io.prestosql.operator.annotations.ScalarImplementationDependency Maven / Gradle / Ivy

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/*
 * 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 io.prestosql.operator.annotations;

import io.prestosql.metadata.FunctionBinding;
import io.prestosql.metadata.FunctionDependencies;
import io.prestosql.metadata.FunctionInvoker;
import io.prestosql.spi.function.InvocationConvention;

import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandleProxies;

import static java.util.Objects.requireNonNull;

public abstract class ScalarImplementationDependency
        implements ImplementationDependency
{
    private final InvocationConvention invocationConvention;
    private final Class type;

    protected ScalarImplementationDependency(InvocationConvention invocationConvention, Class type)
    {
        this.invocationConvention = requireNonNull(invocationConvention, "invocationConvention is null");
        this.type = requireNonNull(type, "type is null");
        if (invocationConvention.supportsInstanceFactor()) {
            throw new IllegalArgumentException(getClass().getSimpleName() + " does not support instance functions");
        }
    }

    protected abstract FunctionInvoker getInvoker(FunctionBinding functionBinding, FunctionDependencies functionDependencies, InvocationConvention invocationConvention);

    @Override
    public Object resolve(FunctionBinding functionBinding, FunctionDependencies functionDependencies)
    {
        MethodHandle methodHandle = getInvoker(functionBinding, functionDependencies, invocationConvention).getMethodHandle();
        if (type == MethodHandle.class) {
            return methodHandle;
        }
        return MethodHandleProxies.asInterfaceInstance(type, methodHandle);
    }

    @Override
    public abstract boolean equals(Object o);

    @Override
    public abstract int hashCode();
}