Move GncDbiSqlConnection into a separate file.

The declaration stays in gnc-backend-dbi.h because the dependencies are
still a little too tangled to be able to separate it.

src/backend/dbi/CMakeLists.txt

@@ -5,7 +5,7 @@ ADD_SUBDIRECTORY(test)
 # Source file gncmod-backend-dbi.c does not appear to be use in Makefile.in, so not included here.
 
 SET (backend_dbi_SOURCES
-  gnc-backend-dbi.cpp
+  gnc-backend-dbi.cpp gnc-dbisqlconnection.cpp
 )
 SET (backend_dbi_noinst_HEADERS
   gnc-backend-dbi.h gnc-backend-dbi.hpp

src/backend/dbi/Makefile.am

@@ -21,7 +21,8 @@ AM_CPPFLAGS = \
   ${WARN_CFLAGS}
 
 libgncmod_backend_dbi_la_SOURCES = \
-  gnc-backend-dbi.cpp
+  gnc-backend-dbi.cpp \
+  gnc-dbisqlconnection.cpp
 
 noinst_HEADERS = \
   gnc-backend-dbi.h \

src/backend/dbi/gnc-backend-dbi.cpp

@@ -125,13 +125,8 @@ static gboolean gnc_dbi_lock_database (QofBackend *qbe, gboolean ignore_lock);
 static void gnc_dbi_unlock (QofBackend *qbe);
 static gboolean save_may_clobber_data (QofBackend* qbe);
 
-static std::string create_index_ddl (const GncSqlConnection* conn,
-                                     const std::string& index_name,
-                                     const std::string& table_name,
-                                     const EntryVec& col_table);
 static GncDbiTestResult conn_test_dbi_library (dbi_conn conn);
 
-#define DBI_MAX_CONN_ATTEMPTS 5
 enum class DbType
 {
     DBI_SQLITE,
@@ -170,57 +165,6 @@ public:
 };
 
 /* ================================================================= */
-
-/* Check if the dbi connection is valid. If not attempt to re-establish it
- * Returns TRUE is there is a valid connection in the end or FALSE otherwise
- */
-bool
-GncDbiSqlConnection::verify () noexcept
-{
-    if (m_conn_ok)
-        return true;
-
-    /* We attempt to connect only once here. The error function will
-     * automatically re-attempt up until DBI_MAX_CONN_ATTEMPTS time to connect
-     * if this call fails.  After all these attempts, conn_ok will indicate if
-     * there is a valid connection or not.
-     */
-    init_error ();
-    m_conn_ok = true;
-    (void)dbi_conn_connect (m_conn);
-
-    return m_conn_ok;
-}
-
-bool
-GncDbiSqlConnection::retry_connection(const char* msg)
-    noexcept
-{
-    while (m_retry && m_error_repeat <= DBI_MAX_CONN_ATTEMPTS)
-    {
-        m_conn_ok = false;
-        if (dbi_conn_connect(m_conn) == 0)
-        {
-            init_error();
-            m_conn_ok = true;
-            return true;
-        }
-#ifdef G_OS_WIN32
-        const guint backoff_msecs = 1;
-        Sleep (backoff_msecs * 2 << ++m_error_repeat);
-#else
-        const guint backoff_usecs = 1000;
-        usleep (backoff_usecs * 2 << ++m_error_repeat);
-#endif
-        PINFO ("DBI error: %s - Reconnecting...\n", msg);
-
-    }
-    PERR ("DBI error: %s - Giving up after %d consecutive attempts.\n", msg,
-                DBI_MAX_CONN_ATTEMPTS);
-    m_conn_ok = false;
-    return false;
-}
-
 /* ================================================================= */
 
 static void
@@ -1103,10 +1047,8 @@ GncDbiProviderImpl<DbType::DBI_MYSQL>::get_index_list (dbi_conn conn)
 template<> void
 GncDbiProviderImpl<DbType::DBI_MYSQL>::drop_index (dbi_conn conn, const std::string& index)
 {
-    unsigned int sep{0}, count{0};
+    auto sep = index.find(' ', 0);
-    while ((sep = index.find(' ', sep)) != std::string::npos)
+    if (index.find(' ', sep + 1) != std::string::npos)
-        ++count;
-    if (count != 1)
     {
         PWARN("Drop index error: invalid MySQL index format (<index> <table>): %s",
               index.c_str());
@@ -1536,33 +1478,6 @@ save_may_clobber_data (QofBackend* qbe)
     return retval;
 }
 
