Move importlib.abc.SourceLoader to _bootstrap.
Required updating code relying on other modules to switch to _bootstrap's
unique module requirements. This led to the realization that
get_code was being too liberal in its exception catching when calling set_data
by blindly grabbing IOError. Shifted the responsibility of safely ignoring
writes to a read-only path to set_data.
Importlib is still not relying on SourceLoader yet; requires creating a
SourcelessLoader and updating the source finder.
diff --git a/Lib/importlib/abc.py b/Lib/importlib/abc.py
index 6a688d1..a9cd3c8 100644
--- a/Lib/importlib/abc.py
+++ b/Lib/importlib/abc.py
@@ -100,7 +100,7 @@
raise NotImplementedError
-class SourceLoader(ResourceLoader, ExecutionLoader):
+class SourceLoader(_bootstrap.SourceLoader, ResourceLoader, ExecutionLoader):
"""Abstract base class for loading source code (and optionally any
corresponding bytecode).
@@ -117,106 +117,6 @@
"""
- def path_mtime(self, path:str) -> int:
- """Optional method that returns the modification time for the specified
- path.
-
- Implementing this method allows the loader to read bytecode files.
-
- """
- raise NotImplementedError
-
- def set_data(self, path:str, data:bytes) -> None:
- """Optional method which writes data to a file path.
-
- Implementing this method allows for the writing of bytecode files.
-
- """
- raise NotImplementedError
-
- def is_package(self, fullname):
- """Concrete implementation of InspectLoader.is_package by checking if
- the path returned by get_filename has a filename of '__init__.py'."""
- filename = os.path.basename(self.get_filename(fullname))
- return os.path.splitext(filename)[0] == '__init__'
-
- def get_source(self, fullname):
- """Concrete implementation of InspectLoader.get_source."""
- path = self.get_filename(fullname)
- try:
- source_bytes = self.get_data(path)
- except IOError:
- raise ImportError("source not available through get_data()")
- encoding = tokenize.detect_encoding(io.BytesIO(source_bytes).readline)
- return source_bytes.decode(encoding[0])
-
- def get_code(self, fullname):
- """Concrete implementation of InspectLoader.get_code.
-
- Reading of bytecode requires path_mtime to be implemented. To write
- bytecode, set_data must also be implemented.
-
- """
- source_path = self.get_filename(fullname)
- bytecode_path = imp.cache_from_source(source_path)
- source_mtime = None
- if bytecode_path is not None:
- try:
- source_mtime = self.path_mtime(source_path)
- except NotImplementedError:
- pass
- else:
- try:
- data = self.get_data(bytecode_path)
- except IOError:
- pass
- else:
- magic = data[:4]
- raw_timestamp = data[4:8]
- if (len(magic) == 4 and len(raw_timestamp) == 4 and
- magic == imp.get_magic() and
- marshal._r_long(raw_timestamp) == source_mtime):
- return marshal.loads(data[8:])
- source_bytes = self.get_data(source_path)
- code_object = compile(source_bytes, source_path, 'exec',
- dont_inherit=True)
- if (not sys.dont_write_bytecode and bytecode_path is not None and
- source_mtime is not None):
- # If e.g. Jython ever implements imp.cache_from_source to have
- # their own cached file format, this block of code will most likely
- # throw an exception.
- data = bytearray(imp.get_magic())
- data.extend(marshal._w_long(source_mtime))
- data.extend(marshal.dumps(code_object))
- try:
- self.set_data(bytecode_path, data)
- except (NotImplementedError, IOError):
- pass
- return code_object
-
- @util.module_for_loader
- def load_module(self, module):
- """Concrete implementation of Loader.load_module.
-
- Requires ExecutionLoader.get_filename and ResourceLoader.get_data to be
- implemented to load source code. Use of bytecode is dictated by whether
- get_code uses/writes bytecode.
-
- """
- name = module.__name__
- code_object = self.get_code(name)
- module.__file__ = self.get_filename(name)
- module.__cached__ = imp.cache_from_source(module.__file__)
- module.__package__ = name
- is_package = self.is_package(name)
- if is_package:
- module.__path__ = [os.path.dirname(module.__file__)]
- else:
- module.__package__ = module.__package__.rpartition('.')[0]
- module.__loader__ = self
- exec(code_object, module.__dict__)
- return module
-
class PyLoader(SourceLoader):