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9 commits

Author SHA1 Message Date
Jeff King
179776f9e6 upload-pack: accept only a single packfile-uri line
When we see a packfile-uri line from the client, we use
string_list_split() to split it on commas and store the result in a
string_list.  A single packfile-uri line is therefore limited to storing
~64kb, the size of a pkt-line.

But we'll happily accept multiple such lines, and each line appends to
the string list, growing without bound.

In theory this could be useful, making:

  0017packfile-uris http
  0018packfile-uris https

equivalent to:

  001dpackfile-uris http,https

But the protocol documentation doesn't indicate that this should work
(and indeed, refers to this in the singular as "the following argument
can be included in the client's request"). And the client-side
implementation in fetch-pack has always sent a single line (JGit appears
to understand the line on the server side but has no client-side
implementation, and libgit2 understands neither).

If we were worried about compatibility, we could instead just put a
limit on the maximum number of values we'd accept. The current client
implementation limits itself to only two values: "http" and "https", so
something like "256" would be more than enough. But accepting only a
single line seems more in line with the protocol documentation, and
matches other parts of the protocol (e.g., we will not accept a second
"filter" line).

We'll also make this more explicit in the protocol documentation; as
above, I think this was always the intent, but there's no harm in making
it clear.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-02-28 14:42:01 -08:00
Jeff King
b065063c57 upload-pack: use a strmap for want-ref lines
When the "ref-in-want" capability is advertised (which it is not by
default), then upload-pack processes a "want-ref" line from the client
by checking that the name is a valid ref and recording it in a
string-list.

In theory this list should grow no larger than the number of refs in the
server-side repository. But since we don't do any de-duplication, a
client which sends "want-ref refs/heads/foo" over and over will cause
the array to grow without bound.

We can fix this by switching to strmap, which efficiently detects
duplicates. There are two client-visible changes here:

  1. The "wanted-refs" response will now be in an apparently-random
     order (based on iterating the hashmap) rather than the order given
     by the client. The protocol documentation is quiet on ordering
     here. The current fetch-pack implementation is happy with any
     order, as it looks up each returned ref using a binary search in
     its local sorted list. JGit seems to implement want-ref on the
     server side, but has no client-side support. libgit2 doesn't
     support either side.

     It would obviously be possible to record the original order or to
     use the strmap as an auxiliary data structure. But if the client
     doesn't care, we may as well do the simplest thing.

  2. We'll now reject duplicates explicitly as a protocol error. The
     client should never send them (and our current implementation, even
     when asked to "git fetch master:one master:two" will de-dup on the
     client side).

     If we wanted to be more forgiving, we could perhaps just throw away
     the duplicates. But then our "wanted-refs" response back to the
     client would omit the duplicates, and it's hard to say what a
     client that accidentally sent a duplicate would do with that. So I
     think we're better off to complain loudly before anybody
     accidentally writes such a client.

Let's also add a note to the protocol documentation clarifying that
duplicates are forbidden. As discussed above, this was already the
intent, but it's not very explicit.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2024-02-28 14:42:01 -08:00
Jean-Noël Avila
2162f9f6f8 doc: enforce dashes in placeholders
The CodingGuidelines documents stipulates that multi-word placeholders
are to be separated by dashes, not underscores nor spaces.

Signed-off-by: Jean-Noël Avila <jn.avila@free.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-12-26 11:06:55 -08:00
Elijah Newren
8936352242 documentation: add missing words
Diff best viewed with --color-diff.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-10-09 12:06:29 -07:00
Andrei Rybak
b39a84185e *: fix typos which duplicate a word
Fix typos in code comments which repeat various words.  Most of the
cases are simple in that they repeat a word that usually cannot be
repeated in a grammatically correct sentence.  Just remove the
incorrectly duplicated word in these cases and rewrap text, if needed.

A tricky case is usage of "that that", which is sometimes grammatically
correct.  However, an instance of this in "t7527-builtin-fsmonitor.sh"
doesn't need two words "that", because there is only one daemon being
discussed, so replace the second "that" with "the".

Reword code comment "entries exist on on-disk index" in function
update_one in file cache-tree.c, by replacing incorrect preposition "on"
with "in".

Signed-off-by: Andrei Rybak <rybak.a.v@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-01-08 10:28:34 +09:00
Ævar Arnfjörð Bjarmason
8b8d9a2298 protocol v2: add server-side "bundle-uri" skeleton
Add a skeleton server-side implementation of a new "bundle-uri" command
to protocol v2. This will allow conforming clients to optionally seed
their initial clones or incremental fetches from URLs containing
"*.bundle" files created with "git bundle create".

This change only performs the basic boilerplate of advertising a new
protocol v2 capability. The new 'bundle-uri' capability allows a client
to request a list of bundles. Right now, the server only returns a flush
packet, which corresponds to an empty advertisement. The bundle.* config
namespace describes which key-value pairs will be communicated across
this interface in future updates.

The critical bit right now is that the new boolean
uploadPack.adverstiseBundleURIs config value signals whether or not this
capability should be advertised at all.

An earlier version of this patch [1] used a different transfer format
than the "key=value" pairs in the current implementation. The change was
made to unify the protocol v2 command with the bundle lists provided by
independent bundle servers. Further, the standard allows for the server
to advertise a URI that contains a bundle list. This allows users
automatically discovering bundle providers that are loosely associated
with the origin server, but without the origin server knowing exactly
which bundles are currently available.

[1] https://lore.kernel.org/git/RFC-patch-v2-01.13-2fc87ce092b-20220311T155841Z-avarab@gmail.com/

The very-deep headings needed to be modified to stop at level 4 due to
documentation build issues. These were not recognized in earlier builds
since the file was previously in the Documentation/technical/ directory
and was built in a different way. With its current location, the
heavily-nested details were causing build issues and they are now
replaced with a bulletted list of details.

Co-authored-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-12-25 16:24:23 +09:00
Todd Zullinger
086eaab8da docs: fix a few recently broken links
Some links were broken in the recent move of various technical docs
c0f6dd49f1 (Merge branch 'ab/tech-docs-to-help', 2022-08-14).

Fix them.

Signed-off-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-09-16 08:38:03 -07:00
Ævar Arnfjörð Bjarmason
1e2320161d docs: move http-protocol docs to man section 5
Continue the move of existing Documentation/technical/* protocol and
file-format documentation into our main documentation space by moving
the http-protocol.txt documentation over. I'm renaming it to
"protocol-http" to be consistent with other things in the new
gitformat-protocol-* namespace.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-04 14:12:24 -07:00
Ævar Arnfjörð Bjarmason
5db921054e docs: move protocol-related docs to man section 5
Continue the move of existing Documentation/technical/* protocol and
file-format documentation into our main documentation space. By moving
the things that discuss the protocol we can properly link from
e.g. lsrefs.unborn and protocol.version documentation to a manpage we
build by default.

So far we have been using the "gitformat-" prefix for the
documentation we've been moving over from Documentation/technical/*,
but for protocol documentation let's use "gitprotocol-*".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-08-04 14:12:23 -07:00
Renamed from Documentation/technical/protocol-v2.txt (Browse further)