ngx_murmur_hash2()

1 files changed, 50 insertions, 0 deletions

diff --git a/src/core/ngx_murmurhash.c b/src/core/ngx_murmurhash.c
new file mode 100644
index 000000000..c31e0e035
--- /dev/null
+++ b/src/core/ngx_murmurhash.c
@@ -0,0 +1,50 @@
+
+/*
+ * Copyright (C) Austin Appleby
+ */
+
+
+#include <ngx_config.h>
+#include <ngx_core.h>
+
+
+uint32_t
+ngx_murmur_hash2(u_char *data, size_t len)
+{
+    uint32_t  h, k;
+
+    h = 0 ^ len;
+
+    while (len >= 4) {
+        k  = data[0];
+        k |= data[1] << 8;
+        k |= data[2] << 16;
+        k |= data[3] << 24;
+
+        k *= 0x5bd1e995;
+        k ^= k >> 24;
+        k *= 0x5bd1e995;
+
+        h *= 0x5bd1e995;
+        h ^= k;
+
+        data += 4;
+        len -= 4;
+    }
+
+    switch (len) {
+    case 3:
+        h ^= data[2] << 16;
+    case 2:
+        h ^= data[1] << 8;
+    case 1:
+        h ^= data[0];
+        h *= 0x5bd1e995;
+    }
+
+    h ^= h >> 13;
+    h *= 0x5bd1e995;
+    h ^= h >> 15;
+
+    return h;
+}