For the M7 RSS gap (core/docs/m7-baseline.md: ~70 MB measured vs ADR 0012's ~45-50 MB estimate) -- "find where before tuning anything". No root here to install massif or heaptrack, so this is a small in-process equivalent: operator new/delete (already overridden for alloc-check's counter) now also track, per call site (one return address via __builtin_return_address(0), cheap enough to run for a whole scenario), live (not-yet-freed) bytes. Runs the same 20-task concurrent scenario as `load`, waits for peak RSS to stop growing, then prints the top sites by live bytes -- resolved via one batched addr2line invocation against /proc/self/exe (dladdr alone only resolves dynamic-symbol-table entries, which misses most of this codebase's internal-linkage call sites), with dladdr as a per-site fallback. Also adds the nothrow operator new/delete overloads alongside the existing plain ones: without them, anything that allocates via the nothrow form (e.g. std::stable_sort's std::get_temporary_buffer, hit once while investigating the RSS gap) falls through to ASan's own default nothrow new while still being freed through this file's plain delete override -- an alloc-dealloc-mismatch ASan correctly flags as a real ABI-level bug in an allocator override that claims to intercept "everything". Using this tool, sum(effective_segments) across all 20 tasks vs. Engine::segment_budget().budget() (now cross-checked and printed together) showed the budget hands out well more than max_active_segments -- the actual root cause, in core/src/segment/budget.cpp, not covered by this commit. 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.