Kathikon.Job.StateMachine (Kathikon v0.2.0)

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Validates job state transitions for Kathikon v0.2.0.

Invalid transitions return {:error, {:invalid_transition, from, to}}. Terminal states reject all outbound transitions.

Allowed transitions

scheduled -> available
scheduled -> cancelled
available -> claimed
available -> cancelled
claimed -> running
claimed -> cancelled
running -> completed
running -> retryable
running -> failed
running -> waiting_for_children
waiting_for_children -> completed
waiting_for_children -> failed
retryable -> scheduled
retryable -> available
failed -> dead
failed -> discarded

Claiming also moves :retryable jobs to :claimed when they are due.

Summary

Functions

allowed?(from, to)

Returns true when to is allowed from from.

reachable_from(state)

Returns the list of states reachable from state.

states()

Returns all supported states.

terminal?(state)

Returns true when the job is in a terminal state.

transition(from, to)

Validates a transition. Returns :ok or {:error, {:invalid_transition, from, to}}.

Functions

allowed?(from, to)

@spec allowed?(atom(), atom()) :: boolean()

Returns true when to is allowed from from.

reachable_from(state)

@spec reachable_from(atom()) :: [atom()]

Returns the list of states reachable from state.

states()

@spec states() :: [atom()]

Returns all supported states.

terminal?(state)

@spec terminal?(atom()) :: boolean()

Returns true when the job is in a terminal state.

transition(from, to)

@spec transition(atom(), atom()) ::
  :ok | {:error, {:invalid_transition, atom(), atom()}}

Validates a transition. Returns :ok or {:error, {:invalid_transition, from, to}}.