1 files changed, 31 insertions, 0 deletions
diff --git a/internal/mapr/server/groupkey.go b/internal/mapr/server/groupkey.go
new file mode 100644
index 0000000..0963e4f
--- /dev/null
+++ b/internal/mapr/server/groupkey.go
@@ -0,0 +1,31 @@
+package server
+
+import (
+	"strings"
+
+	"github.com/mimecast/dtail/internal/protocol"
+)
+
+func buildGroupKey(groupBy []string, fields map[string]string) string {
+	if len(groupBy) == 0 {
+		return ""
+	}
+
+	total := 0
+	for _, field := range groupBy {
+		total += len(fields[field])
+	}
+	total += (len(groupBy) - 1) * len(protocol.AggregateGroupKeyCombinator)
+
+	var sb strings.Builder
+	sb.Grow(total)
+
+	for i, field := range groupBy {
+		if i > 0 {
+			sb.WriteString(protocol.AggregateGroupKeyCombinator)
+		}
+		sb.WriteString(fields[field])
+	}
+
+	return sb.String()
+}