tests/test-atomictempfile.py

sidedatacopies: directly fetch copies information from sidedata

When using the sidedata mode, we don't need a complicated and expensive
`context` object. Instead we directly fetch copies information from the
sidedata (through a changelogrevision object). More optimisations coming.

revision: large amount; added files: large amount; rename small amount; c3b14617fbd7 9ba6ab77fd29
filelog: ! wall 3.679613 comb 3.680000 user 3.580000 sys 0.100000 (median of 3)
base:    ! wall 8.884369 comb 8.880000 user 8.850000 sys 0.030000 (median of 3)
before:  ! wall 4.681985 comb 4.680000 user 4.640000 sys 0.040000 (median of 3)
after:   ! wall 3.955894 comb 3.950000 user 3.940000 sys 0.010000 (median of 3)
revision: large amount; added files: small amount; rename small amount; c3b14617fbd7 f650a9b140d2
filelog: ! wall 0.003357 comb 0.010000 user 0.010000 sys 0.000000 (median of 781)
base:    ! wall 12.398524 comb 12.400000 user 12.330000 sys 0.070000 (median of 3)
before:  ! wall 6.459592 comb 6.470000 user 6.390000 sys 0.080000 (median of 3)
after:   ! wall 5.505774 comb 5.500000 user 5.410000 sys 0.090000 (median of 3)
revision: large amount; added files: large amount; rename large amount; 08ea3258278e d9fa043f30c0
filelog: ! wall 2.754687 comb 2.760000 user 2.650000 sys 0.110000 (median of 4)
base:    ! wall 1.423166 comb 1.420000 user 1.400000 sys 0.020000 (median of 8)
before:  ! wall 0.961048 comb 0.960000 user 0.940000 sys 0.020000 (median of 11)
after:   ! wall 0.882950 comb 0.880000 user 0.880000 sys 0.000000 (median of 11)
revision: small amount; added files: large amount; rename large amount; df6f7a526b60 a83dc6a2d56f
filelog: ! wall 1.552293 comb 1.550000 user 1.510000 sys 0.040000 (median of 6
base:    ! wall 0.022662 comb 0.020000 user 0.020000 sys 0.000000 (median of 128)
before:  ! wall 0.021649 comb 0.020000 user 0.020000 sys 0.000000 (median of 135)
after:   ! wall 0.020951 comb 0.020000 user 0.020000 sys 0.000000 (median of 141)
revision: small amount; added files: large amount; rename small amount; 4aa4e1f8e19a 169138063d63
filelog: ! wall 1.500983 comb 1.500000 user 1.420000 sys 0.080000 (median of 7)
base:    ! wall 0.006956 comb 0.010000 user 0.010000 sys 0.000000 (median of 392)
before:  ! wall 0.004022 comb 0.000000 user 0.000000 sys 0.000000 (median of 735)
after:   ! wall 0.003988 comb 0.000000 user 0.000000 sys 0.000000 (median of 736)
revision: small amount; added files: small amount; rename small amount; 4bc173b045a6 964879152e2e
filelog: ! wall 0.011745 comb 0.020000 user 0.020000 sys 0.000000 (median of 250)
base:    ! wall 0.000156 comb 0.000000 user 0.000000 sys 0.000000 (median of 17180)
before:  ! wall 0.000118 comb 0.000000 user 0.000000 sys 0.000000 (median of 19170)
after:   ! wall 0.000097 comb 0.000000 user 0.000000 sys 0.000000 (median of 27276)
revision: medium amount; added files: large amount; rename medium amount; c95f1ced15f2 2c68e87c3efe
filelog: ! wall 3.228230 comb 3.230000 user 3.110000 sys 0.120000 (median of 4)
base:    ! wall 0.997640 comb 1.000000 user 0.980000 sys 0.020000 (median of 10)
before:  ! wall 0.679500 comb 0.680000 user 0.680000 sys 0.000000 (median of 15)
after:   ! wall 0.596779 comb 0.600000 user 0.600000 sys 0.000000 (median of 17)
revision: medium amount; added files: medium amount; rename small amount; d343da0c55a8 d7746d32bf9d
filelog: ! wall 1.052501 comb 1.060000 user 1.040000 sys 0.020000 (median of 10
base:    ! wall 0.214519 comb 0.220000 user 0.220000 sys 0.000000 (median of 45)
before:  ! wall 0.149675 comb 0.150000 user 0.150000 sys 0.000000 (median of 66)
after:   ! wall 0.130786 comb 0.130000 user 0.130000 sys 0.000000 (median of 75)

Differential Revision: https://phab.mercurial-scm.org/D7072

from __future__ import absolute_import

import glob
import os
import shutil
import stat
import tempfile
import unittest

from mercurial import (
    pycompat,
    util,
)

atomictempfile = util.atomictempfile

if pycompat.ispy3:
    xrange = range


class testatomictempfile(unittest.TestCase):
    def setUp(self):
        self._testdir = tempfile.mkdtemp(b'atomictempfiletest')
        self._filename = os.path.join(self._testdir, b'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, b'.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, b'.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(b'.'))

    # if a programmer screws up and passes bad args to atomictempfile, they
    # get a plain ordinary TypeError, not infinite recursion
    def testoops(self):
        with self.assertRaises(TypeError):
            atomictempfile()

    # checkambig=True avoids ambiguity of timestamp
    def testcheckambig(self):
        def atomicwrite(checkambig):
            f = atomictempfile(self._filename, checkambig=checkambig)
            f.write(b'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[stat.ST_CTIME] != oldstat[stat.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 expected
            for j in xrange(repetition):
                atomicwrite(True)
            newstat = os.stat(self._filename)
            if oldstat[stat.ST_CTIME] != newstat[stat.ST_CTIME]:
                # timestamp ambiguity was naturally avoided while repetition
                continue

            # st_mtime should be advanced "repetition" times, because
            # all atomicwrite() occurred at same time (in sec)
            oldtime = (oldstat[stat.ST_MTIME] + repetition) & 0x7FFFFFFF
            self.assertTrue(newstat[stat.ST_MTIME] == oldtime)
            # 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=b'rb')
        self.assertTrue(file.read(), b'foobar\n')
        file.discard()

    def testcontextmanagersuccess(self):
        """When the context closes, the file is closed"""
        with atomictempfile(b'foo') as f:
            self.assertFalse(os.path.isfile(b'foo'))
            f.write(b'argh\n')
        self.assertTrue(os.path.isfile(b'foo'))

    def testcontextmanagerfailure(self):
        """On exception, the file is discarded"""
        try:
            with atomictempfile(b'foo') as f:
                self.assertFalse(os.path.isfile(b'foo'))
                f.write(b'argh\n')
                raise ValueError
        except ValueError:
            pass
        self.assertFalse(os.path.isfile(b'foo'))


if __name__ == '__main__':
    import silenttestrunner

    silenttestrunner.main(__name__)