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merge latest feature to master branch
Commit Description:
merge latest feature to master branch
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lib/assets/Lib/importlib/_bootstrap.py
| 1781 lines
| 64.0 KiB
| text/x-python
| PythonLexer
|
r584 | """Core implementation of import. | |||
This module is NOT meant to be directly imported! It has been designed such | ||||
that it can be bootstrapped into Python as the implementation of import. As | ||||
such it requires the injection of specific modules and attributes in order to | ||||
work. One should use importlib as the public-facing version of this module. | ||||
""" | ||||
# | ||||
# IMPORTANT: Whenever making changes to this module, be sure to run | ||||
# a top-level make in order to get the frozen version of the module | ||||
# update. Not doing so, will result in the Makefile to fail for | ||||
# all others who don't have a ./python around to freeze the module | ||||
# in the early stages of compilation. | ||||
# | ||||
# See importlib._setup() for what is injected into the global namespace. | ||||
# When editing this code be aware that code executed at import time CANNOT | ||||
# reference any injected objects! This includes not only global code but also | ||||
# anything specified at the class level. | ||||
# XXX Make sure all public names have no single leading underscore and all | ||||
# others do. | ||||
# Bootstrap-related code ###################################################### | ||||
_CASE_INSENSITIVE_PLATFORMS = 'win', 'cygwin', 'darwin' | ||||
def _make_relax_case(): | ||||
if sys.platform.startswith(_CASE_INSENSITIVE_PLATFORMS): | ||||
def _relax_case(): | ||||
"""True if filenames must be checked case-insensitively.""" | ||||
return b'PYTHONCASEOK' in _os.environ | ||||
else: | ||||
def _relax_case(): | ||||
"""True if filenames must be checked case-insensitively.""" | ||||
return False | ||||
return _relax_case | ||||
# TODO: Expose from marshal | ||||
def _w_long(x): | ||||
"""Convert a 32-bit integer to little-endian. | ||||
XXX Temporary until marshal's long functions are exposed. | ||||
""" | ||||
x = int(x) | ||||
int_bytes = [] | ||||
int_bytes.append(x & 0xFF) | ||||
int_bytes.append((x >> 8) & 0xFF) | ||||
int_bytes.append((x >> 16) & 0xFF) | ||||
int_bytes.append((x >> 24) & 0xFF) | ||||
return bytearray(int_bytes) | ||||
# TODO: Expose from marshal | ||||
def _r_long(int_bytes): | ||||
"""Convert 4 bytes in little-endian to an integer. | ||||
XXX Temporary until marshal's long function are exposed. | ||||
""" | ||||
x = int_bytes[0] | ||||
x |= int_bytes[1] << 8 | ||||
x |= int_bytes[2] << 16 | ||||
x |= int_bytes[3] << 24 | ||||
return x | ||||
def _path_join(*path_parts): | ||||
"""Replacement for os.path.join().""" | ||||
new_parts = [] | ||||
for part in path_parts: | ||||
if not part: | ||||
continue | ||||
new_parts.append(part) | ||||
if part[-1] not in path_separators: | ||||
new_parts.append(path_sep) | ||||
return ''.join(new_parts[:-1]) # Drop superfluous path separator. | ||||
def _path_split(path): | ||||
"""Replacement for os.path.split().""" | ||||
for x in reversed(path): | ||||
if x in path_separators: | ||||
sep = x | ||||
break | ||||
else: | ||||
sep = path_sep | ||||
front, _, tail = path.rpartition(sep) | ||||
return front, tail | ||||
def _path_is_mode_type(path, mode): | ||||
"""Test whether the path is the specified mode type.""" | ||||
try: | ||||
stat_info = _os.stat(path) | ||||
except OSError: | ||||
return False | ||||
return (stat_info.st_mode & 0o170000) == mode | ||||
# XXX Could also expose Modules/getpath.c:isfile() | ||||
def _path_isfile(path): | ||||
"""Replacement for os.path.isfile.""" | ||||
return _path_is_mode_type(path, 0o100000) | ||||
# XXX Could also expose Modules/getpath.c:isdir() | ||||
def _path_isdir(path): | ||||
"""Replacement for os.path.isdir.""" | ||||
if not path: | ||||
path = _os.getcwd() | ||||
return _path_is_mode_type(path, 0o040000) | ||||
def _write_atomic(path, data, mode=0o666): | ||||
"""Best-effort function to write data to a path atomically. | ||||
Be prepared to handle a FileExistsError if concurrent writing of the | ||||
temporary file is attempted.""" | ||||
# id() is used to generate a pseudo-random filename. | ||||
path_tmp = '{}.{}'.format(path, id(path)) | ||||
fd = _os.open(path_tmp, | ||||
_os.O_EXCL | _os.O_CREAT | _os.O_WRONLY, mode & 0o666) | ||||
try: | ||||
# We first write data to a temporary file, and then use os.replace() to | ||||
# perform an atomic rename. | ||||
with _io.FileIO(fd, 'wb') as file: | ||||
file.write(data) | ||||
_os.replace(path_tmp, path) | ||||
except OSError: | ||||
try: | ||||
_os.unlink(path_tmp) | ||||
except OSError: | ||||
pass | ||||
raise | ||||
def _wrap(new, old): | ||||
"""Simple substitute for functools.update_wrapper.""" | ||||
for replace in ['__module__', '__name__', '__qualname__', '__doc__']: | ||||
if hasattr(old, replace): | ||||
setattr(new, replace, getattr(old, replace)) | ||||
new.__dict__.update(old.__dict__) | ||||
_code_type = type(_wrap.__code__) | ||||
def new_module(name): | ||||
"""Create a new module. | ||||
The module is not entered into sys.modules. | ||||
""" | ||||
return type(_io)(name) | ||||
# Module-level locking ######################################################## | ||||
# A dict mapping module names to weakrefs of _ModuleLock instances | ||||
_module_locks = {} | ||||
# A dict mapping thread ids to _ModuleLock instances | ||||
_blocking_on = {} | ||||
class _DeadlockError(RuntimeError): | ||||
pass | ||||
class _ModuleLock: | ||||
"""A recursive lock implementation which is able to detect deadlocks | ||||
(e.g. thread 1 trying to take locks A then B, and thread 2 trying to | ||||
take locks B then A). | ||||
""" | ||||
def __init__(self, name): | ||||
self.lock = _thread.allocate_lock() | ||||
self.wakeup = _thread.allocate_lock() | ||||
self.name = name | ||||
self.owner = None | ||||
self.count = 0 | ||||
self.waiters = 0 | ||||
def has_deadlock(self): | ||||
# Deadlock avoidance for concurrent circular imports. | ||||
me = _thread.get_ident() | ||||
tid = self.owner | ||||
while True: | ||||
lock = _blocking_on.get(tid) | ||||
if lock is None: | ||||
return False | ||||
tid = lock.owner | ||||
if tid == me: | ||||
return True | ||||
def acquire(self): | ||||
""" | ||||
Acquire the module lock. If a potential deadlock is detected, | ||||
a _DeadlockError is raised. | ||||
Otherwise, the lock is always acquired and True is returned. | ||||
""" | ||||
tid = _thread.get_ident() | ||||
_blocking_on[tid] = self | ||||
try: | ||||
while True: | ||||
with self.lock: | ||||
if self.count == 0 or self.owner == tid: | ||||
self.owner = tid | ||||
self.count += 1 | ||||
return True | ||||
if self.has_deadlock(): | ||||
raise _DeadlockError("deadlock detected by %r" % self) | ||||
if self.wakeup.acquire(False): | ||||
self.waiters += 1 | ||||
# Wait for a release() call | ||||
self.wakeup.acquire() | ||||
self.wakeup.release() | ||||
finally: | ||||
del _blocking_on[tid] | ||||
def release(self): | ||||
tid = _thread.get_ident() | ||||
with self.lock: | ||||
if self.owner != tid: | ||||
raise RuntimeError("cannot release un-acquired lock") | ||||
assert self.count > 0 | ||||
self.count -= 1 | ||||
if self.count == 0: | ||||
self.owner = None | ||||
if self.waiters: | ||||
self.waiters -= 1 | ||||
self.wakeup.release() | ||||
def __repr__(self): | ||||
return "_ModuleLock(%r) at %d" % (self.name, id(self)) | ||||
class _DummyModuleLock: | ||||
"""A simple _ModuleLock equivalent for Python builds without | ||||
multi-threading support.""" | ||||
def __init__(self, name): | ||||
