add schema caching

pkg/cache/main.go

@@ -0,0 +1,36 @@
+package cache
+
+import (
+	"fmt"
+	"sync"
+)
+
+var mu sync.Mutex
+var schemas map[string][]byte
+
+func init () {
+	schemas = map[string][]byte {}
+}
+
+func WithCache(downloadSchema func(string, string, string) ([]byte, error)) (func (string, string, string) ([]byte, error)) {
+	return func(resourceKind, resourceAPIVersion, k8sVersion string) ([]byte, error) {
+		cacheKey := fmt.Sprintf("%s-%s-%s", resourceKind, resourceAPIVersion, k8sVersion)
+		mu.Lock()
+		cachedSchema, ok := schemas[cacheKey];
+		mu.Unlock()
+		if ok {
+			return cachedSchema, nil
+		}
+
+		schema, err := downloadSchema(resourceKind, resourceAPIVersion, k8sVersion)
+		if err != nil {
+			return schema, err
+		}
+
+		mu.Lock()
+		schemas[cacheKey] = schema
+		mu.Unlock()
+
+		return schema, nil
+	}
+}