##// END OF EJS Templates
named branches: server branchmap wire protocol support (issue736)...
named branches: server branchmap wire protocol support (issue736) The repository command, 'branchmap', returns a dictionary, branchname -> [branchheads], and will be implemented for localrepo, httprepo and sshrepo. The following wire format is used for returning data: branchname1 branch1head2 branch1head2 ... branchname2 ... ... Branch names are URL encoded to escape white space, and branch heads are sent as hex encoded node ids. All branches and all their heads are sent. The background and motivation for this command is the desire for a richer named branch semantics when pushing changesets. The details are explained in the original proposal which is included below. 1. BACKGROUND The algorithm currently implemented in Mercurial only considers the graph theoretical heads when determining whether new heads are created, rather than using the branch heads as a count (the algorithm considers a branch head effectively closed when it is merged into another branch or a new named branch is started from that point onward). Our particular problem with the algorithm is that we'd like to see the following case working without forcing a push: Upsteam has: (0:dev) ---- (1:dev) \ `--- (2:stable) Someone merges stable into dev: (0:dev) ---- (1:dev) ------(3:dev) \ / `--- (2:stable) --------´ This can be pushed without --force (as it should). Now someone else does some coding on stable (a bug fix, say): (0:dev) ---- (1:dev) ------(3:dev) \ / `--- (2:stable) ---------´---------(4:stable) This time we need --force to push. We allow this to be pushed without using --force by getting all the remote branch heads (by extending the wire protocol with a new function). We would, furthermore, also prefer if it is impossible to push a new branch without --force (or a later --newbranch option so --force isn't shoe-horned into too many disparate functions, if need be), except of course in the case where the remote repository is empty. This is what our patches accomplish. 2. ALTERNATIVES We have, of course, considered some alternatives to reconstructing enough information to decide whether we are creating new remote branch heads, before we added the new wire protocol command. 2.1. LOOKUP ON REMOTE The main alternative is to use the information from remote.heads() and remote.lookup() to try to reconstruct enough graph information to decide whether we are creating new heads. This is not adequate as illustrated below. Remember that each lookup is typically a request-response pair over SSH or HTTP(S). If we have a simple repository at the remote end like this: (0:dev) ---- (1:dev) ---- (3:stable) \ `--- (2:dev) then remote.heads() will yield [2, 3]. Assume we have nodes [0, 1, 2] locally and want to create a new node, 4:dev, as a descendant from (1:dev), which should be OK as 1:dev is a branch head. If we do remote.lookup('dev') we will get [2]. Thus, we can get information about whether a branch exists on the remote server or not, but this does not solve our problem of figuring out whether we are creating new heads or not. Pushing 4:dev ought to be OK, since after the push, we still only have two heads on branch a. Using remote.lookup() and remote.heads() is thus not adequate to consistently decide whether we are creating new remote heads (e.g. in this situation the latter would never return 1:dev). 2.2. USING INCOMING TO RECONSTRUCT THE GRAPH An alternative would be to use information equivalent to hg incoming to get the full remote graph in addition to the local graph. To do this, we would have to get a changegroup(subset) bundle representing the remote end (which may be a substantial amount of data), getting the branch heads from an instantiated bundlerepository, deleting the bundle, and finally, we can compute the prepush logic. While this is backwards compatible, it will cause a possibly substantial slowdown of the push command as it first needs to pull in all changes. 3. FURTHER ARGUMENTS IN FAVOUR OF THE BRANCHMAP WIRE-PROTOCOL EXTENSION Currently, the commands incoming and pull, work based on the tip of a given branch if used with "-r branchname", making it hard to get all revisions of a certain branch only (if it has multiple heads). This can be solved by requesting the remote's branchheads and letting the revisions to be used with the command be these heads. This can be done by extending the commands with a new option, e.g.: hg pull -b branchname which will be turned into the equivalent of: hg pull -r branchhead1 -r branchhead2 -r branchhead3 We have a simple follow-up patch that can do this ready as well (although not submitted yet as it is pending the acceptance of the branch patch). 4. WRAP-UP We generally find that the branchmap wire protocol extension can provide better named branch support to Mercurial. Currently, some things, like the initial push scenario in this mail, are fairly counter-intuitive, and the more often you have to force push, the more it is likely you will get a lot of spurious and unnecessary merge nodes. Also, restricting incoming and pull to all changes on a branch rather than changes on the tip-most head would be a sensible extension to making named branches a first class citizen in Mercurial. Currently, named branches sometimes feel like a late-coming unwanted step-child. We have run it in a production environment for a while, with fewer multiple heads occurring in our repositories and fewer confused users as a result. Also, it fixes the long-standing issue 736. Co-contributor: Sune Foldager <cryo@cyanite.org>

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httprepo.py
245 lines | 8.7 KiB | text/x-python | PythonLexer
mpm@selenic.com
Break apart hg.py...
