Source code for minizinc.driver

#  This Source Code Form is subject to the terms of the Mozilla Public
#  License, v. 2.0. If a copy of the MPL was not distributed with this
#  file, You can obtain one at

import os
import platform
import shutil
from abc import ABC, abstractmethod
from ctypes.util import find_library
from pathlib import Path
from typing import List, Optional, Type

from minizinc.instance import Instance

[docs]class Driver(ABC): """The abstract representation of a MiniZinc driver within MiniZinc Python.""" Solver: Type Instance: Instance
[docs] @abstractmethod def make_default(self) -> None: """Method to override the current default MiniZinc Python driver with the current driver. """ pass
@abstractmethod def __init__(self): """Creates a new MiniZinc driver Raises: ConfigurationError: If an the driver version is found to be incompatible with MiniZinc Python """ pass @property @abstractmethod def minizinc_version(self) -> str: """Reports the version of the MiniZinc Driver Report the full version of MiniZinc as reported by the driver, including the driver name, the semantic version, the build reference, and its authors. Returns: str: the version of as reported by the MiniZinc driver """ pass
[docs] @abstractmethod def available_solvers(self, refresh=False): """Returns a list of available solvers This method returns the list of solvers available to the Driver object according to the current environment. Note that the list of solvers might be cached for future usage. The refresh argument can be used to ignore the current cache. Args: refresh (bool): When set to true, the Driver will rediscover the available solvers from the current environment. Returns: Dict[str, List[Solver]]: A dictionary that maps solver tags to MiniZinc solver configurations that can be used with the Driver object. """ pass
[docs]def find_driver( path: Optional[List[str]] = None, name: str = "minizinc" ) -> Optional[Driver]: """Finds MiniZinc Driver on default or specified path. Find driver will look for the the MiniZinc API or the MiniZinc executable to create a Driver for MiniZinc Python. If no path is specified, then the paths given by the environment variables appended by MiniZinc's default locations will be tried. Args: path: List of locations to search. name: Name of the API or executable. Returns: Optional[Driver]: Returns a Driver object when found or None. """ driver: Optional[Driver] = None if path is None: path_bin = os.environ.get("PATH", "").split(os.pathsep) path_lib = os.environ.get("LD_LIBRARY_PATH", "").split(os.pathsep) path_lib.extend(os.environ.get("DYLD_LIBRARY_PATH", "").split(os.pathsep)) # Add default MiniZinc locations to the path if platform.system() == "Darwin": MAC_LOCATIONS = [ str(Path("/Applications/")), str( Path( "~/Applications/" ).expanduser() ), ] path_bin.extend(MAC_LOCATIONS) path_lib.extend(MAC_LOCATIONS) elif platform.system() == "Windows": WIN_LOCATIONS = [ str(Path("c:/Program Files/MiniZinc")), str(Path("c:/Program Files/MiniZinc IDE (bundled)")), str(Path("c:/Program Files (x86)/MiniZinc")), str(Path("c:/Program Files (x86)/MiniZinc IDE (bundled)")), ] path_bin.extend(WIN_LOCATIONS) path_lib.extend(WIN_LOCATIONS) else: path_bin = path path_lib = path path_bin_list = os.pathsep.join(path_bin) path_lib_list = os.pathsep.join(path_lib) # Try to load the MiniZinc C API env_backup = os.environ.copy() os.environ["LD_LIBRARY_PATH"] = path_lib_list os.environ["DYLD_LIBRARY_PATH"] = path_lib_list lib = find_library(name) os.environ.clear() os.environ.update(env_backup) if lib and Path(lib).suffix in [".dll", ".dylib", ".so"]: pass # TODO: # from minizinc.API import APIDriver # library = cdll.LoadLibrary(lib) # driver = APIDriver(library) else: # Try to locate the MiniZinc executable executable = shutil.which(name, path=path_bin_list) if executable is not None: from minizinc.CLI import CLIDriver driver = CLIDriver(Path(executable)) return driver