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
# filelog.py - file history class for mercurial
#
# Copyright 2005-2007 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import
from .i18n import _
from .node import (
nullid,
nullrev,
)
from . import (
error,
repository,
revlog,
)
from .utils import (
interfaceutil,
storageutil,
)
@interfaceutil.implementer(repository.ifilestorage)
class filelog(object):
def __init__(self, opener, path):
self._revlog = revlog.revlog(opener,
'/'.join(('data', path + '.i')),
censorable=True)
# Full name of the user visible file, relative to the repository root.
# Used by LFS.
self._revlog.filename = path
def __len__(self):
return len(self._revlog)
def __iter__(self):
return self._revlog.__iter__()
def hasnode(self, node):
if node in (nullid, nullrev):
return False
try:
self._revlog.rev(node)
return True
except (TypeError, ValueError, IndexError, error.LookupError):
return False
def revs(self, start=0, stop=None):
return self._revlog.revs(start=start, stop=stop)
def parents(self, node):
return self._revlog.parents(node)
def parentrevs(self, rev):
return self._revlog.parentrevs(rev)
def rev(self, node):
return self._revlog.rev(node)
def node(self, rev):
return self._revlog.node(rev)
def lookup(self, node):
return storageutil.fileidlookup(self._revlog, node,
self._revlog.indexfile)
def linkrev(self, rev):
return self._revlog.linkrev(rev)
def commonancestorsheads(self, node1, node2):
return self._revlog.commonancestorsheads(node1, node2)
# Used by dagop.blockdescendants().
def descendants(self, revs):
return self._revlog.descendants(revs)
def heads(self, start=None, stop=None):
return self._revlog.heads(start, stop)
# Used by hgweb, children extension.
def children(self, node):
return self._revlog.children(node)
def iscensored(self, rev):
return self._revlog.iscensored(rev)
def revision(self, node, _df=None, raw=False):
return self._revlog.revision(node, _df=_df, raw=raw)
def emitrevisions(self, nodes, nodesorder=None,
revisiondata=False, assumehaveparentrevisions=False,
deltamode=repository.CG_DELTAMODE_STD):
return self._revlog.emitrevisions(
nodes, nodesorder=nodesorder, revisiondata=revisiondata,
assumehaveparentrevisions=assumehaveparentrevisions,
deltamode=deltamode)
def addrevision(self, revisiondata, transaction, linkrev, p1, p2,
node=None, flags=revlog.REVIDX_DEFAULT_FLAGS,
cachedelta=None):
return self._revlog.addrevision(revisiondata, transaction, linkrev,
p1, p2, node=node, flags=flags,
cachedelta=cachedelta)
def addgroup(self, deltas, linkmapper, transaction, addrevisioncb=None,
maybemissingparents=False):
if maybemissingparents:
raise error.Abort(_('revlog storage does not support missing '
'parents write mode'))
return self._revlog.addgroup(deltas, linkmapper, transaction,
addrevisioncb=addrevisioncb)
def getstrippoint(self, minlink):
return self._revlog.getstrippoint(minlink)
def strip(self, minlink, transaction):
return self._revlog.strip(minlink, transaction)
def censorrevision(self, tr, node, tombstone=b''):
return self._revlog.censorrevision(tr, node, tombstone=tombstone)
def files(self):
return self._revlog.files()
def read(self, node):
return storageutil.filtermetadata(self.revision(node))
def add(self, text, meta, transaction, link, p1=None, p2=None):
if meta or text.startswith('\1\n'):
text = storageutil.packmeta(meta, text)
return self.addrevision(text, transaction, link, p1, p2)
def renamed(self, node):
return storageutil.filerevisioncopied(self, node)
def size(self, rev):
"""return the size of a given revision"""
# for revisions with renames, we have to go the slow way
node = self.node(rev)
if self.renamed(node):
return len(self.read(node))
if self.iscensored(rev):
return 0
# XXX if self.read(node).startswith("\1\n"), this returns (size+4)
return self._revlog.size(rev)
def cmp(self, node, text):
"""compare text with a given file revision
returns True if text is different than what is stored.
"""
return not storageutil.filedataequivalent(self, node, text)
def verifyintegrity(self, state):
return self._revlog.verifyintegrity(state)
def storageinfo(self, exclusivefiles=False, sharedfiles=False,
revisionscount=False, trackedsize=False,
storedsize=False):
return self._revlog.storageinfo(
exclusivefiles=exclusivefiles, sharedfiles=sharedfiles,
revisionscount=revisionscount, trackedsize=trackedsize,
storedsize=storedsize)
# TODO these aren't part of the interface and aren't internal methods.
# Callers should be fixed to not use them.
# Used by bundlefilelog, unionfilelog.
@property
def indexfile(self):
return self._revlog.indexfile
@indexfile.setter
def indexfile(self, value):
self._revlog.indexfile = value
# Used by repo upgrade.
def clone(self, tr, destrevlog, **kwargs):
if not isinstance(destrevlog, filelog):
raise error.ProgrammingError('expected filelog to clone()')
return self._revlog.clone(tr, destrevlog._revlog, **kwargs)
class narrowfilelog(filelog):
"""Filelog variation to be used with narrow stores."""
def __init__(self, opener, path, narrowmatch):
super(narrowfilelog, self).__init__(opener, path)
self._narrowmatch = narrowmatch
def renamed(self, node):
res = super(narrowfilelog, self).renamed(node)
# Renames that come from outside the narrowspec are problematic
# because we may lack the base text for the rename. This can result
# in code attempting to walk the ancestry or compute a diff
# encountering a missing revision. We address this by silently
# removing rename metadata if the source file is outside the
# narrow spec.
#
# A better solution would be to see if the base revision is available,
# rather than assuming it isn't.
#
# An even better solution would be to teach all consumers of rename
# metadata that the base revision may not be available.
#
# TODO consider better ways of doing this.
if res and not self._narrowmatch(res[0]):
return None
return res
def size(self, rev):
# Because we have a custom renamed() that may lie, we need to call
# the base renamed() to report accurate results.
node = self.node(rev)
if super(narrowfilelog, self).renamed(node):
return len(self.read(node))
else:
return super(narrowfilelog, self).size(rev)
def cmp(self, node, text):
different = super(narrowfilelog, self).cmp(node, text)
# Because renamed() may lie, we may get false positives for
# different content. Check for this by comparing against the original
# renamed() implementation.
if different:
if super(narrowfilelog, self).renamed(node):
t2 = self.read(node)
return t2 != text
return different