org.springframework.data.gemfire.function.FunctionContextInjectingArgumentResolver.java Source code

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Here is the source code for org.springframework.data.gemfire.function.FunctionContextInjectingArgumentResolver.java

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/*
 * Copyright 2002-2013 the original author or authors.
 * 
 * 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 org.springframework.data.gemfire.function;

import java.lang.reflect.Method;
import java.util.Map;
import java.util.Set;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.data.gemfire.function.annotation.Filter;
import org.springframework.data.gemfire.function.annotation.RegionData;
import org.springframework.data.gemfire.util.ArrayUtils;
import org.springframework.util.Assert;

import com.gemstone.gemfire.cache.Region;
import com.gemstone.gemfire.cache.execute.FunctionContext;
import com.gemstone.gemfire.cache.execute.RegionFunctionContext;
import com.gemstone.gemfire.cache.execute.ResultSender;
import com.gemstone.gemfire.cache.partition.PartitionRegionHelper;

/**
 * @author David Turanski
 * @since 1.3.0
 *
 */
class FunctionContextInjectingArgumentResolver extends PdxFunctionArgumentResolver {

    private static final Log logger = LogFactory.getLog(FunctionContextInjectingArgumentResolver.class);

    private final int filterParameterPosition;
    private final int functionContextParameterPosition;
    private final int regionParameterPosition;
    private final int resultSenderParameterPosition;

    private final Method method;

    public FunctionContextInjectingArgumentResolver(Method method) {
        this.method = method;

        int regionDataAnnotationParameterPosition = GemfireFunctionUtils.getAnnotationParameterPosition(method,
                RegionData.class, new Class[] { Map.class });

        int regionTypeParameterPosition = getArgumentTypePosition(method, Region.class);

        if (regionDataAnnotationParameterPosition >= 0 && regionTypeParameterPosition >= 0) {
            Assert.isTrue(regionDataAnnotationParameterPosition == regionTypeParameterPosition, String.format(
                    "Function method signature for method %s cannot contain an @RegionData parameter and a different Region type parameter",
                    method.getName()));
        }

        regionParameterPosition = (regionDataAnnotationParameterPosition >= 0
                ? regionDataAnnotationParameterPosition
                : (regionTypeParameterPosition >= 0 ? regionTypeParameterPosition : -1));

        filterParameterPosition = GemfireFunctionUtils.getAnnotationParameterPosition(method, Filter.class,
                new Class[] { Set.class });

        if (regionParameterPosition >= 0 && filterParameterPosition >= 0) {
            Assert.state(regionParameterPosition != filterParameterPosition,
                    "region parameter and filter parameter must be different");
        }

        functionContextParameterPosition = getArgumentTypePosition(method, FunctionContext.class);

        resultSenderParameterPosition = getArgumentTypePosition(method, ResultSender.class);
    }

    @Override
    public Method getFunctionAnnotatedMethod() {
        return method;
    }

    @Override
    public Object[] resolveFunctionArguments(FunctionContext functionContext) {
        Object[] args = super.resolveFunctionArguments(functionContext);

        if (functionContext instanceof RegionFunctionContext) {
            if (this.regionParameterPosition >= 0) {
                args = ArrayUtils.insert(args, regionParameterPosition,
                        getRegionForContext((RegionFunctionContext) functionContext));
            }

            if (this.filterParameterPosition >= 0) {
                args = ArrayUtils.insert(args, filterParameterPosition,
                        ((RegionFunctionContext) functionContext).getFilter());
            }
        }

        if (this.functionContextParameterPosition >= 0) {
            args = ArrayUtils.insert(args, functionContextParameterPosition, functionContext);
        }

        if (this.resultSenderParameterPosition >= 0) {
            args = ArrayUtils.insert(args, resultSenderParameterPosition, functionContext.getResultSender());
        }

        Assert.isTrue(args.length == method.getParameterTypes().length,
                String.format("wrong number of arguments for method %s. Expected %d, but was %d", method.getName(),
                        method.getParameterTypes().length, args.length));

        return args;
    }

    /*
     * (non-Javadoc)
     * @see com.gemstone.gemfire.cache.execute.RegionFunctionContext
     */
    private static Region<?, ?> getRegionForContext(RegionFunctionContext regionFunctionContext) {
        Region<?, ?> region = regionFunctionContext.getDataSet();

        if (PartitionRegionHelper.isPartitionedRegion(region)) {
            if (logger.isDebugEnabled()) {
                logger.debug("this is a partitioned region - filtering local data for context");
            }
            region = PartitionRegionHelper.getLocalDataForContext(regionFunctionContext);
        }

        if (logger.isDebugEnabled()) {
            logger.debug("region contains " + region.size() + " items");
        }

        return region;
    }

    /*
     * (non-Javadoc)
     */
    private static int getArgumentTypePosition(Method method, Class<?> requiredType) {
        int index = 0;
        int position = -1;

        for (Class<?> parameterType : method.getParameterTypes()) {
            if (requiredType.equals(parameterType)) {
                Assert.state(position < 0,
                        String.format("Method %s signature cannot contain more than one parameter of type %s.",
                                method.getName(), requiredType.getName()));

                position = index;
            }

            index++;
        }

        return position;
    }

}