public synchronized void deleteCollection(String name) {
try {
long nameDirectory_recid = getRoot(NAME_DIRECTORY_ROOT);
if (nameDirectory_recid == 0) throw new IOException("Collection not found");
HTree<String, Long> dir = fetch(nameDirectory_recid);
Long recid = dir.get(name);
if (recid == null) throw new IOException("Collection not found");
Object o = fetch(recid);
// we can not use O instance since it is not correctly initialized
if (o instanceof LinkedList2) {
LinkedList2 l = (LinkedList2) o;
l.clear();
delete(l.rootRecid);
} else if (o instanceof BTree) {
((BTree) o).clear();
} else if (o instanceof HTree) {
HTree t = (HTree) o;
t.clear();
HTreeDirectory n = (HTreeDirectory) fetch(t.rootRecid, t.SERIALIZER);
n.deleteAllChildren();
delete(t.rootRecid);
} else {
throw new InternalError("unknown collection type: " + (o == null ? null : o.getClass()));
}
delete(recid);
collections.remove(name);
dir.remove(name);
} catch (IOException e) {
throw new IOError(e);
}
}
/*
test this issue
http://code.google.com/p/jdbm2/issues/detail?id=2
*/
public void testHTreeClear() throws IOException {
final DBAbstract db = newDBCache();
final HTree<String, String> tree = (HTree) db.createHashMap("name");
for (int i = 0; i < 1001; i++) {
tree.put(String.valueOf(i), String.valueOf(i));
}
db.commit();
System.out.println("finished adding");
tree.clear();
db.commit();
System.out.println("finished clearing");
assertTrue(tree.isEmpty());
}
