| /* |
| * 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 freemarker.template.utility; |
| |
| import java.math.BigDecimal; |
| import java.math.BigInteger; |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.List; |
| |
| /** |
| */ |
| public class OptimizerUtil { |
| private static final BigInteger INTEGER_MIN = new BigInteger(Integer.toString(Integer.MIN_VALUE)); |
| private static final BigInteger INTEGER_MAX = new BigInteger(Integer.toString(Integer.MAX_VALUE)); |
| private static final BigInteger LONG_MIN = new BigInteger(Long.toString(Long.MIN_VALUE)); |
| private static final BigInteger LONG_MAX = new BigInteger(Long.toString(Long.MAX_VALUE)); |
| |
| private OptimizerUtil() { |
| } |
| |
| public static List optimizeListStorage(List list) { |
| switch(list.size()) |
| { |
| case 0: |
| { |
| return Collections.EMPTY_LIST; |
| } |
| case 1: |
| { |
| return Collections.singletonList(list.get(0)); |
| } |
| default: |
| { |
| if (list instanceof ArrayList) { |
| ((ArrayList) list).trimToSize(); |
| } |
| return list; |
| } |
| } |
| } |
| |
| /** |
| * This is needed to reverse the extreme conversions in arithmetic |
| * operations so that numbers can be meaningfully used with models that |
| * don't know what to do with a BigDecimal. Of course, this will make |
| * impossible for these models (i.e. Jython) to receive a BigDecimal even if |
| * it was originally placed as such in the data model. However, since |
| * arithmetic operations aggressively erase the information regarding the |
| * original number type, we have no other choice to ensure expected operation |
| * in majority of cases. |
| */ |
| public static Number optimizeNumberRepresentation(Number number) { |
| if (number instanceof BigDecimal) { |
| BigDecimal bd = (BigDecimal) number; |
| if (bd.scale() == 0) { |
| // BigDecimal -> BigInteger |
| number = bd.unscaledValue(); |
| } else { |
| double d = bd.doubleValue(); |
| if (d != Double.POSITIVE_INFINITY && d != Double.NEGATIVE_INFINITY) { |
| // BigDecimal -> Double |
| return Double.valueOf(d); |
| } |
| } |
| } |
| if (number instanceof BigInteger) { |
| BigInteger bi = (BigInteger) number; |
| if (bi.compareTo(INTEGER_MAX) <= 0 && bi.compareTo(INTEGER_MIN) >= 0) { |
| // BigInteger -> Integer |
| return Integer.valueOf(bi.intValue()); |
| } |
| if (bi.compareTo(LONG_MAX) <= 0 && bi.compareTo(LONG_MIN) >= 0) { |
| // BigInteger -> Long |
| return Long.valueOf(bi.longValue()); |
| } |
| } |
| return number; |
| } |
| } |