Method load

openevolve/database.py:639–707

Load the database from disk Args: path: Path to load from

(self, path: str)

        logger.info(f"Saved database with {len(self.programs)} programs to {save_path}")

    def load(self, path: str) -> None:
        """
        Load the database from disk

        Args:
            path: Path to load from
        """
        if not os.path.exists(path):
            logger.warning(f"Database path {path} does not exist, skipping load")
            return

        # Load metadata first
        metadata_path = os.path.join(path, "metadata.json")
        saved_islands = []
        if os.path.exists(metadata_path):
            with open(metadata_path, "r") as f:
                metadata = json.load(f)

            self.island_feature_maps = metadata.get(
                "island_feature_maps", [{} for _ in range(self.config.num_islands)]
            )
            saved_islands = metadata.get("islands", [])
            self.archive = set(metadata.get("archive", []))
            self.best_program_id = metadata.get("best_program_id")
            self.island_best_programs = metadata.get(
                "island_best_programs", [None] * len(saved_islands)
            )
            self.last_iteration = metadata.get("last_iteration", 0)
            self.current_island = metadata.get("current_island", 0)
            self.island_generations = metadata.get("island_generations", [0] * len(saved_islands))
            self.last_migration_generation = metadata.get("last_migration_generation", 0)

            # Load feature_stats for MAP-Elites grid stability
            self.feature_stats = self._deserialize_feature_stats(metadata.get("feature_stats", {}))

            logger.info(f"Loaded database metadata with last_iteration={self.last_iteration}")
            if self.feature_stats:
                logger.info(f"Loaded feature_stats for {len(self.feature_stats)} dimensions")

        # Load programs
        programs_dir = os.path.join(path, "programs")
        if os.path.exists(programs_dir):
            for program_file in os.listdir(programs_dir):
                if program_file.endswith(".json"):
                    program_path = os.path.join(programs_dir, program_file)
                    try:
                        with open(program_path, "r") as f:
                            program_data = json.load(f)

                        program = Program.from_dict(program_data)
                        self.programs[program.id] = program
                    except Exception as e:
                        logger.warning(f"Error loading program {program_file}: {str(e)}")

        # Reconstruct island assignments from metadata
        self._reconstruct_islands(saved_islands)

        # Ensure island_generations list has correct length