Add modified Replicator for avrorouter

Repurposed the Replicator from the CDC integration project as a
replication event processing service. It is similar to the CDC version of
the Replicator and is still in the same namespace but it lacks all of the
cross-thread communication that was a part of the integration project.

server/modules/routing/avrorouter/sql.cc

@@ -0,0 +1,110 @@
+/*
+ * Copyright (c) 2019 MariaDB Corporation Ab
+ *
+ * Use of this software is governed by the Business Source License included
+ * in the LICENSE.TXT file and at www.mariadb.com/bsl11.
+ *
+ * Change Date: 2022-01-01
+ *
+ * On the date above, in accordance with the Business Source License, use
+ * of this software will be governed by version 2 or later of the General
+ * Public License.
+ */
+
+#include "sql.hh"
+
+SQL::SQL(MYSQL* mysql, const cdc::Server& server)
+    : m_mysql(mysql)
+    , m_server(server)
+{
+}
+
+SQL::~SQL()
+{
+    mysql_free_result(m_res);
+    mariadb_rpl_close(m_rpl);
+    mysql_close(m_mysql);
+}
+
+std::pair<std::string, std::unique_ptr<SQL>> SQL::connect(const std::vector<cdc::Server>& servers,
+                                                          int connect_timeout, int read_timeout)
+{
+    std::unique_ptr<SQL> rval;
+    MYSQL* mysql = nullptr;
+    std::string error;
+
+    if (servers.empty())
+    {
+        error = "No servers defined";
+    }
+
+    for (const auto& server : servers)
+    {
+        if (!(mysql = mysql_init(nullptr)))
+        {
+            error = "Connection initialization failed";
+            break;
+        }
+
+        mysql_optionsv(mysql, MYSQL_OPT_CONNECT_TIMEOUT, &connect_timeout);
+        mysql_optionsv(mysql, MYSQL_OPT_READ_TIMEOUT, &read_timeout);
+
+        if (!mysql_real_connect(mysql, server.host.c_str(), server.user.c_str(), server.password.c_str(),
+                                nullptr, server.port, nullptr, 0))
+        {
+            error = "Connection creation failed: " + std::string(mysql_error(mysql));
+            mysql_close(mysql);
+            mysql = nullptr;
+        }
+        else
+        {
+            // Successful connection
+            rval.reset(new SQL(mysql, server));
+            error.clear();
+            break;
+        }
+    }
+
+    return {error, std::move(rval)};
+}
+
+bool SQL::query(const std::string& sql)
+{
+    if (m_res)
+    {
+        mysql_free_result(m_res);
+        m_res = nullptr;
+    }
+
+    return mysql_query(m_mysql, sql.c_str()) == 0;
+}
+
+bool SQL::query(const std::vector<std::string>& sql)
+{
+    for (const auto& a : sql)
+    {
+        if (!query(a.c_str()))
+        {
+            return false;
+        }
+    }
+
+    return true;
+}
+
+bool SQL::replicate(int server_id)
+{
+    if (!(m_rpl = mariadb_rpl_init(m_mysql)))
+    {
+        return false;
+    }
+
+    mariadb_rpl_optionsv(m_rpl, MARIADB_RPL_SERVER_ID, &server_id);
+
+    if (mariadb_rpl_open(m_rpl))
+    {
+        return false;
+    }
+
+    return true;
+}