algebricks/algebricks-examples/piglet-example/src/main/java/org/apache/hyracks/algebricks/examples/piglet/runtime/functions/PigletFunctionRegistry.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.hyracks.algebricks.examples.piglet.runtime.functions;

import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import org.apache.hyracks.algebricks.core.algebra.functions.AlgebricksBuiltinFunctions;
import org.apache.hyracks.algebricks.core.algebra.functions.FunctionIdentifier;
import org.apache.hyracks.algebricks.examples.piglet.exceptions.PigletException;
import org.apache.hyracks.algebricks.runtime.base.ICopyEvaluatorFactory;

public class PigletFunctionRegistry {
    private static final Map<FunctionIdentifier, IPigletFunctionEvaluatorFactoryBuilder> builderMap;

    static {
        Map<FunctionIdentifier, IPigletFunctionEvaluatorFactoryBuilder> temp = new HashMap<FunctionIdentifier, IPigletFunctionEvaluatorFactoryBuilder>();

        temp.put(AlgebricksBuiltinFunctions.EQ, new IPigletFunctionEvaluatorFactoryBuilder() {
            @Override
            public ICopyEvaluatorFactory buildEvaluatorFactory(FunctionIdentifier fid, ICopyEvaluatorFactory[] arguments) {
                return new IntegerEqFunctionEvaluatorFactory(arguments[0], arguments[1]);
            }
        });

        builderMap = Collections.unmodifiableMap(temp);
    }

    public static ICopyEvaluatorFactory createFunctionEvaluatorFactory(FunctionIdentifier fid, ICopyEvaluatorFactory[] args)
            throws PigletException {
        IPigletFunctionEvaluatorFactoryBuilder builder = builderMap.get(fid);
        if (builder == null) {
            throw new PigletException("Unknown function: " + fid);
        }
        return builder.buildEvaluatorFactory(fid, args);
    }
}