opentracker/DESIGN, branch v2.2.0An open and free bittorrent tracker
https://erdgeist.org/gitweb/opentracker/atom?h=v2.2.02026-11-07T18:39:01ZUnify the peerlists for v4 and v62026-11-07T18:39:01ZDirk Englingerdgeist@erdgeist.org2026-11-07T18:39:01Zurn:sha1:589cb500fa5a6df13fa9634d0071922ec11fce17
This commit finishes what started with unifying v4 and v6 trackers, from then on, torrents
carried a peer list per family, with obvious redundancies. With the race to save memory,
these became burdening enough that now these peerlist pointers have been moved into a
single struct, holding both v4 and v6 peers in their respective ot_vectors, so the per-
torrent cost shrunk by another pointer's size.
Each peerlist also lost its peer count cache, as in most cases, it's trivial to load it
directly from the ot_vector's entry count. The seed counts that were kept per family only
to be aggregated later for every consumer, are also merged now.
Total savings depend on the tracker's actual load. In some corner cases, where only one
address family dominates the torrents, we actually use a few bytes more in the ot_vector
for the absent family, but even that mostly becomes noise: before it actually adds to the
memory load, the peer payload will be the deciding factor.
Most wins are on what often is experienced on trackers: A long tail of abandoned torrents
now needs eight fewer bytes, slipping into a smaller allocation unit on glibc's allocator.
Start to opentracker's memory requirements2026-11-07T02:55:27ZDirk Englingerdgeist@erdgeist.org2026-11-07T02:55:27Zurn:sha1:bbfd674e08c6b1fa4081f9c678fd220bead749d7
* peer lists for v4 and v6 are now lazily allocated and, more importantly, will be freed once there are no more peers
* The downloaded count is now per torrent and not per peer list anymore, moving in what was alignment loss, anyway
* The (now) per torrent downloaded and the per peer list peer and seed count shrunk from size_t to uint32_t
* A helper guards accesses to the peer and seed count to prevent null pointer dereferences
* The base time also shrank from time_t to uint32_t, minutes since the epoch currently fits in 25 bits
take -pie out of macos hardening build flags2026-11-06T19:30:27ZDirk Englingerdgeist@erdgeist.org2026-11-06T19:30:27Zurn:sha1:7792b7117bda76873ad8c5339d7441191c132703Enable RELRO everywhere than macos2026-11-06T18:09:43ZDirk Englingerdgeist@erdgeist.org2026-11-06T18:09:43Zurn:sha1:4a01fea4a96374a1359d43a280a236a3ea042a1cAdd hardening parameters to the default builds2026-11-06T18:03:30ZDirk Englingerdgeist@erdgeist.org2026-11-06T18:03:30Zurn:sha1:99a706ded2a79768ce5b850be0d4262d321aa296Add a wall clock helper so that statedumps can be written and re-read2026-11-06T13:24:04ZDirk Englingerdgeist@erdgeist.org2026-11-06T13:24:04Zurn:sha1:355c8ae57d582974f4f6a4ba42f635f2253b84a7Explain the cleaner exception in the wait mechanics2026-11-05T18:03:42ZDirk Englingerdgeist@erdgeist.org2026-11-05T18:03:42Zurn:sha1:7e4b607f628982229315b99d1ac7462512ea710cDocument the reasoning behind the udp not sending an error packet on blacklisted torrents2026-11-05T17:19:42ZDirk Englingerdgeist@erdgeist.org2026-11-05T17:19:42Zurn:sha1:3af4bf15995be50deaef7ced0d0e0fdc2fc35ba5Add the paragraph in the design decisions document2026-11-05T15:28:20ZDirk Englingerdgeist@erdgeist.org2026-11-05T15:28:20Zurn:sha1:50840b5e42f877a0d36d4341e8b949aae1069181Start describing design considerations for the startup (and teardown) order2026-11-05T15:06:27ZDirk Englingerdgeist@erdgeist.org2026-11-05T15:06:27Zurn:sha1:42806212195e30f298d4c9354d56442393bb38a5