update prometheus dependencies (#5520)

Signed-off-by: junot <junotxiang@kubesphere.io>

vendor/github.com/go-openapi/spec/cache.go

@@ -14,7 +14,9 @@
 
 package spec
 
-import "sync"
+import (
+	"sync"
+)
 
 // ResolutionCache a cache for resolving urls
 type ResolutionCache interface {
@@ -27,12 +29,23 @@ type simpleCache struct {
 	store map[string]interface{}
 }
 
+func (s *simpleCache) ShallowClone() ResolutionCache {
+	store := make(map[string]interface{}, len(s.store))
+	s.lock.RLock()
+	for k, v := range s.store {
+		store[k] = v
+	}
+	s.lock.RUnlock()
+
+	return &simpleCache{
+		store: store,
+	}
+}
+
 // Get retrieves a cached URI
 func (s *simpleCache) Get(uri string) (interface{}, bool) {
-	debugLog("getting %q from resolution cache", uri)
 	s.lock.RLock()
 	v, ok := s.store[uri]
-	debugLog("got %q from resolution cache: %t", uri, ok)
 
 	s.lock.RUnlock()
 	return v, ok
@@ -45,16 +58,41 @@ func (s *simpleCache) Set(uri string, data interface{}) {
 	s.lock.Unlock()
 }
 
-var resCache ResolutionCache
+var (
+	// resCache is a package level cache for $ref resolution and expansion.
+	// It is initialized lazily by methods that have the need for it: no
+	// memory is allocated unless some expander methods are called.
+	//
+	// It is initialized with JSON schema and swagger schema,
+	// which do not mutate during normal operations.
+	//
+	// All subsequent utilizations of this cache are produced from a shallow
+	// clone of this initial version.
+	resCache  *simpleCache
+	onceCache sync.Once
 
-func init() {
-	resCache = initResolutionCache()
+	_ ResolutionCache = &simpleCache{}
+)
+
+// initResolutionCache initializes the URI resolution cache. To be wrapped in a sync.Once.Do call.
+func initResolutionCache() {
+	resCache = defaultResolutionCache()
 }
 
-// initResolutionCache initializes the URI resolution cache
-func initResolutionCache() ResolutionCache {
+func defaultResolutionCache() *simpleCache {
 	return &simpleCache{store: map[string]interface{}{
 		"http://swagger.io/v2/schema.json":       MustLoadSwagger20Schema(),
 		"http://json-schema.org/draft-04/schema": MustLoadJSONSchemaDraft04(),
 	}}
 }
+
+func cacheOrDefault(cache ResolutionCache) ResolutionCache {
+	onceCache.Do(initResolutionCache)
+
+	if cache != nil {
+		return cache
+	}
+
+	// get a shallow clone of the base cache with swagger and json schema
+	return resCache.ShallowClone()
+}