self.name = name | ||||
self.count = 0 | ||||
def acquire(self): | ||||
self.count += 1 | ||||
return True | ||||
def release(self): | ||||
if self.count == 0: | ||||
raise RuntimeError("cannot release un-acquired lock") | ||||
self.count -= 1 | ||||
def __repr__(self): | ||||
return "_DummyModuleLock(%r) at %d" % (self.name, id(self)) | ||||
# The following two functions are for consumption by Python/import.c. | ||||
def _get_module_lock(name): | ||||
"""Get or create the module lock for a given module name. | ||||
Should only be called with the import lock taken.""" | ||||
lock = None | ||||
try: | ||||
lock = _module_locks[name]() | ||||
except KeyError: | ||||
pass | ||||
if lock is None: | ||||
if _thread is None: | ||||
lock = _DummyModuleLock(name) | ||||
else: | ||||
lock = _ModuleLock(name) | ||||
def cb(_): | ||||
del _module_locks[name] | ||||
_module_locks[name] = _weakref.ref(lock, cb) | ||||
return lock | ||||
def _lock_unlock_module(name): | ||||
"""Release the global import lock, and acquires then release the | ||||
module lock for a given module name. | ||||
This is used to ensure a module is completely initialized, in the | ||||
event it is being imported by another thread. | ||||
Should only be called with the import lock taken.""" | ||||
lock = _get_module_lock(name) | ||||
_imp.release_lock() | ||||
try: | ||||
lock.acquire() | ||||
except _DeadlockError: | ||||
# Concurrent circular import, we'll accept a partially initialized | ||||
# module object. | ||||
pass | ||||
else: | ||||
lock.release() | ||||
# Frame stripping magic ############################################### | ||||
def _call_with_frames_removed(f, *args, **kwds): | ||||
"""remove_importlib_frames in import.c will always remove sequences | ||||
of importlib frames that end with a call to this function | ||||
Use it instead of a normal call in places where including the importlib | ||||
frames introduces unwanted noise into the traceback (e.g. when executing | ||||
module code) | ||||
""" | ||||
return f(*args, **kwds) | ||||
# Finder/loader utility code ############################################### | ||||
"""Magic word to reject .pyc files generated by other Python versions. | ||||
It should change for each incompatible change to the bytecode. | ||||
The value of CR and LF is incorporated so if you ever read or write | ||||
a .pyc file in text mode the magic number will be wrong; also, the | ||||
Apple MPW compiler swaps their values, botching string constants. | ||||
The magic numbers must be spaced apart at least 2 values, as the | ||||
-U interpeter flag will cause MAGIC+1 being used. They have been | ||||
odd numbers for some time now. | ||||
There were a variety of old schemes for setting the magic number. | ||||
The current working scheme is to increment the previous value by | ||||
10. | ||||
Starting with the adoption of PEP 3147 in Python 3.2, every bump in magic | ||||
number also includes a new "magic tag", i.e. a human readable string used | ||||
to represent the magic number in __pycache__ directories. When you change | ||||
the magic number, you must also set a new unique magic tag. Generally this | ||||
can be named after the Python major version of the magic number bump, but | ||||
it can really be anything, as long as it's different than anything else | ||||
that's come before. The tags are included in the following table, starting | ||||
with Python 3.2a0. | ||||
Known values: | ||||
Python 1.5: 20121 | ||||
Python 1.5.1: 20121 | ||||
Python 1.5.2: 20121 | ||||
Python 1.6: 50428 | ||||
Python 2.0: 50823 | ||||
Python 2.0.1: 50823 | ||||
Python 2.1: 60202 | ||||
Python 2.1.1: 60202 | ||||
Python 2.1.2: 60202 | ||||
Python 2.2: 60717 | ||||
Python 2.3a0: 62011 | ||||
Python 2.3a0: 62021 | ||||
Python 2.3a0: 62011 (!) | ||||
Python 2.4a0: 62041 | ||||
Python 2.4a3: 62051 | ||||
Python 2.4b1: 62061 | ||||
Python 2.5a0: 62071 | ||||
Python 2.5a0: 62081 (ast-branch) | ||||
Python 2.5a0: 62091 (with) | ||||
Python 2.5a0: 62092 (changed WITH_CLEANUP opcode) | ||||
Python 2.5b3: 62101 (fix wrong code: for x, in ...) | ||||
Python 2.5b3: 62111 (fix wrong code: x += yield) | ||||
Python 2.5c1: 62121 (fix wrong lnotab with for loops and | ||||
storing constants that should have been removed) | ||||
Python 2.5c2: 62131 (fix wrong code: for x, in ... in listcomp/genexp) | ||||
Python 2.6a0: 62151 (peephole optimizations and STORE_MAP opcode) | ||||
Python 2.6a1: 62161 (WITH_CLEANUP optimization) | ||||
Python 3000: 3000 | ||||
3010 (removed UNARY_CONVERT) | ||||
3020 (added BUILD_SET) | ||||
3030 (added keyword-only parameters) | ||||
3040 (added signature annotations) | ||||
3050 (print becomes a function) | ||||
3060 (PEP 3115 metaclass syntax) | ||||
3061 (string literals become unicode) | ||||
3071 (PEP 3109 raise changes) | ||||
3081 (PEP 3137 make __file__ and __name__ unicode) | ||||
3091 (kill str8 interning) | ||||
3101 (merge from 2.6a0, see 62151) | ||||
3103 (__file__ points to source file) | ||||
Python 3.0a4: 3111 (WITH_CLEANUP optimization). | ||||
Python 3.0a5: 3131 (lexical exception stacking, including POP_EXCEPT) | ||||
Python 3.1a0: 3141 (optimize list, set and dict comprehensions: | ||||
change LIST_APPEND and SET_ADD, add MAP_ADD) | ||||
Python 3.1a0: 3151 (optimize conditional branches: | ||||
introduce POP_JUMP_IF_FALSE and POP_JUMP_IF_TRUE) | ||||
Python 3.2a0: 3160 (add SETUP_WITH) | ||||
tag: cpython-32 | ||||
Python 3.2a1: 3170 (add DUP_TOP_TWO, remove DUP_TOPX and ROT_FOUR) | ||||
tag: cpython-32 | ||||
Python 3.2a2 3180 (add DELETE_DEREF) | ||||
Python 3.3a0 3190 __class__ super closure changed | ||||
Python 3.3a0 3200 (__qualname__ added) | ||||
3210 (added size modulo 2**32 to the pyc header) | ||||
Python 3.3a1 3220 (changed PEP 380 implementation) | ||||
Python 3.3a4 3230 (revert changes to implicit __class__ closure) | ||||
MAGIC must change whenever the bytecode emitted by the compiler may no | ||||
longer be understood by older implementations of the eval loop (usually | ||||
due to the addition of new opcodes). | ||||
""" | ||||
_RAW_MAGIC_NUMBER = 3230 | ord('\r') << 16 | ord('\n') << 24 | ||||
_MAGIC_BYTES = bytes(_RAW_MAGIC_NUMBER >> n & 0xff for n in range(0, 25, 8)) | ||||
_PYCACHE = '__pycache__' | ||||
SOURCE_SUFFIXES = ['.py'] # _setup() adds .pyw as needed. | ||||
DEBUG_BYTECODE_SUFFIXES = ['.pyc'] | ||||
OPTIMIZED_BYTECODE_SUFFIXES = ['.pyo'] | ||||
def cache_from_source(path, debug_override=None): | ||||
"""Given the path to a .py file, return the path to its .pyc/.pyo file. | ||||
The .py file does not need to exist; this simply returns the path to the | ||||
.pyc/.pyo file calculated as if the .py file were imported. The extension | ||||
will be .pyc unless sys.flags.optimize is non-zero, then it will be .pyo. | ||||
If debug_override is not None, then it must be a boolean and is used in | ||||
place of sys.flags.optimize. | ||||
If sys.implementation.cache_tag is None then NotImplementedError is raised. | ||||
""" | ||||
debug = not sys.flags.optimize if debug_override is None else debug_override | ||||
if debug: | ||||
suffixes = DEBUG_BYTECODE_SUFFIXES | ||||
else: | ||||
suffixes = OPTIMIZED_BYTECODE_SUFFIXES | ||||
head, tail = _path_split(path) | ||||
base_filename, sep, _ = tail.partition('.') | ||||
tag = sys.implementation.cache_tag | ||||
if tag is None: | ||||
raise NotImplementedError('sys.implementation.cache_tag is None') | ||||
filename = ''.join([base_filename, sep, tag, suffixes[0]]) | ||||
return _path_join(head, _PYCACHE, filename) | ||||
def source_from_cache(path): | ||||
"""Given the path to a .pyc./.pyo file, return the path to its .py file. | ||||