-dbi_result
-GncDbiSqlConnection::table_manage_backup (const std::string& table_name,
-                                          TableOpType op)
-{
-    auto new_name = table_name + "_back";
-    dbi_result result = nullptr;
-    switch (op)
-    {
-    case backup:
-        result = dbi_conn_queryf (m_conn, "ALTER TABLE %s RENAME TO %s",
-                                  table_name.c_str(), new_name.c_str());
-        break;
-    case rollback:
-        result = dbi_conn_queryf (m_conn,
-                                  "ALTER TABLE %s RENAME TO %s",
-                                  new_name.c_str(), table_name.c_str());
-        break;
-    case drop_backup:
-        result = dbi_conn_queryf (m_conn, "DROP TABLE %s",
-                                  new_name.c_str());
-        break;
-    default:
-        break;
-    }
-    return result;
-}
-
 /**
  * Perform a specified SQL operation on every table in a
  * database. Possible operations are:
@@ -2142,215 +2057,6 @@ GncDbiSqlResult::size() const noexcept
 }
 
 /* --------------------------------------------------------- */
-class GncDbiSqlStatement : public GncSqlStatement
-{
-public:
-    GncDbiSqlStatement(const GncSqlConnection* conn, const std::string& sql) :
-        m_conn{conn}, m_sql {sql} {}
-    ~GncDbiSqlStatement() {}
-    const char* to_sql() const override;
-    void add_where_cond(QofIdTypeConst, const PairVec&) override;
-
-private:
-    const GncSqlConnection* m_conn;
-    std::string m_sql;
-};
-
-
-const char*
-GncDbiSqlStatement::to_sql() const
-{
-    return m_sql.c_str();
-}
-
-void
-GncDbiSqlStatement::add_where_cond(QofIdTypeConst type_name,
-                                   const PairVec& col_values)
-{
-    m_sql += " WHERE ";
-    for (auto colpair : col_values)
-    {
-        if (colpair != *col_values.begin())
-            m_sql += " AND ";
-        m_sql += colpair.first + " = " +
-            m_conn->quote_string (colpair.second.c_str());
-    }
-}
-
-/* --------------------------------------------------------- */
-GncSqlResultPtr
-GncDbiSqlConnection::execute_select_statement (const GncSqlStatementPtr& stmt)
-    noexcept
-{
-    dbi_result result;
-
-    DEBUG ("SQL: %s\n", stmt->to_sql());
-    gnc_push_locale (LC_NUMERIC, "C");
-    do
-    {
-        init_error ();
-        result = dbi_conn_query (m_conn, stmt->to_sql());
-    }
-    while (m_retry);
-    if (result == nullptr)
-        PERR ("Error executing SQL %s\n", stmt->to_sql());
-    gnc_pop_locale (LC_NUMERIC);
-    return GncSqlResultPtr(new GncDbiSqlResult (this, result));
-}
-
-int
-GncDbiSqlConnection::execute_nonselect_statement (const GncSqlStatementPtr& stmt)
-    noexcept
-{
-    dbi_result result;
-
-    DEBUG ("SQL: %s\n", stmt->to_sql());
-    do
-    {
-        init_error ();
-        result = dbi_conn_query (m_conn, stmt->to_sql());
-    }
-    while (m_retry);
-    if (result == nullptr && m_last_error)
-    {
-        PERR ("Error executing SQL %s\n", stmt->to_sql());
-        return -1;
-    }
-    if (!result)
-        return 0;
-    auto num_rows = (gint)dbi_result_get_numrows_affected (result);
-    auto status = dbi_result_free (result);
-    if (status < 0)
-    {
-        PERR ("Error in dbi_result_free() result\n");
-        qof_backend_set_error (m_qbe, ERR_BACKEND_SERVER_ERR);
-    }
-    return num_rows;
-}
-
-GncSqlStatementPtr
-GncDbiSqlConnection::create_statement_from_sql (const std::string& sql)
-    const noexcept
-{
-    return std::unique_ptr<GncSqlStatement>{new GncDbiSqlStatement (this, sql)};
