SqlScopedTraceLogger.hpp

// SPDX-License-Identifier: Apache-2.0
 
#pragma once
 
#include "Api.hpp"
#include "SqlConnection.hpp"
#include "SqlOdbcWide.hpp"
#include "SqlStatement.hpp"
 
#include <filesystem>
 
namespace Lightweight
{
 
/// @brief Enables protocol-level ODBC trace logging for the given connection.
///
/// The trace logging is active for the lifetime of this object.
///
/// The logging output is sent to the standard output stream.
class LIGHTWEIGHT_API SqlScopedTraceLogger
{
    SQLHDBC m_nativeConnection;
 
  public:
    /// Constructs a scoped trace logger for the given SQL connection, logging to standard output.
    explicit SqlScopedTraceLogger(SqlConnection& connection):
        SqlScopedTraceLogger(connection.NativeHandle(),
#if defined(_WIN32) || defined(_WIN64)
                             "CONOUT$"
#else
                             "/dev/stdout"
#endif
        )
    {
    }
 
    /// Constructs a scoped trace logger for the given SQL statement, logging to standard output.
    explicit SqlScopedTraceLogger(SqlStatement& stmt):
        SqlScopedTraceLogger(stmt.Connection().NativeHandle(),
#if defined(_WIN32) || defined(_WIN64)
                             "CONOUT$"
#else
                             "/dev/stdout"
#endif
        )
    {
    }
 
    /// Constructs a scoped trace logger for the given native ODBC handle, logging to the specified file.
    explicit SqlScopedTraceLogger(SQLHDBC hDbc, std::filesystem::path const& logFile):
        m_nativeConnection { hDbc }
    {
        // Stay on the W path: the rest of the library puts the DBC handle into Unicode-app
        // mode at connect time, so passing an ANSI trace-file name here would mix variants
        // unnecessarily. `path::u16string()` does the platform-correct conversion (UTF-16
        // is path's native form on Windows; UTF-8 → UTF-16 on POSIX).
        auto wLogFile = logFile.u16string();
        SQLSetConnectAttrW(m_nativeConnection, SQL_ATTR_TRACEFILE, detail::AsSqlWChar(wLogFile.data()), SQL_NTS);
        SQLSetConnectAttrW(m_nativeConnection, SQL_ATTR_TRACE, (SQLPOINTER) SQL_OPT_TRACE_ON, SQL_IS_UINTEGER);
    }
 
    SqlScopedTraceLogger(SqlScopedTraceLogger&&) = delete;
    SqlScopedTraceLogger& operator=(SqlScopedTraceLogger&&) = delete;
    SqlScopedTraceLogger(SqlScopedTraceLogger const&) = delete;
    SqlScopedTraceLogger& operator=(SqlScopedTraceLogger const&) = delete;
 
    ~SqlScopedTraceLogger()
    {
        SQLSetConnectAttrW(m_nativeConnection, SQL_ATTR_TRACE, (SQLPOINTER) SQL_OPT_TRACE_OFF, SQL_IS_UINTEGER);
    }
};
 
} // namespace Lightweight