private void clearCache(IJavaProject project, Set<PackageFragmentRootData> toBeKept) {
Collection<PackageFragmentRootData> values;
synchronized (cachedPackageFragmentRootData) {
values = newArrayList(cachedPackageFragmentRootData.values());
}
List<PackageFragmentRootData> toBeRemoved = newArrayList();
for (PackageFragmentRootData data : values) {
if (toBeKept.contains(data)) {
continue;
}
// create a copy of the known associated roots to avoid concurrent modification
// and conflicts with other readers
Map<String, IPackageFragmentRoot> copy = newLinkedHashMap(data.associatedRoots);
Iterator<IPackageFragmentRoot> i = copy.values().iterator();
IPackageFragmentRoot someRoot = null;
boolean didChange = false;
while (i.hasNext()) {
IPackageFragmentRoot root = i.next();
if (project.equals(root.getJavaProject())) {
i.remove();
didChange = true;
} else if (someRoot == null) {
someRoot = root;
}
}
if (copy.size() == 0) {
toBeRemoved.add(data);
} else if (didChange) {
// get rid of cached storages that still point to roots / projects that are no longer
// available
// and recompute them lazily on demand
data.associatedRoots = copy;
final IPackageFragmentRoot rootToProcess = someRoot;
data.uri2Storage =
new ForwardingMap<URI, IStorage>() {
Map<URI, IStorage> delegate;
@Override
protected Map<URI, IStorage> delegate() {
if (delegate == null) {
PackageFragmentRootData newlyCollected = initializeData(rootToProcess);
return delegate = newlyCollected.uri2Storage;
}
return delegate;
}
};
}
}
if (!toBeRemoved.isEmpty()) {
synchronized (cachedPackageFragmentRootData) {
cachedPackageFragmentRootData.values().removeAll(toBeRemoved);
}
}
}