r1089 # httprepo.py - HTTP repository proxy classes for mercurial
#
Vadim Gelfer
update copyrights.
r2859 # Copyright 2005, 2006 Matt Mackall <mpm@selenic.com>
# Copyright 2006 Vadim Gelfer <vadim.gelfer@gmail.com>
mpm@selenic.com
Break apart hg.py...
r1089 #
Martin Geisler
updated license to be explicit about GPL version 2
r8225 # This software may be used and distributed according to the terms of the
# GNU General Public License version 2, incorporated herein by reference.
mpm@selenic.com
Break apart hg.py...
r1089
Matt Mackall
Autodetect static-http
r7211 from node import bin, hex, nullid
Matt Mackall
Simplify i18n imports
r3891 from i18n import _
Simon Heimberg
separate import lines from mercurial and general python modules
r8312 import repo, changegroup, statichttprepo, error, url, util
import os, urllib, urllib2, urlparse, zlib, httplib
import errno, socket
Alexis S. L. Carvalho
Work around urllib2 digest auth bug with Python < 2.5...
r4678
Matt Mackall
remove duplicate zgenerator in httprepo
r3661 def zgenerator(f):
zd = zlib.decompressobj()
try:
for chunk in util.filechunkiter(f):
yield zd.decompress(chunk)
Benoit Boissinot
remove unused variables
r7280 except httplib.HTTPException:
Matt Mackall
remove duplicate zgenerator in httprepo
r3661 raise IOError(None, _('connection ended unexpectedly'))
yield zd.flush()
Matt Mackall
remoterepo: no longer needed...
r6313 class httprepository(repo.repository):
mpm@selenic.com
Break apart hg.py...
r1089 def __init__(self, ui, path):
Vadim Gelfer
hooks: add url to changegroup, incoming, prechangegroup, pretxnchangegroup hooks...
r2673 self.path = path
Vadim Gelfer
http: query server for capabilities
r2442 self.caps = None
Andrei Vermel
Close keepalive connections to fix server traceback
r4132 self.handler = None
Vadim Gelfer
http: fix many problems with url parsing and auth. added proxy test....
r2337 scheme, netloc, urlpath, query, frag = urlparse.urlsplit(path)
if query or frag:
raise util.Abort(_('unsupported URL component: "%s"') %
(query or frag))
# urllib cannot handle URLs with embedded user or passwd
Benoit Boissinot
factor out the url handling from httprepo...
r7270 self._url, authinfo = url.getauthinfo(path)
mpm@selenic.com
Break apart hg.py...
r1089 self.ui = ui
Alexis S. L. Carvalho
httprepo: quote the path part of the URL...
r5066 self.ui.debug(_('using %s\n') % self._url)
Vadim Gelfer
http: fix many problems with url parsing and auth. added proxy test....
r2337
Benoit Boissinot
factor out the url handling from httprepo...
r7270 self.urlopener = url.opener(ui, authinfo)
Thomas Arendsen Hein
Removed trailing whitespace and tabs from python files
r4516
Steve Borho
close sockets on httprepository deletion (issue1487)...
r7752 def __del__(self):
for h in self.urlopener.handlers:
h.close()
if hasattr(h, "close_all"):
h.close_all()
Vadim Gelfer
hooks: add url to changegroup, incoming, prechangegroup, pretxnchangegroup hooks...
r2673 def url(self):
return self.path
Vadim Gelfer
http: query server for capabilities
r2442 # look up capabilities only when needed
def get_caps(self):
if self.caps is None:
try:
Martin Geisler
util: use built-in set and frozenset...
r8150 self.caps = set(self.do_read('capabilities').split())
Matt Mackall
error: move repo errors...
r7637 except error.RepoError:
Martin Geisler
util: use built-in set and frozenset...
