| import json |
| import os |
| import sys |
| import tempfile |
| import threading |
| from contextlib import contextmanager |
| from os.path import abspath |
| from os.path import join as pjoin |
| from subprocess import STDOUT, check_call, check_output |
| |
| from .in_process import _in_proc_script_path |
| |
| __all__ = [ |
| 'BackendUnavailable', |
| 'BackendInvalid', |
| 'HookMissing', |
| 'UnsupportedOperation', |
| 'default_subprocess_runner', |
| 'quiet_subprocess_runner', |
| 'Pep517HookCaller', |
| ] |
| |
| |
| def write_json(obj, path, **kwargs): |
| with open(path, 'w', encoding='utf-8') as f: |
| json.dump(obj, f, **kwargs) |
| |
| |
| def read_json(path): |
| with open(path, encoding='utf-8') as f: |
| return json.load(f) |
| |
| |
| class BackendUnavailable(Exception): |
| """Will be raised if the backend cannot be imported in the hook process.""" |
| def __init__(self, traceback): |
| self.traceback = traceback |
| |
| |
| class BackendInvalid(Exception): |
| """Will be raised if the backend is invalid.""" |
| def __init__(self, backend_name, backend_path, message): |
| self.backend_name = backend_name |
| self.backend_path = backend_path |
| self.message = message |
| |
| |
| class HookMissing(Exception): |
| """Will be raised on missing hooks.""" |
| def __init__(self, hook_name): |
| super().__init__(hook_name) |
| self.hook_name = hook_name |
| |
| |
| class UnsupportedOperation(Exception): |
| """May be raised by build_sdist if the backend indicates that it can't.""" |
| def __init__(self, traceback): |
| self.traceback = traceback |
| |
| |
| def default_subprocess_runner(cmd, cwd=None, extra_environ=None): |
| """The default method of calling the wrapper subprocess.""" |
| env = os.environ.copy() |
| if extra_environ: |
| env.update(extra_environ) |
| |
| check_call(cmd, cwd=cwd, env=env) |
| |
| |
| def quiet_subprocess_runner(cmd, cwd=None, extra_environ=None): |
| """A method of calling the wrapper subprocess while suppressing output.""" |
| env = os.environ.copy() |
| if extra_environ: |
| env.update(extra_environ) |
| |
| check_output(cmd, cwd=cwd, env=env, stderr=STDOUT) |
| |
| |
| def norm_and_check(source_tree, requested): |
| """Normalise and check a backend path. |
| |
| Ensure that the requested backend path is specified as a relative path, |
| and resolves to a location under the given source tree. |
| |
| Return an absolute version of the requested path. |
| """ |
| if os.path.isabs(requested): |
| raise ValueError("paths must be relative") |
| |
| abs_source = os.path.abspath(source_tree) |
| abs_requested = os.path.normpath(os.path.join(abs_source, requested)) |
| # We have to use commonprefix for Python 2.7 compatibility. So we |
| # normalise case to avoid problems because commonprefix is a character |
| # based comparison :-( |
| norm_source = os.path.normcase(abs_source) |
| norm_requested = os.path.normcase(abs_requested) |
| if os.path.commonprefix([norm_source, norm_requested]) != norm_source: |
| raise ValueError("paths must be inside source tree") |
| |
| return abs_requested |
| |
| |
| class Pep517HookCaller: |
| """A wrapper around a source directory to be built with a PEP 517 backend. |
| |
| :param source_dir: The path to the source directory, containing |
| pyproject.toml. |
| :param build_backend: The build backend spec, as per PEP 517, from |
| pyproject.toml. |
| :param backend_path: The backend path, as per PEP 517, from pyproject.toml. |
| :param runner: A callable that invokes the wrapper subprocess. |
| :param python_executable: The Python executable used to invoke the backend |
| |
| The 'runner', if provided, must expect the following: |
| |
| - cmd: a list of strings representing the command and arguments to |
| execute, as would be passed to e.g. 'subprocess.check_call'. |
| - cwd: a string representing the working directory that must be |
| used for the subprocess. Corresponds to the provided source_dir. |
