A sized pool of slices of generic type objects

pool.go

// SizedPool is a channel-based pool of slices objects.
// It retains an arbitrary number of slices of objects and ensures their initial capacity.
type SizedPool[T any] struct {
	pool chan []T
	cap  int
}

func NewSizedPool[T any](size int, cap int) *SizedPool[T] {
	return &SizedPool[T]{
		pool: make(chan []T, size),
		cap:  cap,
	}
}

// Get either returns a slice of T from the pool or creates one anew.
func (p *SizedPool[T]) Get() []T {
	select {
	case b := <-p.pool:
		return b
	default:
		return make([]T, 0, p.cap)
	}
}

// Put returns an object to the pool, resetting it and zeroing its values first.
// It also ensures that the returned object does not exceed its set capacity by allocating a new slice if necessary.
func (p *SizedPool[T]) Put(s []T) {
	for i := range s {
		var t T
		s[i] = t
	}
	s = s[:0]
	if cap(s) > p.cap {
		s = make([]T, 0, p.cap)
	}
	select {
	case p.pool <- s:
	default:
	}
}