move cache to datasource_cache

pkg/cache/cache.go

@@ -1,12 +1,8 @@
 package cache
 
 import (
-	"crypto/sha1"
-	"encoding/hex"
-	"encoding/json"
 	"time"
 
-	"github.com/grafana/grafana-plugin-sdk-go/backend"
 	cache "github.com/patrickmn/go-cache"
 )
 
@@ -19,6 +15,8 @@ const (
 	DefaultExpiration time.Duration = 0
 )
 
+// TODO: since all methods moved to datasource_cache, this can be removed and replaced by go-cache
+
 // Cache is a abstraction over go-cache.
 type Cache struct {
 	cache *cache.Cache
@@ -40,19 +38,3 @@ func (c *Cache) Set(request string, response interface{}) {
 func (c *Cache) Get(request string) (interface{}, bool) {
 	return c.cache.Get(request)
 }
-
-// HashString converts the given text string to hash string
-func HashString(text string) string {
-	hash := sha1.New()
-	hash.Write([]byte(text))
-	return hex.EncodeToString(hash.Sum(nil))
-}
-
-// HashDatasourceInfo converts the given datasource info to hash string
-func HashDatasourceInfo(dsInfo *backend.DataSourceInstanceSettings) string {
-	digester := sha1.New()
-	if err := json.NewEncoder(digester).Encode(dsInfo); err != nil {
-		panic(err) // This shouldn't be possible but just in case DatasourceInfo changes
-	}
-	return hex.EncodeToString(digester.Sum(nil))
-}