-}
-
-bool
-GncDbiSqlConnection::does_table_exist (const std::string& table_name)
-    const noexcept
-{
-    auto dbname = dbi_conn_get_option (m_conn, "dbname");
-    auto tables = dbi_conn_get_table_list (m_conn, dbname, table_name.c_str());
-    auto nTables = dbi_result_get_numrows (tables);
-    auto status = dbi_result_free (tables);
-    if (status < 0)
-    {
-        PERR ("Error in dbi_result_free() result\n");
-        qof_backend_set_error (m_qbe, ERR_BACKEND_SERVER_ERR);
-    }
-
-    return nTables == 1;
-}
-
-bool
-GncDbiSqlConnection::begin_transaction () noexcept
-{
-    dbi_result result;
-
-    DEBUG ("BEGIN\n");
-
-    if (!verify ())
-    {
-        PERR ("gnc_dbi_verify_conn() failed\n");
-        qof_backend_set_error (m_qbe, ERR_BACKEND_SERVER_ERR);
-        return FALSE;
-    }
-
-    do
-    {
-        init_error ();
-        result = dbi_conn_queryf (m_conn, "BEGIN");
-    }
-    while (m_retry);
-
-    auto success = (result != nullptr);
-    auto status = dbi_result_free (result);
-    if (status < 0)
-    {
-        PERR ("Error in dbi_result_free() result\n");
-        qof_backend_set_error (m_qbe, ERR_BACKEND_SERVER_ERR);
-    }
-    if (!success)
-    {
-        PERR ("BEGIN transaction failed()\n");
-        qof_backend_set_error (m_qbe, ERR_BACKEND_SERVER_ERR);
-    }
-
-    return success;
-}
-
-bool
-GncDbiSqlConnection::rollback_transaction () const noexcept
-{
-    DEBUG ("ROLLBACK\n");
-    const char* command =  "ROLLBACK";
-    auto result = dbi_conn_query (m_conn, command);
-    auto success = (result != nullptr);
-
-    auto status = dbi_result_free (result);
-    if (status < 0)
-    {
-        PERR ("Error in dbi_result_free() result\n");
-        qof_backend_set_error (m_qbe, ERR_BACKEND_SERVER_ERR);
-    }
-    if (!success)
-    {
-        PERR ("Error in conn_rollback_transaction()\n");
-        qof_backend_set_error (m_qbe, ERR_BACKEND_SERVER_ERR);
-    }
-
-    return success;
-}
-
-bool
-GncDbiSqlConnection::commit_transaction () const noexcept
-{
-    DEBUG ("COMMIT\n");
-    auto result = dbi_conn_queryf (m_conn, "COMMIT");
-    auto success = (result != nullptr);
-
-    auto status = dbi_result_free (result);
-    if (status < 0)
-    {
-        PERR ("Error in dbi_result_free() result\n");
-        qof_backend_set_error (m_qbe, ERR_BACKEND_SERVER_ERR);
-    }
-    if (!success)
-    {
-        PERR ("Error in conn_commit_transaction()\n");
-        qof_backend_set_error (m_qbe, ERR_BACKEND_SERVER_ERR);
-    }
-
-    return success;
-}
-
-static std::string
-create_index_ddl (const GncSqlConnection* conn, const std::string& index_name,
-                  const std::string& table_name, const EntryVec& col_table)
-{
-    std::string ddl;
-    ddl += "CREATE INDEX " + index_name + " ON " + table_name + "(";
-    for (auto const table_row : col_table)
-    {
-        if (table_row != *col_table.begin())
-        {
-            ddl =+ ", ";
-        }
-        ddl += table_row->name();
-    }
-    ddl += ")";
-    return ddl;
-}
 
 std::string
 add_columns_ddl(const GncSqlConnection* conn,
@@ -2482,7 +2188,7 @@ GncDbiProviderImpl<DbType::DBI_MYSQL>::append_col_def (std::string& ddl,
     ddl += info.m_name + " " + type_name;
     if (info.m_size != 0 && info.m_type == BCT_STRING)
     {
-        ddl += std::to_string(info.m_size);
+        ddl += "(" + std::to_string(info.m_size) + ")";
     }
     if (info.m_unicode)
     {
@@ -2561,86 +2267,6 @@ GncDbiProviderImpl<DbType::DBI_PGSQL>::append_col_def (std::string& ddl,
     }
 }
 
