initial import

core/syncx/resourcemanager.go

@@ -0,0 +1,62 @@
+package syncx
+
+import (
+	"io"
+	"sync"
+
+	"zero/core/errorx"
+)
+
+type ResourceManager struct {
+	resources   map[string]io.Closer
+	sharedCalls SharedCalls
+	lock        sync.RWMutex
+}
+
+func NewResourceManager() *ResourceManager {
+	return &ResourceManager{
+		resources:   make(map[string]io.Closer),
+		sharedCalls: NewSharedCalls(),
+	}
+}
+
+func (manager *ResourceManager) Close() error {
+	manager.lock.Lock()
+	defer manager.lock.Unlock()
+
+	var be errorx.BatchError
+	for _, resource := range manager.resources {
+		if err := resource.Close(); err != nil {
+			be.Add(err)
+		}
+	}
+
+	return be.Err()
+}
+
+func (manager *ResourceManager) GetResource(key string, create func() (io.Closer, error)) (io.Closer, error) {
+	val, err := manager.sharedCalls.Do(key, func() (interface{}, error) {
+		manager.lock.RLock()
+		resource, ok := manager.resources[key]
+		manager.lock.RUnlock()
+		if ok {
+			return resource, nil
+		}
+
+		resource, err := create()
+		if err != nil {
+			return nil, err
+		}
+
+		manager.lock.Lock()
+		manager.resources[key] = resource
+		manager.lock.Unlock()
+
+		return resource, nil
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	return val.(io.Closer), nil
+}