dulwich-users team mailing list archive

[Jelmer Vernooij <jelmer@xxxxxxxxxx>]

On Thu, Jul 12, 2012 at 09:52:55PM -0700, Andi McClure wrote:
> Does this help? Attached are patches for the two changes discussed in this
> thread:
> 
> - send_pack should pass determine_wants a copy of the refs dict, not the
> refs dict, so that the comparison shortly after can't get confused
Thanks, applied.

> - Make usage of 'determine_wants' callbacks explicit in inline documentation
> 
> Things to note: I claim in the documentation that determine_wants changes
> remote heads even on fetch (because this appears to be the case from
> reading the code?); and I do not improve the usage documentation around the
> "generate_pack_contents" callbacks, because I do not understand how they
> are used.
That isn't right - determine_wants for fetch() returns a list of
objects, not a dictionary.

determine_wants probably isn't an entirely appropriate name for what
that function does for send_pack(); it is also slightly confusing that
both send and fetch take an argument with the same name that behaves
slightly differently. Perhaps we should rename the determine_wants
argument for send_pack to update_refs or something like that.

> Also, for future reference, do you prefer proposed patches as patches on
> the mailing list, or pull requests on github, or what?
Preferably git-am style patches (with metadata) on the mailing list, rather than github.

Cheers,

Jelmer

> On Wed, Jul 11, 2012 at 5:26 PM, Jelmer Vernooij <jelmer@xxxxxxxxxx> wrote:
> 
> > On Sun, Jul 08, 2012 at 01:41:18PM -0700, Andi McClure wrote:
> > > Here is a standalone script which reproduces the problem, it's just a
> > > connect, the push and some prints. My expected behavior is that on the
> > > second run it will print "target is already deleted" because the first
> > run
> > > will have deleted it. What I see is that on every run it gets an accurate
> > > list of heads from the server but then has no effect when it tries to
> > > change them. Changing the ZERO_SHA to None has no effect either.
> > >
> > > Since this connects directly to one of my github repos you will probably
> > > get a permissions error if you run it as written, maybe you could clone
> > > https://github.com/mcclure/backup-Polycode and then change the "path"
> > line
> > > to point to your own github account?
> > >
> > > ######## Start
> > >
> > > import dulwich.client
> > > from dulwich.protocol import ZERO_SHA
> > >
> > > client = dulwich.client.SSHGitClient("git@xxxxxxxxxx")
> > > path = "/mcclure/backup-Polycode"
> > > delete_this_head = "refs/heads/bullet279"
> > >
> > > print("client, path is: %s,%s\ntarget is %s\n" %
> > > (client,repr(path),repr(delete_this_head)))
> > >
> > > def changed(refs):
> > > print("determine_wants argument:\n%s\n" % (refs))
> > > if delete_this_head in refs:
> > > refs[delete_this_head] = ZERO_SHA
> > > print("determine_wants returning:\n%s\n" % (refs))
> > > else:
> > > print("target is already deleted!\n")
> > > return refs
> >
> > Unfortunately your mailer seems to have stripped the whitespace from
> > these lines. It looks though like you're trying to modify the existing
> > refs dictionary rather than returning your own.
> >
> > dulwich compares the dictionary it passes in and yours to see if it
> > should make any changes to the remote server. A simple fix for this
> > should be to add "refs = dict(refs)" as the first instruction in the
> > changed() function.
> >
> > We should probably also improve dulwich by making it harder to shoot
> > yourself in the foot like this, and having it take create a copy to
> > pass to you.
> >
> > Cheers,
> >
> > Jelmer
> >
> > >
> > > On Sun, Jul 8, 2012 at 6:27 AM, Jelmer Vernooij <jelmer@xxxxxxxxx>
> > wrote:
> > >
> > > > On Sat, Jul 07, 2012 at 08:07:51PM -0700, Andi McClure wrote:
> > > > > "What do you mean exactly when you say it doesn't work?"
