Membrane.Pipeline.Action (Membrane Core v0.7.0) View Source
This module contains type specifications of actions that can be returned from pipeline callbacks.
Returning actions is a way of pipeline interaction with
other components and parts of framework. Each action may be returned by any
callback (except for Membrane.Pipeline.handle_shutdown/2, as it
does not support returning any actions) unless explicitly stated otherwise.
Link to this section Summary
Types
Action that sends a message to a child identified by name.
Action that sets Logger metadata for the pipeline and all its descendants.
Action that stops, unlinks and removes specified child/children from the pipeline.
Action that instantiates children and links them according to Membrane.ParentSpec.
Starts a timer that will invoke Membrane.Pipeline.handle_tick/3 callback
every interval according to the given clock.
Stops a timer started with start_timer_t/0 action.
Type describing actions that can be returned from pipeline callbacks.
Changes interval of a timer started with start_timer_t/0.
Link to this section Types
Specs
forward_t() ::
{:forward,
{Membrane.Child.name_t(), any()} | [{Membrane.Child.name_t(), any()}]}
Action that sends a message to a child identified by name.
Specs
log_metadata_t() :: {:log_metadata, Keyword.t()}
Action that sets Logger metadata for the pipeline and all its descendants.
Uses Logger.metadata/1 underneath.
Specs
remove_child_t() ::
{:remove_child, Membrane.Child.name_t() | [Membrane.Child.name_t()]}
Action that stops, unlinks and removes specified child/children from the pipeline.
Specs
spec_t() :: {:spec, Membrane.ParentSpec.t()}
Action that instantiates children and links them according to Membrane.ParentSpec.
Children's playback state is changed to the current pipeline state.
Membrane.Pipeline.handle_spec_started/3 callback is executed once it happens.
Specs
start_timer_t() ::
{:start_timer,
{timer_id :: any(), interval :: Ratio.t() | non_neg_integer() | :no_interval}
| {timer_id :: any(),
interval :: Ratio.t() | non_neg_integer() | :no_interval,
clock :: Membrane.Clock.t()}}
Starts a timer that will invoke Membrane.Pipeline.handle_tick/3 callback
every interval according to the given clock.
The timer's id is passed to the Membrane.Pipeline.handle_tick/3
callback and can be used for changing its interval via timer_interval_t/0
or stopping it via stop_timer_t/0.
If interval is set to :no_interval, the timer won't issue any ticks until
the interval is set with timer_interval_t/0 action.
If no clock is passed, pipeline clock is chosen.
Timers use Process.send_after/3 under the hood.
Specs
stop_timer_t() :: {:stop_timer, timer_id :: any()}
Stops a timer started with start_timer_t/0 action.
This action is atomic: stopping timer guarantees that no ticks will arrive from it.
Specs
t() :: forward_t() | spec_t() | remove_child_t() | log_metadata_t() | start_timer_t() | timer_interval_t() | stop_timer_t()
Type describing actions that can be returned from pipeline callbacks.
Returning actions is a way of pipeline interaction with its children and other parts of framework.
Specs
timer_interval_t() ::
{:timer_interval,
{timer_id :: any(), interval :: Ratio.t() | non_neg_integer() | :no_interval}}
Changes interval of a timer started with start_timer_t/0.
Permitted only from Membrane.Pipeline.handle_tick/3, unless the interval
was previously set to :no_interval.
If the interval is :no_interval, the timer won't issue any ticks until
another timer_interval_t/0 action. Otherwise, the timer will issue ticks every
new interval. The next tick after interval change is scheduled at
new_interval + previous_time, where previous_time is the time of the latest
tick or the time of returning start_timer_t/0 action if no tick has been
sent yet. Note that if current_time - previous_time > new_interval, a burst
of div(current_time - previous_time, new_interval) ticks is issued immediately.