Mercurial > hg
view mercurial/wireprotoserver.py @ 48687:f8f2ecdde4b5
branchmap: skip obsolete revisions while computing heads
It's time to make this part of core Mercurial obsolescence-aware.
Not considering obsolete revisions when computing heads is clearly what
Mercurial should do. But there are a couple of small issues:
- Let's say tip of the repo is obsolete. There are two ways of finding tiprev
for branchcache (both are in use): looking at input data for update() and
looking at computed heads after update(). Previously, repo tip would be
tiprev of the branchcache. With this patch, an obsolete revision can no
longer be tiprev. And depending on what way we use for finding tiprev (input
data vs computed heads) we'll get a different result. This is relevant when
recomputing cache key from cache contents, and may lead to updating cache for
obsolete revisions multiple times (not from scratch, because it still would
be considered valid for a subset of revisions in the repo).
- If all commits on a branch are obsolete, the branchcache will include that
branch, but the list of heads will be empty (that's why there's now `if not
heads` when recomputing tiprev/tipnode from cache contents). Having an entry
for every branch is currently required for notify extension (and
test-notify.t to pass), because notify doesn't handle revsets in its
subscription config very well and will throw an error if e.g. a branch
doesn't exist.
- Cloning static HTTP repos may try to stat() a non-existent obsstore file. The
issue is that we now care about obsolescence during clone, but statichttpvfs
doesn't implement a stat method, so a regular vfs.stat() is used, and it
assumes that file is local and calls os.stat(). During a clone, we're trying
to stat() .hg/store/obsstore, but in static HTTP case we provide a literal
URL to the obsstore file on the remote as if it were a local file path. On
windows it actually results in a failure in test-static-http.t.
The first issue is going to be addressed in a series dedicated to making sure
branchcache is properly and timely written on disk (it wasn't perfect even
before this patch, but there aren't enough tests to demonstrate that). The
second issue will be addressed in a future patch for notify extension that will
make it not raise an exception if a branch doesn't exist. And the third one was
partially addressed in the previous patch in this series and will be properly
fixed in a future patch when this series is accepted.
filteredhash() grows a keyword argument to make sure that branchcache is also
invalidated when there are new obsolete revisions in its repo view. This way
the on-disk cache format is unchanged and compatible between versions (although
it will obviously be recomputed when switching versions before/after this patch
and the repo has obsolete revisions).
There's one test that uses plain `hg up` without arguments while updated to a
pruned commit. To make this test pass, simply return current working directory
parent. Later in this series this code will be replaced by what prune command
does: updating to the closest non-obsolete ancestor.
Test changes:
test-branch-change.t: update branch head and cache update message. The head of
default listed in hg heads is changed because revision 2 was rewritten as 7,
and 1 is the closest ancestor on the same branch, so it's the head of default
now.
The cache invalidation message appears now because of the cache hash change,
since we're now accounting for obsolete revisions. Here's some context:
"served.hidden" repo filter means everything is visible (no filtered
revisions), so before this series branch2-served.hidden file would not contain
any cache hash, only revnum and node. Now it also has a hash when there are
obsolete changesets in the repo. The command that the message appears for is
changing branch of 5 and 6, which are now obsolete, so the cache hash changes.
In general, when cache is simply out-of-date, it can be updated using the old
version as a base. But if cache hash differs, then the cache for that
particular repo filter is recomputed (at least with the current
implementation). This is what happens here.
test-obsmarker-template.t: the pull reports 2 heads changed, but after that the
repo correctly sees only 1. The new message could be better, but it's still an
improvement over the previous one where hg pull suggested merging with an
obsolete revision.
test-obsolete.t: we can see these revisions in hg log --hidden, but they
shouldn't be considered heads even with --hidden.
test-rebase-obsolete{,2}.t: there were new heads created previously after
making new orphan changesets, but they weren't detected. Now we are properly
detecting and reporting them.
test-rebase-obsolete4.t: there's only one head now because the other head is
pruned and was falsely reported before.
test-static-http.t: add obsstore to the list of requested files. This file
doesn't exist on the remotes, but clients want it anyway (they get 404). This
is fine, because there are other nonexistent files that clients request, like
.hg/bookmarks or .hg/cache/tags2-served.