> > > >
> > > > > When I say it doesn't work, what I mean is it appears to do nothing.
> > The
> > > > > remote repository is afterward unchanged, looking at github.com.
> > > >
> > > > > If it's okay to paste a big block, here's exactly what is happening.
> > I'm
> > > > > running the following code with the argument "key" = "bullet279" and
> > the
> > > > > referenced value "null_revision_hex" equal to "00"*20.
> > > > Can you condense it down into just the bit that reproduces the issue?
> > > > This should just do the connect and the call to .send_pack().
> > > >
> > > > Actually, come to think of it - you might have to set the value to
> > > > None rather than the ZERO_SHA1 - have you tried that?
> > > >
> > > > Cheers,
> > > >
> > > > Jelmer
> > > >
> > > > >             client, path =
> > > > > > self.git_handler.get_transport_and_path(self.path)
> > > > > >             print("client, path is:")
> > > > > >             print(client)
> > > > > >             print(path)
> > > > > >             def changed(refs):
> > > > > >                 desired = gitrepo.head_prefix + key
> > > > > >                 print("determine_wants argument:")
> > > > > >                 print(refs)
> > > > > >                 if desired in refs:
> > > > > >                     refs[desired] = GitHandler.null_revision_hex
> > > > > >                     print("determine_wants return:")
> > > > > >                     print(refs)
> > > > > >                 return refs
> > > > > >             def adebugger(*args):
> > > > > >                 print("generate_pack_contents arguments:")
> > > > > >                 print(args)
> > > > > >                 import pdb; pdb.set_trace()
> > > > > >                 return args
> > > > > >             genpack = adebugger
> > > > > >             try:
> > > > > >                 self.git_handler.ui.status(_("creating and sending
> > data
> > > > > > for remote bookmark deletion\n"))
> > > > > >                 changed_refs = client.send_pack(path, changed,
> > genpack)
> > > > > >                 print("sent_pack returned:")
> > > > > >                 print(changed_refs)
> > > > > >                 return True
> > > > > >             except (HangupException, GitProtocolError), e:
> > > > > >                 raise hgutil.Abort(_("git remote error: ") +
> > str(e))
> > > >
> > > >
> > > > > This is resulting in the following printed:
> > > >
> > > > > client, path is:
> > > > > > <dulwich.client.SSHGitClient object at 0x118bed0>
> > > > > > /mcclure/backup-Polycode
> > > > > > creating and sending data for remote bookmark deletion
> > > > > > ["git-receive-pack '/mcclure/backup-Polycode'"]
> > > > > > determine_wants argument:
> > > > > > {'refs/heads/screeninfo':
> > '60660e76486583708684ae10aa5df4751f948570',
> > > > > > 'refs/heads/createlua': '54995beed753f0af4d7f1c4f79b520e18fc6d22a',
> > > > > > 'refs/heads/xibfix': 'd69b878d38632f3af8fd07127f05ce9c9e368e23',
> > > > > > 'refs/heads/scene': '1a686b0d0ad3d9344c9ca463dac196be61dfd49e',
> > > > > > 'refs/heads/zlibfix': '79762dc444f66c30710af2d8534956eab27aef7d',
> > > > > > 'refs/heads/sound': 'b7e414ee212e3cc2fa93ed93053eeff71abfbd0a',
> > > > > > 'refs/heads/dashg': '51030fa9ab337006ed2c9db05151b275cc4341f5',
