Struct SnapshotSlot 

pub struct SnapshotSlot { /* private fields */ }

Shared handle to the published custom-state bytes. Held by the shell (producer, audio thread) and the format wrapper (consumer, host / GUI thread), both cloned from one Arc.

Implementations

impl SnapshotSlot

pub fn new() -> Arc<Self>

A fresh slot with its publish buffer pre-warmed to SNAPSHOT_PREALLOC. Nothing is published yet, so Self::read returns None until the first Self::publish.

pub fn publish(&self, write: impl FnOnce(&mut Vec<u8>) -> bool)

Audio thread: publish the current snapshot. The buffer is cleared before write runs (its capacity is retained, so a steady state stays allocation-free), so write just fills it and returns whether a snapshot exists - matching the PluginLogic::snapshot_into contract, where a writer that only extends must not accumulate across blocks. Never blocks - on lock contention with a reader the publish is skipped and the previous snapshot stands.

pub fn is_supported(&self) -> bool

Whether the plugin has ever published a snapshot. Cheap atomic read (no lock). Once true it stays true: a plugin’s decision to publish snapshots is a static capability, latched on the first successful publish.

pub fn read(&self) -> Option<Vec<u8>>

Host / GUI thread: the latest published snapshot, or None when the plugin doesn’t publish snapshots (nothing ever written) so the caller can fall back to the locked save_state() path.