feat: supprt channel priority now & record channel id in log (#484)

* feat: 支持设置渠道优先级 & 日志中显示使用的渠道ID

* fix: 设置渠道优先级未更新 ability

* chore: update implementation

---------

Co-authored-by: Xiangyuan Liu <xiangyuan.liu@ui.com>
Co-authored-by: JustSong <songquanpeng@foxmail.com>
Co-authored-by: JustSong <39998050+songquanpeng@users.noreply.github.com>

model/cache.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"math/rand"
 	"one-api/common"
+	"sort"
 	"strconv"
 	"strings"
 	"sync"
@@ -159,6 +160,17 @@ func InitChannelCache() {
 			}
 		}
 	}
+
+	// sort by priority
+	for group, model2channels := range newGroup2model2channels {
+		for model, channels := range model2channels {
+			sort.Slice(channels, func(i, j int) bool {
+				return channels[i].Priority > channels[j].Priority
+			})
+			newGroup2model2channels[group][model] = channels
+		}
+	}
+
 	channelSyncLock.Lock()
 	group2model2channels = newGroup2model2channels
 	channelSyncLock.Unlock()
@@ -183,6 +195,11 @@ func CacheGetRandomSatisfiedChannel(group string, model string) (*Channel, error
 	if len(channels) == 0 {
 		return nil, errors.New("channel not found")
 	}
+	// choose by priority
+	firstChannel := channels[0]
+	if firstChannel.Priority > 0 {
+		return firstChannel, nil
+	}
 	idx := rand.Intn(len(channels))
 	return channels[idx], nil
 }