-bool
-GncDbiSqlConnection::create_table (const std::string& table_name,
-                                   const ColVec& info_vec) const noexcept
-{
-    auto ddl = m_provider->create_table_ddl(this, table_name, info_vec);
-    if (ddl.empty())
-        return false;
-
-    DEBUG ("SQL: %s\n", ddl.c_str());
-    auto result = dbi_conn_query (m_conn, ddl.c_str());
-    auto status = dbi_result_free (result);
-    if (status < 0)
-    {
-        PERR ("Error in dbi_result_free() result\n");
-        qof_backend_set_error (m_qbe, ERR_BACKEND_SERVER_ERR);
-    }
-
-    return true;
-}
-
-bool
-GncDbiSqlConnection::create_index(const std::string& index_name,
-                                  const std::string& table_name,
-                                  const EntryVec& col_table) const noexcept
-{
-    auto ddl = create_index_ddl (this, index_name, table_name, col_table);
-    if (ddl.empty())
-        return false;
-    DEBUG ("SQL: %s\n", ddl.c_str());
-    auto result = dbi_conn_query (m_conn, ddl.c_str());
-    auto status = dbi_result_free (result);
-    if (status < 0)
-    {
-        PERR ("Error in dbi_result_free() result\n");
-        qof_backend_set_error (m_qbe, ERR_BACKEND_SERVER_ERR);
-    }
-
-    return true;
-}
-
-bool
-GncDbiSqlConnection::add_columns_to_table(const std::string& table_name,
-                                          const ColVec& info_vec)
-    const noexcept
-{
-    auto ddl = add_columns_ddl(this, table_name, info_vec);
-    if (ddl.empty())
-        return false;
-
-    DEBUG ("SQL: %s\n", ddl.c_str());
-    auto result = dbi_conn_query (m_conn, ddl.c_str());
-    auto status = dbi_result_free (result);
-    if (status < 0)
-    {
-        PERR( "Error in dbi_result_free() result\n" );
-        qof_backend_set_error(m_qbe, ERR_BACKEND_SERVER_ERR );
-    }
-
-    return true;
-}
-
-std::string
-GncDbiSqlConnection::quote_string (const std::string& unquoted_str)
-    const noexcept
-{
-    gchar* quoted_str;
-    size_t size;
-
-    size = dbi_conn_quote_string_copy (m_conn, unquoted_str.c_str(),
-                                       &quoted_str);
-    if (size != 0)
-    {
-        return std::string{quoted_str};
-    }
-    else
-    {
-        return std::string{""};
-    }
-}
-
 static std::vector<std::string>
 conn_get_table_list (dbi_conn conn, const std::string& dbname)
 {

