feat: batch device property reads

device.go

@@ -22,6 +22,7 @@ const (
 	deviceSpecUA       = "mijiaAPI/4.1.2"
 	deviceSpecMaxSize  = 8 << 20
 	deviceCacheVersion = 2
+	deviceGetBatchSize = 20
 )
 
 var deviceSpecURL = "https://home.miot-spec.com/spec/"
@@ -705,6 +706,76 @@ func (device *Device) Get(ctx context.Context, name string) (any, error) {
 	return results[0].Value, nil
 }
 
+func (device *Device) GetMany(ctx context.Context, names []string) ([]DevicePropertyResult, error) {
+	if len(names) == 0 {
+		return []DevicePropertyResult{}, nil
+	}
+
+	type propertyIdentity struct {
+		did  string
+		siid int
+		piid int
+	}
+	requests := make([]PropertyRequest, len(names))
+	seenNames := make(map[string]struct{}, len(names))
+	seenIdentities := make(map[propertyIdentity]struct{}, len(names))
+	for index, name := range names {
+		if _, duplicate := seenNames[name]; duplicate {
+			return nil, fmt.Errorf("重复的属性: %s", name)
+		}
+		seenNames[name] = struct{}{}
+		property, ok := device.properties[name]
+		if !ok {
+			return nil, fmt.Errorf("不支持的属性: %s", name)
+		}
+		if !strings.Contains(property.RW, "r") {
+			return nil, fmt.Errorf("属性 %s 不可读取", name)
+		}
+		identity := propertyIdentity{did: device.DID, siid: property.SIID, piid: property.PIID}
+		if _, duplicate := seenIdentities[identity]; duplicate {
+			return nil, fmt.Errorf("属性 %s 与其他请求使用重复的设备属性 identity", name)
+		}
+		seenIdentities[identity] = struct{}{}
+		requests[index] = PropertyRequest{DID: identity.did, SIID: identity.siid, PIID: identity.piid}
+	}
+
+	results := make([]DevicePropertyResult, len(names))
+	for start := 0; start < len(requests); start += deviceGetBatchSize {
+		end := min(start+deviceGetBatchSize, len(requests))
+		chunkResults, err := device.client.GetProperties(ctx, requests[start:end])
+		if err != nil {
+			return nil, err
+		}
+		byIdentity := make(map[propertyIdentity]PropertyResult, len(chunkResults))
+		requested := make(map[propertyIdentity]struct{}, end-start)
+		for _, request := range requests[start:end] {
+			requested[propertyIdentity{did: request.DID, siid: request.SIID, piid: request.PIID}] = struct{}{}
+		}
+		for _, result := range chunkResults {
+			identity := propertyIdentity{did: result.DID, siid: result.SIID, piid: result.PIID}
+			if _, expected := requested[identity]; !expected {
+				return nil, fmt.Errorf("get properties protocol error: unexpected identity (%s,%d,%d)", result.DID, result.SIID, result.PIID)
+			}
+			if _, duplicate := byIdentity[identity]; duplicate {
+				return nil, fmt.Errorf("get properties protocol error: duplicate identity (%s,%d,%d)", result.DID, result.SIID, result.PIID)
+			}
+			byIdentity[identity] = result
+		}
+		for index, request := range requests[start:end] {
+			identity := propertyIdentity{did: request.DID, siid: request.SIID, piid: request.PIID}
+			result, ok := byIdentity[identity]
+			if !ok {
+				return nil, fmt.Errorf("get properties protocol error: missing identity (%s,%d,%d)", request.DID, request.SIID, request.PIID)
+			}
+			results[start+index] = DevicePropertyResult{Name: names[start+index], Value: result.Value, Code: result.Code}
+		}
+	}
+	if err := device.wait(ctx); err != nil {
+		return nil, err
+	}
+	return results, nil
+}
+
 func (device *Device) Set(ctx context.Context, name string, value any) error {
 	property, ok := device.properties[name]
 	if !ok {