Mercurial > hg
view mercurial/bundlerepo.py @ 31765:264baeef3588
show: new extension for displaying various repository data
Currently, Mercurial has a number of commands to show information. And,
there are features coming down the pipe that will introduce more
commands for showing information.
Currently, when introducing a new class of data or a view that we
wish to expose to the user, the strategy is to introduce a new command
or overload an existing command, sometimes both. For example, there is
a desire to formalize the wip/smartlog/underway/mine functionality that
many have devised. There is also a desire to introduce a "topics"
concept. Others would like views of "the current stack." In the
current model, we'd need a new command for wip/smartlog/etc (that
behaves a lot like a pre-defined alias of `hg log`). For topics,
we'd likely overload `hg topic[s]` to both display and manipulate
topics.
Adding new commands for every pre-defined query doesn't scale well
and pollutes `hg help`. Overloading commands to perform read-only and
write operations is arguably an UX anti-pattern: while having all
functionality for a given concept in one command is nice, having a
single command doing multiple discrete operations is not. Furthermore,
a user may be surprised that a command they thought was read-only
actually changes something.
We discussed this at the Mercurial 4.0 Sprint in Paris and decided that
having a single command where we could hang pre-defined views of
various data would be a good idea. Having such a command would:
* Help prevent an explosion of new query-related commands
* Create a clear separation between read and write operations
(mitigates footguns)
* Avoids overloading the meaning of commands that manipulate data
(bookmark, tag, branch, etc) (while we can't take away the
existing behavior for BC reasons, we now won't introduce this
behavior on new commands)
* Allows users to discover informational views more easily by
aggregating them in a single location
* Lowers the barrier to creating the new views (since the barrier
to creating a top-level command is relatively high)
So, this commit introduces the `hg show` command via the "show"
extension. This command accepts a positional argument of the
"view" to show. New views can be registered with a decorator. To
prove it works, we implement the "bookmarks" view, which shows a
table of bookmarks and their associated nodes.
We introduce a new style to hold everything used by `hg show`.
For our initial bookmarks view, the output varies from `hg bookmarks`:
* Padding is performed in the template itself as opposed to Python
* Revision integers are not shown
* shortest() is used to display a 5 character node by default (as
opposed to static 12 characters)
I chose to implement the "bookmarks" view first because it is simple
and shouldn't invite too much bikeshedding that detracts from the
evaluation of `hg show` itself. But there is an important point
to consider: we now have 2 ways to show a list of bookmarks. I'm not
a fan of introducing multiple ways to do very similar things. So it
might be worth discussing how we wish to tackle this issue for
bookmarks, tags, branches, MQ series, etc.
I also made the choice of explicitly declaring the default show
template not part of the standard BC guarantees. History has shown
that we make mistakes and poor choices with output formatting but
can't fix these mistakes later because random tools are parsing
output and we don't want to break these tools. Optimizing for human
consumption is one of my goals for `hg show`. So, by not covering
the formatting as part of BC, the barrier to future change is much
lower and humans benefit.
There are some improvements that can be made to formatting. For
example, we don't yet use label() in the templates. We obviously
want this for color. But I'm not sure if we should reuse the existing
log.* labels or invent new ones. I figure we can punt that to a
follow-up.
At the aforementioned Sprint, we discussed and discarded various
alternatives to `hg show`.
We considered making `hg log <view>` perform this behavior. The main
reason we can't do this is because a positional argument to `hg log`
can be a file path and if there is a conflict between a path name and
a view name, behavior is ambiguous. We could have introduced
`hg log --view` or similar, but we felt that required too much typing
(we don't want to require a command flag to show a view) and wasn't
very discoverable. Furthermore, `hg log` is optimized for showing
changelog data and there are things that `hg display` could display
that aren't changelog centric.
There were concerns about using "show" as the command name.
Some users already have a "show" alias that is similar to `hg export`.
There were also concerns that Git users adapted to `git show` would
be confused by `hg show`'s different behavior. The main difference
here is `git show` prints an `hg export` like view of the current
commit by default and `hg show` requires an argument. `git show`
can also display any Git object. `git show` does not support
displaying more complex views: just single objects. If we
implemented `hg show <hash>` or `hg show <identifier>`, `hg show`
would be a superset of `git show`. Although, I'm hesitant to do that
at this time because I view `hg show` as a higher-level querying
command and there are namespace collisions between valid identifiers
and registered views.