r8150 self.caps = set()
Vadim Gelfer
push over http: client support....
r2465 self.ui.debug(_('capabilities: %s\n') %
(' '.join(self.caps or ['none'])))
Vadim Gelfer
http: query server for capabilities
r2442 return self.caps
capabilities = property(get_caps)
Vadim Gelfer
make push over http print good error message.
r1870 def lock(self):
raise util.Abort(_('operation not supported over http'))
mpm@selenic.com
Break apart hg.py...
r1089 def do_cmd(self, cmd, **args):
Vadim Gelfer
push over http: client support....
r2465 data = args.pop('data', None)
headers = args.pop('headers', {})
Benoit Boissinot
i18n part2: use '_' for all strings who are part of the user interface
r1402 self.ui.debug(_("sending %s command\n") % cmd)
mpm@selenic.com
Break apart hg.py...
r1089 q = {"cmd": cmd}
q.update(args)
Benoit Boissinot
httprepo: record the url after a request, makes pull + redirect works...
r3562 qs = '?%s' % urllib.urlencode(q)
cu = "%s%s" % (self._url, qs)
Thomas Arendsen Hein
Catch urllib's HTTPException and give a meaningful error message to the user....
r2294 try:
Thomas Arendsen Hein
Turn bundle file into a string for http push, for urllib2 over proxies.
r3567 if data:
Alexis S. L. Carvalho
Push over HTTP: really tell the user the size of the bundle
r5333 self.ui.debug(_("sending %s bytes\n") % len(data))
Benoit Boissinot
factor out the url handling from httprepo...
r7270 resp = self.urlopener.open(urllib2.Request(cu, data, headers))
Vadim Gelfer
http client: better work with authorization errors, broken sockets.
r2467 except urllib2.HTTPError, inst:
if inst.code == 401:
raise util.Abort(_('authorization failed'))
raise
Thomas Arendsen Hein
Catch urllib's HTTPException and give a meaningful error message to the user....
r2294 except httplib.HTTPException, inst:
Vadim Gelfer
http: print better error if exception happens.
r2336 self.ui.debug(_('http error while sending %s command\n') % cmd)
Matt Mackall
ui: print_exc() -> traceback()
r8206 self.ui.traceback()
Vadim Gelfer
http: print better error if exception happens.
r2336 raise IOError(None, inst)
Thomas Arendsen Hein
Catch python2.3's IndexError with bogus http proxy settings. (issue203)
r3399 except IndexError:
# this only happens with Python 2.3, later versions raise URLError
raise util.Abort(_('http error, possibly caused by proxy setting'))
Benoit Boissinot
httprepo: record the url after a request, makes pull + redirect works...
r3562 # record the url we got redirected to
Thomas Arendsen Hein
Inform the user about the new URL when being redirected via http....
r3570 resp_url = resp.geturl()
if resp_url.endswith(qs):
resp_url = resp_url[:-len(qs)]
if self._url != resp_url:
self.ui.status(_('real URL is %s\n') % resp_url)
self._url = resp_url
Vadim Gelfer
http client: support persistent connections....
r2435 try:
proto = resp.getheader('content-type')
except AttributeError:
proto = resp.headers['content-type']
mpm@selenic.com
Break apart hg.py...
r1089
Steve Borho
hide passwords in httprepo error messages
r8053 safeurl = url.hidepassword(self._url)
mpm@selenic.com
Break apart hg.py...
r1089 # accept old "text/plain" and "application/hg-changegroup" for now
Thomas Arendsen Hein
Cleanup of whitespace, indentation and line continuation.
r4633 if not (proto.startswith('application/mercurial-') or
proto.startswith('text/plain') or
proto.startswith('application/hg-changegroup')):
Patrick Mezard
Merge with crew-stable
r8055 self.ui.debug(_("requested URL: '%s'\n") % url.hidepassword(cu))
Matt Mackall
error: move repo errors...
r7637 raise error.RepoError(_("'%s' does not appear to be an hg repository")
Steve Borho
hide passwords in httprepo error messages
r8053 % safeurl)
mpm@selenic.com
Break apart hg.py...
r1089
Benoit Boissinot
fix handling of multiple Content-type headers...
r4012 if proto.startswith('application/mercurial-'):
try:
Thomas Arendsen Hein
Avoid float rounding errors when checking http protocol version.
r4356 version = proto.split('-', 1)[1]
version_info = tuple([int(n) for n in version.split('.')])
