59 lines
1.5 KiB
Python
59 lines
1.5 KiB
Python
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import os
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import sys
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import py
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class FDCapture:
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""" Capture IO to/from a given os-level filedescriptor. """
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def __init__(self, targetfd, tmpfile=None):
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self.targetfd = targetfd
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if tmpfile is None:
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tmpfile = self.maketmpfile()
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self.tmpfile = tmpfile
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self._savefd = os.dup(targetfd)
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os.dup2(self.tmpfile.fileno(), targetfd)
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self._patched = []
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def setasfile(self, name, module=sys):
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""" patch <module>.<name> to self.tmpfile
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"""
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key = (module, name)
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self._patched.append((key, getattr(module, name)))
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setattr(module, name, self.tmpfile)
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def unsetfiles(self):
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""" unpatch all patched items
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"""
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while self._patched:
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(module, name), value = self._patched.pop()
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setattr(module, name, value)
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def done(self):
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""" unpatch and clean up, returns the self.tmpfile (file object)
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"""
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os.dup2(self._savefd, self.targetfd)
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self.unsetfiles()
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os.close(self._savefd)
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self.tmpfile.seek(0)
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return self.tmpfile
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def maketmpfile(self):
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""" create a temporary file
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"""
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f = os.tmpfile()
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newf = py.io.dupfile(f)
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f.close()
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return newf
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def writeorg(self, str):
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""" write a string to the original file descriptor
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"""
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tempfp = os.tmpfile()
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try:
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os.dup2(self._savefd, tempfp.fileno())
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tempfp.write(str)
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finally:
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tempfp.close()
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