The .pyc/.pyo file does not need to exist; this simply returns the path to | ||||
the .py file calculated to correspond to the .pyc/.pyo file. If path does | ||||
not conform to PEP 3147 format, ValueError will be raised. If | ||||
sys.implementation.cache_tag is None then NotImplementedError is raised. | ||||
""" | ||||
if sys.implementation.cache_tag is None: | ||||
raise NotImplementedError('sys.implementation.cache_tag is None') | ||||
head, pycache_filename = _path_split(path) | ||||
head, pycache = _path_split(head) | ||||
if pycache != _PYCACHE: | ||||
raise ValueError('{} not bottom-level directory in ' | ||||
'{!r}'.format(_PYCACHE, path)) | ||||
if pycache_filename.count('.') != 2: | ||||
raise ValueError('expected only 2 dots in ' | ||||
'{!r}'.format(pycache_filename)) | ||||
base_filename = pycache_filename.partition('.')[0] | ||||
return _path_join(head, base_filename + SOURCE_SUFFIXES[0]) | ||||
def _get_sourcefile(bytecode_path): | ||||
"""Convert a bytecode file path to a source path (if possible). | ||||
This function exists purely for backwards-compatibility for | ||||
PyImport_ExecCodeModuleWithFilenames() in the C API. | ||||
""" | ||||
if len(bytecode_path) == 0: | ||||
return None | ||||
rest, _, extension = bytecode_path.rpartition('.') | ||||
if not rest or extension.lower()[-3:-1] != 'py': | ||||
return bytecode_path | ||||
try: | ||||
source_path = source_from_cache(bytecode_path) | ||||
except (NotImplementedError, ValueError): | ||||
source_path = bytecode_path[:-1] | ||||
return source_path if _path_isfile(source_path) else bytecode_path | ||||
def _verbose_message(message, *args, verbosity=1): | ||||
"""Print the message to stderr if -v/PYTHONVERBOSE is turned on.""" | ||||
if sys.flags.verbose >= verbosity: | ||||
if not message.startswith(('#', 'import ')): | ||||
message = '# ' + message | ||||
print(message.format(*args), file=sys.stderr) | ||||
def set_package(fxn): | ||||
"""Set __package__ on the returned module.""" | ||||
def set_package_wrapper(*args, **kwargs): | ||||
module = fxn(*args, **kwargs) | ||||
if getattr(module, '__package__', None) is None: | ||||
module.__package__ = module.__name__ | ||||
if not hasattr(module, '__path__'): | ||||
module.__package__ = module.__package__.rpartition('.')[0] | ||||
return module | ||||
_wrap(set_package_wrapper, fxn) | ||||
return set_package_wrapper | ||||
def set_loader(fxn): | ||||
"""Set __loader__ on the returned module.""" | ||||
def set_loader_wrapper(self, *args, **kwargs): | ||||
module = fxn(self, *args, **kwargs) | ||||
if not hasattr(module, '__loader__'): | ||||
module.__loader__ = self | ||||
return module | ||||
_wrap(set_loader_wrapper, fxn) | ||||
return set_loader_wrapper | ||||
def module_for_loader(fxn): | ||||
"""Decorator to handle selecting the proper module for loaders. | ||||
The decorated function is passed the module to use instead of the module | ||||
name. The module passed in to the function is either from sys.modules if | ||||
it already exists or is a new module. If the module is new, then __name__ | ||||
is set the first argument to the method, __loader__ is set to self, and | ||||
__package__ is set accordingly (if self.is_package() is defined) will be set | ||||
before it is passed to the decorated function (if self.is_package() does | ||||
not work for the module it will be set post-load). | ||||
If an exception is raised and the decorator created the module it is | ||||
subsequently removed from sys.modules. | ||||
The decorator assumes that the decorated function takes the module name as | ||||
the second argument. | ||||
""" | ||||
def module_for_loader_wrapper(self, fullname, *args, **kwargs): | ||||
module = sys.modules.get(fullname) | ||||
is_reload = module is not None | ||||
if not is_reload: | ||||
# This must be done before open() is called as the 'io' module | ||||
# implicitly imports 'locale' and would otherwise trigger an | ||||
# infinite loop. | ||||
module = new_module(fullname) | ||||
# This must be done before putting the module in sys.modules | ||||
# (otherwise an optimization shortcut in import.c becomes wrong) | ||||
module.__initializing__ = True | ||||
sys.modules[fullname] = module | ||||
module.__loader__ = self | ||||
try: | ||||
is_package = self.is_package(fullname) | ||||
except (ImportError, AttributeError): | ||||
pass | ||||
else: | ||||
if is_package: | ||||
module.__package__ = fullname | ||||
else: | ||||
module.__package__ = fullname.rpartition('.')[0] | ||||
else: | ||||
module.__initializing__ = True | ||||
try: | ||||
# If __package__ was not set above, __import__() will do it later. | ||||
return fxn(self, module, *args, **kwargs) | ||||
except: | ||||
if not is_reload: | ||||
del sys.modules[fullname] | ||||
raise | ||||
finally: | ||||
module.__initializing__ = False | ||||
_wrap(module_for_loader_wrapper, fxn) | ||||
return module_for_loader_wrapper | ||||
def _check_name(method): | ||||
"""Decorator to verify that the module being requested matches the one the | ||||
loader can handle. | ||||
The first argument (self) must define _name which the second argument is | ||||
compared against. If the comparison fails then ImportError is raised. | ||||
""" | ||||
def _check_name_wrapper(self, name=None, *args, **kwargs): | ||||
if name is None: | ||||
name = self.name | ||||
elif self.name != name: | ||||
raise ImportError("loader cannot handle %s" % name, name=name) | ||||
return method(self, name, *args, **kwargs) | ||||
_wrap(_check_name_wrapper, method) | ||||
return _check_name_wrapper | ||||
def _requires_builtin(fxn): | ||||
"""Decorator to verify the named module is built-in.""" | ||||
def _requires_builtin_wrapper(self, fullname): | ||||
if fullname not in sys.builtin_module_names: | ||||
raise ImportError("{} is not a built-in module".format(fullname), | ||||
name=fullname) | ||||
return fxn(self, fullname) | ||||
_wrap(_requires_builtin_wrapper, fxn) | ||||
return _requires_builtin_wrapper | ||||
def _requires_frozen(fxn): | ||||
"""Decorator to verify the named module is frozen.""" | ||||
def _requires_frozen_wrapper(self, fullname): | ||||
if not _imp.is_frozen(fullname): | ||||
raise ImportError("{} is not a frozen module".format(fullname), | ||||
name=fullname) | ||||
return fxn(self, fullname) | ||||
_wrap(_requires_frozen_wrapper, fxn) | ||||
return _requires_frozen_wrapper | ||||
def _find_module_shim(self, fullname): | ||||
"""Try to find a loader for the specified module by delegating to | ||||
self.find_loader().""" | ||||
# Call find_loader(). If it returns a string (indicating this | ||||
# is a namespace package portion), generate a warning and | ||||
# return None. | ||||
loader, portions = self.find_loader(fullname) | ||||
if loader is None and len(portions): | ||||
msg = "Not importing directory {}: missing __init__" | ||||
_warnings.warn(msg.format(portions[0]), ImportWarning) | ||||
return loader | ||||
# Loaders ##################################################################### | ||||
class BuiltinImporter: | ||||
"""Meta path import for built-in modules. | ||||
All methods are either class or static methods to avoid the need to | ||||
instantiate the class. | ||||
""" | ||||
@classmethod | ||||
def module_repr(cls, module): | ||||
return "<module '{}' (built-in)>".format(module.__name__) | ||||
@classmethod | ||||
def find_module(cls, fullname, path=None): | ||||
"""Find the built-in module. | ||||
If 'path' is ever specified then the search is considered a failure. | ||||
""" | ||||
if path is not None: | ||||
return None | ||||
return cls if _imp.is_builtin(fullname) else None | ||||
@classmethod | ||||
@set_package | ||||
@set_loader | ||||
@_requires_builtin | ||||
def load_module(cls, fullname): | ||||