> > > > > > 'refs/heads/add_dependencies':
> > > > '300bf6ac818221882505b9c8976830c2777a6964',
> > > > > > 'refs/heads/bullet279': 'b13f974ce94790d53bdf166ecc68b499fbf0b629',
> > > > > > 'refs/heads/cmake': '8a024fc8760e93f37229a8ef3f8c71961e1c4bf8',
> > > > > > 'refs/heads/mingw': 'a573d046fe2cb9daad806a4a4c0853e4abf3b7c3',
> > > > > > 'refs/heads/windowsquit':
> > '94f728a23c8ddb93c6d1426eea25ada165af8bd9',
> > > > > > 'refs/heads/zlib127': '67e474d6020f3ed3c20bde1d905f9fc53273416f',
> > > > > > 'refs/heads/clearMesh': '6be76b1b21216485557d5cc1356be321ac761864',
> > > > > > 'refs/heads/safestring':
> > '9de8332077b1b13acb6c40c52479dde51f6d88df',
> > > > > > 'refs/heads/master': '8355b00050696f4ddaaf13bf8ec721b3cf8b08e2',
> > > > > > 'refs/heads/shaderfixes':
> > 'f64acadc1c0ef4b6cfe6ff1e43c61b22bc216673'}
> > > > > > determine_wants return:
> > > > > > {'refs/heads/screeninfo':
> > '60660e76486583708684ae10aa5df4751f948570',
> > > > > > 'refs/heads/createlua': '54995beed753f0af4d7f1c4f79b520e18fc6d22a',
> > > > > > 'refs/heads/xibfix': 'd69b878d38632f3af8fd07127f05ce9c9e368e23',
> > > > > > 'refs/heads/scene': '1a686b0d0ad3d9344c9ca463dac196be61dfd49e',
> > > > > > 'refs/heads/zlibfix': '79762dc444f66c30710af2d8534956eab27aef7d',
> > > > > > 'refs/heads/sound': 'b7e414ee212e3cc2fa93ed93053eeff71abfbd0a',
> > > > > > 'refs/heads/dashg': '51030fa9ab337006ed2c9db05151b275cc4341f5',
> > > > > > 'refs/heads/add_dependencies':
> > > > '300bf6ac818221882505b9c8976830c2777a6964',
> > > > > > 'refs/heads/bullet279': '0000000000000000000000000000000000000000',
> > > > > > 'refs/heads/cmake': '8a024fc8760e93f37229a8ef3f8c71961e1c4bf8',
> > > > > > 'refs/heads/mingw': 'a573d046fe2cb9daad806a4a4c0853e4abf3b7c3',
> > > > > > 'refs/heads/windowsquit':
> > '94f728a23c8ddb93c6d1426eea25ada165af8bd9',
> > > > > > 'refs/heads/zlib127': '67e474d6020f3ed3c20bde1d905f9fc53273416f',
> > > > > > 'refs/heads/clearMesh': '6be76b1b21216485557d5cc1356be321ac761864',
> > > > > > 'refs/heads/safestring':
> > '9de8332077b1b13acb6c40c52479dde51f6d88df',
> > > > > > 'refs/heads/master': '8355b00050696f4ddaaf13bf8ec721b3cf8b08e2',
> > > > > > 'refs/heads/shaderfixes':
> > 'f64acadc1c0ef4b6cfe6ff1e43c61b22bc216673'}
> > > > > > sent_pack returned:
> > > > > > {'refs/heads/screeninfo':
> > '60660e76486583708684ae10aa5df4751f948570',
> > > > > > 'refs/heads/createlua': '54995beed753f0af4d7f1c4f79b520e18fc6d22a',
> > > > > > 'refs/heads/xibfix': 'd69b878d38632f3af8fd07127f05ce9c9e368e23',
> > > > > > 'refs/heads/scene': '1a686b0d0ad3d9344c9ca463dac196be61dfd49e',
> > > > > > 'refs/heads/zlibfix': '79762dc444f66c30710af2d8534956eab27aef7d',
> > > > > > 'refs/heads/sound': 'b7e414ee212e3cc2fa93ed93053eeff71abfbd0a',
> > > > > > 'refs/heads/dashg': '51030fa9ab337006ed2c9db05151b275cc4341f5',
> > > > > > 'refs/heads/add_dependencies':
> > > > '300bf6ac818221882505b9c8976830c2777a6964',
> > > > > > 'refs/heads/bullet279': '0000000000000000000000000000000000000000',
> > > > > > 'refs/heads/cmake': '8a024fc8760e93f37229a8ef3f8c71961e1c4bf8',
> > > > > > 'refs/heads/mingw': 'a573d046fe2cb9daad806a4a4c0853e4abf3b7c3',
> > > > > > 'refs/heads/windowsquit':
> > '94f728a23c8ddb93c6d1426eea25ada165af8bd9',