src/backend/dbi/gnc-dbisqlconnection.cpp

@@ -0,0 +1,405 @@
+/********************************************************************
+ * gnc-dbisqlconnection.cpp: Encapsulate libdbi dbi_conn            *
+ *                                                                  *
+ * Copyright 2016 John Ralls <jralls@ceridwen.us>                   *
+ *                                                                  *
+ * This program is free software; you can redistribute it and/or    *
+ * modify it under the terms of the GNU General Public License as   *
+ * published by the Free Software Foundation; either version 2 of   *
+ * the License, or (at your option) any later version.              *
+ *                                                                  *
+ * This program is distributed in the hope that it will be useful,  *
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of   *
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the    *
+ * GNU General Public License for more details.                     *
+ *                                                                  *
+ * You should have received a copy of the GNU General Public License*
+ * along with this program; if not, contact:                        *
+ *                                                                  *
+ * Free Software Foundation           Voice:  +1-617-542-5942       *
+ * 51 Franklin Street, Fifth Floor    Fax:    +1-617-542-2652       *
+ * Boston, MA  02110-1301,  USA       gnu@gnu.org                   *
+\********************************************************************/
+
+#include <guid.hpp>
+extern "C"
+{
+#include <config.h>
+#include <platform.h>
+#include <gnc-locale-utils.h>
+}
+#include "gnc-backend-dbi.hpp"
+
+static QofLogModule log_module = G_LOG_DOMAIN;
+
+static const unsigned int DBI_MAX_CONN_ATTEMPTS = 5;
+
+
+/* --------------------------------------------------------- */
+class GncDbiSqlStatement : public GncSqlStatement
+{
+public:
+    GncDbiSqlStatement(const GncSqlConnection* conn, const std::string& sql) :
+        m_conn{conn}, m_sql {sql} {}
+    ~GncDbiSqlStatement() {}
+    const char* to_sql() const override;
+    void add_where_cond(QofIdTypeConst, const PairVec&) override;
+
+private:
+    const GncSqlConnection* m_conn;
+    std::string m_sql;
+};
+
+
+const char*
+GncDbiSqlStatement::to_sql() const
+{
+    return m_sql.c_str();
+}
+
+void
+GncDbiSqlStatement::add_where_cond(QofIdTypeConst type_name,
+                                   const PairVec& col_values)
+{
+    m_sql += " WHERE ";
+    for (auto colpair : col_values)
+    {
+        if (colpair != *col_values.begin())
+            m_sql += " AND ";
+        m_sql += colpair.first + " = " +
+            m_conn->quote_string (colpair.second.c_str());
+    }
+}
+
+GncSqlResultPtr
+GncDbiSqlConnection::execute_select_statement (const GncSqlStatementPtr& stmt)
+    noexcept
+{
+    dbi_result result;
+
+    DEBUG ("SQL: %s\n", stmt->to_sql());
+    gnc_push_locale (LC_NUMERIC, "C");
+    do
+    {
+        init_error ();
+        result = dbi_conn_query (m_conn, stmt->to_sql());
+    }
+    while (m_retry);
+    if (result == nullptr)
+        PERR ("Error executing SQL %s\n", stmt->to_sql());
+    gnc_pop_locale (LC_NUMERIC);
+    return GncSqlResultPtr(new GncDbiSqlResult (this, result));
+}
+
+int
+GncDbiSqlConnection::execute_nonselect_statement (const GncSqlStatementPtr& stmt)
+    noexcept
+{
+    dbi_result result;
+
+    DEBUG ("SQL: %s\n", stmt->to_sql());
+    do
+    {
+        init_error ();
+        result = dbi_conn_query (m_conn, stmt->to_sql());
+    }
+    while (m_retry);
+    if (result == nullptr && m_last_error)
+    {
+        PERR ("Error executing SQL %s\n", stmt->to_sql());
+        return -1;
+    }
+    if (!result)
+        return 0;
+    auto num_rows = (gint)dbi_result_get_numrows_affected (result);
+    auto status = dbi_result_free (result);
+    if (status < 0)
+    {
+        PERR ("Error in dbi_result_free() result\n");
+        qof_backend_set_error (m_qbe, ERR_BACKEND_SERVER_ERR);
+    }
+    return num_rows;
+}
+
+GncSqlStatementPtr
