view tests/test-linelog.py @ 48390:322525db4c98

status: use filesystem time boundary to invalidate racy mtime

We record the filesystem time at the start of the status walk and use that as a
boundary to detect files that might be modified during (or right after) the
status run without the mtime allowing that edition to be detected.  We
currently do this at a second precision. In a later patch, we will use
nanosecond precision when available.

To cope with "broken" time on the file system where file could be in the
future, we also keep mtime for file over one day in the future. See inline
comment for details.

Large file tests get a bit more confused as we reduce the odds for race
condition.

As a "side effect", the win32text extension is happy again.

Differential Revision: https://phab.mercurial-scm.org/D11794

from __future__ import absolute_import, print_function

import difflib
import random
import unittest

from mercurial import linelog

vecratio = 3  # number of replacelines / number of replacelines_vec
maxlinenum = 0xFFFFFF
maxb1 = 0xFFFFFF
maxdeltaa = 10
maxdeltab = 10


def _genedits(seed, endrev):
    lines = []
    random.seed(seed)
    for rev in range(0, endrev):
        n = len(lines)
        a1 = random.randint(0, n)
        a2 = random.randint(a1, min(n, a1 + maxdeltaa))
        b1 = random.randint(0, maxb1)
        b2 = random.randint(b1, b1 + maxdeltab)
        usevec = not bool(random.randint(0, vecratio))
        if usevec:
            blines = [
                (random.randint(0, rev), random.randint(0, maxlinenum))
                for _ in range(b1, b2)
            ]
        else:
            blines = [(rev, bidx) for bidx in range(b1, b2)]
        lines[a1:a2] = blines
        yield lines, rev, a1, a2, b1, b2, blines, usevec


class linelogtests(unittest.TestCase):
    def testlinelogencodedecode(self):
        program = [
            linelog._eof(0, 0),
            linelog._jge(41, 42),
            linelog._jump(0, 43),
            linelog._eof(0, 0),
            linelog._jl(44, 45),
            linelog._line(46, 47),
        ]
        ll = linelog.linelog(program, maxrev=100)
        enc = ll.encode()
        # round-trips okay
        self.assertEqual(linelog.linelog.fromdata(enc)._program, ll._program)
        self.assertEqual(linelog.linelog.fromdata(enc), ll)
        # This encoding matches the encoding used by hg-experimental's
        # linelog file, or is supposed to if it doesn't.
        self.assertEqual(
            enc,
            (
                b'\x00\x00\x01\x90\x00\x00\x00\x06'
                b'\x00\x00\x00\xa4\x00\x00\x00*'
                b'\x00\x00\x00\x00\x00\x00\x00+'
                b'\x00\x00\x00\x00\x00\x00\x00\x00'
                b'\x00\x00\x00\xb1\x00\x00\x00-'
                b'\x00\x00\x00\xba\x00\x00\x00/'
            ),
        )

    def testsimpleedits(self):
        ll = linelog.linelog()
        # Initial revision: add lines 0, 1, and 2
        ll.replacelines(1, 0, 0, 0, 3)
        self.assertEqual(
            [(l.rev, l.linenum) for l in ll.annotate(1)],
            [
                (1, 0),
                (1, 1),
                (1, 2),
            ],
        )
        # Replace line 1 with a new line
        ll.replacelines(2, 1, 2, 1, 2)
        self.assertEqual(
            [(l.rev, l.linenum) for l in ll.annotate(2)],
            [
                (1, 0),
                (2, 1),
                (1, 2),
            ],
        )
        # delete a line out of 2
        ll.replacelines(3, 1, 2, 0, 0)
        self.assertEqual(
            [(l.rev, l.linenum) for l in ll.annotate(3)],
            [
                (1, 0),
                (1, 2),
            ],
        )
        # annotation of 1 is unchanged
        self.assertEqual(
            [(l.rev, l.linenum) for l in ll.annotate(1)],
            [
                (1, 0),
                (1, 1),
                (1, 2),
            ],
        )
        ll.annotate(3)  # set internal state to revision 3
        start = ll.getoffset(0)
        end = ll.getoffset(1)
        self.assertEqual(
            ll.getalllines(start, end),
            [
                (1, 0),
                (2, 1),
                (1, 1),
            ],
        )
        self.assertEqual(
            ll.getalllines(),
            [
                (1, 0),
                (2, 1),
                (1, 1),
                (1, 2),
            ],
        )

