Extract object_id and obj_ver_id to separate header

object_id.h

@@ -0,0 +1,53 @@
+#pragma once
+
+#include <stdint.h>
+
+// 16 bytes per object/stripe id
+// stripe includes replica number in 4 least significant bits
+struct __attribute__((__packed__)) object_id
+{
+    uint64_t inode;
+    uint64_t stripe;
+};
+
+inline bool operator == (const object_id & a, const object_id & b)
+{
+    return a.inode == b.inode && a.stripe == b.stripe;
+}
+
+inline bool operator != (const object_id & a, const object_id & b)
+{
+    return a.inode != b.inode || a.stripe != b.stripe;
+}
+
+inline bool operator < (const object_id & a, const object_id & b)
+{
+    return a.inode < b.inode || a.inode == b.inode && a.stripe < b.stripe;
+}
+
+// 56 = 24 + 32 bytes per dirty entry in memory (obj_ver_id => dirty_entry)
+struct __attribute__((__packed__)) obj_ver_id
+{
+    object_id oid;
+    uint64_t version;
+};
+
+inline bool operator < (const obj_ver_id & a, const obj_ver_id & b)
+{
+    return a.oid < b.oid || a.oid == b.oid && a.version < b.version;
+}
+
+namespace std
+{
+    template<> struct hash<object_id>
+    {
+        inline size_t operator()(const object_id &s) const
+        {
+            size_t seed = 0;
+            // Copy-pasted from spp::hash_combine()
+            seed ^= (s.inode + 0xc6a4a7935bd1e995 + (seed << 6) + (seed >> 2));
+            seed ^= (s.stripe + 0xc6a4a7935bd1e995 + (seed << 6) + (seed >> 2));
+            return seed;
+        }
+    };
+}