> > > > > > 'refs/heads/zlib127': '67e474d6020f3ed3c20bde1d905f9fc53273416f',
> > > > > > 'refs/heads/clearMesh': '6be76b1b21216485557d5cc1356be321ac761864',
> > > > > > 'refs/heads/safestring':
> > '9de8332077b1b13acb6c40c52479dde51f6d88df',
> > > > > > 'refs/heads/master': '8355b00050696f4ddaaf13bf8ec721b3cf8b08e2',
> > > > > > 'refs/heads/shaderfixes':
> > 'f64acadc1c0ef4b6cfe6ff1e43c61b22bc216673'}
> > > >
> > > >
> > > > > So some things I notice:
> > > > > - my generate_pack_contents function is never called.
> > > > > - refs/heads/bullet279 is set to the value listed as ZERO_SHA1 in the
> > > > > dulwich source in the return of my "determine_wants" function.
> > > > > - The value returned by send_pack seems to be equal to the value
> > returned
> > > > > by my determine_wants function, indicating I succeeded.
> > > >
> > > > > However after running I check my test repository
> > > > > https://github.com/mcclure/backup-Polycode in a web browser, and in
> > the
> > > > web
> > > > > browser it says bullet279 is still present and pointing to b13f9.
> > > >
> > > > > Have I done anything wrong here?
> > > >
> > > > > "determine_wants() receives a dictionary of refs (refs as keys, the
> > SHA1
> > > > > they references as value) and should return a list of heads that you
> > > > would
> > > > > like to see fetched."
> > > >
> > > > > In the case of send_pack, does this change to "a list of heads that
> > you
> > > > > would like to see written"?
> > > >
> > > > > Thanks.
> > > >
> > > > > (Jelmer, I'm sorry, I originally hit "reply" instead of "reply-all",
> > so
> > > > you
> > > > > will get two copies of this message.)
> > > >
> > > > > On Sat, Jul 7, 2012 at 4:31 AM, Jelmer Vernooij <jelmer@xxxxxxxxx>
> > > > wrote:
> > > >
> > > > > > On Thu, Jul 05, 2012 at 12:51:09AM -0700, Andi McClure wrote:
> > > > > > > Thanks! What I'm personally trying to do is interface with
> > Github. I
> > > > > > don't
> > > > > > > know what extensions they do or don't support.
> > > > > > They support delete-refs.
> > > >
> > > > > > > So, I'm not sure I understand what to do here. ZERO_SHA1 is just
> > 160
> > > > bits
> > > > > > > of 0x00, right? I tried this and it didn't seem to work. What I'm
> > > > doing
> > > > > > is
> > > > > > > again, the "changed" function which is my second argument to
> > > > send_pack,
> > > > > > > when this function is called it gets in a mapping of all git
> > > > repository
> > > > > > > heads to their corresponding git shas, I change the value
> > associated
> > > > with
> > > > > > > (for example) "refs/heads/bullet279" in this dictionary to
> > ("00"*20)
> > > > and
> > > > > > > return the modified dictionary. As far as I can tell (?)
> > returning
> > > > this
> > > > > > > dictionary rewrites what all the ref names point to during the
> > > > pack-- the
> > > > > > > only point of the generate_pack_contents on the other hand seems
> > (?)
> > > > to
> > > > > > be
> > > > > > > to return object files given a sha (the shas returned by
> > > > > > > determine_wants??). However when I set one of these to the
> > > > > > 20-bytes-of-zero
> > > > > > > hash and return it, it appears to have no effect on the Github
> > side.
