pgimpl.h

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/**********************************************************************
 * LeechCraft - modular cross-platform feature rich internet client.
 * Copyright (C) 2006-2014  Georg Rudoy
 *
 * Distributed under the Boost Software License, Version 1.0.
 * (See accompanying file LICENSE or copy at https://www.boost.org/LICENSE_1_0.txt)
 **********************************************************************/
 
#pragma once
 
#include <util/sll/visitor.h>
#include "oraltypes.h"
#include "oraldetailfwd.h"
#include "impldefs.h"
 
namespace LC::Util::oral::detail::PostgreSQL
{
    using QSqlQuery_ptr = std::shared_ptr<QSqlQuery>;
 
    class InsertQueryBuilder final : public IInsertQueryBuilder
    {
        const QSqlDatabase DB_;
 
        QSqlQuery_ptr Default_;
        QSqlQuery_ptr Ignore_;
 
        const QString InsertBase_;
        const QString Updater_;
    public:
        InsertQueryBuilder (const QSqlDatabase& db, const CachedFieldsData& data)
        : DB_ { db }
        , InsertBase_ { "INSERT INTO " + data.Table_ +
                " (" + data.Fields_.join (", ") + ") VALUES (" +
                data.BoundFields_.join (", ") + ") " }
        , Updater_ { Map (data.Fields_, [] (auto&& str) { return str + " = EXCLUDED." + str; }).join (", ") }
        {
        }
 
        QSqlQuery_ptr GetQuery (InsertAction action) override
        {
            return Visit (action.Selector_,
                    [this] (InsertAction::DefaultTag) { return GetDefaultQuery (); },
                    [this] (InsertAction::IgnoreTag) { return GetIgnoreQuery (); },
                    [this] (InsertAction::Replace ct) { return MakeReplaceQuery (ct.Fields_); });
        }
    private:
        QSqlQuery_ptr GetDefaultQuery ()
        {
            if (!Default_)
            {
                Default_ = std::make_shared<QSqlQuery> (DB_);
                Default_->prepare (InsertBase_);
            }
            return Default_;
        }
 
        QSqlQuery_ptr GetIgnoreQuery ()
        {
            if (!Default_)
            {
                Default_ = std::make_shared<QSqlQuery> (DB_);
                Default_->prepare (InsertBase_ + "ON CONFLICT DO NOTHING");
            }
            return Default_;
        }
 
        QSqlQuery_ptr MakeReplaceQuery (const QStringList& constraining)
        {
            auto query = std::make_shared<QSqlQuery> (DB_);
            query->prepare (InsertBase_ + GetReplacer (constraining));
            return query;
        }
 
        QString GetReplacer (const QStringList& constraining) const
        {
            return "ON CONFLICT (" +
                    constraining.join (", ") +
                    ") DO UPDATE SET " +
                    Updater_;
        }
    };
 
    class ImplFactory
    {
    public:
        struct TypeLits
        {
            inline static const QString IntAutoincrement { "SERIAL PRIMARY KEY" };
            inline static const QString Binary { "BYTEA" };
        };
 
        inline static const QString LimitNone { "ALL" };
 
        auto MakeInsertQueryBuilder (const QSqlDatabase& db, const CachedFieldsData& data) const
        {
            return std::make_unique<InsertQueryBuilder> (db, data);
        }
    };
}
 
namespace LC::Util::oral
{
    using PostgreSQLImplFactory = detail::PostgreSQL::ImplFactory;
}