The download entry point the AGENT-CORE brief asked for on day one and
that slipped. DAEMON has an RPC surface and a store and, until this is
agreed, nothing in velox::core to call.
vdm/task/download.hpp — DownloadSpec (the resolved subset DAEMON hands in:
absolute save_path, verbatim browser headers, requested segments/buffer,
optional probe_hint / checksum / auth, allow_resume), EngineState (the
CORE-owned subset of the wire TaskState), Progress / SegmentProgress,
DownloadCallbacks (on_progress <=4 Hz, on_state for every transition
incl. auto-pauses, on_auth_required, on_decision_needed, on_finished
last), DownloadHandle (pause/resume/cancel — idempotent per the ADR 0013
signature — plus provide_auth / decide / refresh_url, and synchronous
state()/progress() snapshots).
vdm/engine.hpp — Engine: start(spec, callbacks) -> handle, segment_budget()
(DAEMON's sched/ admission surface, ADR 0011), live connection.* setters,
a standalone probe() on the pool outside the segment budget.
core/docs/engine-api-m1.md — the review doc: field semantics, the state
machine, threading/lifetime rules (which thread callbacks arrive on, what
is legal from inside one, handle/engine lifetime), the shared-`paused`
idempotency contract as a signature, and five open questions for DAEMON.
Value types compile and are covered by api_compiles_test; Engine /
DownloadHandle bodies land in stage 8, built against whatever DAEMON
signs off here.
Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01HPPSGhiArbvQgwC2DNiURS
util/ carries no wire surface, so it lands before the contract freeze.
- error: enum class Error, the engine-wide failure taxonomy; is_retryable
enumerates every value (no default:) so -Wswitch forces the retry
decision on each future addition. ErrorInfo carries context/http_status.
- result: Result<T> over std::expected<T, ErrorInfo>, Result<void>,
VDM_TRY / VDM_TRY_ASSIGN. Errors returned, never thrown, on the
transfer path.
- bytes: span aliases, LE load_le/store_le (debug-asserted precondition,
not input validation), and a bounds-checked latching ByteReader for the
.veloxpart.meta reader.
- event_bus: typed thread-safe pub/sub; header states plainly that
unsubscribe is not a quiesce point and download_task will need its own
drain.
- thread_pool: std::jthread pool; dtor joins in the body before members
die (fixed a use-after-destruction on cv_/mu_). Header notes shutdown is
drain-only and DAEMON will need a cancel mode.
- log: sink interface (core does no I/O); DAEMON installs one.
Tested: -Werror clean, 6 binaries green under plain / ASan+UBSan / TSan.
Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01HPPSGhiArbvQgwC2DNiURS
samiandClaude Sonnet 5