+GncDbiSqlConnection::create_statement_from_sql (const std::string& sql)
+    const noexcept
+{
+    return std::unique_ptr<GncSqlStatement>{new GncDbiSqlStatement (this, sql)};
+}
+
+bool
+GncDbiSqlConnection::does_table_exist (const std::string& table_name)
+    const noexcept
+{
+    auto dbname = dbi_conn_get_option (m_conn, "dbname");
+    auto tables = dbi_conn_get_table_list (m_conn, dbname, table_name.c_str());
+    auto nTables = dbi_result_get_numrows (tables);
+    auto status = dbi_result_free (tables);
+    if (status < 0)
+    {
+        PERR ("Error in dbi_result_free() result\n");
+        qof_backend_set_error (m_qbe, ERR_BACKEND_SERVER_ERR);
+    }
+
+    return nTables == 1;
+}
+
+bool
+GncDbiSqlConnection::begin_transaction () noexcept
+{
+    dbi_result result;
+
+    DEBUG ("BEGIN\n");
+
+    if (!verify ())
+    {
+        PERR ("gnc_dbi_verify_conn() failed\n");
+        qof_backend_set_error (m_qbe, ERR_BACKEND_SERVER_ERR);
+        return FALSE;
+    }
+
+    do
+    {
+        init_error ();
+        result = dbi_conn_queryf (m_conn, "BEGIN");
+    }
+    while (m_retry);
+
+    auto success = (result != nullptr);
+    auto status = dbi_result_free (result);
+    if (status < 0)
+    {
+        PERR ("Error in dbi_result_free() result\n");
+        qof_backend_set_error (m_qbe, ERR_BACKEND_SERVER_ERR);
+    }
+    if (!success)
+    {
+        PERR ("BEGIN transaction failed()\n");
+        qof_backend_set_error (m_qbe, ERR_BACKEND_SERVER_ERR);
+    }
+
+    return success;
+}
+
+bool
+GncDbiSqlConnection::rollback_transaction () const noexcept
+{
+    DEBUG ("ROLLBACK\n");
+    const char* command =  "ROLLBACK";
+    auto result = dbi_conn_query (m_conn, command);
+    auto success = (result != nullptr);
+
+    auto status = dbi_result_free (result);
+    if (status < 0)
+    {
+        PERR ("Error in dbi_result_free() result\n");
+        qof_backend_set_error (m_qbe, ERR_BACKEND_SERVER_ERR);
+    }
+    if (!success)
+    {
+        PERR ("Error in conn_rollback_transaction()\n");
+        qof_backend_set_error (m_qbe, ERR_BACKEND_SERVER_ERR);
+    }
+
+    return success;
+}
+
+bool
+GncDbiSqlConnection::commit_transaction () const noexcept
+{
+    DEBUG ("COMMIT\n");
+    auto result = dbi_conn_queryf (m_conn, "COMMIT");
+    auto success = (result != nullptr);
+
+    auto status = dbi_result_free (result);
+    if (status < 0)
+    {
+        PERR ("Error in dbi_result_free() result\n");
+        qof_backend_set_error (m_qbe, ERR_BACKEND_SERVER_ERR);
+    }
+    if (!success)
+    {
+        PERR ("Error in conn_commit_transaction()\n");
+        qof_backend_set_error (m_qbe, ERR_BACKEND_SERVER_ERR);
+    }
+
+    return success;
+}
+
+
+bool
+GncDbiSqlConnection::create_table (const std::string& table_name,
+                                   const ColVec& info_vec) const noexcept
+{
+    auto ddl = m_provider->create_table_ddl(this, table_name, info_vec);
+    if (ddl.empty())
+        return false;
+
+    DEBUG ("SQL: %s\n", ddl.c_str());
+    auto result = dbi_conn_query (m_conn, ddl.c_str());
+    auto status = dbi_result_free (result);
+    if (status < 0)
+    {
+        PERR ("Error in dbi_result_free() result\n");
+        qof_backend_set_error (m_qbe, ERR_BACKEND_SERVER_ERR);
+    }
+
+    return true;
+}
+
+static std::string
+create_index_ddl (const GncSqlConnection* conn, const std::string& index_name,
+                  const std::string& table_name, const EntryVec& col_table)
+{
+    std::string ddl;
+    ddl += "CREATE INDEX " + index_name + " ON " + table_name + "(";
+    for (auto const table_row : col_table)
+    {
+        if (table_row != *col_table.begin())
+        {
+            ddl =+ ", ";
+        }
+        ddl += table_row->name();
+    }
+    ddl += ")";
+    return ddl;
+}
+
+bool
+GncDbiSqlConnection::create_index(const std::string& index_name,
+                                  const std::string& table_name,
+                                  const EntryVec& col_table) const noexcept
+{
+    auto ddl = create_index_ddl (this, index_name, table_name, col_table);
+    if (ddl.empty())
+        return false;
