feat(文件归并): 归并同类文件清理辅助代码

ofdgo_backend.go

@@ -21,6 +21,7 @@ import (
 	"image"
 	"io"
 	"reflect"
+	"sync"
 )
 
 // SVG输出模式，控制资源内嵌和对象结构
@@ -34,6 +35,12 @@ const (
 // ErrBackendUnavailable 表示未配置所需后端，不会自动切换其他实现
 var ErrBackendUnavailable = errors.New("render backend unavailable")
 
+// backendRegistry 保存后端工厂，不共享有状态的后端实例
+var backendRegistry = struct {
+	sync.RWMutex
+	factories map[string]func() RenderBackends
+}{factories: make(map[string]func() RenderBackends)}
+
 // Backend 提供稳定的后端标识，不包含前端文案
 type Backend interface {
 	Name() string
@@ -284,3 +291,48 @@ func immutableBackendValue(value reflect.Value) bool {
 	}
 	return true
 }
+
+// RegisterRenderBackend 注册后端组合，工厂应返回独立实例，重复标识不会覆盖已有实现
+// 入参: name 后端标识, factory 后端工厂
+// 返回: error 无效或重复注册错误
+func RegisterRenderBackend(name string, factory func() RenderBackends) error {
+	if name == "" || factory == nil {
+		return fmt.Errorf("backend name and factory are required")
+	}
+	backendRegistry.Lock()
+	defer backendRegistry.Unlock()
+	if _, exists := backendRegistry.factories[name]; exists {
+		return fmt.Errorf("render backend %q already registered", name)
+	}
+	backendRegistry.factories[name] = factory
+	return nil
+}
+
+// NewRenderBackends 创建已注册后端组合，各项能力通过Info报告实际提供者
+// 入参: name 已注册后端标识
+// 返回: RenderBackends 后端组合, error 未知后端错误
+func NewRenderBackends(name string) (RenderBackends, error) {
+	backendRegistry.RLock()
+	factory := backendRegistry.factories[name]
+	backendRegistry.RUnlock()
+	if factory == nil {
+		return RenderBackends{}, fmt.Errorf("unknown render backend %q", name)
+	}
+	return factory(), nil
+}
+
+// RenderBackendInfos 列出已注册组合及其实际能力，供原生程序和WASM共用
+// 返回: map[string]BackendInfo 后端能力
+func RenderBackendInfos() map[string]BackendInfo {
+	backendRegistry.RLock()
+	factories := make(map[string]func() RenderBackends, len(backendRegistry.factories))
+	for name, factory := range backendRegistry.factories {
+		factories[name] = factory
+	}
+	backendRegistry.RUnlock()
+	result := make(map[string]BackendInfo, len(factories))
+	for name, factory := range factories {
+		result[name] = factory().Info()
+	}
+	return result
+}