Refactored seqno and id classes out of provider.hpp

include/wsrep/seqno.hpp

@@ -0,0 +1,74 @@
+//
+// Copyright (C) 2018 Codership Oy <info@codership.com>
+//
+
+#ifndef WSREP_SEQNO_HPP
+#define WSREP_SEQNO_HPP
+
+#include "exception.hpp"
+
+#include <ostream>
+
+namespace wsrep
+{
+    /*! \class seqno
+     *
+     * Sequence number type.
+     *
+     * By convention, nil value is zero, negative values are not allowed.
+     * Relation operators are restricted to < and > on purpose to
+     * enforce correct use.
+     */
+    class seqno
+    {
+    public:
+        seqno()
+            : seqno_()
+        { }
+
+        explicit seqno(long long seqno)
+            : seqno_(seqno)
+        {
+            if (seqno_ < 0)
+            {
+                throw wsrep::runtime_error("Negative seqno given");
+            }
+        }
+
+        long long get() const
+        {
+            return seqno_;
+        }
+
+        bool nil() const
+        {
+            return (seqno_ == 0);
+        }
+
+        bool operator<(seqno other) const
+        {
+            return (seqno_ < other.seqno_);
+        }
+
+        bool operator>(seqno other) const
+        {
+            return (seqno_ > other.seqno_);
+        }
+
+        seqno operator+(seqno other) const
+        {
+            return (seqno(seqno_ + other.seqno_));
+        }
+
+        static seqno undefined() { return seqno(0); }
+    private:
+        long long seqno_;
+    };
+
+    static inline std::ostream& operator<<(std::ostream& os, wsrep::seqno seqno)
+    {
+        return (os << seqno.get());
+    }
+}
+
+#endif // WSREP_SEQNO_HPP