There is also a prefix collision with `hg showconfig`, which is an
alias of `hg config`.
We also considered `hg view`, but that is already used by the "hgk"
extension.
`hg display` was also proposed at one point. It has a prefix collision
with `hg diff`. General consensus was "show" or "view" are the best
verbs. And since "view" was taken, "show" was chosen.
There are a number of inline TODOs in this patch. Some of these
represent decisions yet to be made. Others represent features
requiring non-trivial complexity. Rather than bloat the patch or
invite additional bikeshedding, I figured I'd document future
enhancements via TODO so we can get a minimal implmentation landed.
Something is better than nothing.
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Fri, 24 Mar 2017 19:19:00 -0700 |
parents | 2c4295773436 |
children | 433ab46f6bb4 |
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# bundlerepo.py - repository class for viewing uncompressed bundles # # Copyright 2006, 2007 Benoit Boissinot <bboissin@gmail.com> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. """Repository class for viewing uncompressed bundles. This provides a read-only repository interface to bundles as if they were part of the actual repository. """ from __future__ import absolute_import import os import shutil import tempfile from .i18n import _ from .node import nullid from . import ( bundle2, changegroup, changelog, cmdutil, discovery, error, exchange, filelog, localrepo, manifest, mdiff, node as nodemod, pathutil, phases, pycompat, revlog, util, vfs as vfsmod, ) class bundlerevlog(revlog.revlog): def __init__(self, opener, indexfile, bundle, linkmapper): # How it works: # To retrieve a revision, we need to know the offset of the revision in # the bundle (an unbundle object). We store this offset in the index # (start). The base of the delta is stored in the base field. # # To differentiate a rev in the bundle from a rev in the revlog, we # check revision against repotiprev. opener = vfsmod.readonlyvfs(opener) revlog.revlog.__init__(self, opener, indexfile) self.bundle = bundle n = len(self) self.repotiprev = n - 1 chain = None self.bundlerevs = set() # used by 'bundle()' revset expression getchunk = lambda: bundle.deltachunk(chain) for chunkdata in iter(getchunk, {}): node = chunkdata['node'] p1 = chunkdata['p1'] p2 = chunkdata['p2'] cs = chunkdata['cs'] deltabase = chunkdata['deltabase'] delta = chunkdata['delta'] size = len(delta) start = bundle.tell() - size link = linkmapper(cs) if node in self.nodemap: # this can happen if two branches make the same change chain = node self.bundlerevs.add(self.nodemap[node]) continue for p in (p1, p2): if p not in self.nodemap: raise error.LookupError(p, self.indexfile, _("unknown parent")) if deltabase not in self.nodemap: raise LookupError(deltabase, self.indexfile, _('unknown delta base')) baserev = self.rev(deltabase) # start, size, full unc. size, base (unused), link, p1, p2, node e = (revlog.offset_type(start, 0), size, -1, baserev, link, self.rev(p1), self.rev(p2), node) self.index.insert(-1, e) self.nodemap[node] = n self.bundlerevs.add(n) chain = node n += 1 def _chunk(self, rev): # Warning: in case of bundle, the diff is against what we stored as # delta base, not against rev - 1 # XXX: could use some caching if rev <= self.repotiprev: return revlog.revlog._chunk(self, rev) self.bundle.seek(self.start(rev)) return self.bundle.read(self.length(rev)) def revdiff(self, rev1, rev2): """return or calculate a delta between two revisions""" if rev1 > self.repotiprev and rev2 > self.repotiprev: # hot path for bundle revb = self.index[rev2][3] if revb == rev1: return self._chunk(rev2) elif rev1 <= self.repotiprev and rev2 <= self.repotiprev: return revlog.revlog.revdiff(self, rev1, rev2) return mdiff.textdiff(self.revision(rev1), self.revision(rev2)) def revision(self, nodeorrev, raw=False): """return an uncompressed revision of a given node or revision number. """ if isinstance(nodeorrev, int): rev = nodeorrev node = self.node(rev) else: node = nodeorrev rev = self.rev(node) if node == nullid: return "" text = None chain = [] iterrev = rev # reconstruct the revision if it is from a changegroup while iterrev > self.repotiprev: if self._cache and self._cache[1] == iterrev: text = self._cache[2] break chain.append(iterrev) iterrev = self.index[iterrev][3] if text is None: text = self.baserevision(iterrev) while chain: delta = self._chunk(chain.pop()) text = mdiff.patches(text, [delta]) text, validatehash = self._processflags(text, self.flags(rev), 'read', raw=raw) if validatehash: self.checkhash(text, node, rev=rev) self._cache = (node, rev, text) return text def baserevision(self, nodeorrev): # Revlog subclasses may override 'revision' method to modify format of # content retrieved from revlog. To use bundlerevlog with such class one # needs to override 'baserevision' and make more specific call here. return revlog.revlog.revision(self, nodeorrev) def addrevision(self, text, transaction, link, p1=None, p2=None, d=None): raise NotImplementedError def addgroup(self, revs, linkmapper, transaction): raise NotImplementedError def strip(self, rev, minlink): raise NotImplementedError def checksize(self): raise NotImplementedError class bundlechangelog(bundlerevlog, changelog.changelog): def __init__(self, opener, bundle): changelog.changelog.__init__(self, opener) linkmapper = lambda x: x bundlerevlog.__init__(self, opener, self.indexfile, bundle, linkmapper) def baserevision(self, nodeorrev): # Although changelog doesn't override 'revision' method, some extensions # may replace this class with another that does. Same story with # manifest and filelog classes. # This bypasses filtering on changelog.node() and rev() because we need # revision text of the bundle base even if it is hidden. oldfilter = self.filteredrevs try: self.filteredrevs = () return changelog.changelog.revision(self, nodeorrev) finally: self.filteredrevs = oldfilter class bundlemanifest(bundlerevlog, manifest.manifestrevlog): def __init__(self, opener, bundle, linkmapper, dirlogstarts=None, dir=''): manifest.manifestrevlog.__init__(self, opener, dir=dir) bundlerevlog.__init__(self, opener, self.indexfile, bundle, linkmapper) if dirlogstarts is None: dirlogstarts = {} if self.bundle.version == "03": dirlogstarts = _getfilestarts(self.bundle) self._dirlogstarts = dirlogstarts self._linkmapper = linkmapper def baserevision(self, nodeorrev): node = nodeorrev if isinstance(node, int): node = self.node(node) if node in self.fulltextcache: result = '%s' % self.fulltextcache[node] else: result = manifest.manifestrevlog.revision(self, nodeorrev) return result def dirlog(self, d): if d in self._dirlogstarts: self.bundle.seek(self._dirlogstarts[d]) return bundlemanifest( self.opener, self.bundle, self._linkmapper, self._dirlogstarts, dir=d) return super(bundlemanifest, self).dirlog(d) class bundlefilelog(bundlerevlog, filelog.filelog): def __init__(self, opener, path, bundle, linkmapper): filelog.filelog.__init__(self, opener, path) bundlerevlog.__init__(self, opener, self.indexfile, bundle, linkmapper) def baserevision(self, nodeorrev): return filelog.filelog.revision(self, nodeorrev) class bundlepeer(localrepo.localpeer): def canpush(self): return False class bundlephasecache(phases.phasecache): def __init__(self, *args, **kwargs): super(bundlephasecache, self).__init__(*args, **kwargs) if util.safehasattr(self, 'opener'): self.opener = vfsmod.readonlyvfs(self.opener) def write(self): raise NotImplementedError def _write(self, fp): raise NotImplementedError def _updateroots(self, phase, newroots, tr): self.phaseroots[phase] = newroots self.invalidate() self.dirty = True def _getfilestarts(bundle): bundlefilespos = {} for chunkdata in iter(bundle.filelogheader, {}): fname = chunkdata['filename'] bundlefilespos[fname] = bundle.tell() for chunk in iter(lambda: bundle.deltachunk(None), {}): pass return bundlefilespos class bundlerepository(localrepo.localrepository): def __init__(self, ui, path, bundlename): def _writetempbundle(read, suffix, header=''): """Write a temporary file to disk This is closure because we need to make sure this tracked by self.tempfile for cleanup purposes.""" fdtemp, temp = self.vfs.mkstemp(prefix="hg-bundle-", suffix=".hg10un") self.tempfile = temp with os.fdopen(fdtemp, pycompat.sysstr('wb')) as fptemp: fptemp.write(header) while True: chunk = read(2**18) if not chunk: break fptemp.write(chunk) return self.vfs.open(self.tempfile, mode="rb") self._tempparent = None try: localrepo.localrepository.