Differential Revision: https://phab.mercurial-scm.org/D12097
author | Anton Shestakov <av6@dwimlabs.net> |
---|---|
date | Fri, 07 Jan 2022 11:53:23 +0300 |
parents | 04688c51f81f |
children | 6000f5b25c9b |
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# Copyright 21 May 2005 - (c) 2005 Jake Edge <jake@edge2.net> # Copyright 2005-2007 Olivia Mackall <olivia@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 import contextlib import struct import threading from .i18n import _ from . import ( encoding, error, pycompat, util, wireprototypes, wireprotov1server, ) from .interfaces import util as interfaceutil from .utils import ( compression, stringutil, ) stringio = util.stringio urlerr = util.urlerr urlreq = util.urlreq HTTP_OK = 200 HGTYPE = b'application/mercurial-0.1' HGTYPE2 = b'application/mercurial-0.2' HGERRTYPE = b'application/hg-error' SSHV1 = wireprototypes.SSHV1 def decodevaluefromheaders(req, headerprefix): """Decode a long value from multiple HTTP request headers. Returns the value as a bytes, not a str. """ chunks = [] i = 1 while True: v = req.headers.get(b'%s-%d' % (headerprefix, i)) if v is None: break chunks.append(pycompat.bytesurl(v)) i += 1 return b''.join(chunks) @interfaceutil.implementer(wireprototypes.baseprotocolhandler) class httpv1protocolhandler(object): def __init__(self, req, ui, checkperm): self._req = req self._ui = ui self._checkperm = checkperm self._protocaps = None @property def name(self): return b'http-v1' def getargs(self, args): knownargs = self._args() data = {} keys = args.split() for k in keys: if k == b'*': star = {} for key in knownargs.keys(): if key != b'cmd' and key not in keys: star[key] = knownargs[key][0] data[b'*'] = star else: data[k] = knownargs[k][0] return [data[k] for k in keys] def _args(self): args = self._req.qsparams.asdictoflists() postlen = int(self._req.headers.get(b'X-HgArgs-Post', 0)) if postlen: args.update( urlreq.parseqs( self._req.bodyfh.read(postlen), keep_blank_values=True ) ) return args argvalue = decodevaluefromheaders(self._req, b'X-HgArg') args.update(urlreq.parseqs(argvalue, keep_blank_values=True)) return args def getprotocaps(self): if self._protocaps is None: value = decodevaluefromheaders(self._req, b'X-HgProto') self._protocaps = set(value.split(b' ')) return self._protocaps def getpayload(self): # Existing clients *always* send Content-Length. length = int(self._req.headers[b'Content-Length']) # If httppostargs is used, we need to read Content-Length # minus the amount that was consumed by args. length -= int(self._req.headers.get(b'X-HgArgs-Post', 0)) return util.filechunkiter(self._req.bodyfh, limit=length) @contextlib.contextmanager def mayberedirectstdio(self): oldout = self._ui.fout olderr = self._ui.ferr out = util.stringio() try: self._ui.fout = out self._ui.ferr = out yield out finally: self._ui.fout = oldout self._ui.ferr = olderr def client(self): return b'remote:%s:%s:%s' % ( self._req.urlscheme, urlreq.quote(self._req.remotehost or b''), urlreq.quote(self._req.remoteuser or b''), ) def addcapabilities(self, repo, caps): caps.append(b'batch') caps.append( b'httpheader=%d' % repo.ui.configint(b'server', b'maxhttpheaderlen') ) if repo.ui.configbool(b'experimental', b'httppostargs'): caps.append(b'httppostargs') # FUTURE advertise 0.2rx once support is implemented # FUTURE advertise minrx and mintx after consulting config option caps.append(b'httpmediatype=0.1rx,0.1tx,0.2tx') compengines = wireprototypes.supportedcompengines( repo.ui, compression.SERVERROLE ) if compengines: comptypes = b','.join( urlreq.quote(e.wireprotosupport().name) for