Mercurial > hg
view mercurial/sparse.py @ 35569:964212780daf
rust: implementation of `hg`
This commit provides a mostly-working implementation of the
`hg` script in Rust along with scaffolding to support Rust in
the repository.
If you are familiar with Rust, the contents of the added rust/
directory should be pretty straightforward. We create an "hgcli"
package that implements a binary application to run Mercurial.
The output of this package is an "hg" binary.
Our Rust `hg` (henceforth "rhg") essentially is a port of the existing
`hg` Python script. The main difference is the creation of the embedded
CPython interpreter is handled by the binary itself instead of relying
on the shebang. In that sense, rhg is more similar to the "exe wrapper"
we currently use on Windows. However, unlike the exe wrapper, rhg does
not call the `hg` Python script. Instead, it uses the CPython APIs to
import mercurial modules and call appropriate functions. The amount of
code here is surprisingly small.
It is my intent to replace the existing C-based exe wrapper with rhg.
Preferably in the next Mercurial release. This should be achievable -
at least for some Mercurial distributions. The future/timeline for
rhg on other platforms is less clear. We already ship a hg.exe on
Windows. So if we get the quirks with Rust worked out, shipping a
Rust-based hg.exe should hopefully not be too contentious.
Now onto the implementation.
We're using python27-sys and the cpython crates for talking to the
CPython API. We currently don't use too much functionality of the
cpython crate and could have probably cut it out. However, it does
provide a reasonable abstraction over unsafe {} CPython function
calls. While we still have our fair share of those, at least we're
not dealing with too much refcounting, error checking, etc. So I
think the use of the cpython crate is justified. Plus, there is
not-yet-implemented functionality that could benefit from cpython. I
see our use of this crate only increasing.
The cpython and python27-sys crates are not without their issues.
The cpython crate didn't seem to account for the embedding use case
in its design. Instead, it seems to assume that you are building
a Python extension. It is making some questionable decisions around
certain CPython APIs. For example, it insists that
PyEval_ThreadsInitialized() is called and that the Python code
likely isn't the main thread in the underlying application. It
is also missing some functionality that is important for embedded
use cases (such as exporting the path to the Python interpreter
from its build script). After spending several hours trying to
wrangle python27-sys and cpython, I gave up and forked the project
on GitHub. Our Cargo.toml tracks this fork. I'm optimistic that
the upstream project will accept our contributions and we can
eventually unfork.
There is a non-trivial amount of code in our custom Cargo build
script. Our build.rs (which is called as part of building the hgcli
crate):
* Validates that the Python interpreter that was detected by the
python27-sys crate provides a shared library (we only support
shared library linking at this time - although this restriction
could be loosened).
* Validates that the Python is built with UCS-4 support. This ensures
maximum Unicode compatibility.
* Exports variables to the crate build allowing the built crate to e.g.
find the path to the Python interpreter.
The produced rhg should be considered alpha quality. There are several
known deficiencies. Many of these are documented with inline TODOs.
Probably the biggest limitation of rhg is that it assumes it is
running from the ./rust/target/<target> directory of a source
distribution. So, rhg is currently not very practical for real-world
use. But, if you can `cargo build` it, running the binary *should*
yield a working Mercurial CLI.
In order to support using rhg with the test harness, we needed to hack
up run-tests.py so the path to Mercurial's Python files is set properly.
The change is extremely hacky and is only intended to be a stop-gap
until the test harness gains first-class support for installing rhg.
This will likely occur after we support running rhg outside the
source directory.
Despite its officially alpha quality, rhg copes extremely well with
the test harness (at least on Linux). Using
`run-tests.py --with-hg ../rust/target/debug/hg`, I only encounter
the following failures:
* test-run-tests.t -- Warnings emitted about using an unexpected
Mercurial library. This is due to the hacky nature of setting the
Python directory when run-tests.py detected rhg.
* test-devel-warnings.t -- Expected stack trace missing frame for `hg`
(This is expected since we no longer have an `hg` script!)
