Struct ObjPool 

pub struct ObjPool<T> { /* private fields */ }

A small stack of reusable objects, handed out to workers and returned when they finish.

The sealer this holds carries a per-file subkey cache. Sharing one behind a mutex would serialise every encode on a stream — including the file read that happens under the same critical section. Pooling gives each concurrent worker its own, with the caches surviving between chunks.

Implementations

impl<T> ObjPool<T>

pub fn new(capacity: usize) -> Arc<Self>

pub fn take_or<F: FnOnce() -> T>(&self, make: F) -> T

Take an object, or build one with make if the pool is empty.

pub fn put(&self, obj: T)