    def testparseclinelogfile(self):
        # This data is what the replacements in testsimpleedits
        # produce when fed to the original linelog.c implementation.
        data = (
            b'\x00\x00\x00\x0c\x00\x00\x00\x0f'
            b'\x00\x00\x00\x00\x00\x00\x00\x02'
            b'\x00\x00\x00\x05\x00\x00\x00\x06'
            b'\x00\x00\x00\x06\x00\x00\x00\x00'
            b'\x00\x00\x00\x00\x00\x00\x00\x07'
            b'\x00\x00\x00\x06\x00\x00\x00\x02'
            b'\x00\x00\x00\x00\x00\x00\x00\x00'
            b'\x00\x00\x00\t\x00\x00\x00\t'
            b'\x00\x00\x00\x00\x00\x00\x00\x0c'
            b'\x00\x00\x00\x08\x00\x00\x00\x05'
            b'\x00\x00\x00\x06\x00\x00\x00\x01'
            b'\x00\x00\x00\x00\x00\x00\x00\x05'
            b'\x00\x00\x00\x0c\x00\x00\x00\x05'
            b'\x00\x00\x00\n\x00\x00\x00\x01'
            b'\x00\x00\x00\x00\x00\x00\x00\t'
        )
        llc = linelog.linelog.fromdata(data)
        self.assertEqual(
            [(l.rev, l.linenum) for l in llc.annotate(1)],
            [
                (1, 0),
                (1, 1),
                (1, 2),
            ],
        )
        self.assertEqual(
            [(l.rev, l.linenum) for l in llc.annotate(2)],
            [
                (1, 0),
                (2, 1),
                (1, 2),
            ],
        )
        self.assertEqual(
            [(l.rev, l.linenum) for l in llc.annotate(3)],
            [
                (1, 0),
                (1, 2),
            ],
        )
        # Check we emit the same bytecode.
        ll = linelog.linelog()
        # Initial revision: add lines 0, 1, and 2
        ll.replacelines(1, 0, 0, 0, 3)
        # Replace line 1 with a new line
        ll.replacelines(2, 1, 2, 1, 2)
        # delete a line out of 2
        ll.replacelines(3, 1, 2, 0, 0)
        diff = '\n   ' + '\n   '.join(
            difflib.unified_diff(
                ll.debugstr().splitlines(),
                llc.debugstr().splitlines(),
                'python',
                'c',
                lineterm='',
            )
        )
        self.assertEqual(ll._program, llc._program, 'Program mismatch: ' + diff)
        # Done as a secondary step so we get a better result if the
        # program is where the mismatch is.
        self.assertEqual(ll, llc)
        self.assertEqual(ll.encode(), data)

    def testanothersimplecase(self):
        ll = linelog.linelog()
        ll.replacelines(3, 0, 0, 0, 2)
        ll.replacelines(4, 0, 2, 0, 0)
        self.assertEqual([(l.rev, l.linenum) for l in ll.annotate(4)], [])
        self.assertEqual(
            [(l.rev, l.linenum) for l in ll.annotate(3)], [(3, 0), (3, 1)]
        )
        # rev 2 is empty because contents were only ever introduced in rev 3
        self.assertEqual([(l.rev, l.linenum) for l in ll.annotate(2)], [])

    def testrandomedits(self):
        # Inspired by original linelog tests.
        seed = random.random()
        numrevs = 2000
        ll = linelog.linelog()
        # Populate linelog
        for lines, rev, a1, a2, b1, b2, blines, usevec in _genedits(
            seed, numrevs
        ):
            if usevec:
                ll.replacelines_vec(rev, a1, a2, blines)
            else:
                ll.replacelines(rev, a1, a2, b1, b2)
            ll.annotate(rev)
            self.assertEqual(ll.annotateresult, lines)
        # Verify we can get back these states by annotating each rev
        for lines, rev, a1, a2, b1, b2, blines, usevec in _genedits(
            seed, numrevs
        ):
            ar = ll.annotate(rev)
            self.assertEqual([(l.rev, l.linenum) for l in ar], lines)

    def testinfinitebadprogram(self):
        ll = linelog.linelog.fromdata(
            b'\x00\x00\x00\x00\x00\x00\x00\x02'  # header
            b'\x00\x00\x00\x00\x00\x00\x00\x01'  # JUMP to self
        )
        with self.assertRaises(linelog.LineLogError):
            # should not be an infinite loop and raise
            ll.annotate(1)


if __name__ == '__main__':
    import silenttestrunner

    silenttestrunner.main(__name__)