e in compengines ) caps.append(b'compression=%s' % comptypes) return caps def checkperm(self, perm): return self._checkperm(perm) # This method exists mostly so that extensions like remotefilelog can # disable a kludgey legacy method only over http. As of early 2018, # there are no other known users, so with any luck we can discard this # hook if remotefilelog becomes a first-party extension. def iscmd(cmd): return cmd in wireprotov1server.commands def handlewsgirequest(rctx, req, res, checkperm): """Possibly process a wire protocol request. If the current request is a wire protocol request, the request is processed by this function. ``req`` is a ``parsedrequest`` instance. ``res`` is a ``wsgiresponse`` instance. Returns a bool indicating if the request was serviced. If set, the caller should stop processing the request, as a response has already been issued. """ # Avoid cycle involving hg module. from .hgweb import common as hgwebcommon repo = rctx.repo # HTTP version 1 wire protocol requests are denoted by a "cmd" query # string parameter. If it isn't present, this isn't a wire protocol # request. if b'cmd' not in req.qsparams: return False cmd = req.qsparams[b'cmd'] # The "cmd" request parameter is used by both the wire protocol and hgweb. # While not all wire protocol commands are available for all transports, # if we see a "cmd" value that resembles a known wire protocol command, we # route it to a protocol handler. This is better than routing possible # wire protocol requests to hgweb because it prevents hgweb from using # known wire protocol commands and it is less confusing for machine # clients. if not iscmd(cmd): return False # The "cmd" query string argument is only valid on the root path of the # repo. e.g. ``/?cmd=foo``, ``/repo?cmd=foo``. URL paths within the repo # like ``/blah?cmd=foo`` are not allowed. So don't recognize the request # in this case. We send an HTTP 404 for backwards compatibility reasons. if req.dispatchpath: res.status = hgwebcommon.statusmessage(404) res.headers[b'Content-Type'] = HGTYPE # TODO This is not a good response to issue for this request. This # is mostly for BC for now. res.setbodybytes(b'0\n%s\n' % b'Not Found') return True proto = httpv1protocolhandler( req, repo.ui, lambda perm: checkperm(rctx, req, perm) ) # The permissions checker should be the only thing that can raise an # ErrorResponse. It is kind of a layer violation to catch an hgweb # exception here. So consider refactoring into a exception type that # is associated with the wire protocol. try: _callhttp(repo, req, res, proto, cmd) except hgwebcommon.ErrorResponse as e: for k, v in e.headers: res.headers[k] = v res.status = hgwebcommon.statusmessage( e.code, stringutil.forcebytestr(e) ) # TODO This response body assumes the failed command was # "unbundle." That assumption is not always valid. res.setbodybytes(b'0\n%s\n' % stringutil.forcebytestr(e)) return True def _httpresponsetype(ui, proto, prefer_uncompressed): """Determine the appropriate response type and compression settings. Returns a tuple of (mediatype, compengine, engineopts). """ # Determine the response media type and compression engine based # on the request parameters. if b'0.2' in proto.getprotocaps(): # All clients are expected to support uncompressed data. if prefer_uncompressed: return HGTYPE2, compression._noopengine(), {} # Now find an agreed upon compression format. compformats = wireprotov1server.clientcompressionsupport(proto) for engine in wireprototypes.supportedcompengines( ui, compression.SERVERROLE ): if engine.wireprotosupport().name in compformats: opts = {} level = ui.configint(b'server', b'%slevel' % engine.name()) if level is not None: opts[b'level'] = level return HGTYPE2, engine, opts # No mutually supported compression format. Fall back to the # legacy protocol. # Don't allow untrusted settings because disabling compression or # setting a very high compression level could lead to flooding # the server's network or CPU. opts = {b'level': ui.configint(b'server', b'zliblevel')} return HGTYPE, util.compengines[b'zlib'], opts def _callhttp(repo, req, res, proto, cmd): # Avoid cycle involving hg module. from .hgweb import common as hgwebcommon def genversion2(gen, engine, engineopts): # application/mercurial-0.2 always sends a payload header # identifying the compression engine. name = engine.wireprotosupport().name assert 0 < len(name) < 256 yield struct.pack(b'B', len(name)) yield name for chunk in gen: yield chunk def setresponse(code, contenttype, bodybytes=None, bodygen=None): if code == HTTP_OK: res.status = b'200 Script output follows' else: res.status = hgwebcommon.statusmessage(code) res.headers[b'Content-Type'] = contenttype if bodybytes is not None: res.setbodybytes(bodybytes) if bodygen is not None: res.setbodygen(bodygen) if not wireprotov1server.commands.commandavailable(cmd, proto): setresponse( HTTP_OK, HGERRTYPE, _( b'requested wire protocol command is not available over ' b'HTTP' ), ) return proto.checkperm(wireprotov1server.commands[cmd].permission) rsp = wireprotov1server.dispatch(repo, proto, cmd) if isinstance(rsp, bytes): setresponse(HTTP_OK, HGTYPE, bodybytes=rsp) elif isinstance(rsp, wireprototypes.bytesresponse): setresponse(HTTP_OK, HGTYPE, bodybytes=rsp.data) elif isinstance(rsp, wireprototypes.streamreslegacy): setresponse(HTTP_OK, HGTYPE, bodygen=rsp.gen) elif isinstance(rsp, wireprototypes.streamres): gen = rsp.gen # This code for compression should not be streamres specific. It # is here because we only compress streamres at the moment. mediatype, engine, engineopts = _httpresponsetype( repo.ui, proto, rsp.prefer_uncompressed ) gen = engine.compressstream(gen, engineopts) if mediatype == HGTYPE2: gen = genversion2(gen, engine, engineopts) setresponse(HTTP_OK, mediatype, bodygen=gen) elif isinstance(rsp, wireprototypes.pushres): rsp = b'%d\n%s' % (rsp.res, rsp.output) setresponse(HTTP_OK, HGTYPE, bodybytes=rsp) elif isinstance(rsp, wireprototypes.pusherr): rsp = b'0\n%s\n' % rsp.res res.drain = True setresponse(HTTP_OK, HGTYPE, bodybytes=rsp) elif isinstance(rsp, wireprototypes.ooberror): setresponse(HTTP_OK, HGERRTYPE, bodybytes=rsp.message) else: raise error.ProgrammingError(b'hgweb.protocol internal failure', rsp) def _sshv1respondbytes(fout, value): """Send a bytes response for protocol version 1.""" fout.write(b'%d\n' % len(value)) fout.write(value) fout.flush() def _sshv1respondstream(fout, source): write = fout.write for chunk in source.gen: write(chunk) fout.flush() def _sshv1respondooberror(fout, ferr, rsp): ferr.write(b'%s\n-\n' % rsp) ferr.flush() fout.write(b'\n') fout.flush() @interfaceutil.implementer(wireprototypes.baseprotocolhandler) class sshv1protocolhandler(object): """Handler for requests services via version 1 of SSH protocol.""" def __init__(self, ui, fin, fout): self._ui = ui self._fin = fin self._fout = fout self._protocaps = set() @property def name(self): return wireprototypes.SSHV1 def getargs(self, args): data = {} keys = args.split() for n in pycompat.xrange(len(keys)): argline = self._fin.readline()[:-1] arg, l = argline.split() if arg not in keys: raise error.Abort(_(b"unexpected parameter %r") % arg) if arg == b'*': star = {} for k in pycompat.xrange(int(l)): argline = self._fin.readline()[:-1] arg, l = argline.split() val = self._fin.read(int(l)) star[arg] = val data[b'*'] = star else: val = self._fin.read(int(l)) data[arg] = val return [data[k] for k in keys] def getprotocaps(self): return self._protocaps def getpayload(self): # We initially send an empty response. This tells the client it is # OK to start sending data. If a client sees any other response, it # interprets it as an error. _sshv1respondbytes(self._fout, b'') # The file is in the form: # # <chunk size>\n<chunk> # ... # 0\n count = int(self._fin.readline()) while count: yield self._fin.read(count) count = int(self._fin.readline()) @contextlib.contextmanager def mayberedirectstdio(self): yield None def client(self): client = encoding.environ.get(b'SSH_CLIENT', b'').split(b' ', 1)[0] return b'remote:ssh:' + client def addcapabilities(self, repo, caps): if self.name == wireprototypes.SSHV1: caps.append(b'protocaps') caps.append(b'batch') return caps def checkperm(self, perm): pass def _runsshserver(ui, repo, fin, fout, ev): # This function operates like a state machine of sorts. The following # states are defined: # # protov1-serving # Server is in protocol version 1 serving mode. Commands arrive on # new lines. These commands are processed in this state, one command # after the other. # # shutdown # The server is shutting down, possibly in reaction to a client event. # # And here are their transitions: # # protov1-serving -> shutdown # When server receives an empty request or encounters another # error. state = b'protov1-serving' proto = sshv1protocolhandler(ui, fin, fout) while not ev.is_set(): if state == b'protov1-serving': # Commands are issued on new lines. request = fin.readline()[:-1] # Empty lines signal to terminate the connection. if not request: state = b'shutdown' continue available = wireprotov1server.commands.commandavailable( request, proto ) # This command isn't available. Send an empty response and go # back to waiting for a new command. if not available: _sshv1respondbytes(fout, b'') continue rsp = wireprotov1server.dispatch(repo, proto, request) repo.ui.fout.flush() repo.ui.ferr.flush() if isinstance(rsp, bytes): _sshv1respondbytes(fout, rsp) elif isinstance(rsp, wireprototypes.bytesresponse): _sshv1respondbytes(fout, rsp.data) elif isinstance(rsp, wireprototypes.streamres): _sshv1respondstream(fout, rsp) elif isinstance(rsp, wireprototypes.streamreslegacy): _sshv1respondstream(fout, rsp) elif isinstance(rsp, wireprototypes.pushres): _sshv1respondbytes(fout, b'') _sshv1respondbytes(fout, b'%d' % rsp.res) elif isinstance(rsp, wireprototypes.pusherr): _sshv1respondbytes(fout, rsp.res) elif isinstance(rsp, wireprototypes.ooberror): _sshv1respondooberror(fout, ui.ferr, rsp.message) else: raise error.ProgrammingError( b'unhandled response type from ' b'wire protocol command: %s' % rsp ) elif state == b'shutdown': break else: raise error.ProgrammingError( b'unhandled ssh server state: %s' % state ) class sshserver(object): def __init__(self, ui, repo, logfh=None): self._ui = ui self._repo = repo self._fin, self._fout = ui.protectfinout() # Log write I/O to stdout and stderr if configured. if logfh: self._fout = util.makeloggingfileobject( logfh, self._fout, b'o', logdata=True ) ui.ferr = util.makeloggingfileobject( logfh, ui.ferr, b'e', logdata=True ) def serve_forever(self): self.serveuntil(threading.Event()) self._ui.restorefinout(self._fin, self._fout) def serveuntil(self, ev): """Serve until a threading.Event is set.""" _runsshserver(self._ui, self._repo, self._fin, self._fout, ev)