tests/test-storage.py

rust: switch hg-core and hg-cpython to rust 2018 edition

Many interesting changes have happened in Rust since the Oxidation Plan was
introduced, like the 2018 edition and procedural macros:

    - Opting in to the 2018 edition is a clear benefit in terms of future
      proofing, new (nice to have) syntactical sugar notwithstanding. It
      also has a new non-lexical, non-AST based borrow checker that has
      fewer bugs(!) and allows us to write correct code that in some cases
      would have been rejected by the old one.
    - Procedural macros allow us to use the PyO3 crate which maintainers have
      expressed the clear goal of compiling on stable, which would help in
      code maintainability compared to rust-cpython.

In this patch are the following changes:
    - Removing most `extern crate` uses
    - Updating `use` clauses (`crate` keyword, nested `use`)
    - Removing `mod.rs` in favor of an aptly named module file

Like discussed in the mailing list (
https://www.mercurial-scm.org/pipermail/mercurial-devel/2019-July/132316.html
), until Rust integration in Mercurial is considered to be out of the
experimental phase, the maximum version of Rust allowed is whatever the latest
version Debian packages.

Differential Revision: https://phab.mercurial-scm.org/D6597

# This test verifies the conformance of various classes to various
# storage interfaces.
from __future__ import absolute_import

import silenttestrunner

from mercurial import (
    error,
    filelog,
    revlog,
    transaction,
    ui as uimod,
    vfs as vfsmod,
)

from mercurial.testing import (
    storage as storagetesting,
)

try:
    from hgext import (
        sqlitestore,
    )
except ImportError:
    sqlitestore = None

try:
    import sqlite3
    if sqlite3.sqlite_version_info < (3, 8, 3):
        # WITH clause not supported
        sqlitestore = None
except ImportError:
    pass

try:
    from mercurial import zstd
    zstd.__version__
except ImportError:
    zstd = None

STATE = {
    'lastindex': 0,
    'ui': uimod.ui(),
    'vfs': vfsmod.vfs(b'.', realpath=True),
}

def makefilefn(self):
    """Factory for filelog instances."""
    fl = filelog.filelog(STATE['vfs'], b'filelog-%d' % STATE['lastindex'])
    STATE['lastindex'] += 1
    return fl

def maketransaction(self):
    vfsmap = {b'plain': STATE['vfs'], b'store': STATE['vfs']}

    return transaction.transaction(STATE['ui'].warn, STATE['vfs'], vfsmap,
                                   b'journal', b'undo')

def addrawrevision(self, fl, tr, node, p1, p2, linkrev, rawtext=None,
                   delta=None, censored=False, ellipsis=False, extstored=False):
    flags = 0

    if censored:
        flags |= revlog.REVIDX_ISCENSORED
    if ellipsis:
        flags |= revlog.REVIDX_ELLIPSIS
    if extstored:
        flags |= revlog.REVIDX_EXTSTORED

    if rawtext is not None:
        fl._revlog.addrawrevision(rawtext, tr, linkrev, p1, p2, node, flags)
    elif delta is not None:
        fl._revlog.addrawrevision(rawtext, tr, linkrev, p1, p2, node, flags,
                                  cachedelta=delta)
    else:
        raise error.Abort('must supply rawtext or delta arguments')

    # We may insert bad data. Clear caches to prevent e.g. cache hits to
    # bypass hash verification.
    fl._revlog.clearcaches()

# Assigning module-level attributes that inherit from unittest.TestCase
# is all that is needed to register tests.
filelogindextests = storagetesting.makeifileindextests(makefilefn,
                                                       maketransaction,
                                                       addrawrevision)
filelogdatatests = storagetesting.makeifiledatatests(makefilefn,
                                                     maketransaction,
                                                     addrawrevision)
filelogmutationtests = storagetesting.makeifilemutationtests(makefilefn,
                                                             maketransaction,
                                                             addrawrevision)

def makesqlitefile(self):
    path = STATE['vfs'].join(b'db-%d.db' % STATE['lastindex'])
    STATE['lastindex'] += 1

    db = sqlitestore.makedb(path)

    compression = b'zstd' if zstd else b'zlib'

    return sqlitestore.sqlitefilestore(db, b'dummy-path', compression)

def addrawrevisionsqlite(self, fl, tr, node, p1, p2, linkrev, rawtext=None,
                         delta=None, censored=False, ellipsis=False,
                         extstored=False):
    flags = 0

    if censored:
        flags |= sqlitestore.FLAG_CENSORED

    if ellipsis | extstored:
        raise error.Abort(b'support for ellipsis and extstored flags not '
                          b'supported')

    if rawtext is not None:
        fl._addrawrevision(node, rawtext, tr, linkrev, p1, p2, flags=flags)
    elif delta is not None:
        fl._addrawrevision(node, rawtext, tr, linkrev, p1, p2,
                           storedelta=delta, flags=flags)
    else:
        raise error.Abort(b'must supply rawtext or delta arguments')

if sqlitestore is not None:
    sqlitefileindextests = storagetesting.makeifileindextests(
        makesqlitefile, maketransaction, addrawrevisionsqlite)
    sqlitefiledatatests = storagetesting.makeifiledatatests(
        makesqlitefile, maketransaction, addrawrevisionsqlite)
    sqlitefilemutationtests = storagetesting.makeifilemutationtests(
        makesqlitefile, maketransaction, addrawrevisionsqlite)

if __name__ == '__main__':
    silenttestrunner.main(__name__)