In git-fetch, --depth argument is always relative with the latest
remote refs. This makes it a bit difficult to cover this use case,
where the user wants to make the shallow history, say 3 levels
deeper. It would work if remote refs have not moved yet, but nobody
can guarantee that, especially when that use case is performed a
couple months after the last clone or "git fetch --depth". Also,
modifying shallow boundary using --depth does not work well with
clones created by --since or --not.
This patch fixes that. A new argument --deepen=<N> will add <N> more (*)
parent commits to the current history regardless of where remote refs
are.
Have/Want negotiation is still respected. So if remote refs move, the
server will send two chunks: one between "have" and "want" and another
to extend shallow history. In theory, the client could send no "want"s
in order to get the second chunk only. But the protocol does not allow
that. Either you send no want lines, which means ls-remote; or you
have to send at least one want line that carries deep-relative to the
server..
The main work was done by Dongcan Jiang. I fixed it up here and there.
And of course all the bugs belong to me.
(*) We could even support --deepen=<N> where <N> is negative. In that
case we can cut some history from the shallow clone. This operation
(and --depth=<shorter depth>) does not require interaction with remote
side (and more complicated to implement as a result).
Helped-by: Duy Nguyen <pclouds@gmail.com>
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Dongcan Jiang <dongcan.jiang@gmail.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This should allow the user to say "create a shallow clone of this branch
after version <some-tag>".
Short refs are accepted and expanded at the server side with expand_ref()
because we cannot expand (unknown) refs from the client side.
Like deepen-since, deepen-not cannot be used with deepen. But deepen-not
can be mixed with deepen-since. The result is exactly how you do the
command "git rev-list --since=... --not ref".
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This should allow the user to say "create a shallow clone containing the
work from last year" (once the client side is fixed up, of course).
In theory deepen-since and deepen (aka --depth) can be used together to
draw the shallow boundary (whether it's intersection or union is up to
discussion, but if rev-list is used, it's likely intersection). However,
because deepen goes with a custom commit walker, we can't mix the two
yet.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
On error check_non_tip() will die and not closing file descriptors is no
big deal. The next patch will split the majority of this function out
for reuse in other cases, where die() may not be the only outcome. Same
story for popping SIGPIPE out of the signal chain. So let's make sure we
clean things up properly first.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Also add some more comments in this code because it takes too long to
understand what it does (to me, who should be familiar enough to
understand this code well!)
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
After the last patch, "result" and "backup" are the same. "result" used
to move, but the movement is now contained in send_shallow(). Delete
this redundant variable.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is a prep step for further refactoring. Besides reindentation and
s/shallows\./shallows->/g, no other changes are expected.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When upload-pack serves a client request, it turns to
pack-objects to do the heavy lifting of creating a
packfile. There's no easy way to intercept the call to
pack-objects, but there are a few good reasons to want to do
so:
1. If you're debugging a client or server issue with
fetching, you may want to store a copy of the generated
packfile.
2. If you're gathering data from real-world fetches for
performance analysis or debugging, storing a copy of
the arguments and stdin lets you replay the pack
generation at your leisure.
3. You may want to insert a caching layer around
pack-objects; it is the most CPU- and memory-intensive
part of serving a fetch, and its output is a pure
function[1] of its input, making it an ideal place to
consolidate identical requests.
This patch adds a simple "hook" interface to intercept calls
to pack-objects. The new test demonstrates how it can be
used for debugging (using it for caching is a
straightforward extension; the tricky part is writing the
actual caching layer).
This hook is unlike the normal hook scripts found in the
"hooks/" directory of a repository. Because we promise that
upload-pack is safe to run in an untrusted repository, we
cannot execute arbitrary code or commands found in the
repository (neither in hooks/, nor in the config). So
instead, this hook is triggered from a config variable that
is explicitly ignored in the per-repo config.
The config variable holds the actual shell command to run as
the hook. Another approach would be to simply treat it as a
boolean: "should I respect the upload-pack hooks in this
repo?", and then run the script from "hooks/" as we usually
do. However, that isn't as flexible; there's no way to run a
hook approved by the site administrator (e.g., in
"/etc/gitconfig") on a repository whose contents are not
trusted. The approach taken by this patch is more
fine-grained, if a little less conventional for git hooks
(it does behave similar to other configured commands like
diff.external, etc).
[1] Pack-objects isn't _actually_ a pure function. Its
output depends on the exact packing of the object
database, and if multi-threading is used for delta
compression, can even differ racily. But for the
purposes of caching, that's OK; of the many possible
outputs for a given input, it is sufficient only that we
output one of them.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use the parse-options API rather than a hand-rolled option parser.
