FallbackStreamFunction class final

A StreamFunction over an ordered ChainEntry list with omp's rate-limit policy: rotate keys for free, retry the entry with capped exponential backoff, then fail over to the next entry — every step announced through onNotice.

One instance is stateful and long-lived (a session): entry cooldowns and the activeIndex persist across calls, and a later call starts at the first entry not in cooldown (omp's cooldown-expiry revert policy — the primary model is retried once its cooldown lapses).

Constructors

FallbackStreamFunction({required List<ChainEntry> entries, ModelRolesRetryPolicy policy = const ModelRolesRetryPolicy(), void onNotice(FallbackNotice notice)?, DateTime now()?, double jitterFraction()?, Future<bool> sleeper(Duration delay, CancelToken? cancelToken)?, QueueDeathClassifier? queueClassifier, ProviderQueueState? queueState})
Creates the wrapper. entries must be non-empty. jitterFraction and sleeper are injectable for deterministic tests.

Properties

activeIndex → int
The chain entry the last call started on (display state for /model).
no setter
currentModel → Model
The model currently considered primary for this chain (first entry not in cooldown).
no setter
hashCode → int
The hash code for this object.
no setterinherited
length → int
The chain entry count.
no setter
onNotice → void Function(FallbackNotice notice)?
Receives a FallbackNotice before every retry/rotation/failover.
final
policy → ModelRolesRetryPolicy
Retry/fallback knobs.
final
queueClassifier → QueueDeathClassifier?
The queue death classifier (issue #418); null in roles mode.
final
queueState → ProviderQueueState?
The queue's sticky cursor + per-entry health; null in roles mode.
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

call(Model model, Context context, {CancelToken? cancelToken}) → AssistantMessageEventStream
The StreamFunction entry point. The passed model is ignored — the chain position decides which model is called (the loop passes its configured model; the resolver keeps AgentState.model in sync).
cooldownRemaining(int index) → Duration?
Remaining cooldown of entry index, or null when not cooling down.
isInCooldown(int index) → bool
Whether chain entry index is cooling down right now.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toString() → String
A string representation of this object.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited