juzu.impl.asset.AssetManager Maven / Gradle / Ivy
/*
* Copyright 2013 eXo Platform SAS
*
* 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 juzu.impl.asset;
import juzu.impl.common.Tools;
import java.net.URL;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.Map;
/** @author Julien Viet */
public class AssetManager {
/** . */
private final LinkedHashMap assets = new LinkedHashMap();
/** . */
private final HashMap resources = new HashMap();
/**
* Attempt to add an asset to the manager, the manager will return the asset id
* if the asset was registered or null if it was not.
*
* @param data the asset description
* @param url the asset url
* @return the asset id
* @throws NullPointerException if the metaData argument is nul
* @throws IllegalArgumentException if the metaData does not have an id set
*/
public String addAsset(AssetMetaData data, URL url) throws NullPointerException, IllegalArgumentException {
String id = data.id;
// Use value hashcode if no id is provided
if (id == null) {
id = "" + data.getValue().hashCode();
}
//
if (!assets.keySet().contains(id)) {
AssetNode asset = new AssetNode(id, data.location, data.value, data.dependencies);
for (AssetNode deployed : assets.values()) {
if (deployed.iDependOn.contains(id)) {
asset.dependsOnMe = Tools.addToHashSet(asset.dependsOnMe, deployed.id);
}
if (asset.iDependOn.contains(deployed.id)) {
deployed.dependsOnMe = Tools.addToHashSet(deployed.dependsOnMe, id);
}
}
assets.put(id, asset);
//
switch (data.location) {
case APPLICATION:
case SERVER:
resources.put(data.getValue(), url);
break;
default:
// Nothing to do
break;
}
} else {
// log it ?
}
//
return id;
}
/**
* Resolve an asset as a resource URL or return null if it cannot be found.
*
* @param path the path
* @return the resource
*/
public URL resolveAsset(String path) {
return resources.get(path);
}
/**
* Perform a topological sort of the provided asset script values.
*
* @param scripts the asset id to resolve
* @return the resolved asset or null
* @throws NullPointerException if the asset id argument is null
* @throws IllegalArgumentException when script dependencies cannot be resolved
*/
public Iterable resolveAssets(Iterable scripts) throws
NullPointerException,
IllegalArgumentException {
LinkedHashMap> sub = new LinkedHashMap>();
for (String script : scripts) {
AssetNode asset = assets.get(script);
if (asset != null) {
sub.put(asset.id, new HashSet(asset.iDependOn));
}
else {
throw new IllegalArgumentException("Cannot resolve asset " + script);
}
}
//
LinkedList resolved = new LinkedList();
while (sub.size() > 0) {
boolean found = false;
for (Iterator>> i = sub.entrySet().iterator();i.hasNext();) {
Map.Entry> entry = i.next();
if (entry.getValue().isEmpty()) {
i.remove();
AssetNode asset = assets.get(entry.getKey());
resolved.addLast(Asset.of(asset.getLocation(), asset.getValue()));
for (String dependency : asset.dependsOnMe) {
HashSet foo = sub.get(dependency);
if (foo != null) {
foo.remove(entry.getKey());
}
}
found = true;
break;
}
}
if (!found) {
StringBuilder sb = new StringBuilder("Cannot satisfy asset dependencies:\n");
for (Map.Entry> entry : sub.entrySet()) {
sb.append(entry.getKey()).append(" -> ").append(entry.getValue());
}
throw new IllegalArgumentException(sb.toString());
}
}
//
return resolved;
}
}