ddidderr
0f10108438
Centralize the bulk-transfer sizing in config.rs and bump the values used
on both ends of a QUIC connection:
- CHUNK_SIZE: 32 MiB -> 128 MiB
- QUIC_CONNECTION_DATA_WINDOW: 64 MiB -> 256 MiB
- QUIC_STREAM_DATA_WINDOW: 32 MiB -> 128 MiB
- QUIC_MAX_SEND_BUFFER_SIZE: 32 MiB -> 128 MiB
- QUIC_INITIAL_CONGESTION_WINDOW: 1 MiB -> 4 MiB
- FILE_TRANSFER_BUFFER_SIZE: 64 KiB -> 1 MiB (new constant)
The previous 32 MiB stream window was already comfortably above the
bandwidth-delay product of a sub-millisecond LAN at 2.5 GbE. The further
bump is deliberately generous: the goal is to push flow control and
per-syscall overhead far enough out of the way that they cannot be the
suspect when isolating the remaining LAN download bottleneck (disk, NIC,
or s2n-quic platform offload on the sending host). Memory pressure from
the larger windows is not observable on a desktop client moving GB-sized
games.
stream_file_bytes previously read the local file in 64 KiB chunks. At
multi-Gbit/s send rates that produced many thousands of disk reads per
second; bumping to 1 MiB keeps the per-file syscall load modest with no
measurable latency cost on streamed bulk transfers. The buffer size lives
in config.rs as FILE_TRANSFER_BUFFER_SIZE so it stays adjustable from one
place.
Also add a started/MiB-per-second log line at info level when a file
finishes streaming. This matches the S37 measurement methodology already
used in the peer-cli harness and makes per-file send throughput visible in
normal operation.
The peer-cli extended-scenarios harness uses CHUNK_SIZE as the tolerance
bound for chunk-boundary variance in its assertions, so its constant is
bumped to match. The multi-chunk planning unit test is rewritten to
reference CHUNK_SIZE symbolically (CHUNK_SIZE * 3 + CHUNK_SIZE / 2)
instead of a hardcoded 120 MiB; the previous literal would silently
degrade into a single-chunk test at the new chunk size and stop
exercising the spread-across-peers code path.
Test Plan:
- just fmt
- just clippy
- just test
- python3 crates/lanspread-peer-cli/scripts/run_extended_scenarios.py S37 \
--build-image
- python3 crates/lanspread-peer-cli/scripts/run_extended_scenarios.py S37
Refs: local LAN download performance investigation on 2026-05-20.
Depends-on: d7f7dc737e (QUIC UDP socket buffer sizing).
lanspread-peer-cli
Scriptable peer harness for automated LAN-spread tests. The binary starts the core peer runtime without the Tauri GUI, reads one JSON command per stdin line, and writes JSONL events, results, and errors to stdout.
Running
just peer-cli-build
just peer-cli-image
just peer-cli-run alpha
Useful flags:
--games-dir PATHstores local archives and installs.--state-dir PATHstores the generated peer identity.--fixture GAME_IDseeds a tiny archive that the fixture unpacker can install.
Fixture Game Directories
fixtures/fixture-alpha, fixtures/fixture-bravo, and
fixtures/fixture-charlie are ready-to-use game directories for local CLI
smoke tests. Point --games-dir at one of them to start a peer with several
catalog-backed fake games. Each game includes version.ini and a real RAR
archive renamed to .eti; fixture-alpha and fixture-bravo share ggoo,
while fixture-bravo and fixture-charlie share cnc4.
Commands
Every command is a JSON object with cmd or command; id is optional and is
echoed back on the result or error line.
{"id":"s1","cmd":"status"}
{"id":"p1","cmd":"wait-peers","count":1,"timeout_ms":5000}
{"id":"c1","cmd":"connect","addr":"127.0.0.1:34567"}
{"id":"g1","cmd":"list-games"}
{"id":"d1","cmd":"download","game_id":"fixture-one","install":true}
{"id":"i1","cmd":"install","game_id":"fixture-one"}
{"id":"u1","cmd":"uninstall","game_id":"fixture-one"}
{"id":"q1","cmd":"shutdown"}