drivers extracted SqlRecord cache to own class

- added a nice API

cmake/Modules/TinySources.cmake

@@ -23,6 +23,7 @@ function(tinydrivers_sources out_headers_private out_headers out_sources)
         sqlresult_p.hpp
         support/connectionshash_p.hpp
         support/sqldriverfactory_p.hpp
+        support/sqlrecordcache_p.hpp
         utils/type_p.hpp
     )
 

drivers/common/include_private/include_private.pri

@@ -18,6 +18,7 @@ headersList += \
     $$PWD/orm/drivers/sqlresult_p.hpp \
     $$PWD/orm/drivers/support/connectionshash_p.hpp \
     $$PWD/orm/drivers/support/sqldriverfactory_p.hpp \
+    $$PWD/orm/drivers/support/sqlrecordcache_p.hpp \
     $$PWD/orm/drivers/utils/type_p.hpp \
 
 HEADERS += $$sorted(headersList)

drivers/common/include_private/orm/drivers/support/sqlrecordcache_p.hpp

@@ -0,0 +1,109 @@
+#pragma once
+#ifndef ORM_DRIVERS_SUPPORT_SQLRECORDCACHE_P_HPP
+#define ORM_DRIVERS_SUPPORT_SQLRECORDCACHE_P_HPP
+
+#include "orm/drivers/sqlrecord.hpp"
+
+TINYORM_BEGIN_COMMON_NAMESPACE
+
+namespace Orm::Drivers::Support
+{
+
+    /*! Cache for the record/WithDefaultValues() methods (SqlRecord). */
+    struct SqlRecordCachePrivate
+    {
+        /*! Cached SqlRecord instance. */
+        std::optional<SqlRecord> cache = std::nullopt;
+        /*! Determince whether the cached SqlRecord contains Default Column Values. */
+        bool hasDefaultValues = false;
+
+        /*! Determine if a SqlRecord is cached. */
+        constexpr bool has() const noexcept;
+        /*! Determine if a SqlRecord is cached. */
+        constexpr explicit operator bool() const noexcept;
+
+        /*! Retrieve a SqlRecord from the cache. */
+        constexpr SqlRecord &get() noexcept;
+        /*! Retrieve a SqlRecord from the cache, const version. */
+        constexpr const SqlRecord &get() const noexcept;
+
+        /*! Retrieve a SqlRecord from the cache. */
+        constexpr SqlRecord &operator*() noexcept;
+        /*! Retrieve a SqlRecord from the cache, const version. */
+        constexpr const SqlRecord &operator*() const noexcept;
+
+        /*! Store the given SqlRecord in the cache. */
+        constexpr SqlRecord &put(SqlRecord &&record, bool defaultValues) noexcept;
+        /*! Store the given SqlRecord in the cache (helper method only). */
+        constexpr SqlRecord &put(SqlRecord &record, bool defaultValues) noexcept;
+
+        /*! Clear the cache. */
+        constexpr void clear() noexcept;
+    };
+
+    /* public */
+
+    constexpr bool SqlRecordCachePrivate::has() const noexcept
+    {
+        return cache.has_value();
+    }
+
+    constexpr SqlRecordCachePrivate::operator bool() const noexcept
+    {
+        return cache.has_value();
+    }
+
+    constexpr SqlRecord &SqlRecordCachePrivate::get() noexcept
+    {
+        return *cache;
+    }
+
+    constexpr const SqlRecord &SqlRecordCachePrivate::get() const noexcept
+    {
+        return *cache;
+    }
+
+    constexpr SqlRecord &SqlRecordCachePrivate::operator*() noexcept
+    {
+        return *cache;
+    }
+
+    constexpr const SqlRecord &SqlRecordCachePrivate::operator*() const noexcept
+    {
+        return *cache;
+    }
+
+    constexpr SqlRecord &
+    SqlRecordCachePrivate::put(SqlRecord &&record, const bool defaultValues) noexcept
+    {
+        cache = std::move(record);
+        hasDefaultValues = defaultValues;
+
+        return *cache;
+    }
+
+    constexpr SqlRecord &
+    SqlRecordCachePrivate::put(SqlRecord &record, const bool defaultValues) noexcept
+    {
+        /* This is only a helper method to have a nicer code, it allows to call the return
+           statement like: return cache.put(SqlRecord &). In this case the given SqlRecord
+           must have the same memory address as the current cached SqlRecord.
+           Used with: populateFieldDefaultValues(d->recordCache.get()) */
+        Q_ASSERT(std::addressof(record) == std::addressof(*cache));
+
+        hasDefaultValues = defaultValues;
+
+        return record;
+    }
+
+    constexpr void SqlRecordCachePrivate::clear() noexcept
+    {
+        cache.reset();
+        hasDefaultValues = false;
+    }
+
+} // namespace Orm::Drivers::Support
+
+TINYORM_END_COMMON_NAMESPACE
+
+#endif // ORM_DRIVERS_SUPPORT_SQLRECORDCACHE_P_HPP

