outgoing: rework the handling of the `missingroots` case to be faster The previous implementation was slow, to the point it was taking a significant amount of `hg bundle --type none-streamv2` call. We rework the code to compute the same value much faster, making the operation disappear from the `hg bundle --type none-streamv2` profile. Someone would remark that producing a streamclone does not requires an `outgoing` object. However that is a matter for another day. There is other user of `missingroots` (non stream `hg bundle` call for example), and they will also benefit from this rework. We implement an old TODO in the process, directly computing the missing and common attribute as we have most element at hand already. ### benchmark.name = hg.command.bundle # bin-env-vars.hg.flavor = default # bin-env-vars.hg.py-re2-module = default # benchmark.variants.revs = all # benchmark.variants.type = none-streamv2 ## data-env-vars.name = heptapod-public-2024-03-25-zstd-sparse-revlog before: 7.750458 after: 6.665565 (-14.00%, -1.08) ## data-env-vars.name = mercurial-public-2024-03-22-zstd-sparse-revlog before: 0.700229 after: 0.496050 (-29.16%, -0.20) ## data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog before: 346.508952 after: 316.749699 (-8.59%, -29.76) ## data-env-vars.name = pypy-2024-03-22-zstd-sparse-revlog before: 3.401700 after: 2.915810 (-14.28%, -0.49) ## data-env-vars.name = tryton-public-2024-03-22-zstd-sparse-revlog before: 1.870798 after: 1.461583 (-21.87%, -0.41) note: this whole `missingroots` of outgoing has a limited number of callers and could likely be replace by something simpler (like taking an explicit "missing_revs" set for example). However this is a wider change and we focus on a small impact, quick rework that does not change the API for now.

"""
List-valued configuration keys have an ad-hoc microsyntax. From `hg help config`:

> List values are separated by whitespace or comma, except when values are
> placed in double quotation marks:
>
>     allow_read = "John Doe, PhD", brian, betty
>
> Quotation marks can be escaped by prefixing them with a backslash. Only
> quotation marks at the beginning of a word is counted as a quotation
> (e.g., ``foo"bar baz`` is the list of ``foo"bar`` and ``baz``).

That help documentation is fairly light on details, the actual parser has many
other edge cases. This test tries to cover them.
"""

from mercurial.utils import stringutil


def assert_parselist(input, expected):
    result = stringutil.parselist(input)
    if result != expected:
        raise AssertionError(
            "parse_input(%r)\n     got %r\nexpected %r"
            % (input, result, expected)
        )


# Keep these Python tests in sync with the Rust ones in `rust/hg-core/src/config/values.rs`

assert_parselist(b'', [])
assert_parselist(b',', [])
assert_parselist(b'A', [b'A'])
assert_parselist(b'B,B', [b'B', b'B'])
assert_parselist(b', C, ,C,', [b'C', b'C'])
assert_parselist(b'"', [b'"'])
assert_parselist(b'""', [b'', b''])
assert_parselist(b'D,"', [b'D', b'"'])
assert_parselist(b'E,""', [b'E', b'', b''])
assert_parselist(b'"F,F"', [b'F,F'])
assert_parselist(b'"G,G', [b'"G', b'G'])
assert_parselist(b'"H \\",\\"H', [b'"H', b',', b'H'])
assert_parselist(b'I,I"', [b'I', b'I"'])
assert_parselist(b'J,"J', [b'J', b'"J'])
assert_parselist(b'K K', [b'K', b'K'])
assert_parselist(b'"K" K', [b'K', b'K'])
assert_parselist(b'L\tL', [b'L', b'L'])
assert_parselist(b'"L"\tL', [b'L', b'', b'L'])
assert_parselist(b'M\x0bM', [b'M', b'M'])
assert_parselist(b'"M"\x0bM', [b'M', b'', b'M'])
assert_parselist(b'"N"  , ,"', [b'N"'])
assert_parselist(b'" ,O,  ', [b'"', b'O'])