From c59d387451cd268df31ab76d27ae2cb8155f76b8 Mon Sep 17 00:00:00 2001
From: xfy <i@rua.plus>
Date: Thu, 4 Jun 2026 10:45:04 +0800
Subject: [PATCH] perf(hash): add inline FNV-1a hash functions to internal/hash
 package

Zero-allocation alternative to hash/fnv.New64a(). Computes FNV-1a
inline without heap-allocating a hash.Hash64 object per call.
---
 internal/hash/hash.go | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)
 create mode 100644 internal/hash/hash.go

diff --git a/internal/hash/hash.go b/internal/hash/hash.go
new file mode 100644
index 0000000..55316c1
--- /dev/null
+++ b/internal/hash/hash.go
@@ -0,0 +1,19 @@
+package hash
+
+func FNV64a(key string) uint64 {
+	var h uint64 = 14695981039346656037
+	for i := 0; i < len(key); i++ {
+		h ^= uint64(key[i])
+		h *= 1099511628211
+	}
+	return h
+}
+
+func FNV64aBytes(key []byte) uint64 {
+	var h uint64 = 14695981039346656037
+	for i := 0; i < len(key); i++ {
+		h ^= uint64(key[i])
+		h *= 1099511628211
+	}
+	return h
+}