Description for --stateless-rpc and --advertise-refs come from
42526b4 (Add stateless RPC options to upload-pack,
receive-pack, 2009-10-30).
Signed-off-by: Antoine Queru <antoine.queru@grenoble-inp.org>
Signed-off-by: Matthieu Moy <matthieu.moy@grenoble-inp.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The code for warning_errno/die_errno has been refactored and a new
error_errno() reporting helper is introduced.
* nd/error-errno: (41 commits)
wrapper.c: use warning_errno()
vcs-svn: use error_errno()
upload-pack.c: use error_errno()
unpack-trees.c: use error_errno()
transport-helper.c: use error_errno()
sha1_file.c: use {error,die,warning}_errno()
server-info.c: use error_errno()
sequencer.c: use error_errno()
run-command.c: use error_errno()
rerere.c: use error_errno() and warning_errno()
reachable.c: use error_errno()
mailmap.c: use error_errno()
ident.c: use warning_errno()
http.c: use error_errno() and warning_errno()
grep.c: use error_errno()
gpg-interface.c: use error_errno()
fast-import.c: use error_errno()
entry.c: use error_errno()
editor.c: use error_errno()
diff-no-index.c: use error_errno()
...
Use the argv_array in the child_process structure, to avoid having to
manually maintain an array size.
Signed-off-by: Michael Procter <michael@procter.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert all instances of get_object_hash to use an appropriate reference
to the hash member of the oid member of struct object. This provides no
functional change, as it is essentially a macro substitution.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Jeff King <peff@peff.net>
struct object is one of the major data structures dealing with object
IDs. Convert it to use struct object_id instead of an unsigned char
array. Convert get_object_hash to refer to the new member as well.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Jeff King <peff@peff.net>
Convert most instances where the sha1 member of struct object is
dereferenced to use get_object_hash. Most instances that are passed to
functions that have versions taking struct object_id, such as
get_sha1_hex/get_oid_hex, or instances that can be trivially converted
to use struct object_id instead, are not converted.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Jeff King <peff@peff.net>
In addition to matching stripped refs, one can now add hideRefs
patterns that the full (unstripped) ref is matched against. To
distinguish between stripped and full matches, those new patterns
must be prefixed with a circumflex (^).
This commit also removes support for the undocumented and unintended
hideRefs settings ".have" (suppressing all "have" lines) and
"capabilities^{}" (suppressing the capabilities line).
Signed-off-by: Lukas Fleischer <lfleischer@lfos.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make hideRefs handling in upload-pack consistent with the behavior
described in the documentation by stripping refs before comparing them
with prefixes in hideRefs.
Signed-off-by: Lukas Fleischer <lfleischer@lfos.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Instead of open-coding the function pop_commit() just call it. This
makes the intent clearer and reduces code size.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
for_each_ref() callback functions were taught to name the objects
not with "unsigned char sha1[20]" but with "struct object_id".
* bc/object-id: (56 commits)
struct ref_lock: convert old_sha1 member to object_id
warn_if_dangling_symref(): convert local variable "junk" to object_id
each_ref_fn_adapter(): remove adapter
rev_list_insert_ref(): remove unneeded arguments
rev_list_insert_ref_oid(): new function, taking an object_oid
mark_complete(): remove unneeded arguments
mark_complete_oid(): new function, taking an object_oid
clear_marks(): rewrite to take an object_id argument
mark_complete(): rewrite to take an object_id argument
send_ref(): convert local variable "peeled" to object_id
upload-pack: rewrite functions to take object_id arguments
find_symref(): convert local variable "unused" to object_id
find_symref(): rewrite to take an object_id argument
write_one_ref(): rewrite to take an object_id argument
write_refs_to_temp_dir(): convert local variable sha1 to object_id
submodule: rewrite to take an object_id argument
shallow: rewrite functions to take object_id arguments
handle_one_ref(): rewrite to take an object_id argument
add_info_ref(): rewrite to take an object_id argument
handle_one_reflog(): rewrite to take an object_id argument
...
"git upload-pack" that serves "git fetch" can be told to serve
commits that are not at the tip of any ref, as long as they are
reachable from a ref, with uploadpack.allowReachableSHA1InWant
configuration variable.
* fm/fetch-raw-sha1:
upload-pack: optionally allow fetching reachable sha1
upload-pack: prepare to extend allow-tip-sha1-in-want
config.txt: clarify allowTipSHA1InWant with camelCase
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change typedef each_ref_fn to take a "const struct object_id *oid"
parameter instead of "const unsigned char *sha1".
