1 files changed, 76 insertions, 0 deletions
diff --git a/src/os/kv.h b/src/os/kv.h
new file mode 100644
index 000000000..64048b088
--- /dev/null
+++ b/src/os/kv.h
@@ -0,0 +1,76 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#ifndef CEPH_OS_KV_H
+#define CEPH_OS_KV_H
+
+#include <string>
+#include "include/byteorder.h"
+
+// some key encoding helpers
+template<typename T>
+inline static void _key_encode_u32(uint32_t u, T *key) {
+  uint32_t bu;
+#ifdef CEPH_BIG_ENDIAN
+  bu = u;
+#elif defined(CEPH_LITTLE_ENDIAN)
+  bu = swab(u);
+#else
+# error wtf
+#endif
+  key->append((char*)&bu, 4);
+}
+
+template<typename T>
+inline static void _key_encode_u32(uint32_t u, size_t pos, T *key) {
+  uint32_t bu;
+#ifdef CEPH_BIG_ENDIAN
+  bu = u;
+#elif defined(CEPH_LITTLE_ENDIAN)
+  bu = swab(u);
+#else
+# error wtf
+#endif
+  key->replace(pos, sizeof(bu), (char*)&bu, sizeof(bu));
+}
+
+inline static const char *_key_decode_u32(const char *key, uint32_t *pu) {
+  uint32_t bu;
+  memcpy(&bu, key, 4);
+#ifdef CEPH_BIG_ENDIAN
+  *pu = bu;
+#elif defined(CEPH_LITTLE_ENDIAN)
+  *pu = swab(bu);
+#else
+# error wtf
+#endif
+  return key + 4;
+}
+
+template<typename T>
+inline static void _key_encode_u64(uint64_t u, T *key) {
+  uint64_t bu;
+#ifdef CEPH_BIG_ENDIAN
+  bu = u;
+#elif defined(CEPH_LITTLE_ENDIAN)
+  bu = swab(u);
+#else
+# error wtf
+#endif
+  key->append((char*)&bu, 8);
+}
+
+inline static const char *_key_decode_u64(const char *key, uint64_t *pu) {
+  uint64_t bu;
+  memcpy(&bu, key, 8);
+#ifdef CEPH_BIG_ENDIAN
+  *pu = bu;
+#elif defined(CEPH_LITTLE_ENDIAN)
+  *pu = swab(bu);
+#else
+# error wtf
+#endif
+  return key + 8;
+}
+
+#endif