UnitsCache.java
/* Copyright 2002-2022 CS GROUP
* Licensed to CS GROUP (CS) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* CS 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.orekit.utils.units;
import java.util.HashMap;
import java.util.Map;
/** Cache for parsed units.
* @author Luc Maisonobe
* @since 11.0
*/
public class UnitsCache {
/** Parsed units cache. */
private final Map<String, Unit> cache;
/** Simple constructor.
*/
public UnitsCache() {
this.cache = new HashMap<>();
}
/** Get units from a string specification.
* <p>
* Parsing is performed only the first time a specification is
* encountered, so the cache speeds up cases where the same
* units is encountered many times (for example when parsing
* CCSDS messages with many entries).
* </p>
* @param specification units specification (may be null)
* @return parsed units ({@link Unit#NONE} if specification is null)
*/
public Unit getUnits(final String specification) {
if (specification == null) {
return Unit.NONE;
}
Unit cached = cache.get(specification);
if (cached == null) {
cached = Unit.parse(specification);
cache.put(specification, cached);
}
return cached;
}
}