To aid this transition, implement an adapter that can be used to wrap
old-style functions matching the old typedef, which is now called
"each_ref_sha1_fn"), and make such functions callable via the new
interface. This requires the old function and its cb_data to be
wrapped in a "struct each_ref_fn_sha1_adapter", and that object to be
used as the cb_data for an adapter function, each_ref_fn_adapter().
This is an enormous diff, but most of it consists of simple,
mechanical changes to the sites that call any of the "for_each_ref"
family of functions. Subsequent to this change, the call sites can be
rewritten one by one to use the new interface.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
With uploadpack.allowReachableSHA1InWant configuration option set on the
server side, "git fetch" can make a request with a "want" line that names
an object that has not been advertised (likely to have been obtained out
of band or from a submodule pointer). Only objects reachable from the
branch tips, i.e. the union of advertised branches and branches hidden by
transfer.hideRefs, will be processed. Note that there is an associated
cost of having to walk back the history to check the reachability.
This feature can be used when obtaining the content of a certain commit,
for which the sha1 is known, without the need of cloning the whole
repository, especially if a shallow fetch is used. Useful cases are e.g.
repositories containing large files in the history, fetching only the
needed data for a submodule checkout, when sharing a sha1 without telling
which exact branch it belongs to and in Gerrit, if you think in terms of
commits instead of change numbers. (The Gerrit case has already been
solved through allowTipSHA1InWant as every Gerrit change has a ref.)
Signed-off-by: Fredrik Medley <fredrik.medley@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To allow future extensions, e.g. allowing non-tip sha1, replace the
boolean allow_tip_sha1_in_want variable with the flag-style
allow_request_with_bare_object_name variable.
Signed-off-by: Fredrik Medley <fredrik.medley@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Identify parts of the code that knows that we use SHA-1 hash to
name our objects too much, and use (1) symbolic constants instead
of hardcoded 20 as byte count and/or (2) use struct object_id
instead of unsigned char [20] for object names.
* bc/object-id:
apply: convert threeway_stage to object_id
patch-id: convert to use struct object_id
commit: convert parts to struct object_id
diff: convert struct combine_diff_path to object_id
bulk-checkin.c: convert to use struct object_id
zip: use GIT_SHA1_HEXSZ for trailers
archive.c: convert to use struct object_id
bisect.c: convert leaf functions to use struct object_id
define utility functions for object IDs
define a structure for object IDs
The transfer.hiderefs support did not quite work for smart-http
transport.
* jk/smart-http-hide-refs:
upload-pack: do not check NULL return of lookup_unknown_object
upload-pack: fix transfer.hiderefs over smart-http
Convert struct commit_graft and necessary local parts of commit.c.
Also, convert several constants based on the hex length of an SHA-1 to
use GIT_SHA1_HEXSZ, and move several magic constants into variables for
readability.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We check whether the return value of lookup_unknown_object
is NULL, but some code paths dereference it before our
check. This turns out not to be capable of causing a
segfault, though. The lookup_unknown_object function will
never return NULL, since the whole point is to allocate an
object struct if it does not find an existing one. So the
code here is not wrong, it is just confusing. Let's just
drop the NULL check.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When upload-pack advertises the refs (either for a normal,
non-stateless request, or for the initial contact in a
stateless one), we call for_each_ref with the send_ref
function as its callback. send_ref, in turn, calls
mark_our_ref, which checks whether the ref is hidden, and
sets OUR_REF or HIDDEN_REF on the object as appropriate. If
it is hidden, mark_our_ref also returns "1" to signal
send_ref that the ref should not be advertised.
If we are not advertising refs, (i.e., the follow-up
invocation by an http client to send its "want" lines), we
use mark_our_ref directly as a callback to for_each_ref. Its
marking does the right thing, but when it then returns "1"
to for_each_ref, the latter interprets this as an error and
stops iterating. As a result, we skip marking all of the
refs that come lexicographically after it. Any "want" lines
from the client asking for those objects will fail, as they
were not properly marked with OUR_REF.
To solve this, we introduce a wrapper callback around
mark_our_ref which always returns 0 (even if the ref is
hidden, we want to keep iterating). We also tweak the
signature of mark_our_ref to exclude unnecessary parameters
that were present only to conform to the callback interface.
This should make it less likely for somebody to accidentally
use it as a callback in the future.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When fetching into or pushing from a shallow repository, we want to
aggressively mark edges as uninteresting, since this decreases the pack
size. However, aggressively marking edges can negatively affect
performance on large non-shallow repositories with lots of refs.
