item.get cache won't be hit if tags order are different (#1745)

* cache won't be hit if tags order are not the same

* unit test for get items with tags

pkg/zabbix/methods.go

@@ -2,6 +2,7 @@ package zabbix
 
 import (
 	"context"
+	"sort"
 	"strconv"
 	"strings"
 
@@ -402,6 +403,13 @@ func (ds *Zabbix) GetAllItems(ctx context.Context, hostids []string, appids []st
 				}
 				tagsParams = append(tagsParams, tagParam)
 			}
+			// tags order should be handled for higher cache hit ratio
+			sort.Slice(tagsParams, func(i, j int) bool {
+				if tagsParams[i]["tag"] != tagsParams[j]["tag"] {
+					return tagsParams[i]["tag"] < tagsParams[j]["tag"]
+				}
+				return tagsParams[i]["value"] < tagsParams[j]["value"]
+			})
 			params["tags"] = tagsParams
 			params["evaltype"] = 2
 		}

pkg/zabbix/zabbix_test.go

@@ -2,6 +2,7 @@ package zabbix
 
 import (
 	"context"
+	"github.com/alexanderzobnin/grafana-zabbix/pkg/settings"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -88,3 +89,55 @@ func TestNonCachedQuery(t *testing.T) {
 	result, _ = resp.String()
 	assert.Equal(t, "testNew", result)
 }
+
+func TestItemTagCache(t *testing.T) {
+	zabbixClient, _ := MockZabbixClient(
+		basicDatasourceInfo,
+		`{"result":[{"itemid":"1","name":"test1"}]}`,
+		200,
+	)
+	// tag filtering is on >= 54 version
+	zabbixClient.version = 64
+	zabbixClient.settings.AuthType = settings.AuthTypeToken
+	zabbixClient.api.SetAuth("test")
+	items, err := zabbixClient.GetAllItems(
+		context.Background(),
+		nil,
+		nil,
+		"num",
+		false,
+		"Application: test, interface: test",
+	)
+
+	assert.NoError(t, err)
+	if assert.Len(t, items, 1) {
+		item := items[0]
+		assert.Equal(t, "1", item.ID)
+		assert.Equal(t, "test1", item.Name)
+	}
+
+	zabbixClient, _ = MockZabbixClientResponse(
+		zabbixClient,
+		// intentionally different response to test if the cache hits
+		`{"result":[{"itemid":"2","name":"test2"}]}`,
+		200,
+	)
+	zabbixClient.api.SetAuth("test")
+	items, err = zabbixClient.GetAllItems(
+		context.Background(),
+		nil,
+		nil,
+		"num",
+		false,
+		// change tag order
+		"interface: test, Application: test",
+	)
+
+	assert.NoError(t, err)
+	if assert.Len(t, items, 1) {
+		item := items[0]
+		// test if it still uses cached response
+		assert.Equal(t, "1", item.ID)
+		assert.Equal(t, "test1", item.Name)
+	}
+}