add meson support

[protos/libecoli.git] / src / ecoli_murmurhash.c

diff --git a/src/ecoli_murmurhash.c b/src/ecoli_murmurhash.c
new file mode 100644 (file)
index 0000000..7aafece
--- /dev/null
+++ b/src/ecoli_murmurhash.c
@@ -0,0 +1,40 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright 2016, Olivier MATZ <zer0@droids-corp.org>
+ */
+
+#include <stdint.h>
+
+#include <ecoli_murmurhash.h>
+
+uint32_t ec_murmurhash3(const void *key, int len, uint32_t seed)
+{
+       const uint8_t *data = (const uint8_t *)key;
+       const uint8_t *tail;
+       const int nblocks = len / 4;
+       uint32_t h1 = seed;
+       uint32_t k1;
+       const uint32_t *blocks = (const uint32_t *)(data + nblocks * 4);
+       int i;
+
+       for (i = -nblocks; i; i++) {
+               k1 = blocks[i];
+
+               h1 = ec_murmurhash3_add32(h1, k1);
+               h1 = ec_murmurhash3_mix32(h1);
+       }
+
+       tail = (const uint8_t *)(data + nblocks * 4);
+       k1 = 0;
+
+       switch(len & 3) {
+       case 3: k1 ^= tail[2] << 16;
+       case 2: k1 ^= tail[1] << 8;
+       case 1: k1 ^= tail[0];
+               h1 = ec_murmurhash3_add32(h1, k1);
+       };
+
+       /* finalization */
+       h1 ^= len;
+       h1 = ec_murmurhash3_fmix32(h1);
+       return h1;
+}