--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/ucx/hash_key.c Mon May 22 16:17:26 2023 +0200
@@ -0,0 +1,112 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
+ *
+ * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "cx/hash_key.h"
+#include <string.h>
+
+void cx_hash_murmur(CxHashKey *key) {
+ unsigned char const *data = key->data;
+ if (data == NULL) {
+ // extension: special value for NULL
+ key->hash = 1574210520u;
+ return;
+ }
+ size_t len = key->len;
+
+ unsigned m = 0x5bd1e995;
+ unsigned r = 24;
+ unsigned h = 25 ^ len;
+ unsigned i = 0;
+ while (len >= 4) {
+ unsigned k = data[i + 0] & 0xFF;
+ k |= (data[i + 1] & 0xFF) << 8;
+ k |= (data[i + 2] & 0xFF) << 16;
+ k |= (data[i + 3] & 0xFF) << 24;
+
+ k *= m;
+ k ^= k >> r;
+ k *= m;
+
+ h *= m;
+ h ^= k;
+
+ i += 4;
+ len -= 4;
+ }
+
+ switch (len) {
+ case 3:
+ h ^= (data[i + 2] & 0xFF) << 16;
+ __attribute__((__fallthrough__));
+ case 2:
+ h ^= (data[i + 1] & 0xFF) << 8;
+ __attribute__((__fallthrough__));
+ case 1:
+ h ^= (data[i + 0] & 0xFF);
+ h *= m;
+ __attribute__((__fallthrough__));
+ default: // do nothing
+ ;
+ }
+
+ h ^= h >> 13;
+ h *= m;
+ h ^= h >> 15;
+
+ key->hash = h;
+}
+
+CxHashKey cx_hash_key_str(char const *str) {
+ CxHashKey key;
+ key.data = str;
+ key.len = str == NULL ? 0 : strlen(str);
+ cx_hash_murmur(&key);
+ return key;
+}
+
+CxHashKey cx_hash_key_bytes(
+ unsigned char const *bytes,
+ size_t len
+) {
+ CxHashKey key;
+ key.data = bytes;
+ key.len = len;
+ cx_hash_murmur(&key);
+ return key;
+}
+
+CxHashKey cx_hash_key(
+ void const *obj,
+ size_t len
+) {
+ CxHashKey key;
+ key.data = obj;
+ key.len = len;
+ cx_hash_murmur(&key);
+ return key;
+}