drivers/mysql/include_private/orm/drivers/mysql/mysqlresult_p.hpp

@@ -5,8 +5,8 @@
 #include "orm/drivers/macros/declaresqldriverprivate_p.hpp"
 #include "orm/drivers/mysql/mysqldriver.hpp"
 #include "orm/drivers/mysql/mysqltypes_p.hpp"
-#include "orm/drivers/sqlrecord.hpp"
 #include "orm/drivers/sqlresult_p.hpp"
+#include "orm/drivers/support/sqlrecordcache_p.hpp"
 
 /* All the in vs out bindings/data-related comments and identifier names related
    to the results or prepared bindings are described from the MySQL server perspective and
@@ -120,8 +120,8 @@ namespace Orm::Drivers::MySql
         /*! Is the current result set for the prepared statement? */
         bool preparedQuery = false;
 
-        /*! Cache for the record() method. */
-        mutable std::optional<SqlRecord> recordCache = std::nullopt;
+        /*! Cache for the record/WithDefaultValuesCached() method. */
+        mutable Support::SqlRecordCachePrivate recordCache;
 
     private:
         /* Prepared queries */

drivers/mysql/src/orm/drivers/mysql/mysqlresult.cpp

@@ -145,7 +145,7 @@ bool MySqlResult::exec()
                  "to the SqlQuery::exec(QString) for normal statements, for '%1' MySQL "
                  "database connection in %2()."_s.arg(d->connectionName, __tiny_func__));
 
-    d->recordCache.reset();
+    d->recordCache.clear();
 
     /* Prepared queries don't use metadata the same way as normal queries,
        it's always RESULTSET_METADATA_NONE. */
@@ -292,7 +292,8 @@ const SqlRecord &MySqlResult::recordCached() const
 {
     Q_D(const MySqlResult);
 
-    return d->recordCache ? *d->recordCache : *(d->recordCache = record());
+    return d->recordCache ? *d->recordCache
+                          : d->recordCache.put(record(), false);
 }
 
 QVariant MySqlResult::lastInsertId() const
@@ -337,7 +338,7 @@ bool MySqlResult::fetch(const size_type index)
     if (at() == index)
         return true;
 
-    d->recordCache.reset();
+    d->recordCache.clear();
 
     // Fetch the next row in the result set
     if (d->preparedQuery) {
@@ -396,7 +397,7 @@ bool MySqlResult::fetchNext()
     if (size() == 0)
         return false;
 
-    d->recordCache.reset();
+    d->recordCache.clear();
 
     // Fetch the next row in the result set
     if (d->preparedQuery) {
@@ -501,7 +502,7 @@ void MySqlResult::cleanupForNormal()
 {
     Q_D(MySqlResult);
 
-    d->recordCache.reset();
+    d->recordCache.clear();
 
     // Normal queries
     mysqlFreeResults();
@@ -514,7 +515,7 @@ void MySqlResult::cleanupForPrepared()
 {
     Q_D(MySqlResult);
 
-    d->recordCache.reset();
+    d->recordCache.clear();
 
     // Prepared queries
     // d->meta != nullptr check is inside as the first thing