53 lines
1.6 KiB
Python
53 lines
1.6 KiB
Python
from importlib import _bootstrap_external, _bootstrap
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from urllib.parse import urlparse
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import dns.resolver
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import dns.exception
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class DnsImporter(_bootstrap_external._LoaderBasics):
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def __init__(self, path):
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if not isinstance(path, str):
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raise TypeError(f"expected str, not {type(path)!r}")
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url = urlparse(path)
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if not url.scheme in ('dns+pylib'):
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raise ValueError(f'url scheme not supported: `{url.scheme}`')
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self.base_domain = url.hostname
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def find_spec(self, fullname, target=None):
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module_domain = fullname.rpartition('.')[2] + '.' + self.base_domain
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domains = (
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(module_domain, False),
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('__init__.' + module_domain, True)
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)
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for (domain, is_package) in domains:
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try:
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answer = dns.resolver.resolve(domain, 'TXT')
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self.data = b''.join(
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string
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for rdata in answer
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for string in rdata.strings
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)
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self.domain = domain
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except dns.exception.DNSException as e:
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continue
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spec = _bootstrap.ModuleSpec(
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fullname,
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self, # loader
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origin=f'dns+pylib://{self.domain}',
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is_package=is_package
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)
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if is_package:
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spec.submodule_search_locations.append(f'dns+pylib://{module_domain}')
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return spec
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return None
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def get_code(self, fullname):
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return compile(self.data, self.domain, 'exec', dont_inherit=True)
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