view tests/test-absorb-filefixupstate.py @ 47072:4c041c71ec01

revlog: introduce an explicit tracking of what the revlog is about

Since the dawn of time, people have been forced to rely to lossy introspection
of the index filename to determine what the purpose and role of the revlog they
encounter is. This is hacky, error prone, inflexible, abstraction-leaky,
<insert-your-own-complaints-here>.

In f63299ee7e4d Raphaël introduced a new attribute to track this information:
`revlog_kind`. However it is initialized in an odd place and various instances
end up not having it set. In addition is only tracking some of the information
we end up having to introspect in various pieces of code.

So we add a new attribute that holds more data and is more strictly enforced.
This work is done in collaboration with Raphaël.

The `revlog_kind` one will be removed/adapted in the next changeset. We expect
to be able to clean up various existing piece of code and to simplify coming
work around the newer revlog format.

Differential Revision: https://phab.mercurial-scm.org/D10352

from __future__ import absolute_import, print_function

import itertools
from mercurial import pycompat
from hgext import absorb


class simplefctx(object):
    def __init__(self, content):
        self.content = content

    def data(self):
        return self.content


def insertreturns(x):
    # insert "\n"s after each single char
    if isinstance(x, bytes):
        return b''.join(ch + b'\n' for ch in pycompat.bytestr(x))
    else:
        return pycompat.maplist(insertreturns, x)


def removereturns(x):
    # the revert of "insertreturns"
    if isinstance(x, bytes):
        return x.replace(b'\n', b'')
    else:
        return pycompat.maplist(removereturns, x)


def assertlistequal(lhs, rhs, decorator=lambda x: x):
    if lhs != rhs:
        raise RuntimeError(
            'mismatch:\n actual:   %r\n expected: %r'
            % tuple(map(decorator, [lhs, rhs]))
        )


def testfilefixup(oldcontents, workingcopy, expectedcontents, fixups=None):
    """([str], str, [str], [(rev, a1, a2, b1, b2)]?) -> None

    workingcopy is a string, of which every character denotes a single line.

    oldcontents, expectedcontents are lists of strings, every character of
    every string denots a single line.

    if fixups is not None, it's the expected fixups list and will be checked.
    """
    expectedcontents = insertreturns(expectedcontents)
    oldcontents = insertreturns(oldcontents)
    workingcopy = insertreturns(workingcopy)
    state = absorb.filefixupstate(
        pycompat.maplist(simplefctx, oldcontents), 'path'
    )
    state.diffwith(simplefctx(workingcopy))
    if fixups is not None:
        assertlistequal(state.fixups, fixups)
    state.apply()
    assertlistequal(state.finalcontents, expectedcontents, removereturns)


def buildcontents(linesrevs):
    # linesrevs: [(linecontent : str, revs : [int])]
    revs = set(itertools.chain(*[revs for line, revs in linesrevs]))
    return [b''] + [
        b''.join([l for l, rs in linesrevs if r in rs]) for r in sorted(revs)
    ]


# input case 0: one single commit
case0 = [b'', b'11']

# replace a single chunk
testfilefixup(case0, b'', [b'', b''])
testfilefixup(case0, b'2', [b'', b'2'])
testfilefixup(case0, b'22', [b'', b'22'])
testfilefixup(case0, b'222', [b'', b'222'])

# input case 1: 3 lines, each commit adds one line
case1 = buildcontents(
    [
        (b'1', [1, 2, 3]),
        (b'2', [2, 3]),
        (b'3', [3]),
    ]
)

# 1:1 line mapping
testfilefixup(case1, b'123', case1)
testfilefixup(case1, b'12c', [b'', b'1', b'12', b'12c'])
testfilefixup(case1, b'1b3', [b'', b'1', b'1b', b'1b3'])
testfilefixup(case1, b'1bc', [b'', b'1', b'1b', b'1bc'])
testfilefixup(case1, b'a23', [b'', b'a', b'a2', b'a23'])
testfilefixup(case1, b'a2c', [b'', b'a', b'a2', b'a2c'])
testfilefixup(case1, b'ab3', [b'', b'a', b'ab', b'ab3'])
testfilefixup(case1, b'abc', [b'', b'a', b'ab', b'abc'])

# non 1:1 edits
testfilefixup(case1, b'abcd', case1)
testfilefixup(case1, b'ab', case1)

# deletion
testfilefixup(case1, b'', [b'', b'', b'', b''])
testfilefixup(case1, b'1', [b'', b'1', b'1', b'1'])
testfilefixup(case1, b'2', [b'', b'', b'2', b'2'])
testfilefixup(case1, b'3', [b'', b'', b'', b'3'])
testfilefixup(case1, b'13', [b'', b'1', b'1', b'13'])

