/**
* 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.drill.common.expression;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.drill.common.exceptions.DrillRuntimeException;
import org.apache.drill.common.types.TypeProtos.MajorType;
import com.google.common.collect.Lists;
public class FunctionCallFactory {
static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(FunctionCallFactory.class);
private static Map<String, String> opToFuncTable = new HashMap<>();
static {
opToFuncTable.put("+", "add");
opToFuncTable.put("-", "subtract");
opToFuncTable.put("/", "divide");
opToFuncTable.put("*", "multiply");
opToFuncTable.put("%", "modulo");
opToFuncTable.put("^", "xor");
opToFuncTable.put("||", "concatOperator");
opToFuncTable.put("or", "booleanOr");
opToFuncTable.put("and", "booleanAnd");
opToFuncTable.put(">", "greater_than");
opToFuncTable.put("<", "less_than");
opToFuncTable.put("==", "equal");
opToFuncTable.put("=", "equal");
opToFuncTable.put("!=", "not_equal");
opToFuncTable.put("<>", "not_equal");
opToFuncTable.put(">=", "greater_than_or_equal_to");
opToFuncTable.put("<=", "less_than_or_equal_to");
opToFuncTable.put("is null", "isnull");
opToFuncTable.put("is not null", "isnotnull");
opToFuncTable.put("is true", "istrue");
opToFuncTable.put("is not true", "isnottrue");
opToFuncTable.put("is false", "isfalse");
opToFuncTable.put("is not false", "isnotfalse");
opToFuncTable.put("similar to", "similar_to");
opToFuncTable.put("!", "not");
opToFuncTable.put("u-", "negative");
}
public static String replaceOpWithFuncName(String op) {
return (opToFuncTable.containsKey(op)) ? (opToFuncTable.get(op)) : op;
}
public static boolean isBooleanOperator(String funcName) {
String opName = replaceOpWithFuncName(funcName);
return opName.equals("booleanAnd") || opName.equals("booleanOr");
}
/*
* create a cast function.
* arguments : type -- targetType
* ep -- input expression position
* expr -- input expression
*/
public static LogicalExpression createCast(MajorType type, ExpressionPosition ep, LogicalExpression expr){
return new CastExpression(expr, type, ep);
}
public static LogicalExpression createConvert(String function, String conversionType, LogicalExpression expr, ExpressionPosition ep) {
return new ConvertExpression(function, conversionType, expr, ep);
}
public static LogicalExpression createExpression(String functionName, List<LogicalExpression> args){
return createExpression(functionName, ExpressionPosition.UNKNOWN, args);
}
public static LogicalExpression createExpression(String functionName, ExpressionPosition ep, List<LogicalExpression> args){
String name = replaceOpWithFuncName(functionName);
if (isBooleanOperator(name)) {
return new BooleanOperator(name, args, ep);
} else {
return new FunctionCall(name, args, ep);
}
}
public static LogicalExpression createExpression(String functionName, ExpressionPosition ep, LogicalExpression... e){
return createExpression(functionName, ep, Lists.newArrayList(e));
}
public static LogicalExpression createBooleanOperator(String functionName, List<LogicalExpression> args){
return createBooleanOperator(functionName, ExpressionPosition.UNKNOWN, args);
}
public static LogicalExpression createBooleanOperator(String functionName, ExpressionPosition ep, List<LogicalExpression> args){
return new BooleanOperator(replaceOpWithFuncName(functionName), args, ep);
}
public static LogicalExpression createByOp(List<LogicalExpression> args, ExpressionPosition ep, List<String> opTypes) {
if (args.size() == 1) {
return args.get(0);
}
if (args.size() - 1 != opTypes.size()) {
throw new DrillRuntimeException("Must receive one more expression then the provided number of operators.");
}
LogicalExpression first = args.get(0);
for (int i = 0; i < opTypes.size(); i++) {
List<LogicalExpression> l2 = new ArrayList<LogicalExpression>();
l2.add(first);
l2.add(args.get(i + 1));
first = createExpression(opTypes.get(i), ep, l2);
}
return first;
}
}