__init__(self, ui, path) except error.RepoError: self._tempparent = tempfile.mkdtemp() localrepo.instance(ui, self._tempparent, 1) localrepo.localrepository.__init__(self, ui, self._tempparent) self.ui.setconfig('phases', 'publish', False, 'bundlerepo') if path: self._url = 'bundle:' + util.expandpath(path) + '+' + bundlename else: self._url = 'bundle:' + bundlename self.tempfile = None f = util.posixfile(bundlename, "rb") self.bundlefile = self.bundle = exchange.readbundle(ui, f, bundlename) if isinstance(self.bundle, bundle2.unbundle20): cgstream = None for part in self.bundle.iterparts(): if part.type == 'changegroup': if cgstream is not None: raise NotImplementedError("can't process " "multiple changegroups") cgstream = part version = part.params.get('version', '01') legalcgvers = changegroup.supportedincomingversions(self) if version not in legalcgvers: msg = _('Unsupported changegroup version: %s') raise error.Abort(msg % version) if self.bundle.compressed(): cgstream = _writetempbundle(part.read, ".cg%sun" % version) if cgstream is None: raise error.Abort(_('No changegroups found')) cgstream.seek(0) self.bundle = changegroup.getunbundler(version, cgstream, 'UN') elif self.bundle.compressed(): f = _writetempbundle(self.bundle.read, '.hg10un', header='HG10UN') self.bundlefile = self.bundle = exchange.readbundle(ui, f, bundlename, self.vfs) # dict with the mapping 'filename' -> position in the bundle self.bundlefilespos = {} self.firstnewrev = self.changelog.repotiprev + 1 phases.retractboundary(self, None, phases.draft, [ctx.node() for ctx in self[self.firstnewrev:]]) @localrepo.unfilteredpropertycache def _phasecache(self): return bundlephasecache(self, self._phasedefaults) @localrepo.unfilteredpropertycache def changelog(self): # consume the header if it exists self.bundle.changelogheader() c = bundlechangelog(self.svfs, self.bundle) self.manstart = self.bundle.tell() return c def _constructmanifest(self): self.bundle.seek(self.manstart) # consume the header if it exists self.bundle.manifestheader() linkmapper = self.unfiltered().changelog.rev m = bundlemanifest(self.svfs, self.bundle, linkmapper) self.filestart = self.bundle.tell() return m @localrepo.unfilteredpropertycache def manstart(self): self.changelog return self.manstart @localrepo.unfilteredpropertycache def filestart(self): self.manifestlog return self.filestart def url(self): return self._url def file(self, f): if not self.bundlefilespos: self.bundle.seek(self.filestart) self.bundlefilespos = _getfilestarts(self.bundle) if f in self.bundlefilespos: self.bundle.seek(self.bundlefilespos[f]) linkmapper = self.unfiltered().changelog.rev return bundlefilelog(self.svfs, f, self.bundle, linkmapper) else: return filelog.filelog(self.svfs, f) def close(self): """Close assigned bundle file immediately.""" self.bundlefile.close() if self.tempfile is not None: self.vfs.unlink(self.tempfile) if self._tempparent: shutil.rmtree(self._tempparent, True) def cancopy(self): return False def peer(self): return bundlepeer(self) def getcwd(self): return pycompat.getcwd() # always outside the repo # Check if parents exist in localrepo before setting def setparents(self, p1, p2=nullid): p1rev = self.changelog.rev(p1) p2rev = self.changelog.rev(p2) msg = _("setting parent to node %s that only exists in the bundle\n") if self.changelog.repotiprev < p1rev: self.ui.warn(msg % nodemod.hex(p1)) if self.changelog.repotiprev < p2rev: self.ui.warn(msg % nodemod.hex(p2)) return super(bundlerepository, self).setparents(p1, p2) def instance(ui, path, create): if create: raise error.Abort(_('cannot create new bundle repository')) # internal config: bundle.mainreporoot parentpath = ui.config("bundle", "mainreporoot", "") if not parentpath: # try to