| /* |
| * 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. |
| */ |
| <@pp.dropOutputFile /> |
| |
| |
| |
| <#list aggrtypes3.aggrtypes as aggrtype> |
| <@pp.changeOutputFile name="/org/apache/drill/exec/expr/fn/impl/gaggr/${aggrtype.className}Functions.java" /> |
| |
| <#include "/@includes/license.ftl" /> |
| |
| /* |
| * This class is generated using freemarker and the ${.template_name} template. |
| */ |
| |
| <#-- A utility class that is used to generate java code for aggr functions such as stddev, variance --> |
| |
| package org.apache.drill.exec.expr.fn.impl.gaggr; |
| |
| import org.apache.drill.exec.expr.DrillAggFunc; |
| import org.apache.drill.exec.expr.annotations.FunctionTemplate; |
| import org.apache.drill.exec.expr.annotations.FunctionTemplate.NullHandling; |
| import org.apache.drill.exec.expr.annotations.FunctionTemplate.FunctionScope; |
| import org.apache.drill.exec.expr.annotations.Output; |
| import org.apache.drill.exec.expr.annotations.Param; |
| import org.apache.drill.exec.expr.annotations.Workspace; |
| import org.apache.drill.exec.expr.holders.*; |
| |
| @SuppressWarnings("unused") |
| |
| public class ${aggrtype.className}Functions { |
| static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(${aggrtype.className}Functions.class); |
| |
| <#list aggrtype.types as type> |
| |
| <#if aggrtype.aliasName == ""> |
| @FunctionTemplate(name = "${aggrtype.funcName}", scope = FunctionTemplate.FunctionScope.POINT_AGGREGATE) |
| <#else> |
| @FunctionTemplate(names = {"${aggrtype.funcName}", "${aggrtype.aliasName}"}, scope = FunctionTemplate.FunctionScope.POINT_AGGREGATE) |
| </#if> |
| |
| public static class ${type.inputType}${aggrtype.className} implements DrillAggFunc{ |
| |
| @Param ${type.inputType}Holder in; |
| @Workspace ${type.movingAverageType}Holder avg; |
| @Workspace ${type.movingDeviationType}Holder dev; |
| @Workspace ${type.countRunningType}Holder count; |
| @Workspace BigIntHolder nonNullCount; |
| @Output ${type.outputType}Holder out; |
| |
| public void setup() { |
| avg = new ${type.movingAverageType}Holder(); |
| dev = new ${type.movingDeviationType}Holder(); |
| count = new ${type.countRunningType}Holder(); |
| nonNullCount = new BigIntHolder(); |
| nonNullCount.value = 0; |
| // Initialize the workspace variables |
| avg.value = 0; |
| dev.value = 0; |
| count.value = 1; |
| } |
| |
| @Override |
| public void add() { |
| <#if type.inputType?starts_with("Nullable")> |
| sout: { |
| if (in.isSet == 0) { |
| // processing nullable input and the value is null, so don't do anything... |
| break sout; |
| } |
| </#if> |
| |
| nonNullCount.value = 1; |
| // Welford's approach to compute standard deviation |
| double temp = avg.value; |
| avg.value += ((in.value - temp) / count.value); |
| dev.value += (in.value - temp) * (in.value - avg.value); |
| count.value++; |
| |
| <#if type.inputType?starts_with("Nullable")> |
| } // end of sout block |
| </#if> |
| } |
| |
| @Override |
| public void output() { |
| if (nonNullCount.value > 0) { |
| out.isSet = 1; |
| <#if aggrtype.funcName == "stddev_pop"> |
| if (count.value > 1) |
| out.value = Math.sqrt((dev.value / (count.value - 1))); |
| <#elseif aggrtype.funcName == "var_pop"> |
| if (count.value > 1) |
| out.value = (dev.value / (count.value - 1)); |
| <#elseif aggrtype.funcName == "stddev_samp"> |
| if (count.value > 2) |
| out.value = Math.sqrt((dev.value / (count.value - 2))); |
| <#elseif aggrtype.funcName == "var_samp"> |
| if (count.value > 2) |
| out.value = (dev.value / (count.value - 2)); |
| </#if> |
| } else { |
| out.isSet = 0; |
| } |
| } |
| |
| @Override |
| public void reset() { |
| nonNullCount.value = 0; |
| avg.value = 0; |
| dev.value = 0; |
| count.value = 1; |
| } |
| } |
| |
| |
| </#list> |
| } |
| </#list> |