/*
* Copyright (c) 2016, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
*
* WSO2 Inc. 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.wso2.siddhi.sample.util;
import org.wso2.siddhi.core.config.ExecutionPlanContext;
import org.wso2.siddhi.core.exception.ExecutionPlanCreationException;
import org.wso2.siddhi.core.executor.ExpressionExecutor;
import org.wso2.siddhi.core.executor.function.FunctionExecutor;
import org.wso2.siddhi.core.util.config.ConfigReader;
import org.wso2.siddhi.query.api.definition.Attribute;
import java.util.Map;
public class CustomFunctionExtension extends FunctionExecutor {
private Attribute.Type returnType;
/**
* The initialization method for FunctionExecutor, this method will be called before the other methods
* @param attributeExpressionExecutors are the executors of each function parameters
* @param configReader
* @param executionPlanContext the context of the execution plan
*/
@Override
protected void init(ExpressionExecutor[] attributeExpressionExecutors, ConfigReader configReader,
ExecutionPlanContext executionPlanContext) {
for (ExpressionExecutor expressionExecutor : attributeExpressionExecutors) {
Attribute.Type attributeType = expressionExecutor.getReturnType();
if (attributeType == Attribute.Type.DOUBLE) {
returnType = attributeType;
} else if ((attributeType == Attribute.Type.STRING) || (attributeType == Attribute.Type.BOOL)) {
throw new ExecutionPlanCreationException("Plus cannot have parameters with types String or Bool");
} else {
returnType = Attribute.Type.LONG;
}
}
}
/**
* The main execution method which will be called upon event arrival
* when there are more then one function parameter
*
* @param data the runtime values of function parameters
* @return the function result
*/
@Override
protected Object execute(Object[] data) {
if (returnType == Attribute.Type.DOUBLE) {
double total = 0;
for (Object aObj : data) {
total += Double.parseDouble(String.valueOf(aObj));
}
return total;
} else {
long total = 0;
for (Object aObj : data) {
total += Long.parseLong(String.valueOf(aObj));
}
return total;
}
}
/**
* The main execution method which will be called upon event arrival
* when there are zero or one function parameter
*
* @param data null if the function parameter count is zero or
* runtime data value of the function parameter
* @return the function result
*/
@Override
protected Object execute(Object data) {
if (returnType == Attribute.Type.DOUBLE) {
return Double.parseDouble(String.valueOf(data));
} else {
return Long.parseLong(String.valueOf(data));
}
}
/**
* This will be called only once and this can be used to acquire
* required resources for the processing element.
* This will be called after initializing the system and before
* starting to process the events.
*/
@Override
public void start() {
}
/**
* This will be called only once and this can be used to release
* the acquired resources for processing.
* This will be called before shutting down the system.
*/
@Override
public void stop() {
}
@Override
public Attribute.Type getReturnType() {
return returnType;
}
/**
* Used to collect the serializable state of the processing element, that need to be
* persisted for the reconstructing the element to the same state on a different point of time
*
* @return stateful objects of the processing element as an array
*/
@Override
public Map<String, Object> currentState() {
return null;
}
/**
* Used to restore serialized state of the processing element, for reconstructing
* the element to the same state as if was on a previous point of time.
*
* @param state the stateful objects of the element as an array on
* the same order provided by currentState().
*/
@Override
public void restoreState(Map<String, Object> state) {
}
}