"""Load a built-in module.""" | ||||
is_reload = fullname in sys.modules | ||||
try: | ||||
return _call_with_frames_removed(_imp.init_builtin, fullname) | ||||
except: | ||||
if not is_reload and fullname in sys.modules: | ||||
del sys.modules[fullname] | ||||
raise | ||||
@classmethod | ||||
@_requires_builtin | ||||
def get_code(cls, fullname): | ||||
"""Return None as built-in modules do not have code objects.""" | ||||
return None | ||||
@classmethod | ||||
@_requires_builtin | ||||
def get_source(cls, fullname): | ||||
"""Return None as built-in modules do not have source code.""" | ||||
return None | ||||
@classmethod | ||||
@_requires_builtin | ||||
def is_package(cls, fullname): | ||||
"""Return False as built-in modules are never packages.""" | ||||
return False | ||||
class FrozenImporter: | ||||
"""Meta path import for frozen modules. | ||||
All methods are either class or static methods to avoid the need to | ||||
instantiate the class. | ||||
""" | ||||
@classmethod | ||||
def module_repr(cls, m): | ||||
return "<module '{}' (frozen)>".format(m.__name__) | ||||
@classmethod | ||||
def find_module(cls, fullname, path=None): | ||||
"""Find a frozen module.""" | ||||
return cls if _imp.is_frozen(fullname) else None | ||||
@classmethod | ||||
@set_package | ||||
@set_loader | ||||
@_requires_frozen | ||||
def load_module(cls, fullname): | ||||
"""Load a frozen module.""" | ||||
is_reload = fullname in sys.modules | ||||
try: | ||||
m = _call_with_frames_removed(_imp.init_frozen, fullname) | ||||
# Let our own module_repr() method produce a suitable repr. | ||||
del m.__file__ | ||||
return m | ||||
except: | ||||
if not is_reload and fullname in sys.modules: | ||||
del sys.modules[fullname] | ||||
raise | ||||
@classmethod | ||||
@_requires_frozen | ||||
def get_code(cls, fullname): | ||||
"""Return the code object for the frozen module.""" | ||||
return _imp.get_frozen_object(fullname) | ||||
@classmethod | ||||
@_requires_frozen | ||||
def get_source(cls, fullname): | ||||
"""Return None as frozen modules do not have source code.""" | ||||
return None | ||||
@classmethod | ||||
@_requires_frozen | ||||
def is_package(cls, fullname): | ||||
"""Return True if the frozen module is a package.""" | ||||
return _imp.is_frozen_package(fullname) | ||||
class WindowsRegistryFinder: | ||||
"""Meta path finder for modules declared in the Windows registry. | ||||
""" | ||||
REGISTRY_KEY = ( | ||||
"Software\\Python\\PythonCore\\{sys_version}" | ||||
"\\Modules\\{fullname}") | ||||
REGISTRY_KEY_DEBUG = ( | ||||
"Software\\Python\\PythonCore\\{sys_version}" | ||||
"\\Modules\\{fullname}\\Debug") | ||||
DEBUG_BUILD = False # Changed in _setup() | ||||
@classmethod | ||||
def _open_registry(cls, key): | ||||
try: | ||||
return _winreg.OpenKey(_winreg.HKEY_CURRENT_USER, key) | ||||
except WindowsError: | ||||
return _winreg.OpenKey(_winreg.HKEY_LOCAL_MACHINE, key) | ||||
@classmethod | ||||
def _search_registry(cls, fullname): | ||||
if cls.DEBUG_BUILD: | ||||
registry_key = cls.REGISTRY_KEY_DEBUG | ||||
else: | ||||
registry_key = cls.REGISTRY_KEY | ||||
key = registry_key.format(fullname=fullname, | ||||
sys_version=sys.version[:3]) | ||||
try: | ||||
with cls._open_registry(key) as hkey: | ||||
filepath = _winreg.QueryValue(hkey, "") | ||||
except WindowsError: | ||||
return None | ||||
return filepath | ||||
@classmethod | ||||
def find_module(cls, fullname, path=None): | ||||
"""Find module named in the registry.""" | ||||
filepath = cls._search_registry(fullname) | ||||
if filepath is None: | ||||
return None | ||||
try: | ||||
_os.stat(filepath) | ||||
except OSError: | ||||
return None | ||||
for loader, suffixes in _get_supported_file_loaders(): | ||||
if filepath.endswith(tuple(suffixes)): | ||||
return loader(fullname, filepath) | ||||
class _LoaderBasics: | ||||
"""Base class of common code needed by both SourceLoader and | ||||
SourcelessFileLoader.""" | ||||
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 = _path_split(self.get_filename(fullname))[1] | ||||
filename_base = filename.rsplit('.', 1)[0] | ||||
tail_name = fullname.rpartition('.')[2] | ||||
return filename_base == '__init__' and tail_name != '__init__' | ||||
def _bytes_from_bytecode(self, fullname, data, bytecode_path, source_stats): | ||||
"""Return the marshalled bytes from bytecode, verifying the magic | ||||
number, timestamp and source size along the way. | ||||
If source_stats is None then skip the timestamp check. | ||||
""" | ||||
magic = data[:4] | ||||
raw_timestamp = data[4:8] | ||||
raw_size = data[8:12] | ||||
if magic != _MAGIC_BYTES: | ||||
msg = 'bad magic number in {!r}: {!r}'.format(fullname, magic) | ||||
_verbose_message(msg) | ||||
raise ImportError(msg, name=fullname, path=bytecode_path) | ||||
elif len(raw_timestamp) != 4: | ||||
message = 'bad timestamp in {}'.format(fullname) | ||||
_verbose_message(message) | ||||
raise EOFError(message) | ||||
elif len(raw_size) != 4: | ||||
message = 'bad size in {}'.format(fullname) | ||||
_verbose_message(message) | ||||
raise EOFError(message) | ||||
if source_stats is not None: | ||||
try: | ||||
source_mtime = int(source_stats['mtime']) | ||||
except KeyError: | ||||
pass | ||||
else: | ||||
if _r_long(raw_timestamp) != source_mtime: | ||||
message = 'bytecode is stale for {}'.format(fullname) | ||||
_verbose_message(message) | ||||
raise ImportError(message, name=fullname, | ||||
path=bytecode_path) | ||||
try: | ||||
source_size = source_stats['size'] & 0xFFFFFFFF | ||||
except KeyError: | ||||
pass | ||||
else: | ||||
if _r_long(raw_size) != source_size: | ||||
raise ImportError( | ||||
"bytecode is stale for {}".format(fullname), | ||||
name=fullname, path=bytecode_path) | ||||
# Can't return the code object as errors from marshal loading need to | ||||
# propagate even when source is available. | ||||
return data[12:] | ||||
@module_for_loader | ||||
def _load_module(self, module, *, sourceless=False): | ||||
"""Helper for load_module able to handle either source or sourceless | ||||
loading.""" | ||||
name = module.__name__ | ||||
code_object = self.get_code(name) | ||||
module.__file__ = self.get_filename(name) | ||||
if not sourceless: | ||||
try: | ||||
module.__cached__ = cache_from_source(module.__file__) | ||||
except NotImplementedError: | ||||
module.__cached__ = module.__file__ | ||||
else: | ||||
module.__cached__ = module.__file__ | ||||
module.__package__ = name | ||||
if self.is_package(name): | ||||
module.__path__ = [_path_split(module.__file__)[0]] | ||||
else: | ||||
module.__package__ = module.__package__.rpartition('.')[0] | ||||
module.__loader__ = self | ||||
_call_with_frames_removed(exec, code_object, module.__dict__) | ||||
return module | ||||
class SourceLoader(_LoaderBasics): | ||||
def path_mtime(self, path): | ||||
"""Optional method that returns the modification time (an int) for the | ||||
specified path, where path is a str. | ||||
""" | ||||
raise NotImplementedError | ||||
def path_stats(self, path): | ||||
"""Optional method returning a metadata dict for the specified path | ||||
to by the path (str). | ||||
Possible keys: | ||||
- 'mtime' (mandatory) is the numeric timestamp of last source | ||||
code modification; | ||||
- 'size' (optional) is the size in bytes of the source code. | ||||
Implementing this method allows the loader to read bytecode files. | ||||
""" | ||||
return {'mtime': self.path_mtime(path)} | ||||
def _cache_bytecode(self, source_path, cache_path, data): | ||||
"""Optional method which writes data (bytes) to a file path (a str). | ||||
Implementing this method allows for the writing of bytecode files. | ||||
