Mercurial > hg
view mercurial/rewriteutil.py @ 47093:787ff5d21bcd
dirstate-tree: Make Rust DirstateMap bindings go through a trait object
This changeset starts a series that adds an experiment to make status faster
by changing the dirstate (first only in memory and later also on disk) to
be shaped as a tree matching the directory structure, instead of the current
flat collection of entries. The status algorithm can then traverse this tree
dirstate at the same time as it traverses the filesystem.
We (Octobus) have made prototypes that show promising results but are prone
to bitrot. We would like to start upstreaming some experimental Rust code that
goes in this direction, but to avoid disrupting users it should only be
enabled by some run-time opt-in while keeping the existing dirstate structure
and status algorithm as-is.
The `DirstateMap` type and `status` function look like the appropriate
boundary. This adds a new trait that abstracts everything Python bindings need
and makes those bindings go through a `dyn` trait object. Later we’ll have two
implementations of this trait, and the same bindings can use either.
Differential Revision: https://phab.mercurial-scm.org/D10362
author | Simon Sapin <simon.sapin@octobus.net> |
---|---|
date | Tue, 30 Mar 2021 14:15:23 +0200 |
parents | d90f6237b3aa |
children | 055f7b9f2307 |
line wrap: on
line source
# rewriteutil.py - utility functions for rewriting changesets # # Copyright 2017 Octobus <contact@octobus.net> # # 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 import re from .i18n import _ from .node import ( hex, nullrev, ) from . import ( error, node, obsolete, obsutil, revset, scmutil, util, ) NODE_RE = re.compile(br'\b[0-9a-f]{6,64}\b') def _formatrevs(repo, revs, maxrevs=4): """returns a string summarizing revisions in a decent size If there are few enough revisions, we list them all. Otherwise we display a summary of the form: 1ea73414a91b and 5 others """ tonode = repo.changelog.node numrevs = len(revs) if numrevs < maxrevs: shorts = [node.short(tonode(r)) for r in revs] summary = b', '.join(shorts) else: first = revs.first() summary = _(b'%s and %d others') summary %= (node.short(tonode(first)), numrevs - 1) return summary def precheck(repo, revs, action=b'rewrite'): """check if revs can be rewritten action is used to control the error message. Make sure this function is called after taking the lock. """ if nullrev in revs: msg = _(b"cannot %s the null revision") % action hint = _(b"no changeset checked out") raise error.InputError(msg, hint=hint) if any(util.safehasattr(r, 'rev') for r in revs): repo.ui.develwarn(b"rewriteutil.precheck called with ctx not revs") revs = (r.rev() for r in revs) if len(repo[None].parents()) > 1: raise error.StateError( _(b"cannot %s changesets while merging") % action ) publicrevs = repo.revs(b'%ld and public()', revs) if publicrevs: summary = _formatrevs(repo, publicrevs) msg = _(b"cannot %s public changesets: %s") % (action, summary) hint = _(b"see 'hg help phases' for details") raise error.InputError(msg, hint=hint) newunstable = disallowednewunstable(repo, revs) if newunstable: hint = _(b"see 'hg help evolution.instability'") raise error.InputError( _(b"cannot %s changeset, as that will orphan %d descendants") % (action, len(newunstable)), hint=hint, ) if not obsolete.isenabled(repo, obsolete.allowdivergenceopt): new_divergence = _find_new_divergence(repo, revs) if new_divergence: local_ctx, other_ctx, base_ctx = new_divergence msg = _( b'cannot %s %s, as that creates content-divergence with %s' ) % ( action, local_ctx, other_ctx, ) if local_ctx.rev() != base_ctx.rev(): msg += _(b', from %s') % base_ctx if repo.ui.verbose: if local_ctx.rev() != base_ctx.rev(): msg += _( b'\n changeset %s is a successor of ' b'changeset %s' ) % (local_ctx, base_ctx) msg += _( b'\n changeset %s already has a successor in ' b'changeset %s\n' b' rewriting changeset %s would create ' b'"content-divergence"\n' b' set experimental.evolution.allowdivergence=True to ' b'skip this check' ) % (base_ctx, other_ctx, local_ctx) raise error.InputError(msg) else: raise error.InputError( msg, hint=_(b"add --verbose for details") ) def disallowednewunstable(repo, revs): """Checks whether editing the revs will create new unstable changesets and are we allowed to create them. To allow new unstable changesets, set the config: `experimental.evolution.allowunstable=True` """ allowunstable = obsolete.isenabled(repo, obsolete.allowunstableopt) if allowunstable: return revset.baseset() return repo.revs(b"(%ld::) - %ld", revs, revs) def _find_new_divergence(repo, revs): obsrevs = repo.revs(b'%ld and obsolete()', revs) for r in obsrevs: div = find_new_divergence_from(repo, repo[r]) if div: return (repo[r], repo[div[0]], repo[div[1]]) return None def find_new_divergence_from(repo, ctx): """return divergent revision if rewriting an obsolete cset (ctx) will create divergence Returns (<other node>, <common ancestor node>) or None """ if not ctx.obsolete(): return None # We need to check two cases that can cause divergence: # case 1: the rev being rewritten has a non-obsolete successor (easily # detected by successorssets) sset = obsutil.successorssets(repo, ctx.node()) if sset: return (sset[0][0], ctx.node()) else: # case 2: one of the precursors of the rev being revived has a # non-obsolete successor (we need divergentsets for this) divsets = obsutil.divergentsets(repo, ctx) if divsets: nsuccset = divsets[0][b'divergentnodes'] prec = divsets[0][b'commonpredecessor'] return (nsuccset[0], prec) return None def skip_empty_successor(ui, command): empty_successor = ui.config(b'rewrite', b'empty-successor') if empty_successor == b'skip': return True elif empty_successor == b'keep': return False else: raise error.ConfigError( _( b"%s doesn't know how to handle config " b"rewrite.empty-successor=%s (only 'skip' and 'keep' are " b"supported)" ) % (command, empty_successor) ) def update_hash_refs(repo, commitmsg, pending=None): """Replace all obsolete commit hashes in the message with the current hash. If the obsolete commit was split or is divergent, the hash is not replaced as there's no way to know which successor to choose. For commands that update a series of commits in the current transaction, the new obsolete markers can be considered by setting ``pending`` to a mapping of ``pending[oldnode] = [successor_node1, successor_node2,..]``. """ if not pending: pending = {} cache = {} hashes = re.findall(NODE_RE, commitmsg) unfi = repo.unfiltered() for h in hashes: fullnode = scmutil.resolvehexnodeidprefix(unfi, h) if fullnode is None: continue ctx = unfi[fullnode] if not ctx.obsolete(): successors = pending.get(fullnode) if successors is None: continue # obsutil.successorssets() returns a list of list of nodes successors = [successors] else: successors = obsutil.successorssets(repo, ctx.node(), cache=cache) # We can't make any assumptions about how to update the hash if the # cset in question was split or diverged. if len(successors) == 1 and len(successors[0]) == 1: successor = successors[0][0] if successor is not None: newhash = hex(successor) commitmsg = commitmsg.replace(h, newhash[: len(h)]) else: repo.ui.note( _( b'The stale commit message reference to %s could ' b'not be updated\n(The referenced commit was dropped)\n' ) % h ) else: repo.ui.note( _( b'The stale commit message reference to %s could ' b'not be updated\n' ) % h ) return commitmsg