| - extra_environ: a dict mapping environment variable names to values |
| which must be set for the subprocess execution. |
| """ |
| def __init__( |
| self, |
| source_dir, |
| build_backend, |
| backend_path=None, |
| runner=None, |
| python_executable=None, |
| ): |
| if runner is None: |
| runner = default_subprocess_runner |
| |
| self.source_dir = abspath(source_dir) |
| self.build_backend = build_backend |
| if backend_path: |
| backend_path = [ |
| norm_and_check(self.source_dir, p) for p in backend_path |
| ] |
| self.backend_path = backend_path |
| self._subprocess_runner = runner |
| if not python_executable: |
| python_executable = sys.executable |
| self.python_executable = python_executable |
| |
| @contextmanager |
| def subprocess_runner(self, runner): |
| """A context manager for temporarily overriding the default subprocess |
| runner. |
| """ |
| prev = self._subprocess_runner |
| self._subprocess_runner = runner |
| try: |
| yield |
| finally: |
| self._subprocess_runner = prev |
| |
| def _supported_features(self): |
| """Return the list of optional features supported by the backend.""" |
| return self._call_hook('_supported_features', {}) |
| |
| def get_requires_for_build_wheel(self, config_settings=None): |
| """Identify packages required for building a wheel |
| |
| Returns a list of dependency specifications, e.g.:: |
| |
| ["wheel >= 0.25", "setuptools"] |
| |
| This does not include requirements specified in pyproject.toml. |
| It returns the result of calling the equivalently named hook in a |
| subprocess. |
| """ |
| return self._call_hook('get_requires_for_build_wheel', { |
| 'config_settings': config_settings |
| }) |
| |
| def prepare_metadata_for_build_wheel( |
| self, metadata_directory, config_settings=None, |
| _allow_fallback=True): |
| """Prepare a ``*.dist-info`` folder with metadata for this project. |
| |
| Returns the name of the newly created folder. |
| |
| If the build backend defines a hook with this name, it will be called |
| in a subprocess. If not, the backend will be asked to build a wheel, |
| and the dist-info extracted from that (unless _allow_fallback is |
| False). |
| """ |
| return self._call_hook('prepare_metadata_for_build_wheel', { |
| 'metadata_directory': abspath(metadata_directory), |
| 'config_settings': config_settings, |
| '_allow_fallback': _allow_fallback, |
| }) |
| |
| def build_wheel( |
| self, wheel_directory, config_settings=None, |
| metadata_directory=None): |
| """Build a wheel from this project. |
| |
| Returns the name of the newly created file. |
| |
| In general, this will call the 'build_wheel' hook in the backend. |
| However, if that was previously called by |
| 'prepare_metadata_for_build_wheel', and the same metadata_directory is |
| used, the previously built wheel will be copied to wheel_directory. |
| """ |
| if metadata_directory is not None: |
| metadata_directory = abspath(metadata_directory) |
| return self._call_hook('build_wheel', { |
| 'wheel_directory': abspath(wheel_directory), |
| 'config_settings': config_settings, |
| 'metadata_directory': metadata_directory, |
| }) |
| |
| def get_requires_for_build_editable(self, config_settings=None): |
| """Identify packages required for building an editable wheel |
| |
| Returns a list of dependency specifications, e.g.:: |
| |
| ["wheel >= 0.25", "setuptools"] |
| |
| This does not include requirements specified in pyproject.toml. |
| It returns the result of calling the equivalently named hook in a |
| subprocess. |
| """ |
| return self._call_hook('get_requires_for_build_editable', { |
| 'config_settings': config_settings |
| }) |
| |
| def prepare_metadata_for_build_editable( |
| self, metadata_directory, config_settings=None, |
| _allow_fallback=True): |
| """Prepare a ``*.dist-info`` folder with metadata for this project. |
| |
| Returns the name of the newly created folder. |
| |
| If the build backend defines a hook with this name, it will be called |
