move cache to datasource_cache

pkg/datasource/datasource_cache.go

@@ -0,0 +1,51 @@
+package datasource
+
+import (
+	"crypto/sha1"
+	"encoding/hex"
+	"encoding/json"
+	"time"
+
+	"github.com/alexanderzobnin/grafana-zabbix/pkg/cache"
+	"github.com/grafana/grafana-plugin-sdk-go/backend"
+)
+
+// DatasourceCache is a cache for datasource instance.
+type DatasourceCache struct {
+	cache *cache.Cache
+}
+
+// NewDatasourceCache creates a DatasourceCache with expiration(ttl) time and cleanupInterval.
+func NewDatasourceCache(ttl time.Duration, cleanupInterval time.Duration) *DatasourceCache {
+	return &DatasourceCache{
+		cache.NewCache(ttl, cleanupInterval),
+	}
+}
+
+// GetAPIRequest gets request response from cache
+func (c *DatasourceCache) GetAPIRequest(request *ZabbixAPIRequest) (interface{}, bool) {
+	requestHash := HashString(request.String())
+	return c.cache.Get(requestHash)
+}
+
+// SetAPIRequest writes request response to cache
+func (c *DatasourceCache) SetAPIRequest(request *ZabbixAPIRequest, response interface{}) {
+	requestHash := HashString(request.String())
+	c.cache.Set(requestHash, response)
+}
+
+// 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))
+}