The source path is needed in order to correctly transfer permissions | ||||
""" | ||||
# For backwards compatibility, we delegate to set_data() | ||||
return self.set_data(cache_path, data) | ||||
def set_data(self, path, data): | ||||
"""Optional method which writes data (bytes) to a file path (a str). | ||||
Implementing this method allows for the writing of bytecode files. | ||||
""" | ||||
raise NotImplementedError | ||||
def get_source(self, fullname): | ||||
"""Concrete implementation of InspectLoader.get_source.""" | ||||
import tokenize | ||||
path = self.get_filename(fullname) | ||||
try: | ||||
source_bytes = self.get_data(path) | ||||
except IOError as exc: | ||||
raise ImportError("source not available through get_data()", | ||||
name=fullname) from exc | ||||
readsource = _io.BytesIO(source_bytes).readline | ||||
try: | ||||
encoding = tokenize.detect_encoding(readsource) | ||||
except SyntaxError as exc: | ||||
raise ImportError("Failed to detect encoding", | ||||
name=fullname) from exc | ||||
newline_decoder = _io.IncrementalNewlineDecoder(None, True) | ||||
try: | ||||
return newline_decoder.decode(source_bytes.decode(encoding[0])) | ||||
except UnicodeDecodeError as exc: | ||||
raise ImportError("Failed to decode source file", | ||||
name=fullname) from exc | ||||
def get_code(self, fullname): | ||||
"""Concrete implementation of InspectLoader.get_code. | ||||
Reading of bytecode requires path_stats to be implemented. To write | ||||
bytecode, set_data must also be implemented. | ||||
""" | ||||
source_path = self.get_filename(fullname) | ||||
source_mtime = None | ||||
try: | ||||
bytecode_path = cache_from_source(source_path) | ||||
except NotImplementedError: | ||||
bytecode_path = None | ||||
else: | ||||
try: | ||||
st = self.path_stats(source_path) | ||||
except NotImplementedError: | ||||
pass | ||||
else: | ||||
source_mtime = int(st['mtime']) | ||||
try: | ||||
data = self.get_data(bytecode_path) | ||||
except IOError: | ||||
pass | ||||
else: | ||||
try: | ||||
bytes_data = self._bytes_from_bytecode(fullname, data, | ||||
bytecode_path, | ||||
st) | ||||
except (ImportError, EOFError): | ||||
pass | ||||
else: | ||||
_verbose_message('{} matches {}', bytecode_path, | ||||
source_path) | ||||
found = marshal.loads(bytes_data) | ||||
if isinstance(found, _code_type): | ||||
_imp._fix_co_filename(found, source_path) | ||||
_verbose_message('code object from {}', | ||||
bytecode_path) | ||||
return found | ||||
else: | ||||
msg = "Non-code object in {}" | ||||
raise ImportError(msg.format(bytecode_path), | ||||
name=fullname, path=bytecode_path) | ||||
source_bytes = self.get_data(source_path) | ||||
code_object = _call_with_frames_removed(compile, | ||||
source_bytes, source_path, 'exec', | ||||
dont_inherit=True) | ||||
_verbose_message('code object from {}', source_path) | ||||
if (not sys.dont_write_bytecode and bytecode_path is not None and | ||||
source_mtime is not None): | ||||
data = bytearray(_MAGIC_BYTES) | ||||
data.extend(_w_long(source_mtime)) | ||||
data.extend(_w_long(len(source_bytes))) | ||||
data.extend(marshal.dumps(code_object)) | ||||
try: | ||||
self._cache_bytecode(source_path, bytecode_path, data) | ||||
_verbose_message('wrote {!r}', bytecode_path) | ||||
except NotImplementedError: | ||||
pass | ||||
return code_object | ||||
def load_module(self, fullname): | ||||
"""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. | ||||
""" | ||||
return self._load_module(fullname) | ||||
class FileLoader: | ||||
"""Base file loader class which implements the loader protocol methods that | ||||
require file system usage.""" | ||||
def __init__(self, fullname, path): | ||||
"""Cache the module name and the path to the file found by the | ||||
finder.""" | ||||
self.name = fullname | ||||
self.path = path | ||||
@_check_name | ||||
def load_module(self, fullname): | ||||
"""Load a module from a file.""" | ||||
# Issue #14857: Avoid the zero-argument form so the implementation | ||||
# of that form can be updated without breaking the frozen module | ||||
return super(FileLoader, self).load_module(fullname) | ||||
@_check_name | ||||
def get_filename(self, fullname): | ||||
"""Return the path to the source file as found by the finder.""" | ||||
return self.path | ||||
def get_data(self, path): | ||||
"""Return the data from path as raw bytes.""" | ||||
with _io.FileIO(path, 'r') as file: | ||||
return file.read() | ||||
class SourceFileLoader(FileLoader, SourceLoader): | ||||
"""Concrete implementation of SourceLoader using the file system.""" | ||||
def path_stats(self, path): | ||||
"""Return the metadata for the path.""" | ||||
st = _os.stat(path) | ||||
return {'mtime': st.st_mtime, 'size': st.st_size} | ||||
def _cache_bytecode(self, source_path, bytecode_path, data): | ||||
# Adapt between the two APIs | ||||
try: | ||||
mode = _os.stat(source_path).st_mode | ||||
except OSError: | ||||
mode = 0o666 | ||||
# We always ensure write access so we can update cached files | ||||
# later even when the source files are read-only on Windows (#6074) | ||||
mode |= 0o200 | ||||
return self.set_data(bytecode_path, data, _mode=mode) | ||||
def set_data(self, path, data, *, _mode=0o666): | ||||
"""Write bytes data to a file.""" | ||||
parent, filename = _path_split(path) | ||||
path_parts = [] | ||||
# Figure out what directories are missing. | ||||
while parent and not _path_isdir(parent): | ||||
parent, part = _path_split(parent) | ||||
path_parts.append(part) | ||||
# Create needed directories. | ||||
for part in reversed(path_parts): | ||||
parent = _path_join(parent, part) | ||||
try: | ||||
_os.mkdir(parent) | ||||
except FileExistsError: | ||||
# Probably another Python process already created the dir. | ||||
continue | ||||
except OSError as exc: | ||||
# Could be a permission error, read-only filesystem: just forget | ||||
# about writing the data. | ||||
_verbose_message('could not create {!r}: {!r}', parent, exc) | ||||
return | ||||
try: | ||||
_write_atomic(path, data, _mode) | ||||
_verbose_message('created {!r}', path) | ||||
except OSError as exc: | ||||
# Same as above: just don't write the bytecode. | ||||
_verbose_message('could not create {!r}: {!r}', path, exc) | ||||
class SourcelessFileLoader(FileLoader, _LoaderBasics): | ||||
"""Loader which handles sourceless file imports.""" | ||||
def load_module(self, fullname): | ||||
return self._load_module(fullname, sourceless=True) | ||||
def get_code(self, fullname): | ||||
path = self.get_filename(fullname) | ||||
data = self.get_data(path) | ||||
bytes_data = self._bytes_from_bytecode(fullname, data, path, None) | ||||
found = marshal.loads(bytes_data) | ||||
if isinstance(found, _code_type): | ||||
_verbose_message('code object from {!r}', path) | ||||
return found | ||||
else: | ||||
raise ImportError("Non-code object in {}".format(path), | ||||
name=fullname, path=path) | ||||
def get_source(self, fullname): | ||||
"""Return None as there is no source code.""" | ||||
return None | ||||
# Filled in by _setup(). | ||||
EXTENSION_SUFFIXES = [] | ||||
class ExtensionFileLoader: | ||||
"""Loader for extension modules. | ||||
The constructor is designed to work with FileFinder. | ||||
""" | ||||
def __init__(self, name, path): | ||||
self.name = name | ||||
self.path = path | ||||
@_check_name | ||||
@set_package | ||||
@set_loader | ||||
def load_module(self, fullname): | ||||
"""Load an extension module.""" | ||||
is_reload = fullname in sys.modules | ||||
try: | ||||
module = _call_with_frames_removed(_imp.load_dynamic, | ||||
fullname, self.path) | ||||
_verbose_message('extension module loaded from {!r}', self.path) | ||||
if self.is_package(fullname) and not hasattr(module, '__path__'): | ||||
