Add parsing of string for sizes

Checks the suffix of the string to create the size of the int64

server/opts.go

@@ -1691,12 +1691,40 @@ func getInterfaceValue(v interface{}) (int64, error) {
 		return 0, fmt.Errorf("must be int64 or string")
 	}
 
-	i, err := strconv.Atoi(v.(string))
+	num, err := stringStorageSize(v.(string))
 	if err != nil {
-		return 0, fmt.Errorf("must represent an int64")
+		return 0, err
 	}
 
-	return int64(i), nil
+	return int64(num), nil
+}
+
+func stringStorageSize(s string) (int, error) {
+	suffix := strings.ToUpper(s[len(s)-1:])
+	prefix := s[:len(s)-1]
+	var num int
+	var err error
+	switch suffix {
+	case "K":
+		num, err = strconv.Atoi(prefix)
+		num = num * 1024
+	case "M":
+		num, err = strconv.Atoi(prefix)
+		num = num * 1048576
+	case "G":
+		num, err = strconv.Atoi(prefix)
+		num = num * 1073741824
+	case "T":
+		num, err = strconv.Atoi(prefix)
+		num = num * 1099511627776
+	default:
+		return 0, fmt.Errorf("sizes defined as strings must end in K, M, G, T")
+	}
+	if err != nil {
+		return 0, err
+	}
+
+	return num, nil
 }
 
 // Parse enablement of jetstream for a server.

server/opts_test.go

@@ -3256,3 +3256,31 @@ func TestMaxSubTokens(t *testing.T) {
 		t.Fatal("Did not get the permissions error")
 	}
 }
+
+func TestStringStoreSize(t *testing.T) {
+	tt := []struct {
+		input string
+		want  int64
+		err   bool
+	}{
+		{"1K", 1024, false},
+		{"1M", 1048576, false},
+		{"1G", 1073741824, false},
+		{"1T", 1099511627776, false},
+		{"1L", 0, true},
+		{"TT", 0, true},
+	}
+
+	for _, v := range tt {
+		var testErr bool
+		got, err := getInterfaceValue(v.input)
+		if err != nil {
+			testErr = true
+		}
+
+		if got != v.want || v.err != testErr {
+			t.Errorf("Got: %v, want %v with error: %v", got, v.want, testErr)
+		}
+	}
+
+}