> > > > I
> > > > > > > don't get an error or anything, just... nothing happens. Any idea
> > > > what I
> > > > > > > might be doing wrong, or how to debug this further? I'm using
> > Dulwich
> > > > > > 0.8.2.
> > > > > > What do you mean exactly when you say it doesn't work? The ref
> > doesn't
> > > > > > go away, or it simply gets its value set to the ZERO_SHA1?
> > > >
> > > > > > > By the way, there might be room for improvement in the
> > documentation
> > > > > > here.
> > > > > > > If you look at the GitClient documentation:
> > > >
> > > > > >
> > > >
> > http://www.samba.org/~jelmer/dulwich/apidocs/dulwich.client.GitClient.html#send_pack
> > > > > > > send_pack does not have its "determine_wants" argument
> > documented at
> > > > all.
> > > > > > > The fetch() method documents an argument by that name with
> > "Optional
> > > > > > > function to determine what refs to fetch", but this doesn't seem
> > to
> > > > > > answer
> > > > > > > questions like, what are the arguments to this optional function
> > and
> > > > what
> > > > > > > does it return? The description of the generate_pack_contents
> > > > argument of
> > > > > > > send_pack is similarly vague in terms of what this function
> > takes as
> > > > an
> > > > > > > argument and what it returns (I'm afraid I'm misunderstanding
> > what it
> > > > > > does
> > > > > > > completely...).
> > > > > > determine_wants() receives a dictionary of refs (refs as keys, the
> > > > > > SHA1 they references as value) and should return a list of heads
> > that
> > > > > > you would like to see fetched.
> > > >
> > > > > > Patches to improve the documentation are very much welcome.
> > > >
> > > > > > Cheers,
> > > >
> > > > > > Jelmer
> > > >
> > > >
> > > > > > > On Wed, Jul 4, 2012 at 3:34 PM, Jelmer Vernooij <
> > jelmer@xxxxxxxxx>
> > > > > > wrote:
> > > >
> > > > > > > > On Tue, Jul 03, 2012 at 11:04:30PM -0700, Andi McClure wrote:
> > > > > > > > > Hello, I am trying to patch the "hg-git" project, which is
> > based
> > > > on
> > > > > > > > > Dulwich. I do not understand very much about what I am doing
> > and
> > > > am
> > > > > > > > mostly
> > > > > > > > > working by studying the surrounding code. What I am trying
> > to do
> > > > is
> > > > > > add a
> > > > > > > > > feature where I delete a remote branch by name.
> > > >
> > > > > > > > > As far as I can tell, the way I'm meant to communicate with
> > the
> > > > > > server is
> > > > > > > > > to call
> > > > > > > > > client.send_pack(path, changed, genpack)
> > > > > > > > > where client is a GitClient object, path is the appropriate
> > git
> > > > path,
> > > > > > > > > "changed" is a method taking a dictionary of branch-name
> > > > > > > > > ->branch-points-to-rev and returning a new dictionary
> > describing
> > > > > > same,
> > > > > > > > and
> > > > > > > > > "genpack" is
> > > > > > dulwich.object_store.BaseObjectStore.generate_pack_contents.
> > > > > > > > > The existing hg-git code uses this interface to upload
> > objects
> > > > and
> > > > > > assign
> > > > > > > > > refs.
> > > >
> > > > > > > > > How can I use the GitClient object to *delete* a ref, though?
> > > > > > > > You should be able to do this by setting a particular ref to
> > the
> > > > > > > > ZERO_SHA1.
> > > >
> > > > > > > > Note that the server has to support the 'delete-refs'
> > capability
> > > > for
> > > > > > > > this to work.
> > > >
> > > > > > > > Cheers,
> > > >
> > > > > > > > Jelmer
> > > >
> > > >
> > > >
> > > > --
> > > >
> >