mirror of
https://github.com/python/cpython.git
synced 2024-11-29 12:54:02 +08:00
7ecb9c6c72
svn+ssh://pythondev@svn.python.org/python/trunk ........ r76746 | tarek.ziade | 2009-12-10 16:29:03 +0100 (Thu, 10 Dec 2009) | 1 line added test coverage for distutils.dep_util, and cleaned up the module ........
89 lines
3.4 KiB
Python
89 lines
3.4 KiB
Python
"""distutils.dep_util
|
|
|
|
Utility functions for simple, timestamp-based dependency of files
|
|
and groups of files; also, function based entirely on such
|
|
timestamp dependency analysis."""
|
|
|
|
__revision__ = "$Id$"
|
|
|
|
import os
|
|
from distutils.errors import DistutilsFileError
|
|
|
|
def newer(source, target):
|
|
"""Tells if the target is newer than the source.
|
|
|
|
Return true if 'source' exists and is more recently modified than
|
|
'target', or if 'source' exists and 'target' doesn't.
|
|
|
|
Return false if both exist and 'target' is the same age or younger
|
|
than 'source'. Raise DistutilsFileError if 'source' does not exist.
|
|
|
|
Note that this test is not very accurate: files created in the same second
|
|
will have the same "age".
|
|
"""
|
|
if not os.path.exists(source):
|
|
raise DistutilsFileError("file '%s' does not exist" %
|
|
os.path.abspath(source))
|
|
if not os.path.exists(target):
|
|
return True
|
|
|
|
return os.stat(source).st_mtime > os.stat(target).st_mtime
|
|
|
|
def newer_pairwise(sources, targets):
|
|
"""Walk two filename lists in parallel, testing if each source is newer
|
|
than its corresponding target. Return a pair of lists (sources,
|
|
targets) where source is newer than target, according to the semantics
|
|
of 'newer()'.
|
|
"""
|
|
if len(sources) != len(targets):
|
|
raise ValueError("'sources' and 'targets' must be same length")
|
|
|
|
# build a pair of lists (sources, targets) where source is newer
|
|
n_sources = []
|
|
n_targets = []
|
|
for source, target in zip(sources, targets):
|
|
if newer(source, target):
|
|
n_sources.append(source)
|
|
n_targets.append(target)
|
|
|
|
return n_sources, n_targets
|
|
|
|
def newer_group(sources, target, missing='error'):
|
|
"""Return true if 'target' is out-of-date with respect to any file
|
|
listed in 'sources'.
|
|
|
|
In other words, if 'target' exists and is newer
|
|
than every file in 'sources', return false; otherwise return true.
|
|
'missing' controls what we do when a source file is missing; the
|
|
default ("error") is to blow up with an OSError from inside 'stat()';
|
|
if it is "ignore", we silently drop any missing source files; if it is
|
|
"newer", any missing source files make us assume that 'target' is
|
|
out-of-date (this is handy in "dry-run" mode: it'll make you pretend to
|
|
carry out commands that wouldn't work because inputs are missing, but
|
|
that doesn't matter because you're not actually going to run the
|
|
commands).
|
|
"""
|
|
# If the target doesn't even exist, then it's definitely out-of-date.
|
|
if not os.path.exists(target):
|
|
return True
|
|
|
|
# Otherwise we have to find out the hard way: if *any* source file
|
|
# is more recent than 'target', then 'target' is out-of-date and
|
|
# we can immediately return true. If we fall through to the end
|
|
# of the loop, then 'target' is up-to-date and we return false.
|
|
target_mtime = os.stat(target).st_mtime
|
|
|
|
for source in sources:
|
|
if not os.path.exists(source):
|
|
if missing == 'error': # blow up when we stat() the file
|
|
pass
|
|
elif missing == 'ignore': # missing source dropped from
|
|
continue # target's dependency list
|
|
elif missing == 'newer': # missing source means target is
|
|
return True # out-of-date
|
|
|
|
if os.stat(source).st_mtime > target_mtime:
|
|
return True
|
|
|
|
return False
|