fix(ability): report an emptied group as no channel, not DB corruption

model/ability.go

@@ -60,7 +60,9 @@ func GetAllEnableAbilities() []Ability {
 	return abilities
 }
 
-func getPriority(group string, model string, retry int) (int, error) {
+// getPriority reports the priority to use for this retry step, and whether the
+// group still serves the model.
+func getPriority(group string, model string, retry int) (int, bool, error) {
 
 	var priorities []int
 	err := DB.Model(&Ability{}).
@@ -71,12 +73,13 @@ func getPriority(group string, model string, retry int) (int, error) {
 
 	if err != nil {
 		// 处理错误
-		return 0, err
+		return 0, false, err
 	}
 
 	if len(priorities) == 0 {
-		// 如果没有查询到优先级，则返回错误
-		return 0, errors.New("数据库一致性被破坏")
+		// 分组内已无该模型的启用渠道，属于正常的无可用渠道。
+		// 重试期间可达：自动禁用会把刚失败的渠道置为禁用。
+		return 0, false, nil
 	}
 
 	// 确定要使用的优先级
@@ -87,19 +90,21 @@ func getPriority(group string, model string, retry int) (int, error) {
 	} else {
 		priorityToUse = priorities[retry]
 	}
-	return priorityToUse, nil
+	return priorityToUse, true, nil
 }
 
 func getChannelQuery(group string, model string, retry int) (*gorm.DB, error) {
 	maxPrioritySubQuery := DB.Model(&Ability{}).Select("MAX(priority)").Where(commonGroupCol+" = ? and model = ? and enabled = ?", group, model, true)
 	channelQuery := DB.Where(commonGroupCol+" = ? and model = ? and enabled = ? and priority = (?)", group, model, true, maxPrioritySubQuery)
 	if retry != 0 {
-		priority, err := getPriority(group, model, retry)
+		priority, found, err := getPriority(group, model, retry)
 		if err != nil {
 			return nil, err
-		} else {
-			channelQuery = DB.Where(commonGroupCol+" = ? and model = ? and enabled = ? and priority = ?", group, model, true, priority)
 		}
+		if !found {
+			return nil, nil
+		}
+		channelQuery = DB.Where(commonGroupCol+" = ? and model = ? and enabled = ? and priority = ?", group, model, true, priority)
 	}
 
 	return channelQuery, nil
@@ -113,6 +118,9 @@ func GetChannel(group string, model string, retry int, requestPath string) (*Cha
 	if err != nil {
 		return nil, err
 	}
+	if channelQuery == nil {
+		return nil, nil
+	}
 	if common.UsingMainDatabase(common.DatabaseTypeSQLite) || common.UsingMainDatabase(common.DatabaseTypePostgreSQL) {
 		err = channelQuery.Order("weight DESC").Find(&abilities).Error
 	} else {

model/ability_no_channel_test.go

@@ -0,0 +1,57 @@
+package model
+
+import (
+	"testing"
+
+	"github.com/QuantumNous/new-api/common"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// TestGetChannelReportsNoChannelAfterLastAbilityDisabled reproduces what a client
+// sees when auto-ban disables the last channel serving a model in its group while
+// a request is still retrying: the retry re-queries the group, finds nothing, and
+// must report "no available channel" rather than a database consistency failure.
+func TestGetChannelReportsNoChannelAfterLastAbilityDisabled(t *testing.T) {
+	prevMemoryCache := common.MemoryCacheEnabled
+	common.MemoryCacheEnabled = false
+	t.Cleanup(func() { common.MemoryCacheEnabled = prevMemoryCache })
+
+	require.NoError(t, DB.AutoMigrate(&Channel{}, &Ability{}))
+	require.NoError(t, DB.Exec("DELETE FROM abilities").Error)
+	require.NoError(t, DB.Exec("DELETE FROM channels").Error)
+	t.Cleanup(func() {
+		require.NoError(t, DB.Exec("DELETE FROM abilities").Error)
+		require.NoError(t, DB.Exec("DELETE FROM channels").Error)
+	})
+
+	priority := int64(100)
+	channel := &Channel{
+		Status:   common.ChannelStatusEnabled,
+		Name:     "only-channel",
+		Group:    "chat",
+		Models:   "gpt-test",
+		Priority: &priority,
+	}
+	require.NoError(t, DB.Create(channel).Error)
+	require.NoError(t, DB.Create(&Ability{
+		Group:     "chat",
+		Model:     "gpt-test",
+		ChannelId: channel.Id,
+		Enabled:   true,
+		Priority:  &priority,
+	}).Error)
+
+	selected, err := GetChannel("chat", "gpt-test", 0, "")
+	require.NoError(t, err)
+	require.NotNil(t, selected, "the first attempt must find the only channel")
+
+	// The channel fails and auto-ban disables it, exactly as UpdateAbilityStatus
+	// does when a relay error trips the disable threshold.
+	require.NoError(t, UpdateAbilityStatus(channel.Id, false))
+
+	// The in-flight request now retries against a group that has become empty.
+	selected, err = GetChannel("chat", "gpt-test", 1, "")
+	assert.NoError(t, err, "an emptied group is an ordinary no-channel result, not a database consistency failure")
+	assert.Nil(t, selected)
+}