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))
-}

pkg/datasource/datasource.go

@@ -27,7 +27,7 @@ type ZabbixDatasourceInstance struct {
 	zabbixAPI  *zabbixapi.ZabbixAPI
 	dsInfo     *backend.DataSourceInstanceSettings
 	Settings   *ZabbixDatasourceSettings
-	queryCache *cache.Cache
+	queryCache *DatasourceCache
 	logger     log.Logger
 }
 
@@ -54,7 +54,7 @@ func NewZabbixDatasourceInstance(dsInfo *backend.DataSourceInstanceSettings) (*Z
 		dsInfo:     dsInfo,
 		zabbixAPI:  zabbixAPI,
 		Settings:   zabbixSettings,
-		queryCache: cache.NewCache(zabbixSettings.CacheTTL, 10*time.Minute),
+		queryCache: NewDatasourceCache(zabbixSettings.CacheTTL, 10*time.Minute),
 		logger:     log.New(),
 	}, nil
 }
@@ -121,11 +121,11 @@ func (ds *ZabbixDatasource) GetDatasource(pluginContext backend.PluginContext) (
 	dsSettings := pluginContext.DataSourceInstanceSettings
 	dsKey := fmt.Sprintf("%d-%d", pluginContext.OrgID, dsSettings.ID)
 	// Get hash to check if settings changed
-	dsInfoHash := cache.HashDatasourceInfo(dsSettings)
+	dsInfoHash := HashDatasourceInfo(dsSettings)
 
 	if cachedData, ok := ds.datasourceCache.Get(dsKey); ok {
 		if cachedDS, ok := cachedData.(*ZabbixDatasourceInstance); ok {
-			cachedDSHash := cache.HashDatasourceInfo(cachedDS.dsInfo)
+			cachedDSHash := HashDatasourceInfo(cachedDS.dsInfo)
 			if cachedDSHash == dsInfoHash {
 				return cachedDS, nil
 			}

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))
+}

pkg/datasource/datasource_cache_test.go

@@ -1,4 +1,4 @@
-package cache
+package datasource
 
 import (
 	"testing"

pkg/datasource/zabbix.go

@@ -6,7 +6,6 @@ import (
 	"regexp"
 	"time"
 
-	"github.com/alexanderzobnin/grafana-zabbix/pkg/cache"
 	"github.com/alexanderzobnin/grafana-zabbix/pkg/zabbixapi"
 	simplejson "github.com/bitly/go-simplejson"
 	"github.com/grafana/grafana-plugin-sdk-go/backend"
@@ -28,9 +27,8 @@ var CachedMethods = map[string]bool{
 func (ds *ZabbixDatasourceInstance) ZabbixQuery(ctx context.Context, apiReq *ZabbixAPIRequest) (*simplejson.Json, error) {
 	var resultJson *simplejson.Json
 	var err error
-	requestHash := cache.HashString(apiReq.String())
 
-	cachedResult, queryExistInCache := ds.queryCache.Get(requestHash)
+	cachedResult, queryExistInCache := ds.queryCache.GetAPIRequest(apiReq)
 	if !queryExistInCache {
 		resultJson, err = ds.ZabbixRequest(ctx, apiReq.Method, apiReq.Params)
 		if err != nil {
@@ -39,7 +37,7 @@ func (ds *ZabbixDatasourceInstance) ZabbixQuery(ctx context.Context, apiReq *Zab
 
 		if _, ok := CachedMethods[apiReq.Method]; ok {
 			ds.logger.Debug("Write result to cache", "method", apiReq.Method)
-			ds.queryCache.Set(requestHash, resultJson)
+			ds.queryCache.SetAPIRequest(apiReq, resultJson)
 		}
 	} else {
 		var ok bool

pkg/datasource/zabbix_test.go

@@ -50,7 +50,7 @@ func MockZabbixDataSource(body string, statusCode int) *ZabbixDatasourceInstance
 		dsInfo:     basicDatasourceInfo,
 		zabbixAPI:  zabbixAPI,
 		Settings:   zabbixSettings,
-		queryCache: cache.NewCache(cache.NoExpiration, 10*time.Minute),
+		queryCache: NewDatasourceCache(cache.NoExpiration, 10*time.Minute),
 		logger:     log.New(),
 	}
 }