Mercurial > hg
view tests/test-atomictempfile.py @ 29859:a1092e2d70a3
help: internals topic for wire protocol
The Mercurial wire protocol is under-documented. This includes a lack
of source docstrings and comments as well as pages on the official
wiki.
This patch adds the beginnings of "internals" documentation on the
wire protocol.
The documentation should have nearly complete coverage on the
lower-level parts of the protocol, such as the different transport
mechanims, how commands and arguments are sent, capabilities, and,
of course, the commands themselves.
As part of writing this documentation, I discovered a number of
deficiencies in the protocol and bugs in the implementation. I've
started sending patches for some of the issues. I hope to send a lot
more.
This patch starts with the scaffolding for a new internals page.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Mon, 22 Aug 2016 19:46:39 -0700 |
parents | 6d96658a22b0 |
children | 318a24b52eeb |
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from __future__ import absolute_import import glob import os import shutil import tempfile import unittest from mercurial import ( util, ) atomictempfile = util.atomictempfile class testatomictempfile(unittest.TestCase): def setUp(self): self._testdir = tempfile.mkdtemp('atomictempfiletest') self._filename = os.path.join(self._testdir, 'testfilename') def tearDown(self): shutil.rmtree(self._testdir, True) def testsimple(self): file = atomictempfile(self._filename) self.assertFalse(os.path.isfile(self._filename)) tempfilename = file._tempname self.assertTrue(tempfilename in glob.glob( os.path.join(self._testdir, '.testfilename-*'))) file.write(b'argh\n') file.close() self.assertTrue(os.path.isfile(self._filename)) self.assertTrue(tempfilename not in glob.glob( os.path.join(self._testdir, '.testfilename-*'))) # discard() removes the temp file without making the write permanent def testdiscard(self): file = atomictempfile(self._filename) (dir, basename) = os.path.split(file._tempname) file.write(b'yo\n') file.discard() self.assertFalse(os.path.isfile(self._filename)) self.assertTrue(basename not in os.listdir('.')) # if a programmer screws up and passes bad args to atomictempfile, they # get a plain ordinary TypeError, not infinite recursion def testoops(self): self.assertRaises(TypeError, atomictempfile) # checkambig=True avoids ambiguity of timestamp def testcheckambig(self): def atomicwrite(checkambig): f = atomictempfile(self._filename, checkambig=checkambig) f.write('FOO') f.close() # try some times, because reproduction of ambiguity depends on # "filesystem time" for i in xrange(5): atomicwrite(False) oldstat = os.stat(self._filename) if oldstat.st_ctime != oldstat.st_mtime: # subsequent changing never causes ambiguity continue repetition = 3 # repeat atomic write with checkambig=True, to examine # whether st_mtime is advanced multiple times as expecetd for j in xrange(repetition): atomicwrite(True) newstat = os.stat(self._filename) if oldstat.st_ctime != newstat.st_ctime: # timestamp ambiguity was naturally avoided while repetition continue # st_mtime should be advanced "repetition" times, because # all atomicwrite() occured at same time (in sec) self.assertTrue(newstat.st_mtime == ((oldstat.st_mtime + repetition) & 0x7fffffff)) # no more examination is needed, if assumption above is true break else: # This platform seems too slow to examine anti-ambiguity # of file timestamp (or test happened to be executed at # bad timing). Exit silently in this case, because running # on other faster platforms can detect problems pass def testread(self): with open(self._filename, 'wb') as f: f.write(b'foobar\n') file = atomictempfile(self._filename, mode='rb') self.assertTrue(file.read(), b'foobar\n') file.discard() def testcontextmanagersuccess(self): """When the context closes, the file is closed""" with atomictempfile('foo') as f: self.assertFalse(os.path.isfile('foo')) f.write(b'argh\n') self.assertTrue(os.path.isfile('foo')) def testcontextmanagerfailure(self): """On exception, the file is discarded""" try: with atomictempfile('foo') as f: self.assertFalse(os.path.isfile('foo')) f.write(b'argh\n') raise ValueError except ValueError: pass self.assertFalse(os.path.isfile('foo')) if __name__ == '__main__': import silenttestrunner silenttestrunner.main(__name__)