hyperhive/hive-jobq
Repository files (latest commit first)
Filename Latest commit message Latest commit date
atlas b9aab7e923 refactor(#2808): the wire state enum is the scheduler's own
`hive_host_sock::jobs::State` was a hand-maintained copy of
`hive_jobq::State` — five variants spelled the same in both, kept in sync
by whoever remembered. Adding `Skipped` last week meant adding it twice.
The wire crate now re-exports the scheduler's enum and `to_wire_state` is
gone.

Two states that were hidden now reach clients. `to_wire_state` renamed
`Pending` to `Queued` and folded `Finishing` into `Running`, so the
dashboard could not distinguish a node waiting on its dependencies from
one whose own work is done while its sub-nodes still run. Both are now
visible, and consumers say which they mean.

Every consumer had to move with it, and only the Rust ones said so: the
exhaustive matches in `hivectl` and `DagView::rollup_state` failed to
compile, while the dashboard's fourteen string comparisons would have
gone quietly wrong — a `finishing` node no longer counting as running,
a `pending` node no longer as queued.

The frontend also builds CSS class names out of the state string
(`rqe-` + state, `rqe-node-` + state) and keys its glyph map on it, all
lowercase. Those go through a `stateSlug` helper now; comparisons use the
wire spelling, presentation lowercases. Without that split every queue
entry and node chip would have silently lost its styling.

Dropping the `State as JobState` alias in hive-c0re falls out of this:
the alias only existed to tell two `State` types apart, and there is one
now.
2026-07-27 21:50:24 +02:00
..
src refactor(#2808): the wire state enum is the scheduler's own 2026-07-27 21:50:24 +02:00
Cargo.toml build(#2772): declare enumflags2 at the workspace level 2026-07-27 19:06:27 +02:00
README.md docs(#2627): add READMEs for hive-jobq + the socket wire crates 2026-07-23 12:34:22 +02:00

hive-jobq

A persistent job-DAG scheduler, extracted from hive-c0re's in-tree job_queue as a domain-agnostic library. It schedules a single persistent graph of nodes over named resources; it knows nothing about containers, rebuilds, or any hyperhive type — the node payload N and resource name R are both generic, so the caller supplies its own domain.

When to use it

Reach for this crate whenever you need to run a DAG of interdependent work items under bounded, named concurrency — the hive-c0re rebuild/lifecycle queue is the first consumer, but nothing here is specific to it. The caller defines the node kinds, wires deps, and supplies a runner; the scheduler decides what can start.

Model

One persistent graph for the whole system, not a DAG per job. Enqueuing inserts a self-contained sub-DAG and returns the new node ids; the scheduler runs a continuous loop, starting every node whose deps are satisfied:

  • Resource deps are named counting semaphores over a caller-chosen type R — e.g. build-slot (capacity N), agent/<name> (capacity 1), or any unconfigured name (capacity 1, created on use). A node acquires all its resource deps atomically at start (all-or-nothing) — no hold-and-wait, so no deadlock.
  • Node deps wait on another node per DepWhen: AfterOk needs success (a failed dep cancels the dependent), AfterAny only needs terminal.

A node carries two independent axes: its Deps (ordering + resource needs) and its parent (structural grouping). The parent chain, not the node edges, is what the scheduler consults for resource re-entrancy: a resource unit is held for the acquiring node plus its whole parent subtree, and a descendant needing a resource an ancestor already holds re-uses that grant (a re-entrant borrow, one branch at a time) rather than taking a fresh unit.

A NodeId is opaque, stable, and monotonic (safe to persist). The scheduler is single-threaded — it owns the resource table and mutates it directly.

Shape

  • Graph<N, R> — the persistent node store. insert mints ids and validates dep/parent references; set_state is the single state-transition choke point (and where each node's lifecycle timestamps — started_at / finished_at, DateTime<Utc> — are stamped).
  • Node<N, R>{ id, parent, payload, deps, state, started_at, finished_at, error }. All fields public; derives serde for persistence + the wire.
  • Scheduler<N, R> — drives the graph: settle() starts every ready node (acquiring resources atomically), complete(id, outcome) reports a finished node's result and rolls terminality up the parent chain, releasing grants once a subtree is done. Outcome::{Done, Failed(String)} — the failure reason rides Failed onto the node's error.
  • ResourceTable<R> — per-name capacities; unconfigured names default to capacity 1.

See the crate-root and scheduler module //! docs for the full borrow/release model.