view tests/test-linelog.py @ 40570:ad71c792a8d8

fix: add extra field to fixed revisions to avoid creating obsolescence cycles

The extra field prevents sequential invocations of fix from producing the same
hash twice. Previously, this could cause problems because it would create an
obsolescence cycle instead of the expected new successor.

This change also adds an explicit check for whether a new revision should be
committed. Until now, the code relied on memctx.commit() to quietly do nothing
if the node already exists. Because of the new extra field, this no longer
covers the case where we don't want to replace an unchanged node.

Differential Revision: https://phab.mercurial-scm.org/D5245

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)
    rev = 0
    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)
            ar = 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__)