From df1eb5912f1bccf6c3831cfa308ff3d2c8693d2c Mon Sep 17 00:00:00 2001
From: Sebastian Reimers <hallo@studio-link.de>
Date: Mon, 25 Jul 2022 17:28:02 +0200
Subject: [PATCH] hash: add hash_fast_murmur()

---
 include/re_hash.h |  1 +
 src/hash/func.c   | 19 +++++++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/include/re_hash.h b/include/re_hash.h
index cf9e4f149..2c1dbdab0 100644
--- a/include/re_hash.h
+++ b/include/re_hash.h
@@ -33,3 +33,4 @@ uint32_t hash_joaat_pl(const struct pl *pl);
 uint32_t hash_joaat_pl_ci(const struct pl *pl);
 uint32_t hash_fast(const char *k, size_t len);
 uint32_t hash_fast_str(const char *str);
+uint32_t hash_fast_murmur(uint32_t key);
diff --git a/src/hash/func.c b/src/hash/func.c
index 10a8d9202..935342125 100644
--- a/src/hash/func.c
+++ b/src/hash/func.c
@@ -185,3 +185,22 @@ uint32_t hash_fast_str(const char *str)
 
 	return h;
 }
+
+
+/**
+ * Calculate hash-value using modified murmur (fast finalize part)
+ *
+ * @param key    Key value
+ *
+ * @return Calculated hash-value
+ */
+uint32_t hash_fast_murmur(uint32_t key)
+{
+	key ^= key >> 16;
+	key *= 0x85ebca6b;
+	key ^= key >> 13;
+	key *= 0xc2b2ae35;
+	key ^= key >> 16;
+
+	return key;
+}