/**
* Returns a set containing all collections in the existing database.
*
* @return an set of names
* @throws MongoException
*/
public Set<String> getCollectionNames() {
DBCollection namespaces = getCollection("system.namespaces");
if (namespaces == null) throw new RuntimeException("this is impossible");
Iterator<DBObject> i =
namespaces.__find(
new BasicDBObject(), null, 0, 0, 0, getOptions(), getReadPreference(), null);
if (i == null) return new HashSet<String>();
List<String> tables = new ArrayList<String>();
for (; i.hasNext(); ) {
DBObject o = i.next();
if (o.get("name") == null) {
throw new MongoException("how is name null : " + o);
}
String n = o.get("name").toString();
int idx = n.indexOf(".");
String root = n.substring(0, idx);
if (!root.equals(_name)) continue;
if (n.indexOf("$") >= 0) continue;
String table = n.substring(idx + 1);
tables.add(table);
}
Collections.sort(tables);
return new LinkedHashSet<String>(tables);
}
DBObject isMasterCmd() {
DBCollection collection = _mongo.getDB("admin").getCollection("$cmd");
Iterator<DBObject> i = collection.__find(_isMaster, null, 0, 1, 0);
if (i == null || !i.hasNext()) throw new MongoException("no result for ismaster query?");
DBObject res = i.next();
if (i.hasNext()) throw new MongoException("what's going on");
return res;
}