# replaces
testfilefixup(case1, b'1bb3', [b'', b'1', b'1bb', b'1bb3'])

# (confusing) replaces
testfilefixup(case1, b'1bbb', case1)
testfilefixup(case1, b'bbbb', case1)
testfilefixup(case1, b'bbb3', case1)
testfilefixup(case1, b'1b', case1)
testfilefixup(case1, b'bb', case1)
testfilefixup(case1, b'b3', case1)

# insertions at the beginning and the end
testfilefixup(case1, b'123c', [b'', b'1', b'12', b'123c'])
testfilefixup(case1, b'a123', [b'', b'a1', b'a12', b'a123'])

# (confusing) insertions
testfilefixup(case1, b'1a23', case1)
testfilefixup(case1, b'12b3', case1)

# input case 2: delete in the middle
case2 = buildcontents(
    [
        (b'11', [1, 2]),
        (b'22', [1]),
        (b'33', [1, 2]),
    ]
)

# deletion (optimize code should make it 2 chunks)
testfilefixup(
    case2, b'', [b'', b'22', b''], fixups=[(4, 0, 2, 0, 0), (4, 2, 4, 0, 0)]
)

# 1:1 line mapping
testfilefixup(case2, b'aaaa', [b'', b'aa22aa', b'aaaa'])

# non 1:1 edits
# note: unlike case0, the chunk is not "continuous" and no edit allowed
testfilefixup(case2, b'aaa', case2)

# input case 3: rev 3 reverts rev 2
case3 = buildcontents(
    [
        (b'1', [1, 2, 3]),
        (b'2', [2]),
        (b'3', [1, 2, 3]),
    ]
)

# 1:1 line mapping
testfilefixup(case3, b'13', case3)
testfilefixup(case3, b'1b', [b'', b'1b', b'12b', b'1b'])
testfilefixup(case3, b'a3', [b'', b'a3', b'a23', b'a3'])
testfilefixup(case3, b'ab', [b'', b'ab', b'a2b', b'ab'])

# non 1:1 edits
testfilefixup(case3, b'a', case3)
testfilefixup(case3, b'abc', case3)

# deletion
testfilefixup(case3, b'', [b'', b'', b'2', b''])

# insertion
testfilefixup(case3, b'a13c', [b'', b'a13c', b'a123c', b'a13c'])

# input case 4: a slightly complex case
case4 = buildcontents(
    [
        (b'1', [1, 2, 3]),
        (b'2', [2, 3]),
        (
            b'3',
            [
                1,
                2,
            ],
        ),
        (b'4', [1, 3]),
        (b'5', [3]),
        (b'6', [2, 3]),
        (b'7', [2]),
        (b'8', [2, 3]),
        (b'9', [3]),
    ]
)

testfilefixup(case4, b'1245689', case4)
testfilefixup(case4, b'1a2456bbb', case4)
testfilefixup(case4, b'1abc5689', case4)
testfilefixup(case4, b'1ab5689', [b'', b'134', b'1a3678', b'1ab5689'])
testfilefixup(case4, b'aa2bcd8ee', [b'', b'aa34', b'aa23d78', b'aa2bcd8ee'])
testfilefixup(case4, b'aa2bcdd8ee', [b'', b'aa34', b'aa23678', b'aa24568ee'])
testfilefixup(case4, b'aaaaaa', case4)
testfilefixup(case4, b'aa258b', [b'', b'aa34', b'aa2378', b'aa258b'])
testfilefixup(case4, b'25bb', [b'', b'34', b'23678', b'25689'])
testfilefixup(case4, b'27', [b'', b'34', b'23678', b'245689'])
testfilefixup(case4, b'28', [b'', b'34', b'2378', b'28'])
testfilefixup(case4, b'', [b'', b'34', b'37', b''])

# input case 5: replace a small chunk which is near a deleted line
case5 = buildcontents(
    [
        (b'12', [1, 2]),
        (b'3', [1]),
        (b'4', [1, 2]),
    ]
)

testfilefixup(case5, b'1cd4', [b'', b'1cd34', b'1cd4'])

# input case 6: base "changeset" is immutable
case6 = [b'1357', b'0125678']

testfilefixup(case6, b'0125678', case6)
testfilefixup(case6, b'0a25678', case6)
testfilefixup(case6, b'0a256b8', case6)
testfilefixup(case6, b'abcdefg', [b'1357', b'a1c5e7g'])
testfilefixup(case6, b'abcdef', case6)
testfilefixup(case6, b'', [b'1357', b'157'])
testfilefixup(case6, b'0123456789', [b'1357', b'0123456789'])

# input case 7: change an empty file
case7 = [b'']

testfilefixup(case7, b'1', case7)