https://felixcorpus.pages.dev/tags/systems/ Recent content in Systems on felix corpus Hugo en Sat, 10 Oct 2026 00:00:00 +0000 https://felixcorpus.pages.dev/projects/bittorrent-client/ Sat, 10 Oct 2026 00:00:00 +0000 https://felixcorpus.pages.dev/projects/bittorrent-client/ <p>A BitTorrent client written from scratch in C++, built bottom-up to show a complex protocol architecture turned into working software.</p> <ul> <li><strong>Done and validated:</strong> bencode decoder, .torrent abstraction, HTTP tracker manager (libcurl multi-socket inside a libev event loop, with reannounce and backoff), and a connection manager that completes BEP 3 handshakes with live peers.</li> <li><strong>In progress:</strong> the transfer manager (peer wire messages, piece selection and hashing), then the file manager.</li> <li><strong>Design:</strong> two-thread peer/transfer architecture with SPSC queues and <code>ev_async</code> handoffs, a ring-buffer transport using scatter-gather <code>recvmsg</code>/<code>sendmsg</code>, and rarest-first piece selection. Checked under AddressSanitizer and UBSan.</li> </ul> <p>Link the repository here.</p>