add Recycler to compliment Supplier #21
Description
Supplier is used to construct new instances, however the user may also want to control the maximum size allowed when items go back into the pool to avoid OOM.
I recommend the name Recycler, although you can use whatever name you think is fitting.
use case:
extern crate lifeguard;
use lifeguard::*;
fn main() {
let pool : Pool<String> = pool()
// The pool will allocate 128 values for immediate use. More will be allocated on demand.
.with(StartingSize(128))
// The pool will only grow up to 4096 values. Further values will be dropped.
.with(MaxSize(4096))
// The pool will use this closure (or other object implementing Supply<T>) to allocate
.with(Supplier(|| String::with_capacity(1024)))
// The pool will use this closure when adding recycled items back to the pool
.with(Recycler(|s| {
s.clear()
// nightly only
if s.capacity() > 4096 {
s.shrink_to(4096);
}
})
.build();
// ...
}