module.__path__ = [_path_split(self.path)[0]] | ||||
return module | ||||
except: | ||||
if not is_reload and fullname in sys.modules: | ||||
del sys.modules[fullname] | ||||
raise | ||||
def is_package(self, fullname): | ||||
"""Return True if the extension module is a package.""" | ||||
file_name = _path_split(self.path)[1] | ||||
return any(file_name == '__init__' + suffix | ||||
for suffix in EXTENSION_SUFFIXES) | ||||
def get_code(self, fullname): | ||||
"""Return None as an extension module cannot create a code object.""" | ||||
return None | ||||
def get_source(self, fullname): | ||||
"""Return None as extension modules have no source code.""" | ||||
return None | ||||
class _NamespacePath: | ||||
"""Represents a namespace package's path. It uses the module name | ||||
to find its parent module, and from there it looks up the parent's | ||||
__path__. When this changes, the module's own path is recomputed, | ||||
using path_finder. For top-level modules, the parent module's path | ||||
is sys.path.""" | ||||
def __init__(self, name, path, path_finder): | ||||
self._name = name | ||||
self._path = path | ||||
self._last_parent_path = tuple(self._get_parent_path()) | ||||
self._path_finder = path_finder | ||||
def _find_parent_path_names(self): | ||||
"""Returns a tuple of (parent-module-name, parent-path-attr-name)""" | ||||
parent, dot, me = self._name.rpartition('.') | ||||
if dot == '': | ||||
# This is a top-level module. sys.path contains the parent path. | ||||
return 'sys', 'path' | ||||
# Not a top-level module. parent-module.__path__ contains the | ||||
# parent path. | ||||
return parent, '__path__' | ||||
def _get_parent_path(self): | ||||
parent_module_name, path_attr_name = self._find_parent_path_names() | ||||
return getattr(sys.modules[parent_module_name], path_attr_name) | ||||
def _recalculate(self): | ||||
# If the parent's path has changed, recalculate _path | ||||
parent_path = tuple(self._get_parent_path()) # Make a copy | ||||
if parent_path != self._last_parent_path: | ||||
loader, new_path = self._path_finder(self._name, parent_path) | ||||
# Note that no changes are made if a loader is returned, but we | ||||
# do remember the new parent path | ||||
if loader is None: | ||||
self._path = new_path | ||||
self._last_parent_path = parent_path # Save the copy | ||||
return self._path | ||||
def __iter__(self): | ||||
return iter(self._recalculate()) | ||||
def __len__(self): | ||||
return len(self._recalculate()) | ||||
def __repr__(self): | ||||
return "_NamespacePath({!r})".format(self._path) | ||||
def __contains__(self, item): | ||||
return item in self._recalculate() | ||||
def append(self, item): | ||||
self._path.append(item) | ||||
class NamespaceLoader: | ||||
def __init__(self, name, path, path_finder): | ||||
self._path = _NamespacePath(name, path, path_finder) | ||||
@classmethod | ||||
def module_repr(cls, module): | ||||
return "<module '{}' (namespace)>".format(module.__name__) | ||||
@module_for_loader | ||||
def load_module(self, module): | ||||
"""Load a namespace module.""" | ||||
_verbose_message('namespace module loaded with path {!r}', self._path) | ||||
module.__path__ = self._path | ||||
return module | ||||
# Finders ##################################################################### | ||||
class PathFinder: | ||||
"""Meta path finder for sys.path and package __path__ attributes.""" | ||||
@classmethod | ||||
def invalidate_caches(cls): | ||||
"""Call the invalidate_caches() method on all path entry finders | ||||
stored in sys.path_importer_caches (where implemented).""" | ||||
for finder in sys.path_importer_cache.values(): | ||||
if hasattr(finder, 'invalidate_caches'): | ||||
finder.invalidate_caches() | ||||
@classmethod | ||||
def _path_hooks(cls, path): | ||||
"""Search sequence of hooks for a finder for 'path'. | ||||
If 'hooks' is false then use sys.path_hooks. | ||||
""" | ||||
if not sys.path_hooks: | ||||
_warnings.warn('sys.path_hooks is empty', ImportWarning) | ||||
for hook in sys.path_hooks: | ||||
try: | ||||
return hook(path) | ||||
except ImportError: | ||||
continue | ||||
else: | ||||
return None | ||||
@classmethod | ||||
def _path_importer_cache(cls, path): | ||||
"""Get the finder for the path entry from sys.path_importer_cache. | ||||
If the path entry is not in the cache, find the appropriate finder | ||||
and cache it. If no finder is available, store None. | ||||
""" | ||||
if path == '': | ||||
path = '.' | ||||
try: | ||||
finder = sys.path_importer_cache[path] | ||||
except KeyError: | ||||
finder = cls._path_hooks(path) | ||||
sys.path_importer_cache[path] = finder | ||||
return finder | ||||
@classmethod | ||||
def _get_loader(cls, fullname, path): | ||||
"""Find the loader or namespace_path for this module/package name.""" | ||||
# If this ends up being a namespace package, namespace_path is | ||||
# the list of paths that will become its __path__ | ||||
namespace_path = [] | ||||
for entry in path: | ||||
if not isinstance(entry, (str, bytes)): | ||||
continue | ||||
finder = cls._path_importer_cache(entry) | ||||
if finder is not None: | ||||
if hasattr(finder, 'find_loader'): | ||||
loader, portions = finder.find_loader(fullname) | ||||
else: | ||||
loader = finder.find_module(fullname) | ||||
portions = [] | ||||
if loader is not None: | ||||
# We found a loader: return it immediately. | ||||
return loader, namespace_path | ||||
# This is possibly part of a namespace package. | ||||
# Remember these path entries (if any) for when we | ||||
# create a namespace package, and continue iterating | ||||
# on path. | ||||
namespace_path.extend(portions) | ||||
else: | ||||
return None, namespace_path | ||||
@classmethod | ||||
def find_module(cls, fullname, path=None): | ||||
"""Find the module on sys.path or 'path' based on sys.path_hooks and | ||||
sys.path_importer_cache.""" | ||||
if path is None: | ||||
path = sys.path | ||||
loader, namespace_path = cls._get_loader(fullname, path) | ||||
if loader is not None: | ||||
return loader | ||||
else: | ||||
if namespace_path: | ||||
# We found at least one namespace path. Return a | ||||
# loader which can create the namespace package. | ||||
return NamespaceLoader(fullname, namespace_path, cls._get_loader) | ||||
else: | ||||
return None | ||||
class FileFinder: | ||||
"""File-based finder. | ||||
Interactions with the file system are cached for performance, being | ||||
refreshed when the directory the finder is handling has been modified. | ||||
""" | ||||
def __init__(self, path, *loader_details): | ||||
"""Initialize with the path to search on and a variable number of | ||||
2-tuples containing the loader and the file suffixes the loader | ||||
recognizes.""" | ||||
loaders = [] | ||||
for loader, suffixes in loader_details: | ||||
loaders.extend((suffix, loader) for suffix in suffixes) | ||||
self._loaders = loaders | ||||
# Base (directory) path | ||||
self.path = path or '.' | ||||
self._path_mtime = -1 | ||||
self._path_cache = set() | ||||
self._relaxed_path_cache = set() | ||||
def invalidate_caches(self): | ||||
"""Invalidate the directory mtime.""" | ||||
self._path_mtime = -1 | ||||
find_module = _find_module_shim | ||||
def find_loader(self, fullname): | ||||
"""Try to find a loader for the specified module, or the namespace | ||||
package portions. Returns (loader, list-of-portions).""" | ||||
is_namespace = False | ||||
tail_module = fullname.rpartition('.')[2] | ||||
try: | ||||
mtime = _os.stat(self.path).st_mtime | ||||
except OSError: | ||||
mtime = -1 | ||||
if mtime != self._path_mtime: | ||||
self._fill_cache() | ||||
self._path_mtime = mtime | ||||
