LazyLoadedDataContext.java
/* Contributed in the public domain.
* 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.data;
import org.orekit.bodies.LazyLoadedCelestialBodies;
import org.orekit.forces.gravity.potential.LazyLoadedGravityFields;
import org.orekit.frames.Frame;
import org.orekit.frames.LazyLoadedEop;
import org.orekit.frames.LazyLoadedFrames;
import org.orekit.models.earth.LazyLoadedGeoMagneticFields;
import org.orekit.time.LazyLoadedTimeScales;
/**
* A data context that aims to match the behavior of Orekit 10.0 regarding auxiliary data.
* This data context only loads auxiliary data when it is first accessed. It allows data
* loaders to be added before the data is loaded.
*
* @author Evan Ward
* @since 10.1
*/
public class LazyLoadedDataContext implements DataContext {
/** The data provider manager. */
private final DataProvidersManager dataProvidersManager;
/** EOP loader. */
private final LazyLoadedEop eop;
/** The time scales. */
private final LazyLoadedTimeScales timeScales;
/** The reference frames. */
private LazyLoadedFrames frames;
/** The celestial bodies. */
private LazyLoadedCelestialBodies bodies;
/** The gravity fields. */
private final LazyLoadedGravityFields gravityFields;
/** The magnetic fields. */
private final LazyLoadedGeoMagneticFields geoMagneticFields;
/**
* Create a new data context that only loads auxiliary data when it is first accessed
* and allows configuration of the auxiliary data sources until then.
*/
public LazyLoadedDataContext() {
this.dataProvidersManager = new DataProvidersManager();
this.eop = new LazyLoadedEop(dataProvidersManager);
this.timeScales = new LazyLoadedTimeScales(eop);
this.gravityFields =
new LazyLoadedGravityFields(dataProvidersManager, timeScales.getTT());
this.geoMagneticFields = new LazyLoadedGeoMagneticFields(dataProvidersManager);
// creating Frames and CelestialBodies here creates an initialization problem for
// DataContext.getDefault(). Delay creating them until they are used for the first
// time.
}
/**
* Get the provider of auxiliary data for this data context.
*
* @return the provider that supplies auxiliary data to all of the other methods of
* this data context.
*/
public DataProvidersManager getDataProvidersManager() {
return dataProvidersManager;
}
@Override
public LazyLoadedTimeScales getTimeScales() {
return timeScales;
}
@Override
public LazyLoadedFrames getFrames() {
synchronized (this) {
if (this.frames == null) {
this.frames = new LazyLoadedFrames(
eop, getTimeScales(), getCelestialBodies());
}
return this.frames;
}
}
@Override
public LazyLoadedCelestialBodies getCelestialBodies() {
synchronized (this) {
if (this.bodies == null) {
final Frame gcrf = Frame.getRoot();
this.bodies = new LazyLoadedCelestialBodies(
getDataProvidersManager(), getTimeScales(), gcrf);
}
return this.bodies;
}
}
@Override
public LazyLoadedGravityFields getGravityFields() {
return gravityFields;
}
@Override
public LazyLoadedGeoMagneticFields getGeoMagneticFields() {
return geoMagneticFields;
}
}