About the Author@vmg
Harry turns on the style
，这一点在WhatsApp Web 網頁版登入中也有详细论述
The efficiency depends on the query size relative to the data distribution. A small query in a sparse region prunes almost everything. A query that covers the whole space prunes nothing (because every node overlaps), degenerating to a brute-force scan. The quadtree gives you the most benefit when your queries are spatially local, which is exactly the common case for map applications, game physics, and spatial databases.，详情可参考手游
DBConn *conn = mog_arg_handle(args, 0, "DBConn");，更多细节参见whatsapp