Struct UserLabels 

pub struct UserLabels<const E: usize, const N: usize = 4> { /* private fields */ }

Shared registry of every endpoint’s UserLabel LabelList.

Persisted as a single TLV blob under USER_LABELS_KEY — every successful write to any UserLabelHandler re-serialises the whole registry and stores it. Read paths take the lock briefly to copy labels into the TLV builder.

Const generics:

• E — max number of endpoints that may have a LabelList. Bound on the in-memory Vec of per-endpoint slots.
• N — max number of LabelEntry rows per endpoint. Bound on each slot’s inner Vec. Defaults to 4.

Lock holds are bounded — the Mutex<RefCell<_>> is never held across an .await, so the registry is sound under a work-stealing executor.

Implementations

impl<const E: usize, const N: usize> UserLabels<E, N>

pub const fn new() -> UserLabels<E, N>

Create an empty registry. It is populated from KV at startup via Self::load_persist, driven by the LifecycleOp::Startup lifecycle operation delivered to the data model.

Prefer Self::init for non-trivial E * N so the registry’s storage can be initialised in-place (typically in a StaticCell) instead of being constructed on the stack and moved. The two paths produce structurally identical instances.

pub fn init() -> impl Init<UserLabels<E, N>>

Return an in-place initialiser for an empty registry. Use this when E * N * size_of::<LabelEntry> is large enough that stack-constructing a Self::new instance and moving it into long-lived storage would overflow the stack or bloat .rodata. Typical usage:

static USER_LABELS: StaticCell<UserLabels<8, 4>> = StaticCell::new();
let user_labels = USER_LABELS.uninit().init_with(UserLabels::init());

pub fn load_persist<S>(&self, store: S, buf: &mut [u8]) -> Result<(), Error>

where S: KvBlobStore,

Re-hydrate the registry from store under USER_LABELS_KEY, so subsequent reads see the labels written before the last reboot.

Called on startup via the LifecycleOp::Startup lifecycle operation delivered to the UserLabelHandler instance(s) borrowing this registry.

Missing key (first boot, or persistence cleared) is not an error — the registry simply stays empty.

pub fn reset_persist<S>(&self, store: S, buf: &mut [u8]) -> Result<(), Error>

where S: KvBlobStore,

Reset the registry to empty and remove its persisted blob from store (under USER_LABELS_KEY).

Called on factory reset via the LifecycleOp::FactoryReset lifecycle operation delivered to the UserLabelHandler instance(s) borrowing this registry.

Trait Implementations

impl<const E: usize, const N: usize> Default for UserLabels<E, N>

fn default() -> UserLabels<E, N>

Returns the “default value” for a type.