1#@!#!123s

: / usr / local / src / Python-3.9.9 / Lib / test / libregrtest /
Filename : save_env.py
back
import asyncio
import builtins
import locale
import logging
import os
import shutil
import sys
import sysconfig
import threading
import urllib.request
import warnings
from test import support
from test.libregrtest.utils import print_warning
try:
    import _multiprocessing, multiprocessing.process
except ImportError:
    multiprocessing = None


# Unit tests are supposed to leave the execution environment unchanged
# once they complete.  But sometimes tests have bugs, especially when
# tests fail, and the changes to environment go on to mess up other
# tests.  This can cause issues with buildbot stability, since tests
# are run in random order and so problems may appear to come and go.
# There are a few things we can save and restore to mitigate this, and
# the following context manager handles this task.

class saved_test_environment:
    """Save bits of the test environment and restore them at block exit.

        with saved_test_environment(testname, verbose, quiet):
            #stuff

    Unless quiet is True, a warning is printed to stderr if any of
    the saved items was changed by the test.  The attribute 'changed'
    is initially False, but is set to True if a change is detected.

    If verbose is more than 1, the before and after state of changed
    items is also printed.
    """

    changed = False

    def __init__(self, testname, verbose=0, quiet=False, *, pgo=False):
        self.testname = testname
        self.verbose = verbose
        self.quiet = quiet
        self.pgo = pgo

    # To add things to save and restore, add a name XXX to the resources list
    # and add corresponding get_XXX/restore_XXX functions.  get_XXX should
    # return the value to be saved and compared against a second call to the
    # get function when test execution completes.  restore_XXX should accept
    # the saved value and restore the resource using it.  It will be called if
    # and only if a change in the value is detected.
    #
    # Note: XXX will have any '.' replaced with '_' characters when determining
    # the corresponding method names.

    resources = ('sys.argv', 'cwd', 'sys.stdin', 'sys.stdout', 'sys.stderr',
                 'os.environ', 'sys.path', 'sys.path_hooks', '__import__',
                 'warnings.filters', 'asyncore.socket_map',
                 'logging._handlers', 'logging._handlerList', 'sys.gettrace',
                 'sys.warnoptions',
                 # multiprocessing.process._cleanup() may release ref
                 # to a thread, so check processes first.
                 'multiprocessing.process._dangling', 'threading._dangling',
                 'sysconfig._CONFIG_VARS', 'sysconfig._INSTALL_SCHEMES',
                 'files', 'locale', 'warnings.showwarning',
                 'shutil_archive_formats', 'shutil_unpack_formats',
                 'asyncio.events._event_loop_policy',
                 'urllib.requests._url_tempfiles', 'urllib.requests._opener',
                )

    def get_urllib_requests__url_tempfiles(self):
        return list(urllib.request._url_tempfiles)
    def restore_urllib_requests__url_tempfiles(self, tempfiles):
        for filename in tempfiles:
            support.unlink(filename)

    def get_urllib_requests__opener(self):
        return urllib.request._opener
    def restore_urllib_requests__opener(self, opener):
        urllib.request._opener = opener

    def get_asyncio_events__event_loop_policy(self):
        return support.maybe_get_event_loop_policy()
    def restore_asyncio_events__event_loop_policy(self, policy):
        asyncio.set_event_loop_policy(policy)

    def get_sys_argv(self):
        return id(sys.argv), sys.argv, sys.argv[:]
    def restore_sys_argv(self, saved_argv):
        sys.argv = saved_argv[1]
        sys.argv[:] = saved_argv[2]

    def get_cwd(self):
        return os.getcwd()
    def restore_cwd(self, saved_cwd):
        os.chdir(saved_cwd)

    def get_sys_stdout(self):
        return sys.stdout
    def restore_sys_stdout(self, saved_stdout):
        sys.stdout = saved_stdout

    def get_sys_stderr(self):
        return sys.stderr
    def restore_sys_stderr(self, saved_stderr):
        sys.stderr = saved_stderr

    def get_sys_stdin(self):
        return sys.stdin
    def restore_sys_stdin(self, saved_stdin):
        sys.stdin = saved_stdin

    def get_os_environ(self):
        return id(os.environ), os.environ, dict(os.environ)
    def restore_os_environ(self, saved_environ):
        os.environ = saved_environ[1]
        os.environ.clear()
        os.environ.update(saved_environ[2])

    def get_sys_path(self):
        return id(sys.path), sys.path, sys.path[:]
    def restore_sys_path(self, saved_path):
        sys.path = saved_path[1]
        sys.path[:] = saved_path[2]

    def get_sys_path_hooks(self):
        return id(sys.path_hooks), sys.path_hooks, sys.path_hooks[:]
    def restore_sys_path_hooks(self, saved_hooks):
        sys.path_hooks = saved_hooks[1]
        sys.path_hooks[:] = saved_hooks[2]

    def get_sys_gettrace(self):
        return sys.gettrace()
    def restore_sys_gettrace(self, trace_fxn):
        sys.settrace(trace_fxn)

    def get___import__(self):
        return builtins.__import__
    def restore___import__(self, import_):
        builtins.__import__ = import_

    def get_warnings_filters(self):
        return id(warnings.filters), warnings.filters, warnings.filters[:]
    def restore_warnings_filters(self, saved_filters):
        warnings.filters = saved_filters[1]
        warnings.filters[:] = saved_filters[2]

    def get_asyncore_socket_map(self):
        asyncore = sys.modules.get('asyncore')
        # XXX Making a copy keeps objects alive until __exit__ gets called.
        return asyncore and asyncore.socket_map.copy() or {}
    def restore_asyncore_socket_map(self, saved_map):
        asyncore = sys.modules.get('asyncore')
        if asyncore is not None:
            asyncore.close_all(ignore_all=True)
            asyncore.socket_map.update(saved_map)

