cmd, core, eth, light, trie: add trie read caching layer

vendor/github.com/allegro/bigcache/fnv.go

@@ -0,0 +1,28 @@
+package bigcache
+
+// newDefaultHasher returns a new 64-bit FNV-1a Hasher which makes no memory allocations.
+// Its Sum64 method will lay the value out in big-endian byte order.
+// See https://en.wikipedia.org/wiki/Fowler–Noll–Vo_hash_function
+func newDefaultHasher() Hasher {
+	return fnv64a{}
+}
+
+type fnv64a struct{}
+
+const (
+	// offset64 FNVa offset basis. See https://en.wikipedia.org/wiki/Fowler–Noll–Vo_hash_function#FNV-1a_hash
+	offset64 = 14695981039346656037
+	// prime64 FNVa prime value. See https://en.wikipedia.org/wiki/Fowler–Noll–Vo_hash_function#FNV-1a_hash
+	prime64 = 1099511628211
+)
+
+// Sum64 gets the string and returns its uint64 hash value.
+func (f fnv64a) Sum64(key string) uint64 {
+	var hash uint64 = offset64
+	for i := 0; i < len(key); i++ {
+		hash ^= uint64(key[i])
+		hash *= prime64
+	}
+
+	return hash
+}