Files
OCRmyPDF/src/ocrmypdf/_plugin_manager.py
T
2020-11-11 02:59:37 -08:00

104 lines
3.0 KiB
Python

# © 2020 James R. Barlow: github.com/jbarlow83
#
# 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 http://mozilla.org/MPL/2.0/.
import argparse
import importlib
import importlib.util
import sys
from functools import partial
from pathlib import Path
from typing import Callable, List, Tuple, Union
import pluggy
from ocrmypdf import pluginspec
from ocrmypdf.cli import get_parser, plugins_only_parser
class OcrmypdfPluginManager(pluggy.PluginManager):
"""pluggy.PluginManager that can fork.
Capable of reconstructing itself in child workers.
Arguments:
setup_func: callback that initializes the plugin manager with all
standard plugins
"""
def __init__(
self, *args, setup_func: Callable[[pluggy.PluginManager], None], **kwargs
):
self._init_args = args
self._setup_func = setup_func
self._init_kwargs = kwargs
super().__init__(*args, **kwargs)
setup_func(self)
def __getstate__(self):
state = dict(
_init_args=self._init_args,
_setup_func=self._setup_func,
_init_kwargs=self._init_kwargs,
)
return state
def __setstate__(self, state):
self.__init__(
*state['_init_args'],
setup_func=state['_setup_func'],
**state['_init_kwargs'],
)
def _setup_plugins(
pm: pluggy.PluginManager, plugins: List[Union[str, Path]], builtins: bool = True
):
pm.add_hookspecs(pluginspec)
all_plugins: List[Union[str, Path]] = []
if builtins:
all_plugins.extend(
[
'ocrmypdf.builtin_plugins.ghostscript',
'ocrmypdf.builtin_plugins.tesseract_ocr',
]
)
all_plugins.extend(plugins)
for name in all_plugins:
if isinstance(name, Path) or name.endswith('.py'):
# Import by filename
module_name = Path(name).stem
spec = importlib.util.spec_from_file_location(module_name, name)
module = importlib.util.module_from_spec(spec)
sys.modules[module_name] = module
spec.loader.exec_module(module)
else:
# Import by dotted module name
module = importlib.import_module(name)
pm.register(module)
def get_plugin_manager(plugins: List[Union[str, Path]], builtins=True):
pm = OcrmypdfPluginManager(
project_name='ocrmypdf',
setup_func=partial(_setup_plugins, plugins=plugins, builtins=builtins),
)
return pm
def get_parser_options_plugins(
args,
) -> Tuple[argparse.ArgumentParser, argparse.Namespace, pluggy.PluginManager]:
pre_options, _unused = plugins_only_parser.parse_known_args(args=args)
plugin_manager = get_plugin_manager(pre_options.plugins)
parser = get_parser()
plugin_manager.hook.add_options(parser=parser) # pylint: disable=no-member
options = parser.parse_args(args=args)
return parser, options, plugin_manager