Initial QSfera import

Server/pkg/sync/mutex.go

@@ -0,0 +1,49 @@
+package sync
+
+import (
+	"sync"
+)
+
+// NamedRWMutex works the same as RWMutex, the only difference is that it stores mutexes in a map and reuses them.
+// It's handy if you want to write-lock, write-unlock, read-lock and read-unlock for specific names only.
+type NamedRWMutex struct {
+	pool sync.Pool
+	mus  sync.Map
+}
+
+// NewNamedRWMutex returns a new instance of NamedRWMutex.
+func NewNamedRWMutex() NamedRWMutex {
+	return NamedRWMutex{pool: sync.Pool{New: func() any {
+		return new(sync.RWMutex)
+	}}}
+}
+
+// Lock locks rw for writing.
+func (m *NamedRWMutex) Lock(name string) {
+	m.loadOrStore(name).Lock()
+}
+
+// Unlock unlocks rw for writing.
+func (m *NamedRWMutex) Unlock(name string) {
+	m.loadOrStore(name).Unlock()
+}
+
+// RLock locks rw for reading.
+func (m *NamedRWMutex) RLock(name string) {
+	m.loadOrStore(name).RLock()
+}
+
+// RUnlock undoes a single RLock call.
+func (m *NamedRWMutex) RUnlock(name string) {
+	m.loadOrStore(name).RUnlock()
+}
+
+func (m *NamedRWMutex) loadOrStore(name string) *sync.RWMutex {
+	pmu := m.pool.Get()
+	mmu, loaded := m.mus.LoadOrStore(name, pmu)
+	if loaded {
+		m.pool.Put(pmu)
+	}
+
+	return mmu.(*sync.RWMutex)
+}