pulp::playback::ProgramWireAutomationLaneRecord Struct Reference

instance_token is the producer's own AutomationProgram::instance_token() carried verbatim, because lane identity is not (lane_id, generation) alone. More...

#include <program_wire.hpp>

Public Attributes
std::uint64_t	lane_id = 0
std::uint64_t	generation = 0
std::uint64_t	instance_token = 0
	Nonzero always.
std::uint32_t	segment_first = 0
std::uint32_t	segment_count = 0
float	leading_value = 0.0f
std::uint8_t	target_kind = 0
std::uint8_t	evaluation_rate = 0
std::uint16_t	pad0 = 0
std::uint64_t	device_placement_id = 0
	Zero unless target_kind is DeviceParameter.
std::uint32_t	device_param_id = 0
	Zero unless target_kind is DeviceParameter.
std::uint8_t	mixer_parameter = 0
	Zero unless target_kind is TrackMixer.
std::uint8_t	pad1 [3] = {}

Detailed Description

instance_token is the producer's own AutomationProgram::instance_token() carried verbatim, because lane identity is not (lane_id, generation) alone.

In-process, AutomationCursor decides Unchanged on the lane key and the token together, so the token is what stops two different programs that share a key from being mistaken for one; a consumer computing Unchanged without it reaches the opposite answer to the cursor and renders a stale lane, silently, with no decode error to notice.

The objection this answers is that the token is a producer-process-local allocation counter, so a foreign one names nothing a consumer can look up. True, and beside the point: a consumer never compares a foreign token to one of its own. It compares two foreign tokens to each other, within one producer_epoch, where they came from the same counter and mean exactly what they mean in process. Across epochs they are indeed incomparable — and across epochs the epoch has already decided, so the token is not consulted.

Equality only. A larger token does not mean newer on the wire: ordering is (producer_epoch, generation)'s job, and a producer is free to publish programs compiled out of order. Zero is refused for the reason a zero epoch is — it would compare equal to every other zero and quietly merge two distinct programs into one — but at the decoder only, not at both ends like the epoch: AutomationProgram's constructor is private to the compiler, which always mints a nonzero token, so an encoder-side check would be unreachable. The decoder is where a foreign payload arrives, which is the end that needs it.

The incremental compiler reuses a lane's program when that lane did not change, so its token is stable across a publish that touched only its neighbours. Per-lane rather than per-publication is what preserves that: a consumer re-adopts the lanes that actually moved and keeps its cursor state for the rest.

Member Data Documentation

device_param_id

std::uint32_t pulp::playback::ProgramWireAutomationLaneRecord::device_param_id = 0

Zero unless target_kind is DeviceParameter.

device_placement_id

std::uint64_t pulp::playback::ProgramWireAutomationLaneRecord::device_placement_id = 0

Zero unless target_kind is DeviceParameter.

evaluation_rate

std::uint8_t pulp::playback::ProgramWireAutomationLaneRecord::evaluation_rate = 0

generation

std::uint64_t pulp::playback::ProgramWireAutomationLaneRecord::generation = 0

instance_token

std::uint64_t pulp::playback::ProgramWireAutomationLaneRecord::instance_token = 0

Nonzero always.

Comparable only against another token carrying the same producer_epoch, and only for equality.

lane_id

std::uint64_t pulp::playback::ProgramWireAutomationLaneRecord::lane_id = 0

leading_value

float pulp::playback::ProgramWireAutomationLaneRecord::leading_value = 0.0f

mixer_parameter

std::uint8_t pulp::playback::ProgramWireAutomationLaneRecord::mixer_parameter = 0

Zero unless target_kind is TrackMixer.

pad0

std::uint16_t pulp::playback::ProgramWireAutomationLaneRecord::pad0 = 0

pad1

std::uint8_t pulp::playback::ProgramWireAutomationLaneRecord::pad1[3] = {}

segment_count

std::uint32_t pulp::playback::ProgramWireAutomationLaneRecord::segment_count = 0

segment_first

std::uint32_t pulp::playback::ProgramWireAutomationLaneRecord::segment_first = 0

target_kind

std::uint8_t pulp::playback::ProgramWireAutomationLaneRecord::target_kind = 0

---

The documentation for this struct was generated from the following file:

• /home/runner/work/pulp/pulp/core/playback/include/pulp/playback/program_wire.hpp