find the correct path to the working directory repo parentpath = cmdutil.findrepo(pycompat.getcwd()) if parentpath is None: parentpath = '' if parentpath: # Try to make the full path relative so we get a nice, short URL. # In particular, we don't want temp dir names in test outputs. cwd = pycompat.getcwd() if parentpath == cwd: parentpath = '' else: cwd = pathutil.normasprefix(cwd) if parentpath.startswith(cwd): parentpath = parentpath[len(cwd):] u = util.url(path) path = u.localpath() if u.scheme == 'bundle': s = path.split("+", 1) if len(s) == 1: repopath, bundlename = parentpath, s[0] else: repopath, bundlename = s else: repopath, bundlename = parentpath, path return bundlerepository(ui, repopath, bundlename) class bundletransactionmanager(object): def transaction(self): return None def close(self): raise NotImplementedError def release(self): raise NotImplementedError def getremotechanges(ui, repo, other, onlyheads=None, bundlename=None, force=False): '''obtains a bundle of changes incoming from other "onlyheads" restricts the returned changes to those reachable from the specified heads. "bundlename", if given, stores the bundle to this file path permanently; otherwise it's stored to a temp file and gets deleted again when you call the returned "cleanupfn". "force" indicates whether to proceed on unrelated repos. Returns a tuple (local, csets, cleanupfn): "local" is a local repo from which to obtain the actual incoming changesets; it is a bundlerepo for the obtained bundle when the original "other" is remote. "csets" lists the incoming changeset node ids. "cleanupfn" must be called without arguments when you're done processing the changes; it closes both the original "other" and the one returned here. ''' tmp = discovery.findcommonincoming(repo, other, heads=onlyheads, force=force) common, incoming, rheads = tmp if not incoming: try: if bundlename: os.unlink(bundlename) except OSError: pass return repo, [], other.close commonset = set(common) rheads = [x for x in rheads if x not in commonset] bundle = None bundlerepo = None localrepo = other.local() if bundlename or not localrepo: # create a bundle (uncompressed if other repo is not local) # developer config: devel.legacy.exchange legexc = ui.configlist('devel', 'legacy.exchange') forcebundle1 = 'bundle2' not in legexc and 'bundle1' in legexc canbundle2 = (not forcebundle1 and other.capable('getbundle') and other.capable('bundle2')) if canbundle2: kwargs = {} kwargs['common'] = common kwargs['heads'] = rheads kwargs['bundlecaps'] = exchange.caps20to10(repo) kwargs['cg'] = True b2 = other.getbundle('incoming', **kwargs) fname = bundle = changegroup.writechunks(ui, b2._forwardchunks(), bundlename) else: if other.capable('getbundle'): cg = other.getbundle('incoming', common=common, heads=rheads) elif onlyheads is None and not other.capable('changegroupsubset'): # compat with older servers when pulling all remote heads cg = other.changegroup(incoming, "incoming") rheads = None else: cg = other.changegroupsubset(incoming, rheads, 'incoming') if localrepo: bundletype = "HG10BZ" else: bundletype = "HG10UN" fname = bundle = bundle2.writebundle(ui, cg, bundlename, bundletype) # keep written bundle? if bundlename: bundle = None if not localrepo: # use the created uncompressed bundlerepo localrepo = bundlerepo = bundlerepository(repo.baseui, repo.root, fname) # this repo contains local and other now, so filter out local again common = repo.heads() if localrepo: # Part of common may be remotely filtered # So use an unfiltered version # The discovery process probably need cleanup to avoid that localrepo = localrepo.unfiltered() csets = localrepo.changelog.findmissing(common, rheads) if bundlerepo: reponodes = [ctx.node() for ctx in bundlerepo[bundlerepo.firstnewrev:]] remotephases = other.listkeys('phases') pullop = exchange.pulloperation(bundlerepo, other, heads=reponodes) pullop.trmanager = bundletransactionmanager() exchange._pullapplyphases(pullop, remotephases) def cleanup(): if bundlerepo: bundlerepo.close() if bundle: os.unlink(bundle) other.close() return (localrepo, csets, cleanup)