gotosocial/vendor/codeberg.org/gruf/go-mutexes/hash_map.go

56 lines
1,005 B
Go

package mutexes
type hashmap struct {
m map[string]*rwmutex
n int
}
func (m *hashmap) init(cap int) {
m.m = make(map[string]*rwmutex, cap)
m.n = cap
}
func (m *hashmap) Get(key string) *rwmutex { return m.m[key] }
func (m *hashmap) Put(key string, mu *rwmutex) {
m.m[key] = mu
if n := len(m.m); n > m.n {
m.n = n
}
}
func (m *hashmap) Delete(key string) {
delete(m.m, key)
}
func (m *hashmap) Compact() {
// Noop when hashmap size
// is too small to matter.
if m.n < 2048 {
return
}
// Difference between maximum map
// size and the current map size.
diff := m.n - len(m.m)
// Maximum load factor before
// runtime allocates new hmap:
// maxLoad = 13 / 16
//
// So we apply the inverse/2, once
// $maxLoad/2 % of hmap is empty we
// compact the map to drop buckets.
if 2*16*diff > m.n*13 {
// Create new map only as big as required.
m2 := make(map[string]*rwmutex, len(m.m))
for k, v := range m.m {
m2[k] = v
}
// Set new.
m.m = m2
m.n = len(m2)
}
}