# tail_module keeps the original casing, for __file__ and friends | ||||
if _relax_case(): | ||||
cache = self._relaxed_path_cache | ||||
cache_module = tail_module.lower() | ||||
else: | ||||
cache = self._path_cache | ||||
cache_module = tail_module | ||||
# Check if the module is the name of a directory (and thus a package). | ||||
if cache_module in cache: | ||||
base_path = _path_join(self.path, tail_module) | ||||
if _path_isdir(base_path): | ||||
for suffix, loader in self._loaders: | ||||
init_filename = '__init__' + suffix | ||||
full_path = _path_join(base_path, init_filename) | ||||
if _path_isfile(full_path): | ||||
return (loader(fullname, full_path), [base_path]) | ||||
else: | ||||
# A namespace package, return the path if we don't also | ||||
# find a module in the next section. | ||||
is_namespace = True | ||||
# Check for a file w/ a proper suffix exists. | ||||
for suffix, loader in self._loaders: | ||||
full_path = _path_join(self.path, tail_module + suffix) | ||||
_verbose_message('trying {}'.format(full_path), verbosity=2) | ||||
if cache_module + suffix in cache: | ||||
if _path_isfile(full_path): | ||||
return (loader(fullname, full_path), []) | ||||
if is_namespace: | ||||
_verbose_message('possible namespace for {}'.format(base_path)) | ||||
return (None, [base_path]) | ||||
return (None, []) | ||||
def _fill_cache(self): | ||||
"""Fill the cache of potential modules and packages for this directory.""" | ||||
path = self.path | ||||
try: | ||||
contents = _os.listdir(path) | ||||
except (FileNotFoundError, PermissionError, NotADirectoryError): | ||||
# Directory has either been removed, turned into a file, or made | ||||
# unreadable. | ||||
contents = [] | ||||
# We store two cached versions, to handle runtime changes of the | ||||
# PYTHONCASEOK environment variable. | ||||
if not sys.platform.startswith('win'): | ||||
self._path_cache = set(contents) | ||||
else: | ||||
# Windows users can import modules with case-insensitive file | ||||
# suffixes (for legacy reasons). Make the suffix lowercase here | ||||
# so it's done once instead of for every import. This is safe as | ||||
# the specified suffixes to check against are always specified in a | ||||
# case-sensitive manner. | ||||
lower_suffix_contents = set() | ||||
for item in contents: | ||||
name, dot, suffix = item.partition('.') | ||||
if dot: | ||||
new_name = '{}.{}'.format(name, suffix.lower()) | ||||
else: | ||||
new_name = name | ||||
lower_suffix_contents.add(new_name) | ||||
self._path_cache = lower_suffix_contents | ||||
if sys.platform.startswith(_CASE_INSENSITIVE_PLATFORMS): | ||||
self._relaxed_path_cache = set(fn.lower() for fn in contents) | ||||
@classmethod | ||||
def path_hook(cls, *loader_details): | ||||
"""A class method which returns a closure to use on sys.path_hook | ||||
which will return an instance using the specified loaders and the path | ||||
called on the closure. | ||||
If the path called on the closure is not a directory, ImportError is | ||||
raised. | ||||
""" | ||||
def path_hook_for_FileFinder(path): | ||||
"""Path hook for importlib.machinery.FileFinder.""" | ||||
if not _path_isdir(path): | ||||
raise ImportError("only directories are supported", path=path) | ||||
return cls(path, *loader_details) | ||||
return path_hook_for_FileFinder | ||||
def __repr__(self): | ||||
return "FileFinder(%r)" % (self.path,) | ||||
# Import itself ############################################################### | ||||
class _ImportLockContext: | ||||
"""Context manager for the import lock.""" | ||||
def __enter__(self): | ||||
"""Acquire the import lock.""" | ||||
_imp.acquire_lock() | ||||
def __exit__(self, exc_type, exc_value, exc_traceback): | ||||
"""Release the import lock regardless of any raised exceptions.""" | ||||
_imp.release_lock() | ||||
def _resolve_name(name, package, level): | ||||
"""Resolve a relative module name to an absolute one.""" | ||||
bits = package.rsplit('.', level - 1) | ||||
if len(bits) < level: | ||||
raise ValueError('attempted relative import beyond top-level package') | ||||
base = bits[0] | ||||
return '{}.{}'.format(base, name) if name else base | ||||
def _find_module(name, path): | ||||
"""Find a module's loader.""" | ||||
if not sys.meta_path: | ||||
_warnings.warn('sys.meta_path is empty', ImportWarning) | ||||
for finder in sys.meta_path: | ||||
#with _ImportLockContext(): | ||||
# loader = finder.find_module(name, path) | ||||
loader = finder.find_module(name, path) | ||||
if loader is not None: | ||||
# The parent import may have already imported this module. | ||||
if name not in sys.modules: | ||||
return loader | ||||
else: | ||||
return sys.modules[name].__loader__ | ||||
else: | ||||
return None | ||||
def _sanity_check(name, package, level): | ||||
"""Verify arguments are "sane".""" | ||||
if not isinstance(name, str): | ||||
raise TypeError("module name must be str, not {}".format(type(name))) | ||||
if level < 0: | ||||
raise ValueError('level must be >= 0') | ||||
if package: | ||||
if not isinstance(package, str): | ||||
raise TypeError("__package__ not set to a string") | ||||
elif package not in sys.modules: | ||||
msg = ("Parent module {!r} not loaded, cannot perform relative " | ||||
"import") | ||||
raise SystemError(msg.format(package)) | ||||
if not name and level == 0: | ||||
raise ValueError("Empty module name") | ||||
_ERR_MSG = 'No module named {!r}' | ||||
def _find_and_load_unlocked(name, import_): | ||||
path = None | ||||
parent = name.rpartition('.')[0] | ||||
if parent: | ||||
if parent not in sys.modules: | ||||
_call_with_frames_removed(import_, parent) | ||||
# Crazy side-effects! | ||||
if name in sys.modules: | ||||
return sys.modules[name] | ||||
# Backwards-compatibility; be nicer to skip the dict lookup. | ||||
parent_module = sys.modules[parent] | ||||
try: | ||||
path = parent_module.__path__ | ||||
except AttributeError: | ||||
msg = (_ERR_MSG + '; {} is not a package').format(name, parent) | ||||
raise ImportError(msg, name=name) | ||||
loader = _find_module(name, path) | ||||
if loader is None: | ||||
exc = ImportError(_ERR_MSG.format(name), name=name) | ||||
# TODO(brett): switch to a proper ModuleNotFound exception in Python | ||||
# 3.4. | ||||
exc._not_found = True | ||||
raise exc | ||||
elif name not in sys.modules: | ||||
# The parent import may have already imported this module. | ||||
loader.load_module(name) | ||||
_verbose_message('import {!r} # {!r}', name, loader) | ||||
# Backwards-compatibility; be nicer to skip the dict lookup. | ||||
module = sys.modules[name] | ||||
if parent: | ||||
# Set the module as an attribute on its parent. | ||||
parent_module = sys.modules[parent] | ||||
setattr(parent_module, name.rpartition('.')[2], module) | ||||
# Set __package__ if the loader did not. | ||||
if getattr(module, '__package__', None) is None: | ||||
try: | ||||
module.__package__ = module.__name__ | ||||
if not hasattr(module, '__path__'): | ||||
module.__package__ = module.__package__.rpartition('.')[0] | ||||
except AttributeError: | ||||
pass | ||||
# Set loader if need be. | ||||
if not hasattr(module, '__loader__'): | ||||
try: | ||||
module.__loader__ = loader | ||||
except AttributeError: | ||||
pass | ||||
return module | ||||
def _find_and_load(name, import_): | ||||
"""Find and load the module, and release the import lock.""" | ||||
try: | ||||
lock = _get_module_lock(name) | ||||
finally: | ||||
_imp.release_lock() | ||||
lock.acquire() | ||||
try: | ||||
return _find_and_load_unlocked(name, import_) | ||||
finally: | ||||
lock.release() | ||||
def _gcd_import(name, package=None, level=0): | ||||
"""Import and return the module based on its name, the package the call is | ||||
