MDB overview

To efficiently store messages on your device, Midlegram implements its very own message database (MessageDB, or MDB for short).

The overall structure of MDB is like this:

flowchart subgraph Fixed-length pivot data storage pd["Pivot descriptor & ToC"] fwds["Forward files \n(many)"] bcks["Backward files \n(many)"] pd --> fwds pd --> bcks end subgraph Variable-length data storage pgs["Page files \n(many)"] pg_idxs["Page indexes \n(for each page)"] toc["ToC"] toc --> pg_idxs pg_idxs --> pgs end subgraph File storage subgraph FS VLS fpgs["Page files \n(many)"] fpg_idxs["Page indexes \n(for each page)"] ftoc["ToC"] ftoc --> fpg_idxs fpg_idxs --> fpgs end fls["Files \n(many)"] fpgs --> fls end fwds --> ftoc fwds --> toc bcks --> ftoc bcks --> toc