+    DEBUG ("SQL: %s\n", ddl.c_str());
+    auto result = dbi_conn_query (m_conn, ddl.c_str());
+    auto status = dbi_result_free (result);
+    if (status < 0)
+    {
+        PERR ("Error in dbi_result_free() result\n");
+        qof_backend_set_error (m_qbe, ERR_BACKEND_SERVER_ERR);
+    }
+
+    return true;
+}
+
+bool
+GncDbiSqlConnection::add_columns_to_table(const std::string& table_name,
+                                          const ColVec& info_vec)
+    const noexcept
+{
+    auto ddl = add_columns_ddl(this, table_name, info_vec);
+    if (ddl.empty())
+        return false;
+
+    DEBUG ("SQL: %s\n", ddl.c_str());
+    auto result = dbi_conn_query (m_conn, ddl.c_str());
+    auto status = dbi_result_free (result);
+    if (status < 0)
+    {
+        PERR( "Error in dbi_result_free() result\n" );
+        qof_backend_set_error(m_qbe, ERR_BACKEND_SERVER_ERR );
+    }
+
+    return true;
+}
+
+std::string
+GncDbiSqlConnection::quote_string (const std::string& unquoted_str)
+    const noexcept
+{
+    gchar* quoted_str;
+    size_t size;
+
+    size = dbi_conn_quote_string_copy (m_conn, unquoted_str.c_str(),
+                                       &quoted_str);
+    if (size != 0)
+    {
+        return std::string{quoted_str};
+    }
+    else
+    {
+        return std::string{""};
+    }
+}
+
+/* Check if the dbi connection is valid. If not attempt to re-establish it
+ * Returns TRUE is there is a valid connection in the end or FALSE otherwise
+ */
+bool
+GncDbiSqlConnection::verify () noexcept
+{
+    if (m_conn_ok)
+        return true;
+
+    /* We attempt to connect only once here. The error function will
+     * automatically re-attempt up until DBI_MAX_CONN_ATTEMPTS time to connect
+     * if this call fails.  After all these attempts, conn_ok will indicate if
+     * there is a valid connection or not.
+     */
+    init_error ();
+    m_conn_ok = true;
+    (void)dbi_conn_connect (m_conn);
+
+    return m_conn_ok;
+}
+
+bool
+GncDbiSqlConnection::retry_connection(const char* msg)
+    noexcept
+{
+    while (m_retry && m_error_repeat <= DBI_MAX_CONN_ATTEMPTS)
+    {
+        m_conn_ok = false;
+        if (dbi_conn_connect(m_conn) == 0)
+        {
+            init_error();
+            m_conn_ok = true;
+            return true;
+        }
+#ifdef G_OS_WIN32
+        const guint backoff_msecs = 1;
+        Sleep (backoff_msecs * 2 << ++m_error_repeat);
+#else
+        const guint backoff_usecs = 1000;
+        usleep (backoff_usecs * 2 << ++m_error_repeat);
+#endif
+        PINFO ("DBI error: %s - Reconnecting...\n", msg);
+
+    }
+    PERR ("DBI error: %s - Giving up after %d consecutive attempts.\n", msg,
+                DBI_MAX_CONN_ATTEMPTS);
+    m_conn_ok = false;
+    return false;
+}
+
+
+dbi_result
+GncDbiSqlConnection::table_manage_backup (const std::string& table_name,
+                                          TableOpType op)
+{
+    auto new_name = table_name + "_back";
+    dbi_result result = nullptr;
+    switch (op)
+    {
+    case backup:
+        result = dbi_conn_queryf (m_conn, "ALTER TABLE %s RENAME TO %s",
+                                  table_name.c_str(), new_name.c_str());
+        break;
+    case rollback:
+        result = dbi_conn_queryf (m_conn,
+                                  "ALTER TABLE %s RENAME TO %s",
+                                  new_name.c_str(), table_name.c_str());
+        break;
+    case drop_backup:
+        result = dbi_conn_queryf (m_conn, "DROP TABLE %s",
+                                  new_name.c_str());
+        break;
+    default:
+        break;
+    }
+    return result;
+}

src/backend/dbi/test/CMakeLists.txt

@@ -19,6 +19,7 @@ SET(test_dbi_backend_SOURCES
   test-dbi-business-stuff.cpp
   test-dbi-stuff.cpp
   ../gnc-backend-dbi.cpp
+  ../gnc-dbisqlconnection.cpp
 )
 
 # This test does not work on Win32

src/backend/dbi/test/Makefile.am

@@ -61,6 +61,7 @@ test_backend_dbi_SOURCES = \
     test-backend-dbi-basic.cpp \
     test-dbi-stuff.cpp \
     test-dbi-business-stuff.cpp \
+    ../gnc-dbisqlconnection.cpp \
     ../gnc-backend-dbi.cpp
 
 test_backend_dbi_CPPFLAGS = \