Benoit Boissinot
fix handling of multiple Content-type headers...
r4012 except ValueError:
Matt Mackall
error: move repo errors...
r7637 raise error.RepoError(_("'%s' sent a broken Content-Type "
Steve Borho
hide passwords in httprepo error messages
r8053 "header (%s)") % (safeurl, proto))
Thomas Arendsen Hein
Avoid float rounding errors when checking http protocol version.
r4356 if version_info > (0, 1):
Matt Mackall
error: move repo errors...
r7637 raise error.RepoError(_("'%s' uses newer protocol %s") %
Steve Borho
hide passwords in httprepo error messages
r8053 (safeurl, version))
mpm@selenic.com
Break apart hg.py...
r1089
return resp
Vadim Gelfer
http client: support persistent connections....
r2435 def do_read(self, cmd, **args):
fp = self.do_cmd(cmd, **args)
try:
return fp.read()
finally:
# if using keepalive, allow connection to be reused
fp.close()
Eric Hopper
Adding changegroupsubset and lookup to web protocol so pull -r and...
r3444 def lookup(self, key):
Bryan O'Sullivan
Push capability checking into protocol-level code.
r5259 self.requirecap('lookup', _('look up remote revision'))
Matt Mackall
httprepo: add support for passing lookup exception data
r3445 d = self.do_cmd("lookup", key = key).read()
success, data = d[:-1].split(' ', 1)
if int(success):
return bin(data)
Matt Mackall
error: move repo errors...
r7637 raise error.RepoError(data)
Eric Hopper
Adding changegroupsubset and lookup to web protocol so pull -r and...
r3444
mpm@selenic.com
Break apart hg.py...
r1089 def heads(self):
Vadim Gelfer
http client: support persistent connections....
r2435 d = self.do_read("heads")
mpm@selenic.com
Break apart hg.py...
r1089 try:
return map(bin, d[:-1].split(" "))
except:
Matt Mackall
error: move UnexpectedOutput (now ResponseError)
r7641 raise error.ResponseError(_("unexpected response:"), d)
mpm@selenic.com
Break apart hg.py...
r1089
def branches(self, nodes):
n = " ".join(map(hex, nodes))
Vadim Gelfer
http client: support persistent connections....
r2435 d = self.do_read("branches", nodes=n)
mpm@selenic.com
Break apart hg.py...
r1089 try:
br = [ tuple(map(bin, b.split(" "))) for b in d.splitlines() ]
return br
except:
Matt Mackall
error: move UnexpectedOutput (now ResponseError)
r7641 raise error.ResponseError(_("unexpected response:"), d)
mpm@selenic.com
Break apart hg.py...
r1089
def between(self, pairs):
Matt Mackall
protocol: avoid sending outrageously large between requests
r7342 batch = 8 # avoid giant requests
r = []
for i in xrange(0, len(pairs), batch):
n = " ".join(["-".join(map(hex, p)) for p in pairs[i:i + batch]])
d = self.do_read("between", pairs=n)
try:
r += [ l and map(bin, l.split(" ")) or [] for l in d.splitlines() ]
except:
Matt Mackall
error: move UnexpectedOutput (now ResponseError)
r7641 raise error.ResponseError(_("unexpected response:"), d)
Matt Mackall
protocol: avoid sending outrageously large between requests
r7342 return r
mpm@selenic.com
Break apart hg.py...
r1089
Vadim Gelfer
add preoutgoing and outgoing hooks....
r1736 def changegroup(self, nodes, kind):
mpm@selenic.com
Break apart hg.py...
r1089 n = " ".join(map(hex, nodes))
f = self.do_cmd("changegroup", roots=n)
Matt Mackall
remove duplicate zgenerator in httprepo
r3661 return util.chunkbuffer(zgenerator(f))
Eric Hopper
Adding changegroupsubset and lookup to web protocol so pull -r and...
r3444
def changegroupsubset(self, bases, heads, source):
Bryan O'Sullivan
Push capability checking into protocol-level code.
r5259 self.requirecap('changegroupsubset', _('look up remote changes'))
Eric Hopper
Adding changegroupsubset and lookup to web protocol so pull -r and...
