"""Implements an importer that looks only in specific path (ignoring
sys.path), and uses a per-path cache in addition to sys.modules. This is
necessary because test modules in different directories frequently have the
same names, which means that the first loaded would mask the rest when using
the builtin importer.
"""
import logging
import os
import sys
from nose.config import Config
from imp import find_module, load_module, acquire_lock, release_lock
log = logging.getLogger(__name__)
try:
_samefile = os.path.samefile
except AttributeError:
def _samefile(src, dst):
return (os.path.normcase(os.path.realpath(src)) ==
os.path.normcase(os.path.realpath(dst)))
class Importer(object):
"""An importer class that does only path-specific imports. That
is, the given module is not searched for on sys.path, but only at
the path or in the directory specified.
"""
def __init__(self, config=None):
if config is None:
config = Config()
self.config = config
def importFromPath(self, path, fqname):
"""Import a dotted-name package whose tail is at path. In other words,
given foo.bar and path/to/foo/bar.py, import foo from path/to/foo then
bar from path/to/foo/bar, returning bar.
"""
# find the base dir of the package
path_parts = os.path.normpath(os.path.abspath(path)).split(os.sep)
name_parts = fqname.split('.')
if path_parts[-1] == '__init__.py':
path_parts.pop()
path_parts = path_parts[:-(len(name_parts))]
dir_path = os.sep.join(path_parts)
# then import fqname starting from that dir
return self.importFromDir(dir_path, fqname)
def importFromDir(self, dir, fqname):
"""Import a module *only* from path, ignoring sys.path and
reloading if the version in sys.modules is not the one we want.
"""
dir = os.path.normpath(os.path.abspath(dir))
log.debug("Import %s from %s", fqname, dir)
# FIXME reimplement local per-dir cache?
# special case for __main__
if fqname == '__main__':
return sys.modules[fqname]
if self.config.addPaths:
add_path(dir, self.config)
path = [dir]
parts = fqname.split('.')
part_fqname = ''
mod = parent = fh = None
for part in parts:
if part_fqname == '':
part_fqname = part
else:
part_fqname = "%s.%s" % (part_fqname, part)
try:
acquire_lock()
log.debug("find module part %s (%s) in %s",
part, part_fqname, path)
fh, filename, desc = find_module(part, path)
old = sys.modules.get(part_fqname)
if old is not None:
# test modules frequently have name overlap; make sure
# we get a fresh copy of anything we are trying to load
# from a new path
log.debug("sys.modules has %s as %s", part_fqname, old)
if (self.sameModule(old, filename)
or (self.config.firstPackageWins and
getattr(old, '__path__', None))):
mod = old
else:
del sys.modules[part_fqname]
mod = load_module(part_fqname, fh, filename, desc)
else:
mod = load_module(part_fqname, fh, filename, desc)
finally:
if fh:
fh.close()
release_lock()
if parent:
setattr(parent, part, mod)
if hasattr(mod, '__path__'):
path = mod.__path__
parent = mod
return mod
def _dirname_if_file(self, filename):
# We only take the dirname if we have a path to a non-dir,
# because taking the dirname of a symlink to a directory does not
# give the actual directory parent.
if os.path.isdir(filename):
return filename
else:
return os.path.dirname(filename)
def sameModule(self, mod, filename):
mod_paths = []
if hasattr(mod, '__path__'):
for path in mod.__path__:
mod_paths.append(self._dirname_if_file(path))
elif hasattr(mod, '__file__'):
mod_paths.append(self._dirname_if_file(mod.__file__))
else:
# builtin or other module-like object that
# doesn't have __file__; must be new
return False
new_path = self._dirname_if_file(filename)
for mod_path in mod_paths:
log.debug(
"module already loaded? mod: %s new: %s",
mod_path, new_path)
if _samefile(mod_path, new_path):
return True
return False
def add_path(path, config=None):
"""Ensure that the path, or the root of the current package (if
path is in a package), is in sys.path.
"""
# FIXME add any src-looking dirs seen too... need to get config for that
log.debug('Add path %s' % path)
if not path:
return []
added = []
parent = os.path.dirname(path)
if (parent
and os.path.exists(os.path.join(path, '__init__.py'))):
added.extend(add_path(parent, config))
elif not path in sys.path:
log.debug("insert %s into sys.path", path)
sys.path.insert(0, path)
added.append(path)
if config and config.srcDirs:
for dirname in config.srcDirs:
dirpath = os.path.join(path, dirname)
if os.path.isdir(dirpath):
sys.path.insert(0, dirpath)
added.append(dirpath)
return added
def remove_path(path):
log.debug('Remove path %s' % path)
if path in sys.path:
sys.path.remove(path)
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