    def get_shutil_archive_formats(self):
        # we could call get_archives_formats() but that only returns the
        # registry keys; we want to check the values too (the functions that
        # are registered)
        return shutil._ARCHIVE_FORMATS, shutil._ARCHIVE_FORMATS.copy()
    def restore_shutil_archive_formats(self, saved):
        shutil._ARCHIVE_FORMATS = saved[0]
        shutil._ARCHIVE_FORMATS.clear()
        shutil._ARCHIVE_FORMATS.update(saved[1])

    def get_shutil_unpack_formats(self):
        return shutil._UNPACK_FORMATS, shutil._UNPACK_FORMATS.copy()
    def restore_shutil_unpack_formats(self, saved):
        shutil._UNPACK_FORMATS = saved[0]
        shutil._UNPACK_FORMATS.clear()
        shutil._UNPACK_FORMATS.update(saved[1])

    def get_logging__handlers(self):
        # _handlers is a WeakValueDictionary
        return id(logging._handlers), logging._handlers, logging._handlers.copy()
    def restore_logging__handlers(self, saved_handlers):
        # Can't easily revert the logging state
        pass

    def get_logging__handlerList(self):
        # _handlerList is a list of weakrefs to handlers
        return id(logging._handlerList), logging._handlerList, logging._handlerList[:]
    def restore_logging__handlerList(self, saved_handlerList):
        # Can't easily revert the logging state
        pass

    def get_sys_warnoptions(self):
        return id(sys.warnoptions), sys.warnoptions, sys.warnoptions[:]
    def restore_sys_warnoptions(self, saved_options):
        sys.warnoptions = saved_options[1]
        sys.warnoptions[:] = saved_options[2]

    # Controlling dangling references to Thread objects can make it easier
    # to track reference leaks.
    def get_threading__dangling(self):
        # This copies the weakrefs without making any strong reference
        return threading._dangling.copy()
    def restore_threading__dangling(self, saved):
        threading._dangling.clear()
        threading._dangling.update(saved)

    # Same for Process objects
    def get_multiprocessing_process__dangling(self):
        if not multiprocessing:
            return None
        # Unjoined process objects can survive after process exits
        multiprocessing.process._cleanup()
        # This copies the weakrefs without making any strong reference
        return multiprocessing.process._dangling.copy()
    def restore_multiprocessing_process__dangling(self, saved):
        if not multiprocessing:
            return
        multiprocessing.process._dangling.clear()
        multiprocessing.process._dangling.update(saved)

    def get_sysconfig__CONFIG_VARS(self):
        # make sure the dict is initialized
        sysconfig.get_config_var('prefix')
        return (id(sysconfig._CONFIG_VARS), sysconfig._CONFIG_VARS,
                dict(sysconfig._CONFIG_VARS))
    def restore_sysconfig__CONFIG_VARS(self, saved):
        sysconfig._CONFIG_VARS = saved[1]
        sysconfig._CONFIG_VARS.clear()
        sysconfig._CONFIG_VARS.update(saved[2])

    def get_sysconfig__INSTALL_SCHEMES(self):
        return (id(sysconfig._INSTALL_SCHEMES), sysconfig._INSTALL_SCHEMES,
                sysconfig._INSTALL_SCHEMES.copy())
    def restore_sysconfig__INSTALL_SCHEMES(self, saved):
        sysconfig._INSTALL_SCHEMES = saved[1]
        sysconfig._INSTALL_SCHEMES.clear()
        sysconfig._INSTALL_SCHEMES.update(saved[2])

    def get_files(self):
        return sorted(fn + ('/' if os.path.isdir(fn) else '')
                      for fn in os.listdir())
    def restore_files(self, saved_value):
        fn = support.TESTFN
        if fn not in saved_value and (fn + '/') not in saved_value:
            if os.path.isfile(fn):
                support.unlink(fn)
            elif os.path.isdir(fn):
                support.rmtree(fn)

    _lc = [getattr(locale, lc) for lc in dir(locale)
           if lc.startswith('LC_')]
    def get_locale(self):
        pairings = []
        for lc in self._lc:
            try:
                pairings.append((lc, locale.setlocale(lc, None)))
            except (TypeError, ValueError):
                continue
        return pairings
    def restore_locale(self, saved):
        for lc, setting in saved:
            locale.setlocale(lc, setting)

    def get_warnings_showwarning(self):
        return warnings.showwarning
    def restore_warnings_showwarning(self, fxn):
        warnings.showwarning = fxn

    def resource_info(self):
        for name in self.resources:
            method_suffix = name.replace('.', '_')
            get_name = 'get_' + method_suffix
            restore_name = 'restore_' + method_suffix
            yield name, getattr(self, get_name), getattr(self, restore_name)

    def __enter__(self):
        self.saved_values = dict((name, get()) for name, get, restore
                                                   in self.resource_info())
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        saved_values = self.saved_values
        del self.saved_values

        # Some resources use weak references
        support.gc_collect()

        # Read support.environment_altered, set by support helper functions
        self.changed |= support.environment_altered

        for name, get, restore in self.resource_info():
            current = get()
            original = saved_values.pop(name)
            # Check for changes to the resource's value
            if current != original:
                self.changed = True
                restore(original)
                if not self.quiet and not self.pgo:
                    print_warning(f"{name} was modified by {self.testname}")
                    print(f"  Before: {original}\n  After:  {current} ",
                          file=sys.stderr, flush=True)
        return False