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"""distutils.dep_util |
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Utility functions for simple, timestamp-based dependency of files |
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and groups of files; also, function based entirely on such |
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timestamp dependency analysis.""" |
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import os |
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from distutils.errors import DistutilsFileError |
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def newer(source, target): |
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"""Return true if 'source' exists and is more recently modified than |
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'target', or if 'source' exists and 'target' doesn't. Return false if |
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both exist and 'target' is the same age or younger than 'source'. |
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Raise DistutilsFileError if 'source' does not exist. |
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""" |
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if not os.path.exists(source): |
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raise DistutilsFileError("file '%s' does not exist" % os.path.abspath(source)) |
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if not os.path.exists(target): |
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return 1 |
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from stat import ST_MTIME |
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mtime1 = os.stat(source)[ST_MTIME] |
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mtime2 = os.stat(target)[ST_MTIME] |
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return mtime1 > mtime2 |
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def newer_pairwise(sources, targets): |
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"""Walk two filename lists in parallel, testing if each source is newer |
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than its corresponding target. Return a pair of lists (sources, |
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targets) where source is newer than target, according to the semantics |
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of 'newer()'. |
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""" |
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if len(sources) != len(targets): |
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raise ValueError("'sources' and 'targets' must be same length") |
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n_sources = [] |
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n_targets = [] |
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for i in range(len(sources)): |
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if newer(sources[i], targets[i]): |
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n_sources.append(sources[i]) |
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n_targets.append(targets[i]) |
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return (n_sources, n_targets) |
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def newer_group(sources, target, missing='error'): |
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"""Return true if 'target' is out-of-date with respect to any file |
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listed in 'sources'. In other words, if 'target' exists and is newer |
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than every file in 'sources', return false; otherwise return true. |
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'missing' controls what we do when a source file is missing; the |
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default ("error") is to blow up with an OSError from inside 'stat()'; |
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if it is "ignore", we silently drop any missing source files; if it is |
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"newer", any missing source files make us assume that 'target' is |
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out-of-date (this is handy in "dry-run" mode: it'll make you pretend to |
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carry out commands that wouldn't work because inputs are missing, but |
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that doesn't matter because you're not actually going to run the |
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commands). |
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""" |
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if not os.path.exists(target): |
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return 1 |
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from stat import ST_MTIME |
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target_mtime = os.stat(target)[ST_MTIME] |
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for source in sources: |
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if not os.path.exists(source): |
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if missing == 'error': |
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pass |
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elif missing == 'ignore': |
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continue |
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elif missing == 'newer': |
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return 1 |
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source_mtime = os.stat(source)[ST_MTIME] |
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if source_mtime > target_mtime: |
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return 1 |
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else: |
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return 0 |
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