//*****************************************************************************
// Copyright 2018 NVIDIA Corporation. All rights reserved.
//*****************************************************************************
/// \file
/// \brief API component that provides access to the database configuration.
//*****************************************************************************

#ifndef MI_NEURAYLIB_IDATABASE_CONFIGURATION_H
#define MI_NEURAYLIB_IDATABASE_CONFIGURATION_H

#include <mi/base/interface_declare.h>

namespace mi
{

namespace neuraylib
{

/** \addtogroup mi_neuray_configuration
@{
*/

/// This interface is used to query and change the database configuration.
class IDatabase_configuration : public mi::base::Interface_declare<0x8f725100, 0xf66c, 0x4fa3, 0xbf,
                                  0x89, 0xb5, 0xbf, 0xea, 0x6c, 0x4c, 0x30>
{
public:
  /// Sets the limits for memory usage of the database.
  ///
  /// The database attempts to keep the total amount of memory used by database elements and jobs
  /// below a configurable limit called \c high \c water \c mark. If that limit is exceeded the
  /// database takes actions to reduce the memory usage until another limit, the \c low \c water
  /// \c mark, is reached (or no further memory reduction is possible). An internal binary format
  /// is used which can be read into the database again very fast. This method can be called at
  /// any time from any thread but no guarantee can be given if and when the new memory limits
  /// will be reached.
  ///
  /// Possible actions taken by the database to reduce memory usage are:
  /// - Discarding results of database jobs.
  /// - Discarding local copies of elements and jobs that are not required (some copies might be
  ///   required to meet the configured redundancy level).
  /// - If disk swapping is enabled, offload database elements to disk.
  ///
  /// \see #get_memory_limits(), #set_disk_swapping(), #get_disk_swapping(),
  ///      #mi::neuraylib::INetwork_configuration::set_redundancy_level(),
  ///      #mi::neuraylib::INetwork_configuration::get_redundancy_level()
  ///
  /// \if DICE_API \see #mi::neuraylib::IElement::get_size(), #mi::neuraylib::IJob::get_size()
  /// \endif
  ///
  /// \param low_water         Flushing stops when memory usage (in bytes) drops below this value.
  /// \param high_water        Flushing starts when memory usage (in bytes) exceeds this value.
  ///                          The value 0 disables flushing completely.
  /// \return                  0 in case of success, -1 in case of failure (\p low_water not less
  ///                          than \p high_water unless \p high_water equals zero).
  virtual Sint32 set_memory_limits(Size low_water, Size high_water) = 0;

  /// Returns the limits for memory usage of the database.
  ///
  /// \see #set_memory_limits(), #set_disk_swapping(), #get_disk_swapping()
  ///
  /// \param[out] low_water    The current low water mark (in bytes).
  /// \param[out] high_water   The current high water mark (in bytes).
  virtual void get_memory_limits(Size* low_water, Size* high_water) const = 0;

  /// Configures the directory for disk swapping.
  ///
  /// If no directory is configured (the default) disk swapping is disabled.
  ///
  /// \note The configured directory must be used exclusively from one instance of this API
  /// component. Sharing the directory between multiple nodes in a network, or between different
  /// instances of this API component on the same node (same or different processes) leads to
  /// wrong behavior.
  ///
  /// \see #get_disk_swapping(), #set_memory_limits(), #get_memory_limits()
  ///
  /// \if DICE_API \see #mi::neuraylib::IElement::get_offload_to_disk() \endif
  ///
  /// \param path              The path to the directory to use for disk swapping.
  /// \return                  0, in case of success, -1 in case of failure.
  virtual Sint32 set_disk_swapping(const char* path) = 0;

  /// Returns the configured directory for disk swapping.
  ///
  /// \see #set_disk_swapping(), #set_memory_limits(), #get_memory_limits()
  ///
  /// \if DICE_API \see #mi::neuraylib::IElement::get_offload_to_disk() \endif
  ///
  /// \return                  The configured directory, or \c NULL if disabled.
  virtual const char* get_disk_swapping() const = 0;
};

/*@}*/ // end group mi_neuray_configuration

} // namespace neuraylib

} // namespace mi

#endif // MI_NEURAYLIB_IDATABASE_CONFIGURATION_H