being made from, and the level adjustment. | ||||
This function represents the greatest common denominator of functionality | ||||
between import_module and __import__. This includes setting __package__ if | ||||
the loader did not. | ||||
""" | ||||
_sanity_check(name, package, level) | ||||
if level > 0: | ||||
name = _resolve_name(name, package, level) | ||||
_imp.acquire_lock() | ||||
if name not in sys.modules: | ||||
return _find_and_load(name, _gcd_import) | ||||
module = sys.modules[name] | ||||
if module is None: | ||||
_imp.release_lock() | ||||
message = ("import of {} halted; " | ||||
"None in sys.modules".format(name)) | ||||
raise ImportError(message, name=name) | ||||
_lock_unlock_module(name) | ||||
return module | ||||
def _handle_fromlist(module, fromlist, import_): | ||||
"""Figure out what __import__ should return. | ||||
The import_ parameter is a callable which takes the name of module to | ||||
import. It is required to decouple the function from assuming importlib's | ||||
import implementation is desired. | ||||
""" | ||||
# The hell that is fromlist ... | ||||
# If a package was imported, try to import stuff from fromlist. | ||||
if hasattr(module, '__path__'): | ||||
if '*' in fromlist: | ||||
fromlist = list(fromlist) | ||||
fromlist.remove('*') | ||||
if hasattr(module, '__all__'): | ||||
fromlist.extend(module.__all__) | ||||
for x in fromlist: | ||||
if not hasattr(module, x): | ||||
from_name = '{}.{}'.format(module.__name__, x) | ||||
try: | ||||
_call_with_frames_removed(import_, from_name) | ||||
except ImportError as exc: | ||||
# Backwards-compatibility dictates we ignore failed | ||||
# imports triggered by fromlist for modules that don't | ||||
# exist. | ||||
# TODO(brett): In Python 3.4, have import raise | ||||
# ModuleNotFound and catch that. | ||||
if getattr(exc, '_not_found', False): | ||||
if exc.name == from_name: | ||||
continue | ||||
raise | ||||
return module | ||||
def _calc___package__(globals): | ||||
"""Calculate what __package__ should be. | ||||
__package__ is not guaranteed to be defined or could be set to None | ||||
to represent that its proper value is unknown. | ||||
""" | ||||
package = globals.get('__package__') | ||||
if package is None: | ||||
package = globals['__name__'] | ||||
if '__path__' not in globals: | ||||
package = package.rpartition('.')[0] | ||||
return package | ||||
def _get_supported_file_loaders(): | ||||
"""Returns a list of file-based module loaders. | ||||
Each item is a tuple (loader, suffixes). | ||||
""" | ||||
extensions = ExtensionFileLoader, _imp.extension_suffixes() | ||||
source = SourceFileLoader, SOURCE_SUFFIXES | ||||
bytecode = SourcelessFileLoader, BYTECODE_SUFFIXES | ||||
return [extensions, source, bytecode] | ||||
def __import__(name, globals=None, locals=None, fromlist=(), level=0): | ||||
"""Import a module. | ||||
The 'globals' argument is used to infer where the import is occuring from | ||||
to handle relative imports. The 'locals' argument is ignored. The | ||||
'fromlist' argument specifies what should exist as attributes on the module | ||||
being imported (e.g. ``from module import <fromlist>``). The 'level' | ||||
argument represents the package location to import from in a relative | ||||
import (e.g. ``from ..pkg import mod`` would have a 'level' of 2). | ||||
""" | ||||
if level == 0: | ||||
module = _gcd_import(name) | ||||
else: | ||||
globals_ = globals if globals is not None else {} | ||||
package = _calc___package__(globals_) | ||||
module = _gcd_import(name, package, level) | ||||
if not fromlist: | ||||
# Return up to the first dot in 'name'. This is complicated by the fact | ||||
# that 'name' may be relative. | ||||
if level == 0: | ||||
return _gcd_import(name.partition('.')[0]) | ||||
elif not name: | ||||
return module | ||||
else: | ||||
# Figure out where to slice the module's name up to the first dot | ||||
# in 'name'. | ||||
cut_off = len(name) - len(name.partition('.')[0]) | ||||
# Slice end needs to be positive to alleviate need to special-case | ||||
# when ``'.' not in name``. | ||||
return sys.modules[module.__name__[:len(module.__name__)-cut_off]] | ||||
else: | ||||
return _handle_fromlist(module, fromlist, _gcd_import) | ||||
def _setup(sys_module, _imp_module): | ||||
"""Setup importlib by importing needed built-in modules and injecting them | ||||
into the global namespace. | ||||
As sys is needed for sys.modules access and _imp is needed to load built-in | ||||
modules, those two modules must be explicitly passed in. | ||||
""" | ||||
global _imp, sys, BYTECODE_SUFFIXES | ||||
_imp = _imp_module | ||||
sys = sys_module | ||||
if sys.flags.optimize: | ||||
BYTECODE_SUFFIXES = OPTIMIZED_BYTECODE_SUFFIXES | ||||
else: | ||||
BYTECODE_SUFFIXES = DEBUG_BYTECODE_SUFFIXES | ||||
module_type = type(sys) | ||||
for name, module in sys.modules.items(): | ||||
if isinstance(module, module_type): | ||||
if not hasattr(module, '__loader__'): | ||||
if name in sys.builtin_module_names: | ||||
module.__loader__ = BuiltinImporter | ||||
#fix me brython | ||||
#elif _imp.is_frozen(name): | ||||
# module.__loader__ = FrozenImporter | ||||
self_module = sys.modules[__name__] | ||||
for builtin_name in ('_io', '_warnings', 'builtins'): #, 'marshal'): | ||||
if builtin_name not in sys.modules: | ||||
builtin_module = BuiltinImporter.load_module(builtin_name) | ||||
else: | ||||
builtin_module = sys.modules[builtin_name] | ||||
setattr(self_module, builtin_name, builtin_module) | ||||
os_details = ('posix', ['/']), ('nt', ['\\', '/']), ('os2', ['\\', '/']) | ||||
for builtin_os, path_separators in os_details: | ||||
# Assumption made in _path_join() | ||||
assert all(len(sep) == 1 for sep in path_separators) | ||||
path_sep = path_separators[0] | ||||
if builtin_os in sys.modules: | ||||
os_module = sys.modules[builtin_os] | ||||
break | ||||
else: | ||||
try: | ||||
os_module = BuiltinImporter.load_module(builtin_os) | ||||
# TODO: rip out os2 code after 3.3 is released as per PEP 11 | ||||
if builtin_os == 'os2' and 'EMX GCC' in sys.version: | ||||
path_sep = path_separators[1] | ||||
break | ||||
except ImportError: | ||||
continue | ||||
else: | ||||
raise ImportError('importlib requires posix or nt') | ||||
try: | ||||
thread_module = BuiltinImporter.load_module('_thread') | ||||
except ImportError: | ||||
# Python was built without threads | ||||
thread_module = None | ||||
weakref_module = BuiltinImporter.load_module('_weakref') | ||||
if builtin_os == 'nt': | ||||
winreg_module = BuiltinImporter.load_module('winreg') | ||||
setattr(self_module, '_winreg', winreg_module) | ||||
setattr(self_module, '_os', os_module) | ||||
setattr(self_module, '_thread', thread_module) | ||||
setattr(self_module, '_weakref', weakref_module) | ||||
setattr(self_module, 'path_sep', path_sep) | ||||
setattr(self_module, 'path_separators', set(path_separators)) | ||||
# Constants | ||||
setattr(self_module, '_relax_case', _make_relax_case()) | ||||
EXTENSION_SUFFIXES.extend(_imp.extension_suffixes()) | ||||
if builtin_os == 'nt': | ||||
SOURCE_SUFFIXES.append('.pyw') | ||||
if '_d.pyd' in EXTENSION_SUFFIXES: | ||||
WindowsRegistryFinder.DEBUG_BUILD = True | ||||
def _install(sys_module, _imp_module): | ||||
"""Install importlib as the implementation of import.""" | ||||
_setup(sys_module, _imp_module) | ||||
supported_loaders = _get_supported_file_loaders() | ||||
sys.path_hooks.extend([FileFinder.path_hook(*supported_loaders)]) | ||||
sys.meta_path.append(BuiltinImporter) | ||||
sys.meta_path.append(FrozenImporter) | ||||
if _os.__name__ == 'nt': | ||||
sys.meta_path.append(WindowsRegistryFinder) | ||||
sys.meta_path.append(PathFinder) | ||||