Feline.Processor behaviour (feline v0.1.0-rc.1)

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Behaviour for pipeline processors.

Each processor implements callbacks to receive frames, transform them, and push results downstream or upstream. Use use Feline.Processor to adopt the behaviour and generate a child_spec/1 that wraps the module in a Feline.Processor.Server GenServer.

Callbacks

  • init/1 — initialize processor state from keyword options
  • handle_frame/4 — process a frame, return {:ok, state}, {:push, frame, direction, state}, or {:push_many, frames, state}
  • handle_info/3 — handle non-frame messages (optional)
  • handle_setup/2 — called once after pipeline linking (optional)
  • handle_cleanup/1 — called on processor shutdown (optional)

Summary

Types

direction()
push_fn()
state()

Callbacks

handle_cleanup(state)
handle_frame(frame, direction, push_fn, state)
handle_info(msg, push_fn, state)
handle_setup(setup, state)
init(opts)

Functions

link(processor, next_processor)
queue_frame(pid, frame, direction \\ :downstream)
setup(pid, setup)

Types

direction()

@type direction() :: :downstream | :upstream

push_fn()

@type push_fn() :: (struct(), direction() -> :ok)

state()

@type state() :: term()

Callbacks

handle_cleanup(state)

(optional) 
@callback handle_cleanup(state()) :: :ok

handle_frame(frame, direction, push_fn, state)

@callback handle_frame(frame :: struct(), direction(), push_fn(), state()) ::
  {:ok, state()}
  | {:push, struct(), direction(), state()}
  | {:push_many, [{struct(), direction()}], state()}

handle_info(msg, push_fn, state)

(optional) 
@callback handle_info(msg :: term(), push_fn(), state()) :: {:ok, state()}

handle_setup(setup, state)

(optional) 
@callback handle_setup(setup :: map(), state()) :: {:ok, state()}

init(opts)

@callback init(opts :: keyword()) :: {:ok, state()}

Functions

link(processor, next_processor)

queue_frame(pid, frame, direction \\ :downstream)

setup(pid, setup)