优化结构

internal/conf/runtime.go

@@ -0,0 +1,128 @@
+package conf
+
+import (
+	"sync"
+	"sync/atomic"
+
+	"google.golang.org/protobuf/proto"
+)
+
+// Runtime owns the active immutable configuration snapshot. Callers always
+// receive clones so a config file reload cannot race with request handling.
+type Runtime struct {
+	snapshot  atomic.Pointer[runtimeSnapshot]
+	mu        sync.RWMutex
+	nextID    uint64
+	listeners map[uint64]func(*Data, *AdminBackend)
+}
+
+type runtimeSnapshot struct {
+	data  *Data
+	admin *AdminBackend
+}
+
+func NewRuntime(data *Data, admin *AdminBackend) *Runtime {
+	runtime := &Runtime{listeners: make(map[uint64]func(*Data, *AdminBackend))}
+	runtime.Replace(data, admin)
+	return runtime
+}
+
+func cloneData(value *Data) *Data {
+	if value == nil {
+		return nil
+	}
+	return proto.Clone(value).(*Data)
+}
+
+func cloneAdmin(value *AdminBackend) *AdminBackend {
+	if value == nil {
+		return nil
+	}
+	return proto.Clone(value).(*AdminBackend)
+}
+
+func (r *Runtime) Replace(data *Data, admin *AdminBackend) {
+	data = cloneData(data)
+	admin = cloneAdmin(admin)
+	r.snapshot.Store(&runtimeSnapshot{data: data, admin: admin})
+	r.mu.RLock()
+	listeners := make([]func(*Data, *AdminBackend), 0, len(r.listeners))
+	for _, listener := range r.listeners {
+		listeners = append(listeners, listener)
+	}
+	r.mu.RUnlock()
+	for _, listener := range listeners {
+		listener(cloneData(data), cloneAdmin(admin))
+	}
+}
+
+// Subscribe registers a callback invoked after every successful runtime
+// configuration replacement. It is used by long-lived clients such as the
+// logger and other long-lived clients that must follow runtime config changes.
+func (r *Runtime) Subscribe(listener func(*Data, *AdminBackend)) func() {
+	if listener == nil {
+		return func() {}
+	}
+	r.mu.Lock()
+	r.nextID++
+	id := r.nextID
+	r.listeners[id] = listener
+	r.mu.Unlock()
+	return func() {
+		r.mu.Lock()
+		delete(r.listeners, id)
+		r.mu.Unlock()
+	}
+}
+
+func (r *Runtime) Data() *Data {
+	snapshot := r.snapshot.Load()
+	if snapshot == nil {
+		return nil
+	}
+	return cloneData(snapshot.data)
+}
+
+func (r *Runtime) Admin() *AdminBackend {
+	snapshot := r.snapshot.Load()
+	if snapshot == nil {
+		return nil
+	}
+	return cloneAdmin(snapshot.admin)
+}
+
+func (r *Runtime) Values() (*Data, *AdminBackend) {
+	snapshot := r.snapshot.Load()
+	if snapshot == nil {
+		return nil, nil
+	}
+	return cloneData(snapshot.data), cloneAdmin(snapshot.admin)
+}
+
+func (r *Runtime) ConfigPath() string {
+	snapshot := r.snapshot.Load()
+	if snapshot == nil || snapshot.admin == nil {
+		return ""
+	}
+	return snapshot.admin.ConfigPath
+}
+
+func (r *Runtime) UpdateDatabase(database *Data_Database) {
+	for {
+		current := r.snapshot.Load()
+		var data *Data
+		var admin *AdminBackend
+		if current != nil {
+			data = cloneData(current.data)
+			admin = cloneAdmin(current.admin)
+		}
+		if data == nil {
+			data = &Data{}
+		}
+		data.Database = proto.Clone(database).(*Data_Database)
+		next := &runtimeSnapshot{data: data, admin: admin}
+		if r.snapshot.CompareAndSwap(current, next) {
+			return
+		}
+	}
+}