/*
* Copyright 2008-2009 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 net.hasor.data.ql.runtime;
import net.hasor.data.ql.dsl.domain.*;
import net.hasor.data.ql.runtime.task.*;
import java.util.List;
/**
* 解析查询模型，将其转换成为执行任务树
* @author 赵永春(zyc@hasor.net)
* @version : 2017-03-23
*/
public class TaskParser {
//
/** 解析查询模型，将其转换成为执行任务树 */
public AbstractPrintTask doParser(QueryDomain domain) {
return (AbstractPrintTask) doParser("$", null, domain).fixRouteDep();
}
private AbstractPrintTask doParser(String nameOfParent, AbstractPrintTask parent, QueryDomain domain) {
AbstractPrintTask dataSource = null;
if (domain.getUDF() != null) {
dataSource = this.parserUDF(nameOfParent, parent, domain.getUDF());
}
//
ReturnType returnType = domain.getReturnType();
switch (returnType) {
case Object: {
List<String> fieldNames = domain.getFieldNames();
ObjectTask ost = new ObjectTask(nameOfParent, parent, dataSource);
for (String name : fieldNames) {
DValue domainField = domain.getField(name);
AbstractPrintTask fieldTask = this.parseField(name, ost, domainField);
ost.addField(name, fieldTask);
}
return ost;
}
case ListObject: {
ListTask lst = new ListTask(nameOfParent, parent, dataSource);
//
List<String> fieldNames = domain.getFieldNames();
ObjectTask ost = new ObjectTask(nameOfParent, lst, null);
for (String name : fieldNames) {
DValue domainField = domain.getField(name);
AbstractPrintTask fieldTask = this.parseField(name, ost, domainField);
ost.addField(name, fieldTask);
}
//
lst.setListBody(ost);
return lst;
}
case ListValue: {
ListTask lst = new ListTask(nameOfParent, parent, dataSource);
//
List<String> fieldNames = domain.getFieldNames();
String fieldName = fieldNames.get(0);
DValue domainField = domain.getField(fieldName);
AbstractPrintTask fieldTask = this.parseField(fieldName, lst, domainField);
//
lst.setListBody(fieldTask);
return lst;
}
case Original:
if (dataSource != null) {
return dataSource;
}
throw new UnsupportedOperationException("dataSource is null.");
default:
throw new UnsupportedOperationException("unsupported ReturnType.");
}
//
}
private AbstractPrintTask parserUDF(String nameOfParent, AbstractPrintTask parent, DataUDF graphUDF) {
if (graphUDF == null) {
return null;
}
CallerTask caller = new CallerTask(nameOfParent, parent, graphUDF.getName());
List<String> paramNames = graphUDF.getParamNames();
for (String name : paramNames) {
DValue field = graphUDF.getParam(name);
caller.addParam(name, field.getEqType(), parseField(name, parent, field));
}
return caller;
}
private AbstractPrintTask parseField(String nameOfParent, AbstractPrintTask parent, DValue defSource) {
if (defSource instanceof QueryValue) {
//
QueryValue queryValue = (QueryValue) defSource;
QueryDomain queryDomain = queryValue.getQueryDomain();
return this.doParser(nameOfParent, parent, queryDomain);
} else if (defSource instanceof FixedValue) {
//
FixedValue varValue = (FixedValue) defSource;
Object value = varValue.getValue();
ValueType valueType = varValue.getValueType();
return new ValueTask(nameOfParent, parent, value, valueType);
} else if (defSource instanceof RouteValue) {
//
RouteTask rst = new RouteTask(nameOfParent, parent, null);
String routeExpression = ((RouteValue) defSource).getRouteExpression();
rst.setRouteExpression(routeExpression);
//
// - 解析路由表达式，定位到必要的 DS，依赖它。
if (routeExpression.contains(".")) {
AbstractTask fieldTask = findRouteDSTask(routeExpression, rst);
if (fieldTask != null) {
rst.addDepTask(fieldTask);
}
} else {
AbstractTask dataSource = TaskUtils.nearDS(rst); //先找到根节点，然后定位根节点的数据源
rst.addDepTask(dataSource);
}
//
return rst;
}
throw new UnsupportedOperationException("unsupported DValue. type is = " + defSource.getClass());
}
//
//
/** 带有路径的路由解析，需要找到路由对应数据的那个 DS */
private AbstractTask findRouteDSTask(final String routeExpression, final AbstractTask atTask) {
AbstractTask dataTask = atTask;
AbstractTask dataSource = atTask.getDataSource();
//
// - 根节点
if (routeExpression.charAt(0) == '$') {
while (dataTask.getParent() != null) {
dataTask = dataTask.getParent();
}
dataSource = TaskUtils.nearDS(dataTask); //先找到根节点，然后定位根节点的数据源
}
// - 最近的DS
if (routeExpression.charAt(0) == '~') {
dataSource = TaskUtils.nearDS(dataTask);//最近的数据源
}
// - 其它
if (dataSource == null) {
AbstractTask tempTask = dataTask;
while (tempTask != null) {
dataSource = tempTask.findFieldTask(routeExpression.split("\\.")[0]);
if (dataSource != null) {
if (TaskType.F == dataSource.getTaskType()) {
return dataSource;
}
dataSource = TaskUtils.nearDS(dataSource);
break;
}
tempTask = tempTask.getParent();
}
}
//
return dataSource;
}
}