1 files changed, 19 insertions, 0 deletions
diff --git a/core/hash.go b/core/hash.go
new file mode 100644
index 0000000..af15546
--- /dev/null
+++ b/core/hash.go
@@ -0,0 +1,19 @@
+package core
+
+import "hash/fnv"
+
+const DefaultMaxParallelism = 128
+
+func AssignToKeyGroup(key string, maxParallelism int) int {
+
+	if maxParallelism <= 0 {
+		maxParallelism = DefaultMaxParallelism
+	}
+
+	// hash
+	h := fnv.New32a()
+	h.Write([]byte(key))
+	hash := h.Sum32()
+
+	return int(hash % uint32(maxParallelism))
+}