No description
Rongsong Shen
40196be2e5
Measured sustained worker-fact throughput against the pre-feature baseline. Commit throughput is unregressed (~2.5% delta, within noise) and no per-fact synchronous commit barrier exists, confirming Req 11.4's core claim. But apply/observable throughput -- the new hop this spec introduces -- regressed 56% with clearly superlinear scaling (2x volume -> 5.2x elapsed). Root cause: apply_pump_read_entry has no memory across calls -- every LSN lookup re-lists WAL segments and rescans its segment from byte 0 -- while its only caller applies committed entries one at a time in strict ascending order, turning a sequential access pattern into O(n^2) total work. Fixed with a minimal segment-read cache on persist_t (fd + offset + expected next LSN, guarded by the existing apply_pump_lock): a fast path reads the next expected LSN directly at a remembered offset, falling back unchanged to full rediscovery on any miss. Correctness never depends on the cache, only performance does. Invalidated on init, fini, recovery, and WAL truncation -- the four points a stale cursor could otherwise misread from. Two review rounds: round 1 caught a missing lock guard in the recovery invalidation path and an inaccurate risk claim about the cache/trim interaction (a real, bounded behavior change deferred to the existing APPLY_DIVERGENT fence, not "no worse than before") -- both corrected and re-verified in round 2. Post-fix apply-throughput scales sublinearly (1.46x elapsed for 2x volume) and exceeds the pre-feature baseline. Zero new test failures across the pump, correctness-verification, recovery, and truncation groups. An intermittent, pre-existing client hang in the synchronous jobsub path and a trim-floor/apply-lag architectural gap were surfaced but are explicitly out of scope for this fix -- flagged for separate follow-up. |
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|---|---|---|
| .claude | ||
| .kiro | ||
| .wolf | ||
| docs/superpowers/plans | ||
| ha/data | ||
| raft | ||
| reports | ||
| src | ||
| .clang-format | ||
| .gitignore | ||
| .mcp.json | ||
| .opencode.json | ||
| CLAUDE.md | ||
| README.md | ||
| uninstall-code-review-graph.sh | ||
1. commit 规则
- 每个人 fork 自己的 branch， 从自己的 branch 做 PR，review 完再 commit
2. code format
2.1. C
推荐使用 clang-format，公共配置放在源码里面 xce/.clang-format
（理论上直接使用源码里面 xce/.clang-format 文件格式不会变）
2.1.1. vscode 可以在配置中加上如下内容
"C_Cpp.clang_format_style": "WebKit",
"C_Cpp.clang_format_fallbackStyle": "WebKit",
2.1.2. vim & emacs
clang-format -style="{BasedOnStyle: webkit}" -i XX.c
2.2. golang
使用默认 gofmt
3. build environment and build (example of ubuntu)
3.1 build environment
- Install nix package management tool
sh <(curl -L https://nixos.org/nix/install) --daemon
- Edit /etc/nix/nix.conf to make sure
experimental-features = nix-command flakes
sandbox = true
sandbox-fallback = false
substituters = https://mirrors.ustc.edu.cn/nix-channels/store https://cache.nixos.org https://cache.nixos.org/
trusted-users = root <your account>
make sure that you have restarted nix-daemon service after you have changed /etc/nix/nix.conf
- Install socat and config ssh (for clone by ssh protocol)
nix profile add nixpkgs#socat
.ssh/config
Host gitea.shenrs.eu
HostName gitea.shenrs.eu
IdentityFile ~/.ssh/id_ed25519
ProxyCommand socat - openssl-connect:gitea.shenrs.eu:2022,snihost=gitea.shenrs.eu,verify=0
3.2 checkout source code
3.3 build (for package and release)
cd xce/src
# for build debug version
nix build --option sandbox false .#xcecore_debug
# for normal build
nix build --option sandbox false .#xcecore
You can find the generated binaries at =result= directory
3.4 build (for daily develop)
cd xce/src
nix develop
# using meson to generated build configuration (debug and address sanitize)
meson setup build --buildtype=debug -Db_sanitize=address
# run meson to build
meson compile -C build
# The generated files will be in build/
3.5 build AppImage package
cd xce/src
nix bundle --bundler github:ralismark/nix-appimage --option sandbox false .#xce
This will create all in one AppImage file which contains everything for package delivery.
4. misc
4.1. Windows remap ctrl and alt key
create a reg file, e.g. remapkey.reg
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Keyboard Layout]
"Scancode Map"=hex:00,00,00,00,00,00,00,00,05,00,00,00,38,00,1d,00,1d,00,38,00,38,e0,1d,e0,1d,e0,38,e0,00,00,00,00
then double click remapkey.reg to import it. Restart OS.