* test-convert.t -- Test running `$PYTHON "$BINDIR"/hg`, which obviously
assumes `hg` is a Python script.
* test-merge-tools.t -- Same assumption about `hg` being executable with
Python.
* test-http-bad-server.t -- Seeing exit code 255 instead of 1 around
line 358.
* test-blackbox.t -- Exit code 255 instead of 1.
* test-basic.t -- Exit code 255 instead of 1.
It certainly looks like we have a bug around exit code handling. I
don't think it is severe enough to hold up review and landing of this
initial implementation. Perfect is the enemy of good.
Differential Revision: https://phab.mercurial-scm.org/D1581
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Wed, 10 Jan 2018 08:53:22 -0800 |
parents | b4955650eb57 |
children | 72b91f905065 |
line wrap: on
line source
# sparse.py - functionality for sparse checkouts # # Copyright 2014 Facebook, Inc. # # 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 collections import hashlib import os from .i18n import _ from .node import nullid from . import ( error, match as matchmod, merge as mergemod, pathutil, pycompat, scmutil, util, ) # Whether sparse features are enabled. This variable is intended to be # temporary to facilitate porting sparse to core. It should eventually be # a per-repo option, possibly a repo requirement. enabled = False def parseconfig(ui, raw): """Parse sparse config file content. Returns a tuple of includes, excludes, and profiles. """ includes = set() excludes = set() profiles = set() current = None havesection = False for line in raw.split('\n'): line = line.strip() if not line or line.startswith('#'): # empty or comment line, skip continue elif line.startswith('%include '): line = line[9:].strip() if line: profiles.add(line) elif line == '[include]': if havesection and current != includes: # TODO pass filename into this API so we can report it. raise error.Abort(_('sparse config cannot have includes ' + 'after excludes')) havesection = True current = includes continue elif line == '[exclude]': havesection = True current = excludes elif line: if current is None: raise error.Abort(_('sparse config entry outside of ' 'section: %s') % line, hint=_('add an [include] or [exclude] line ' 'to declare the entry type')) if line.strip().startswith('/'): ui.warn(_('warning: sparse profile cannot use' + ' paths starting with /, ignoring %s\n') % line) continue current.add(line) return includes, excludes, profiles # Exists as separate function to facilitate monkeypatching. def readprofile(repo, profile, changeid): """Resolve the raw content of a sparse profile file.""" # TODO add some kind of cache here because this incurs a manifest # resolve and can be slow. return repo.filectx(profile, changeid=changeid).data() def patternsforrev(repo, rev): """Obtain sparse checkout patterns for the given rev. Returns a tuple of iterables representing includes, excludes, and patterns. """ # Feature isn't enabled. No-op. if not enabled: return set(), set(), set() raw = repo.vfs.tryread('sparse') if not raw: return set(), set(), set() if rev is None: raise error.Abort(_('cannot parse sparse patterns from working ' 'directory')) includes, excludes, profiles = parseconfig(repo.ui, raw) ctx = repo[rev] if profiles: visited = set() while profiles: profile = profiles.pop() if profile in visited: continue visited.add(profile) try: raw = readprofile(repo, profile, rev) except error.ManifestLookupError: msg = ( "warning: sparse profile '%s' not found " "in rev %s - ignoring it\n" % (profile, ctx)) # experimental config: sparse.missingwarning if repo.ui.configbool( 'sparse', 'missingwarning'): repo.ui.warn(msg) else: repo.ui.debug(msg) continue pincludes, pexcludes, subprofs = parseconfig(repo.ui, raw) includes.update(pincludes) excludes.update(pexcludes) profiles.update(subprofs) profiles = visited if includes: includes.add('.hg*') return includes, excludes, profiles def activeconfig(repo): """Determine the active sparse config rules. Rules are constructed by reading the current sparse config and bringing