Feat: refreshcache

utils/refreshCache/refreshCache.go

@@ -0,0 +1,48 @@
+package refreshcache
+
+import (
+	"sync"
+	"time"
+)
+
+type RefreshCache[T any] struct {
+	lock        sync.RWMutex
+	last        time.Time
+	maxAge      time.Duration
+	refreshFunc func() (T, error)
+	data        T
+}
+
+func NewRefreshCache[T any](refreshFunc func() (T, error), maxAge time.Duration) *RefreshCache[T] {
+	if refreshFunc == nil {
+		panic("refreshFunc cannot be nil")
+	}
+	if maxAge <= 0 {
+		panic("maxAge must be positive")
+	}
+	return &RefreshCache[T]{
+		refreshFunc: refreshFunc,
+		maxAge:      maxAge,
+	}
+}
+
+func (r *RefreshCache[T]) Get() (data T, err error) {
+	r.lock.RLock()
+	if time.Since(r.last) < r.maxAge {
+		r.lock.RUnlock()
+		return r.data, nil
+	}
+	r.lock.RUnlock()
+	r.lock.Lock()
+	defer r.lock.Unlock()
+	if time.Since(r.last) < r.maxAge {
+		return r.data, nil
+	}
+	defer func() {
+		if err == nil {
+			r.data = data
+			r.last = time.Now()
+		}
+	}()
+	return r.refreshFunc()
+}

vendors/bilibili/buvid.go

@@ -3,58 +3,46 @@ package bilibili
 import (
 	"errors"
 	"net/http"
-	"sync"
 	"time"
 
 	json "github.com/json-iterator/go"
 	"github.com/synctv-org/synctv/utils"
+	refreshcache "github.com/synctv-org/synctv/utils/refreshCache"
 )
 
-var (
-	bLock           sync.RWMutex
-	b3, b4          string
-	bLastUpdateTime time.Time
-)
+type buvid struct {
+	b3, b4 string
+}
+
+var buvidCache = refreshcache.NewRefreshCache[buvid](func() (buvid, error) {
+	b3, b4, err := newBuvid()
+	if err != nil {
+		return buvid{}, err
+	}
+	return buvid{
+		b3: b3,
+		b4: b4,
+	}, nil
+}, time.Hour)
 
 func getBuvidCookies() ([]*http.Cookie, error) {
-	b3, b4, err := getBuvid()
+	buvid, err := buvidCache.Get()
 	if err != nil {
 		return nil, err
 	}
 	return []*http.Cookie{
 		{
 			Name:  "buvid3",
-			Value: b3,
+			Value: buvid.b3,
 		},
 		{
 			Name:  "buvid4",
-			Value: b4,
+			Value: buvid.b4,
 		},
 	}, nil
 }
 
-func getBuvid() (string, string, error) {
-	bLock.RLock()
-	if time.Since(bLastUpdateTime) < time.Hour {
-		bLock.RUnlock()
-		return b3, b4, nil
-	}
-	bLock.RUnlock()
-	bLock.Lock()
-	defer bLock.Unlock()
-	if time.Since(bLastUpdateTime) < time.Hour {
-		return b3, b4, nil
-	}
-	var err error
-	b3, b4, err = newBuvid()
-	if err != nil {
-		return "", "", err
-	}
-	bLastUpdateTime = time.Now()
-	return b3, b4, nil
-}
-
-type buvid struct {
+type spiResp struct {
 	Code int `json:"code"`
 	Data struct {
 		B3 string `json:"b_3"`
@@ -75,7 +63,7 @@ func newBuvid() (string, string, error) {
 		return "", "", err
 	}
 	defer resp.Body.Close()
-	var b buvid
+	var b spiResp
 	err = json.NewDecoder(resp.Body).Decode(&b)
 	if err != nil {
 		return "", "", err

vendors/bilibili/wbi.go

@@ -8,11 +8,11 @@ import (
 	"sort"
 	"strconv"
 	"strings"
-	"sync"
 	"time"
 
 	json "github.com/json-iterator/go"
 	"github.com/synctv-org/synctv/utils"
+	refreshcache "github.com/synctv-org/synctv/utils/refreshCache"
 )
 
 var (
@@ -22,17 +22,25 @@ var (
 		61, 26, 17, 0, 1, 60, 51, 30, 4, 22, 25, 54, 21, 56, 59, 6, 63, 57, 62, 11,
 		36, 20, 34, 44, 52,
 	}
-	lock           sync.RWMutex
-	imgKey, subKey string
-	lastUpdateTime time.Time
+	wbiCache = refreshcache.NewRefreshCache[key](func() (key, error) {
+		imgKey, subKey, err := getWbiKeys()
+		if err != nil {
+			return key{}, err
+		}
+		return key{imgKey, subKey}, nil
+	}, time.Minute*10)
 )
 
+type key struct {
+	imgKey, subKey string
+}
+
 func signAndGenerateURL(urlStr string) (string, error) {
 	urlObj, err := url.Parse(urlStr)
 	if err != nil {
 		return "", err
 	}
-	imgKey, subKey, err := getWbiKeysCached()
+	key, err := wbiCache.Get()
 	if err != nil {
 		return "", err
 	}
@@ -41,7 +49,7 @@ func signAndGenerateURL(urlStr string) (string, error) {
 	for k, v := range query {
 		params[k] = v[0]
 	}
-	newParams := encWbi(params, imgKey, subKey)
+	newParams := encWbi(params, key.imgKey, key.subKey)
 	for k, v := range newParams {
 		query.Set(k, v)
 	}
@@ -94,27 +102,6 @@ func sanitizeString(s string) string {
 	return s
 }
 
-func getWbiKeysCached() (string, string, error) {
-	lock.RLock()
-	if time.Since(lastUpdateTime).Minutes() < 10 {
-		defer lock.RUnlock()
-		return imgKey, subKey, nil
-	}
-	lock.RUnlock()
-	lock.Lock()
-	defer lock.Unlock()
-	if time.Since(lastUpdateTime).Minutes() < 10 {
-		return imgKey, subKey, nil
-	}
-	var err error
-	imgKey, subKey, err = getWbiKeys()
-	if err != nil {
-		return "", "", err
-	}
-	lastUpdateTime = time.Now()
-	return imgKey, subKey, nil
-}
-
 func getWbiKeys() (string, string, error) {
 	req, err := http.NewRequest(http.MethodGet, "https://api.bilibili.com/x/web-interface/nav", nil)
 	if err != nil {