Refactored seqno and id classes out of provider.hpp

include/wsrep/id.hpp

@@ -0,0 +1,75 @@
+//
+// Copyright (C) 2018 Codership Oy <info@codership.com>
+//
+
+/*! \file id.hpp
+ *
+ * A generic identifier utility class.
+ */
+#ifndef WSREP_ID_HPP
+#define WSREP_ID_HPP
+
+#include "exception.hpp"
+
+#include <iosfwd>
+#include <cstring> // std::memset()
+
+namespace wsrep
+{
+    /*!
+     * The idientifier class stores identifiers either in UUID
+     * format or in string format. The storage format is decided
+     * upon construction. If the given string contains a valid
+     * UUID, the storage format will be binary. Otherwise the
+     * string will be copied verbatim. If the string format is used,
+     * the maximum length of the identifier is limited to 16 bytes.
+     */
+    class id
+    {
+    public:
+        /*!
+         * Default constructor. Constructs an empty identifier.
+         */
+        id() : data_() { std::memset(data_, 0, sizeof(data_)); }
+
+        /*!
+         * Construct from string. The input string may contain either
+         * valid UUID or a string with maximum 16 bytes length.
+         */
+        id(const std::string&);
+
+        /*!
+         * Construct from void pointer.
+         */
+        id (const void* data, size_t size) : data_()
+        {
+            if (size > 16)
+            {
+                throw wsrep::runtime_error("Too long identifier");
+            }
+            std::memset(data_, 0, sizeof(data_));
+            std::memcpy(data_, data, size);
+        }
+
+        bool operator<(const id& other) const
+        {
+            return (std::memcmp(data_, other.data_, sizeof(data_)) < 0);
+        }
+
+        bool operator==(const id& other) const
+        {
+            return (std::memcmp(data_, other.data_, sizeof(data_)) == 0);
+        }
+
+        const void* data() const { return data_; }
+
+        size_t size() const { return sizeof(data_); }
+
+    private:
+        unsigned char data_[16];
+    };
+
+    std::ostream& operator<<(std::ostream&, const wsrep::id& id);
+}
+
+#endif // WSREP_ID_HPP