initial code repo

[stor4nfv.git] / src / ceph / src / include / blobhash.h

diff --git a/src/ceph/src/include/blobhash.h b/src/ceph/src/include/blobhash.h
new file mode 100644 (file)
index 0000000..597884e
--- /dev/null
+++ b/src/ceph/src/include/blobhash.h
@@ -0,0 +1,47 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- 
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software 
+ * Foundation.  See file COPYING.
+ * 
+ */
+
+#ifndef CEPH_BLOBHASH_H
+#define CEPH_BLOBHASH_H
+
+#include "hash.h"
+
+/*
+- this is to make some of the STL types work with 64 bit values, string hash keys, etc.
+- added when i was using an old STL.. maybe try taking these out and see if things 
+  compile now?
+*/
+
+class blobhash {
+public:
+  uint32_t operator()(const char *p, unsigned len) {
+    static rjhash<uint32_t> H;
+    uint32_t acc = 0;
+    while (len >= sizeof(acc)) {
+      acc ^= *(uint32_t*)p;
+      p += sizeof(uint32_t);
+      len -= sizeof(uint32_t);
+    }
+    int sh = 0;
+    while (len) {
+      acc ^= (uint32_t)*p << sh;
+      sh += 8;
+      len--;
+      p++;
+    }
+    return H(acc);
+  }
+};
+
+
+#endif