r3444 baselst = " ".join([hex(n) for n in bases])
headlst = " ".join([hex(n) for n in heads])
f = self.do_cmd("changegroupsubset", bases=baselst, heads=headlst)
Matt Mackall
remove duplicate zgenerator in httprepo
r3661 return util.chunkbuffer(zgenerator(f))
mpm@selenic.com
Break apart hg.py...
r1089
Vadim Gelfer
extend network protocol to stop clients from locking servers...
r2439 def unbundle(self, cg, heads, source):
Vadim Gelfer
push over http: client support....
r2465 # have to stream bundle to a temp file because we do not have
# http 1.1 chunked transfer.
Matt Mackall
unduplicate bundle writing code from httprepo
r3662 type = ""
types = self.capable('unbundle')
Alexis S. L. Carvalho
fix push over HTTP to older servers
r3703 # servers older than d1b16a746db6 will send 'unbundle' as a
# boolean capability
try:
types = types.split(',')
except AttributeError:
types = [""]
Matt Mackall
unduplicate bundle writing code from httprepo
r3662 if types:
Alexis S. L. Carvalho
fix push over HTTP to older servers
r3703 for x in types:
Matt Mackall
unduplicate bundle writing code from httprepo
r3662 if x in changegroup.bundletypes:
type = x
break
Thomas Arendsen Hein
Client support for hgweb unbundle with versions.
r3613
Matt Mackall
unduplicate bundle writing code from httprepo
r3662 tempname = changegroup.writebundle(cg, None, type)
Benoit Boissinot
factor out the url handling from httprepo...
r7270 fp = url.httpsendfile(tempname, "rb")
Vadim Gelfer
push over http: client support....
r2465 try:
try:
Benoit Boissinot
enhance the error output in case of failure during http push
r7010 resp = self.do_read(
'unbundle', data=fp,
headers={'Content-Type': 'application/octet-stream'},
heads=' '.join(map(hex, heads)))
resp_code, output = resp.split('\n', 1)
Vadim Gelfer
http client: better work with authorization errors, broken sockets.
r2467 try:
Benoit Boissinot
enhance the error output in case of failure during http push
r7010 ret = int(resp_code)
except ValueError, err:
Matt Mackall
error: move UnexpectedOutput (now ResponseError)
r7641 raise error.ResponseError(
Benoit Boissinot
enhance the error output in case of failure during http push
r7010 _('push failed (unexpected response):'), resp)
self.ui.write(output)
return ret
Vadim Gelfer
http client: better work with authorization errors, broken sockets.
r2467 except socket.error, err:
if err[0] in (errno.ECONNRESET, errno.EPIPE):
Thomas Arendsen Hein
Never apply string formatting to generated errors with util.Abort....
r3072 raise util.Abort(_('push failed: %s') % err[1])
Vadim Gelfer
http client: better work with authorization errors, broken sockets.
r2467 raise util.Abort(err[1])
Vadim Gelfer
push over http: client support....
r2465 finally:
fp.close()
os.unlink(tempname)
Vadim Gelfer
extend network protocol to stop clients from locking servers...
r2439
Vadim Gelfer
add support for streaming clone....
r2612 def stream_out(self):
return self.do_cmd('stream_out')
mpm@selenic.com
Break apart hg.py...
r1089 class httpsrepository(httprepository):
Alexis S. L. Carvalho
HTTPS: fix python2.3, persistent connections, don't explode if SSL is not available...
r2569 def __init__(self, ui, path):
Benoit Boissinot
Fix https availability checking...
r7279 if not url.has_https:
Alexis S. L. Carvalho
HTTPS: fix python2.3, persistent connections, don't explode if SSL is not available...
r2569 raise util.Abort(_('Python support for SSL and HTTPS '
'is not installed'))
httprepository.__init__(self, ui, path)
Vadim Gelfer
clean up hg.py: move repo constructor code into each repo module
r2740
def instance(ui, path, create):
if create:
raise util.Abort(_('cannot create new http repository'))
Matt Mackall
Autodetect static-http
r7211 try:
if path.startswith('https:'):
inst = httpsrepository(ui, path)
else:
inst = httprepository(ui, path)
inst.between([(nullid, nullid)])
return inst
Matt Mackall
error: move repo errors...
r7637 except error.RepoError:
Matt Mackall
Autodetect static-http
r7211 ui.note('(falling back to static-http)\n')
return statichttprepo.instance(ui, "static-" + path, create)