in referenced profiles from parents of the working directory. """ revs = [repo.changelog.rev(node) for node in repo.dirstate.parents() if node != nullid] allincludes = set() allexcludes = set() allprofiles = set() for rev in revs: includes, excludes, profiles = patternsforrev(repo, rev) allincludes |= includes allexcludes |= excludes allprofiles |= profiles return allincludes, allexcludes, allprofiles def configsignature(repo, includetemp=True): """Obtain the signature string for the current sparse configuration. This is used to construct a cache key for matchers. """ cache = repo._sparsesignaturecache signature = cache.get('signature') if includetemp: tempsignature = cache.get('tempsignature') else: tempsignature = '0' if signature is None or (includetemp and tempsignature is None): signature = hashlib.sha1(repo.vfs.tryread('sparse')).hexdigest() cache['signature'] = signature if includetemp: raw = repo.vfs.tryread('tempsparse') tempsignature = hashlib.sha1(raw).hexdigest() cache['tempsignature'] = tempsignature return '%s %s' % (signature, tempsignature) def writeconfig(repo, includes, excludes, profiles): """Write the sparse config file given a sparse configuration.""" with repo.vfs('sparse', 'wb') as fh: for p in sorted(profiles): fh.write('%%include %s\n' % p) if includes: fh.write('[include]\n') for i in sorted(includes): fh.write(i) fh.write('\n') if excludes: fh.write('[exclude]\n') for e in sorted(excludes): fh.write(e) fh.write('\n') repo._sparsesignaturecache.clear() def readtemporaryincludes(repo): raw = repo.vfs.tryread('tempsparse') if not raw: return set() return set(raw.split('\n')) def writetemporaryincludes(repo, includes): repo.vfs.write('tempsparse', '\n'.join(sorted(includes))) repo._sparsesignaturecache.clear() def addtemporaryincludes(repo, additional): includes = readtemporaryincludes(repo) for i in additional: includes.add(i) writetemporaryincludes(repo, includes) def prunetemporaryincludes(repo): if not enabled or not repo.vfs.exists('tempsparse'): return s = repo.status() if s.modified or s.added or s.removed or s.deleted: # Still have pending changes. Don't bother trying to prune. return sparsematch = matcher(repo, includetemp=False) dirstate = repo.dirstate actions = [] dropped = [] tempincludes = readtemporaryincludes(repo) for file in tempincludes: if file in dirstate and not sparsematch(file): message = _('dropping temporarily included sparse files') actions.append((file, None, message)) dropped.append(file) typeactions = collections.defaultdict(list) typeactions['r'] = actions mergemod.applyupdates(repo, typeactions, repo[None], repo['.'], False) # Fix dirstate for file in dropped: dirstate.drop(file) repo.vfs.unlink('tempsparse') repo._sparsesignaturecache.clear() msg = _('cleaned up %d temporarily added file(s) from the ' 'sparse checkout\n') repo.ui.status(msg % len(tempincludes)) def forceincludematcher(matcher, includes): """Returns a matcher that returns true for any of the forced includes before testing against the actual matcher.""" kindpats = [('path', include, '') for include in includes] includematcher = matchmod.includematcher('', '', kindpats) return matchmod.unionmatcher([includematcher, matcher]) def matcher(repo, revs=None, includetemp=True): """Obtain a matcher for sparse working directories for the given revs. If multiple revisions are specified, the matcher is the union of all revs. ``includetemp`` indicates whether to use the temporary sparse profile. """ # If sparse isn't enabled, sparse matcher matches everything. if not enabled: return matchmod.always(repo.root, '') if not revs or revs == [None]: revs = [repo.changelog.rev(node) for node in repo.dirstate.parents() if node != nullid] signature = configsignature(repo, includetemp=includetemp) key = '%s %s' % (signature, ' '.join(map(pycompat.bytestr, revs))) result = repo._sparsematchercache.get(key) if result: return result matchers = [] for rev in revs: try: includes, excludes, profiles = patternsforrev(repo, rev) if includes or excludes: # Explicitly include subdirectories of includes so # status will walk them down to the actual include. subdirs = set() for include in includes: # TODO consider using posix path functions here so Windows # \ directory separators don't come into play. dirname = os.path.dirname(include) # basename is used to avoid issues with absolute # paths (which on Windows can include the drive). while os.path.basename(dirname): subdirs.add(dirname) dirname = os.path.dirname(dirname) matcher = matchmod.match(repo.root, '', [], include=includes, exclude=excludes, default='relpath') if subdirs: matcher = forceincludematcher(matcher, subdirs) matchers.append(matcher) except IOError: pass if not matchers: result = matchmod.always(repo.root, '') elif len(matchers) == 1: result = matchers[0] else: result = matchmod.unionmatcher(matchers) if includetemp: tempincludes = readtemporaryincludes(repo) result = forceincludematcher(result, tempincludes) repo._sparsematchercache[key] = result return result def filterupdatesactions(repo, wctx, mctx, branchmerge, actions): """Filter updates to only lay out files that match the sparse rules.""" if not enabled: return actions oldrevs = [pctx.rev() for pctx in wctx.parents()] oldsparsematch = matcher(repo, oldrevs) if oldsparsematch.always(): return actions files = set() prunedactions = {} if branchmerge: # If we're merging, use the wctx filter, since we're merging into # the wctx. sparsematch = matcher(repo, [wctx.parents()[0].rev()]) else: # If we're updating, use the target context's filter, since we're # moving to the target context. sparsematch = matcher(repo, [mctx.rev()]) temporaryfiles = [] for file, action in actions.iteritems(): type, args, msg = action files.add(file) if sparsematch(file): prunedactions[file] = action elif type == 'm': temporaryfiles.append(file) prunedactions[file] = action elif branchmerge: if type != 'k': temporaryfiles.append(file) prunedactions[file] = action elif type == 'f': prunedactions[file] = action elif file in wctx: prunedactions[file] = ('r', args, msg) if len(temporaryfiles) > 0: repo.ui.status(_('temporarily included %d file(s) in the sparse ' 'checkout for merging\n') % len(temporaryfiles)) addtemporaryincludes(repo, temporaryfiles) # Add the new files to the working copy so they can be merged, etc actions = [] message = 'temporarily adding to sparse checkout' wctxmanifest = repo[None].manifest() for file in temporaryfiles: if file in wctxmanifest: fctx = repo[None][file] actions.append((file, (fctx.flags(), False), message)) typeactions = collections.defaultdict(list) typeactions['g'] = actions mergemod.applyupdates(repo, typeactions, repo[None], repo['.'], False) dirstate = repo.dirstate for file, flags, msg in actions: dirstate.normal(file) profiles = activeconfig(repo)[2] changedprofiles = profiles & files # If an active profile changed during the update, refresh the checkout. # Don't do this during a branch merge, since all incoming changes should # have been handled by the temporary includes above. if changedprofiles and not branchmerge: mf = mctx.manifest() for file in mf: old = oldsparsematch(file) new = sparsematch(file) if not old and new: flags = mf.flags(file) prunedactions[file] = ('g', (flags, False), '') elif old and not new: prunedactions[file] = ('r', [], '') return prunedactions def refreshwdir(repo, origstatus, origsparsematch, force=False): """Refreshes working directory by taking sparse config into account. The old status and sparse matcher is compared against the current sparse matcher. Will abort if a file with pending changes is being excluded or included unless ``force`` is True. """ # Verify there are no pending changes pending = set() pending.update(origstatus.modified) pending.update(origstatus.added) pending.update(origstatus.removed) sparsematch = matcher(repo) abort = False for f in pending: if not sparsematch(f): repo.ui.warn(_("pending changes to '%s'\n") % f) abort = not force if abort: raise error.Abort(_('could not update sparseness due to