/*
* 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.operator.scalar;
import com.facebook.presto.metadata.BoundVariables;
import com.facebook.presto.metadata.FunctionRegistry;
import com.facebook.presto.metadata.Signature;
import com.facebook.presto.metadata.SqlScalarFunction;
import com.facebook.presto.operator.scalar.annotations.ScalarImplementation;
import com.facebook.presto.operator.scalar.annotations.ScalarImplementation.MethodHandleAndConstructor;
import com.facebook.presto.operator.scalar.annotations.ScalarImplementations;
import com.facebook.presto.spi.PrestoException;
import com.facebook.presto.spi.type.TypeManager;
import java.util.Optional;
import static com.facebook.presto.metadata.SignatureBinder.applyBoundVariables;
import static com.facebook.presto.spi.StandardErrorCode.AMBIGUOUS_FUNCTION_IMPLEMENTATION;
import static com.facebook.presto.spi.StandardErrorCode.FUNCTION_IMPLEMENTATION_ERROR;
import static com.facebook.presto.spi.StandardErrorCode.FUNCTION_IMPLEMENTATION_MISSING;
import static com.facebook.presto.util.Failures.checkCondition;
import static java.lang.String.format;
import static java.util.Objects.requireNonNull;
public class ParametricScalar
extends SqlScalarFunction
{
private final ScalarHeader details;
private final ScalarImplementations implementations;
public ParametricScalar(
Signature signature,
ScalarHeader details,
ScalarImplementations implementations)
{
super(signature);
this.details = requireNonNull(details);
this.implementations = requireNonNull(implementations);
}
@Override
public boolean isHidden()
{
return details.isHidden();
}
@Override
public boolean isDeterministic()
{
return details.isDeterministic();
}
@Override
public String getDescription()
{
return details.getDescription().isPresent() ? details.getDescription().get() : "";
}
@Override
public ScalarFunctionImplementation specialize(BoundVariables boundVariables, int arity, TypeManager typeManager, FunctionRegistry functionRegistry)
{
Signature boundSignature = applyBoundVariables(getSignature(), boundVariables, arity);
if (implementations.getExactImplementations().containsKey(boundSignature)) {
ScalarImplementation implementation = implementations.getExactImplementations().get(boundSignature);
Optional<MethodHandleAndConstructor> methodHandleAndConstructor = implementation.specialize(boundSignature, boundVariables, typeManager, functionRegistry);
checkCondition(methodHandleAndConstructor.isPresent(), FUNCTION_IMPLEMENTATION_ERROR, String.format("Exact implementation of %s do not match expected java types.", boundSignature.getName()));
return new ScalarFunctionImplementation(implementation.isNullable(), implementation.getNullableArguments(), implementation.getNullFlags(), methodHandleAndConstructor.get().getMethodHandle(), methodHandleAndConstructor.get().getConstructor(), isDeterministic());
}
ScalarFunctionImplementation selectedImplementation = null;
for (ScalarImplementation implementation : implementations.getSpecializedImplementations()) {
Optional<MethodHandleAndConstructor> methodHandle = implementation.specialize(boundSignature, boundVariables, typeManager, functionRegistry);
if (methodHandle.isPresent()) {
checkCondition(selectedImplementation == null, AMBIGUOUS_FUNCTION_IMPLEMENTATION, "Ambiguous implementation for %s with bindings %s", getSignature(), boundVariables.getTypeVariables());
selectedImplementation = new ScalarFunctionImplementation(implementation.isNullable(), implementation.getNullableArguments(), implementation.getNullFlags(), methodHandle.get().getMethodHandle(), methodHandle.get().getConstructor(), isDeterministic());
}
}
if (selectedImplementation != null) {
return selectedImplementation;
}
for (ScalarImplementation implementation : implementations.getGenericImplementations()) {
Optional<MethodHandleAndConstructor> methodHandle = implementation.specialize(boundSignature, boundVariables, typeManager, functionRegistry);
if (methodHandle.isPresent()) {
checkCondition(selectedImplementation == null, AMBIGUOUS_FUNCTION_IMPLEMENTATION, "Ambiguous implementation for %s with bindings %s", getSignature(), boundVariables.getTypeVariables());
selectedImplementation = new ScalarFunctionImplementation(implementation.isNullable(), implementation.getNullableArguments(), implementation.getNullFlags(), methodHandle.get().getMethodHandle(), methodHandle.get().getConstructor(), isDeterministic());
}
}
if (selectedImplementation != null) {
return selectedImplementation;
}
throw new PrestoException(FUNCTION_IMPLEMENTATION_MISSING, format("Unsupported type parameters (%s) for %s", boundVariables, getSignature()));
}
}