| in a subprocess. If not, the backend will be asked to build an editable |
| wheel, and the dist-info extracted from that (unless _allow_fallback is |
| False). |
| """ |
| return self._call_hook('prepare_metadata_for_build_editable', { |
| 'metadata_directory': abspath(metadata_directory), |
| 'config_settings': config_settings, |
| '_allow_fallback': _allow_fallback, |
| }) |
| |
| def build_editable( |
| self, wheel_directory, config_settings=None, |
| metadata_directory=None): |
| """Build an editable wheel from this project. |
| |
| Returns the name of the newly created file. |
| |
| In general, this will call the 'build_editable' hook in the backend. |
| However, if that was previously called by |
| 'prepare_metadata_for_build_editable', and the same metadata_directory |
| is used, the previously built wheel will be copied to wheel_directory. |
| """ |
| if metadata_directory is not None: |
| metadata_directory = abspath(metadata_directory) |
| return self._call_hook('build_editable', { |
| 'wheel_directory': abspath(wheel_directory), |
| 'config_settings': config_settings, |
| 'metadata_directory': metadata_directory, |
| }) |
| |
| def get_requires_for_build_sdist(self, config_settings=None): |
| """Identify packages required for building a wheel |
| |
| Returns a list of dependency specifications, e.g.:: |
| |
| ["setuptools >= 26"] |
| |
| This does not include requirements specified in pyproject.toml. |
| It returns the result of calling the equivalently named hook in a |
| subprocess. |
| """ |
| return self._call_hook('get_requires_for_build_sdist', { |
| 'config_settings': config_settings |
| }) |
| |
| def build_sdist(self, sdist_directory, config_settings=None): |
| """Build an sdist from this project. |
| |
| Returns the name of the newly created file. |
| |
| This calls the 'build_sdist' backend hook in a subprocess. |
| """ |
| return self._call_hook('build_sdist', { |
| 'sdist_directory': abspath(sdist_directory), |
| 'config_settings': config_settings, |
| }) |
| |
| def _call_hook(self, hook_name, kwargs): |
| extra_environ = {'PEP517_BUILD_BACKEND': self.build_backend} |
| |
| if self.backend_path: |
| backend_path = os.pathsep.join(self.backend_path) |
| extra_environ['PEP517_BACKEND_PATH'] = backend_path |
| |
| with tempfile.TemporaryDirectory() as td: |
| hook_input = {'kwargs': kwargs} |
| write_json(hook_input, pjoin(td, 'input.json'), indent=2) |
| |
| # Run the hook in a subprocess |
| with _in_proc_script_path() as script: |
| python = self.python_executable |
| self._subprocess_runner( |
| [python, abspath(str(script)), hook_name, td], |
| cwd=self.source_dir, |
| extra_environ=extra_environ |
| ) |
| |
| data = read_json(pjoin(td, 'output.json')) |
| if data.get('unsupported'): |
| raise UnsupportedOperation(data.get('traceback', '')) |
| if data.get('no_backend'): |
| raise BackendUnavailable(data.get('traceback', '')) |
| if data.get('backend_invalid'): |
| raise BackendInvalid( |
| backend_name=self.build_backend, |
| backend_path=self.backend_path, |
| message=data.get('backend_error', '') |
| ) |
| if data.get('hook_missing'): |
| raise HookMissing(data.get('missing_hook_name') or hook_name) |
| return data['return_val'] |
| |
| |
| class LoggerWrapper(threading.Thread): |
| """ |
| Read messages from a pipe and redirect them |
| to a logger (see python's logging module). |
| """ |
| |
| def __init__(self, logger, level): |
| threading.Thread.__init__(self) |
| self.daemon = True |
| |
| self.logger = logger |
| self.level = level |
| |
| # create the pipe and reader |
| self.fd_read, self.fd_write = os.pipe() |
| self.reader = os.fdopen(self.fd_read) |
| |
| self.start() |
| |
| def fileno(self): |
| return self.fd_write |
| |
| @staticmethod |
| def remove_newline(msg): |
| return msg[:-1] if msg.endswith(os.linesep) else msg |
| |
| def run(self): |
| for line in self.reader: |
| self._write(self.remove_newline(line)) |
| |
| def _write(self, message): |
| self.logger.log(self.level, message) |