pending ' 'changes')) # Calculate actions dirstate = repo.dirstate ctx = repo['.'] added = [] lookup = [] dropped = [] mf = ctx.manifest() files = set(mf) actions = {} for file in files: old = origsparsematch(file) new = sparsematch(file) # Add files that are newly included, or that don't exist in # the dirstate yet. if (new and not old) or (old and new and not file in dirstate): fl = mf.flags(file) if repo.wvfs.exists(file): actions[file] = ('e', (fl,), '') lookup.append(file) else: actions[file] = ('g', (fl, False), '') added.append(file) # Drop files that are newly excluded, or that still exist in # the dirstate. elif (old and not new) or (not old and not new and file in dirstate): dropped.append(file) if file not in pending: actions[file] = ('r', [], '') # Verify there are no pending changes in newly included files abort = False for file in lookup: repo.ui.warn(_("pending changes to '%s'\n") % file) abort = not force if abort: raise error.Abort(_('cannot change sparseness due to pending ' 'changes (delete the files or use ' '--force to bring them back dirty)')) # Check for files that were only in the dirstate. for file, state in dirstate.iteritems(): if not file in files: old = origsparsematch(file) new = sparsematch(file) if old and not new: dropped.append(file) # Apply changes to disk typeactions = dict((m, []) for m in 'a f g am cd dc r dm dg m e k p pr'.split()) for f, (m, args, msg) in actions.iteritems(): if m not in typeactions: typeactions[m] = [] typeactions[m].append((f, args, msg)) mergemod.applyupdates(repo, typeactions, repo[None], repo['.'], False) # Fix dirstate for file in added: dirstate.normal(file) for file in dropped: dirstate.drop(file) for file in lookup: # File exists on disk, and we're bringing it back in an unknown state. dirstate.normallookup(file) return added, dropped, lookup def aftercommit(repo, node): """Perform actions after a working directory commit.""" # This function is called unconditionally, even if sparse isn't # enabled. ctx = repo[node] profiles = patternsforrev(repo, ctx.rev())[2] # profiles will only have data if sparse is enabled. if profiles & set(ctx.files()): origstatus = repo.status() origsparsematch = matcher(repo) refreshwdir(repo, origstatus, origsparsematch, force=True) prunetemporaryincludes(repo) def _updateconfigandrefreshwdir(repo, includes, excludes, profiles, force=False, removing=False): """Update the sparse config and working directory state.""" raw = repo.vfs.tryread('sparse') oldincludes, oldexcludes, oldprofiles = parseconfig(repo.ui, raw) oldstatus = repo.status() oldmatch = matcher(repo) oldrequires = set(repo.requirements) # TODO remove this try..except once the matcher integrates better # with dirstate. We currently have to write the updated config # because that will invalidate the matcher cache and force a # re-read. We ideally want to update the cached matcher on the # repo instance then flush the new config to disk once wdir is # updated. But this requires massive rework to matcher() and its # consumers. if 'exp-sparse' in oldrequires and removing: repo.requirements.discard('exp-sparse') scmutil.writerequires(repo.vfs, repo.requirements) elif 'exp-sparse' not in oldrequires: repo.requirements.add('exp-sparse') scmutil.writerequires(repo.vfs, repo.requirements) try: writeconfig(repo, includes, excludes, profiles) return refreshwdir(repo, oldstatus, oldmatch, force=force) except Exception: if repo.requirements != oldrequires: repo.requirements.clear() repo.requirements |= oldrequires scmutil.writerequires(repo.vfs, repo.requirements) writeconfig(repo, oldincludes, oldexcludes, oldprofiles) raise def clearrules(repo, force=False): """Clears include/exclude rules from the sparse config. The remaining sparse config only has profiles, if defined. The working directory is refreshed, as needed. """ with repo.wlock(): raw = repo.vfs.tryread('sparse') includes, excludes, profiles = parseconfig(repo.ui, raw) if not includes and not excludes: return _updateconfigandrefreshwdir(repo, set(), set(), profiles, force=force) def importfromfiles(repo, opts, paths, force=False): """Import sparse config rules from files. The updated sparse config is written out and the working directory is refreshed, as needed. """ with repo.wlock(): # read current configuration raw = repo.vfs.tryread('sparse') includes, excludes, profiles = parseconfig(repo.ui, raw) aincludes, aexcludes, aprofiles = activeconfig(repo) # Import rules on top; only take in rules that are not yet # part of the active rules. changed = False for p in paths: with util.posixfile(util.expandpath(p)) as fh: raw = fh.read() iincludes, iexcludes, iprofiles = parseconfig(repo.ui, raw) oldsize = len(includes) + len(excludes) + len(profiles) includes.update(iincludes - aincludes) excludes.update(iexcludes - aexcludes) profiles.update(iprofiles - aprofiles) if len(includes) + len(excludes) + len(profiles) > oldsize: changed = True profilecount = includecount = excludecount = 0 fcounts = (0, 0, 0) if changed: profilecount = len(profiles - aprofiles) includecount = len(includes - aincludes) excludecount = len(excludes - aexcludes) fcounts = map(len, _updateconfigandrefreshwdir( repo, includes, excludes, profiles, force=force)) printchanges(repo.ui, opts, profilecount, includecount, excludecount, *fcounts) def updateconfig(repo, pats, opts, include=False, exclude=False, reset=False, delete=False, enableprofile=False, disableprofile=False, force=False, usereporootpaths=False): """Perform a sparse config update. Only one of the actions may be performed. The new config is written out and a working directory refresh is performed. """ with repo.wlock(): raw = repo.vfs.tryread('sparse') oldinclude, oldexclude, oldprofiles = parseconfig(repo.ui, raw) if reset: newinclude = set() newexclude = set() newprofiles = set() else: newinclude = set(oldinclude) newexclude = set(oldexclude) newprofiles = set(oldprofiles) if any(os.path.isabs(pat) for pat in pats): raise error.Abort(_('paths cannot be absolute')) if not usereporootpaths: # let's treat paths as relative to cwd root, cwd = repo.root, repo.getcwd() abspats = [] for kindpat in pats: kind, pat = matchmod._patsplit(kindpat, None) if kind in matchmod.cwdrelativepatternkinds or kind is None: ap = (kind + ':' if kind else '') +\ pathutil.canonpath(root, cwd, pat) abspats.append(ap) else: abspats.append(kindpat) pats = abspats if include: newinclude.update(pats) elif exclude: newexclude.update(pats) elif enableprofile: newprofiles.update(pats) elif disableprofile: newprofiles.difference_update(pats) elif delete: newinclude.difference_update(pats) newexclude.difference_update(pats) profilecount = (len(newprofiles - oldprofiles) - len(oldprofiles - newprofiles)) includecount = (len(newinclude - oldinclude) - len(oldinclude - newinclude)) excludecount = (len(newexclude - oldexclude) - len(oldexclude - newexclude)) fcounts = map(len, _updateconfigandrefreshwdir( repo, newinclude, newexclude, newprofiles, force=force, removing=reset)) printchanges(repo.ui, opts, profilecount, includecount, excludecount, *fcounts) def printchanges(ui, opts, profilecount=0, includecount=0, excludecount=0, added=0, dropped=0, conflicting=0): """Print output summarizing sparse config changes.""" with ui.formatter('sparse', opts) as fm: fm.startitem() fm.condwrite(ui.verbose, 'profiles_added', _('Profiles changed: %d\n'), profilecount) fm.condwrite(ui.verbose, 'include_rules_added', _('Include rules changed: %d\n'), includecount) fm.condwrite(ui.verbose, 'exclude_rules_added', _('Exclude rules changed: %d\n'), excludecount) # In 'plain' verbose mode, mergemod.applyupdates already outputs what # files are added or removed outside of the templating formatter # framework. No point in repeating ourselves in that case. if not fm.isplain(): fm.condwrite(ui.verbose, 'files_added', _('Files added: %d\n'), added) fm.condwrite(ui.verbose, 'files_dropped', _('Files dropped: %d\n'), dropped) fm.condwrite(ui.verbose, 'files_conflicting', _('Files conflicting: %d\n'), conflicting)