.spi.type.TypeSignature;
import com.google.common.collect.ImmutableList;
import java.util.List;
import static com.facebook.presto.metadata.FunctionKind.AGGREGATE;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.collect.ImmutableList.toImmutableList;
import static java.util.Objects.requireNonNull;
public abstract class SqlAggregationFunction
implements SqlFunction
{
private final Signature signature;
public static List<SqlAggregationFunction> createByAnnotations(Class<?> aggregationDefinition)
{
return AggregationCompiler.generateBindableAggregationFunctions(aggregationDefinition)
.stream()
.map(x -> (SqlAggregationFunction) x)
.collect(toImmutableList());
}
protected SqlAggregationFunction(Signature signature)
{
requireNonNull(signature, "signature is null");
this.signature = signature;
}
protected SqlAggregationFunction(
String name,
List<TypeVariableConstraint> typeVariableConstraints,
List<LongVariableConstraint> longVariableConstraints,
TypeSignature returnType,
List<TypeSignature> argumentTypes)
{
this(name, typeVariableConstraints, longVariableConstraints, returnType, argumentTypes, AGGREGATE);
}
protected SqlAggregationFunction(
String name,
List<TypeVariableConstraint> typeVariableConstraints,
List<LongVariableConstraint> longVariableConstraints,
TypeSignature returnType,
List<TypeSignature> argumentTypes,
FunctionKind kind)
{
requireNonNull(name, "name is null");
requireNonNull(typeVariableConstraints, "typeVariableConstraints is null");
requireNonNull(longVariableConstraints, "longVariableConstraints is null");
requireNonNull(returnType, "returnType is null");
requireNonNull(argumentTypes, "argumentTypes is null");
checkArgument(kind == AGGREGATE, "kind must be an aggregate");
this.signature = new Signature(
name,
kind,
ImmutableList.copyOf(typeVariableConstraints),
ImmutableList.copyOf(longVariableConstraints),
returnType,
ImmutableList.copyOf(argumentTypes),
false);
}
@Override
public final Signature getSignature()
{
return signature;
}
@Override
public boolean isHidden()
{
return false;
}
@Override
public boolean isDeterministic()
{
return true;
}
public abstract InternalAggregationFunction specialize(BoundVariables boundVariables, int arity, TypeManager typeManager, FunctionRegistry functionRegistry);
}