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); } }
/** * Obtain the record id of a named object. Returns 0 if named object doesn't exist. Named objects * are used to store Map views and other well known objects. */ protected synchronized long getNamedObject(String name) throws IOException { long nameDirectory_recid = getRoot(NAME_DIRECTORY_ROOT); if (nameDirectory_recid == 0) { return 0; } HTree<String, Long> m = fetch(nameDirectory_recid); Long res = m.get(name); if (res == null) return 0; return res; }