nix-state.hh

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/* ========================================================================== *
 *
 * @file flox/core/nix-state.hh
 *
 * @brief Manages a `nix` runtime state blob with associated helpers.
 *
 *
 * -------------------------------------------------------------------------- */
 
#pragma once
 
#include <memory>
 
#include <nix/eval.hh>
#include <nix/ref.hh>
#include <nix/repair-flag.hh>
#include <nix/search-path.hh>
#include <nix/store-api.hh>
 
 
/* -------------------------------------------------------------------------- */
 
/* Forward Declarations. */
 
namespace nix {
class Logger;
}
 
 
/* -------------------------------------------------------------------------- */
 
namespace flox {
 
/* -------------------------------------------------------------------------- */
 
nix::Logger *
makeFilteredLogger( bool printBuildLogs );
 
 
/* -------------------------------------------------------------------------- */
 
void
initNix();
 
 
/* -------------------------------------------------------------------------- */
 
class NixStoreMixin
{
 
private:
 
  std::shared_ptr<nix::Store> store; 
public:
 
  /* Copy/Move base class boilerplate */
  NixStoreMixin( const NixStoreMixin & ) = default;
  NixStoreMixin( NixStoreMixin && )      = default;
 
  virtual ~NixStoreMixin() = default;
 
  NixStoreMixin &
  operator=( const NixStoreMixin & )
    = default;
  NixStoreMixin &
  operator=( NixStoreMixin && )
    = default;
 
 
  explicit NixStoreMixin( const nix::ref<nix::Store> & store )
    : store( static_cast<std::shared_ptr<nix::Store>>( store ) )
  {
    initNix();
  }
 
  NixStoreMixin() { initNix(); }
 
 
  nix::ref<nix::Store>
  getStore()
  {
    if ( this->store == nullptr ) { this->store = nix::openStore(); }
    return static_cast<nix::ref<nix::Store>>( this->store );
  }
 
 
}; /* End class `NixStoreMixin' */
 
 
/* -------------------------------------------------------------------------- */
 
class NixState : public NixStoreMixin
{
 
private:
 
  /* From `NixStoreMixin':
   *   std::shared_ptr<nix::Store> store
   */
 
  std::shared_ptr<nix::EvalState> state; 
public:
 
  NixState() = default;
 
  explicit NixState( nix::ref<nix::Store> & store ) : NixStoreMixin( store ) {}
 
 
  nix::ref<nix::EvalState>
  getState()
  {
    if ( this->state == nullptr )
      {
        this->state = std::make_shared<nix::EvalState>( nix::SearchPath(),
                                                        this->getStore(),
                                                        this->getStore() );
        this->state->repair = nix::NoRepair;
      }
    return static_cast<nix::ref<nix::EvalState>>( this->state );
  }
 
 
}; /* End class `NixState' */
 
 
/* -------------------------------------------------------------------------- */
 
}  // namespace flox
 
 
/* -------------------------------------------------------------------------- *
 *
 *
 *
 * ========================================================================== */