The peer listener died with "Too many open files (os error 24)" on any
long-lived non-daemon session: only the daemon raised RLIMIT_NOFILE, and
peer sockets were unbounded — no idle reaping, no deadlines on accepted
transfer streams, and one peer could hold two connections under split
registry identities.
- raise the open-file limit at the top of run(), for every entry point,
and warn from Client::connect when the soft limit is below 1024
- reap peer control connections idle for five minutes; a clean
disconnect no longer discards the peer's queued uploads
- give listener-supplied download streams and upload serving the same
read/write deadlines dialled sockets already had
- register inbound peers under their plain username so the registry
holds one connection per peer, and announce them like pierced ones
- hold the registry lock across actor spawn + insert and surface
thread-spawn failure, so an instantly-dead peer cannot leave a
zombie entry
The slot cap merged from master defaults to 2 uploads, and the CLI capped
downloads at 5. Those are the numbers you pick when your own bandwidth is the
scarce resource, but a Soulseek transfer is paced by the peer on the other end
— usually a few hundred KiB/s — so what fills a modern link is many transfers
at once, not faster ones. Upload slots go to 10, downloads to 20. The queue
itself stays: privileged users being able to jump it is a condition of being a
tolerated third-party client.
serve_file also slept half a second after the last byte so the downloader could
drain before the socket closed. With a cap that is time no other peer can use,
and 64 uploads over 10 slots paid it six times over. A half-close says "that is
the whole file" and TCP still delivers everything written before the FIN.
Measured with 64 waiting peers: 2 slots 24.2s, 8 slots 6.2s, 32 slots 3.1s; at
10 slots the linger alone was 5.4s to 3.05s.
Downloads buffered the whole file in memory and wrote it out only on
success, so an interrupted transfer left nothing behind and always
started over. The START_DOWNLOAD offset was hardcoded to zero on the
download side and discarded on the upload side, so neither half of the
protocol's resume support was wired up.
Bytes now stream into `<file>.part` as they arrive and it is renamed
only once the file is whole. A new attempt sends the partial file's
length as the START_DOWNLOAD offset, and `serve_file` seeks to the
offset a peer asks for rather than replaying from the start. A `.part`
at or past the expected size is treated as stale and restarted.
Partial files are kept out of the share index, since the download
directory is shared by default.
serve_file streams in chunks, updating a shared byte counter and
aborting with Interrupted when a cancel flag is set. Each served upload
is registered (peer, virtual path, size, live progress, status) and
exposed via Client::uploads(); Client::cancel_upload flags a matching
in-progress transfer. e2e: the download test now also asserts the
uploader recorded a completed upload with the right peer and byte
count.
Implement the upload path so a peer can download our shared files:
- fix the mis-coded PlaceInQueueResponse (43 -> 44) and add a real QueueUpload
handler (code 43) -> PeerMessage::IncomingQueueUpload;
- the peer actor forwards it as ClientOperation::QueueUpload; the client looks
the file up in its shares, mints an upload token (high half of the token
space, disjoint from md5 download tokens), and offers it via ServeUpload ->
build_upload_transfer_request (peer code 40, direction=upload);
- a TransferResponse for one of our serving tokens is handled by a surgical
early-return that emits StartUpload, leaving the download path untouched;
- StartUpload resolves the downloader's address (GetPeerAddress, cached) and
streams the file via a new peer::upload_peer::serve_file over an F connection.
Tested: build_upload_transfer_request decodes via the production Transfer
parser; serve_file streams a file correctly over a loopback F connection.
Michel de Graaf