samiandClaude Sonnet 5
6163898c14
HttpClient::Impl::drain_commands() default-constructed a std::deque<Command> every call, on every iteration of the worker thread's event loop (once per curl_multi_poll wake -- i.e. once per socket-readiness event on the transfer hot path), then swapped the (usually empty) command queue into it. In libstdc++, an empty std::deque still allocates its map array on construction, so this was a real allocation on the hot path regardless of whether any command (add/pause/resume/cancel) was actually pending -- which is the common case, since those are rare next to data arriving. Found via tools/bench's alloc-check, which is built in this change and exists specifically to catch this class of bug (AGENT-CORE.md: "no allocation in the curl write callback... checked in review and by a bench assertion"): before this fix it reported thousands of allocations/sec under a sustained transfer; after, single digits. Fixed by checking `w.queue.empty()` under the lock before touching `local` at all, so the deque is only constructed when there's actually something to swap into it. Co-Authored-By: Claude Sonnet 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Q3QrF7rCt21bkAjt9BCDFQ
Velox Download Manager (VDM)
An IDM-class download manager for Ubuntu 26.04 LTS: multi-segment accelerated HTTP(S) downloading, resume, categories and automatic file distribution, queues and scheduler, speed limiter, a Firefox extension that captures downloads automatically, and clipboard link capture.
Name is a placeholder. Binaries are
veloxd,velox-gui,velox,velox-nmhost. Rename before first release if you want something else — do it in M0, never later.
Status
Phase M0 — scaffolding. No implementation code exists yet. This repository currently contains the architecture, the wire contract, the roadmap, and one brief per build lane so that several agents can work in parallel without colliding.
Start here:
| Document | What it answers |
|---|---|
| docs/01-architecture.md | Process model, why four binaries, framework choices and why |
| docs/02-roadmap.md | Milestones M0–M7, what runs in parallel, exit gates |
| docs/03-gui-spec.md | IDM-parity UI: every window, dialog, column, menu |
| docs/04-engine-design.md | Segmentation, resume, buffers, rate limiting, disk I/O |
| docs/05-extension-spec.md | Firefox capture, transports, pairing, media grabber |
| docs/06-risks-and-spikes.md | Snap Firefox, Wayland clipboard, and the other landmines |
| docs/07-packaging.md | .deb/PPA, Flatpak, AMO signing, install layout |
| contracts/README.md | The interface. Both sides build against this |
| CLAUDE.md | Rules of engagement for agents working in this repo |
Per-lane briefs live in docs/agents/ — one per agent, each with an owned directory list, a definition of done, and the files it must never touch. To dispatch the agents, use docs/agents/PROMPTS.md — six copy-paste prompts plus the worktree commands and the wave order.
Architecture in one picture
┌────────────────────┐ native messaging (stdio JSON) ┌──────────────┐
│ Firefox extension │◄───────────── or ──────────────►│ velox-nmhost │
│ (MV3, TS) │ loopback WS 127.0.0.1 + token └──────┬───────┘
└────────────────────┘ │
│
┌────────────────────┐ ▼
│ velox-gui (Qt 6) │◄──── JSON-RPC 2.0 over Unix socket ──► ┌─────────────┐
└────────────────────┘ $XDG_RUNTIME_DIR/velox/velox.sock │ veloxd │
│ (daemon) │
┌────────────────────┐ │ │
│ velox (CLI) │◄───────────────────────────────────────┤ libveloxcore│
└────────────────────┘ └──────┬──────┘
│
SQLite + sparse files
The daemon owns all state and all sockets. The GUI is a view — closing it does not stop a download. The extension never touches the disk; it hands URL + headers + cookies to the daemon and gets a task id back.
Repository layout
vdm/
├── contracts/ ⭐ Wire contract: JSON Schema, fixtures, codegen. Frozen per version.
├── core/ C++23 libveloxcore — engine. No UI, no RPC, no SQL.
├── daemon/ C++23 veloxd — RPC server, scheduler, queues, SQLite store.
├── gui/ C++23 velox-gui — Qt 6 Widgets, IDM-parity UI.
├── cli/ C++23 velox — scriptable client.
├── nmhost/ C++23 velox-nmhost — Firefox native-messaging bridge (thin pipe).
├── extension/ TS Firefox MV3 WebExtension.
├── tools/
│ ├── mockd/ TS mock daemon — lets GUI + extension work before veloxd exists.
│ ├── testserver/ Deliberately hostile HTTP server (no Range, flaky, redirects, auth).
│ ├── bench/ Throughput and CPU benchmarks.
│ └── fuzz/ libFuzzer targets for parsers.
├── tests/
│ ├── conformance/ Protocol suite. Every lane must pass it. Gate for merging.
│ ├── integration/ veloxd + testserver.
│ └── e2e/ Playwright: real Firefox + real daemon + real file on disk.
├── packaging/ debian/, flatpak/, appimage/, native-host manifests.
└── docs/ Everything above, plus adr/ and agents/.
Toolchain bootstrap
Surveyed on this machine 2026-09-09 — most of it is already installed:
| Present | Version |
|---|---|
| git · cmake · ninja · g++ · gdb | 2.53.0 · 4.2.3 · — · 15.2.0 (C++23 ready) |
| qt6-base-dev · qt6-tools-dev · qt6-tools-dev-tools | ✓ |
| libcurl4-openssl-dev · libsqlite3-dev · nlohmann-json3-dev · libssl-dev | ✓ |
| libavformat-dev · libavcodec-dev · ffmpeg | ✓ |
| clang-format · clang-tidy · python3 · pkg-config | ✓ |
| python3-jsonschema · python3-referencing (conformance static runner) | ✓ |
Only these four are missing:
sudo apt update && sudo apt install -y \
qt6-svg-dev \ # GUI: SVG icon rendering
libsecret-1-dev \ # DAEMON: Secret Service for site logins
nodejs npm \ # EXT + PROTO: extension build, mockd, conformance runner
clang # optional: libFuzzer targets in M7
Node in the 26.04 archive may lag; if the extension toolchain needs 22+, use nvm.
Verify with cmake --preset dev && cmake --build --preset dev once lane CORE lands its
first target. Note CMake 4.2.3 is installed — newer than the 3.28 floor in
CMakeLists.txt, and it hard-errors on cmake_minimum_required below 3.5, so no
dependency may ship a pre-3.5 CMake file.