Teach pack-objects a --shallow option to indicate that we're pushing
from or fetching into a shallow repository. Use
--objects-edge-aggressive only for shallow repositories and otherwise
use --objects-edge, which performs better in the general case. Update
the callers to pass the --shallow option when they are dealing with a
shallow repository.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
resolve_ref_unsafe takes a boolean argument for reading (a nonexistent ref
resolves successfully for writing but not for reading). Change this to be
a flags field instead, and pass the new constant RESOLVE_REF_READING when
we want this behaviour.
While at it, swap two of the arguments in the function to put output
arguments at the end. As a nice side effect, this ensures that we can
catch callers that were unaware of the new API so they can be audited.
Give the wrapper functions resolve_refdup and read_ref_full the same
treatment for consistency.
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We used to pass -1000 to poll(2), expecting it to also mean "no
timeout", which should be spelled as -1.
* et/spell-poll-infinite-with-minus-one-only:
upload-pack: keep poll(2)'s timeout to -1
Keep poll's timeout at -1 when uploadpack.keepalive = 0, instead of
setting it to -1000, since some pedantic old systems (eg HP-UX) and
the gnulib compat/poll will treat only -1 as the valid value for
an infinite timeout.
Signed-off-by: Edward Thomson <ethomson@microsoft.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Most struct child_process variables are cleared using memset first after
declaration. Provide a macro, CHILD_PROCESS_INIT, that can be used to
initialize them statically instead. That's shorter, doesn't require a
function call and is slightly more readable (especially given that we
already have STRBUF_INIT, ARGV_ARRAY_INIT etc.).
Helped-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Attempts to show where a single-strand-of-pearls break in "git log"
output.
* nd/log-show-linear-break:
log: add --show-linear-break to help see non-linear history
object.h: centralize object flag allocation
While the field "flags" is mainly used by the revision walker, it is
also used in many other places. Centralize the whole flag allocation to
one place for a better overview (and easier to move flags if we have
too).
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Serving objects from a shallow repository needs to write a
temporary file to be used, but the serving upload-pack may not have
write access to the repository which is meant to be read-only.
Instead feed these temporary shallow bounds from the standard input
of pack-objects so that we do not have to use a temporary file.
* nd/upload-pack-shallow:
upload-pack: send shallow info over stdin to pack-objects
Serving objects from a shallow repository needs to write a
new file to hold the temporary shallow boundaries but it was not
cleaned when we exit due to die() or a signal.
* jk/shallow-update-fix:
shallow: verify shallow file after taking lock
shallow: automatically clean up shallow tempfiles
shallow: use stat_validity to check for up-to-date file
Before cdab485 (upload-pack: delegate rev walking in shallow fetch to
pack-objects - 2013-08-16) upload-pack does not write to the source
repository. cdab485 starts to write $GIT_DIR/shallow_XXXXXX if it's a
shallow fetch, so the source repo must be writable.
git:// servers do not need write access to repos and usually don't
have it, which means cdab485 breaks shallow clone over git://
Instead of using a temporary file as the media for shallow points, we
can send them over stdin to pack-objects as well. Prepend shallow
SHA-1 with --shallow so pack-objects knows what is what.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We sometimes write tempfiles of the form "shallow_XXXXXX"
during fetch/push operations with shallow repositories.
Under normal circumstances, we clean up the result when we
are done. However, we do no take steps to clean up after
ourselves when we exit due to die() or signal death.
This patch teaches the tempfile creation code to register
handlers to clean up after ourselves. To handle this, we
change the ownership semantics of the filename returned by
setup_temporary_shallow. It now keeps a copy of the filename
itself, and returns only a const pointer to it.
We can also do away with explicit tempfile removal in the
callers. They all exit not long after finishing with the
file, so they can rely on the auto-cleanup, simplifying the
code.
Note that we keep things simple and maintain only a single
filename to be cleaned. This is sufficient for the current
caller, but we future-proof it with a die("BUG").
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The semantics of this flag was changed in commit
e1111cef23 inline lookup_replace_object() calls
but wasn't renamed at the time to minimize code churn. Rename it now,
and add a comment explaining its use.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fetching from a shallow-cloned repository used to be forbidden,
primarily because the codepaths involved were not carefully vetted
and we did not bother supporting such usage. This attempts to allow
object transfer out of a shallow-cloned repository in a controlled
way (i.e. the receiver become a shallow repository with truncated
history).
* nd/shallow-clone: (31 commits)
t5537: fix incorrect expectation in test case 10
shallow: remove unused code
send-pack.c: mark a file-local function static
git-clone.txt: remove shallow clone limitations
prune: clean .git/shallow after pruning objects
clone: use git protocol for cloning shallow repo locally
send-pack: support pushing from a shallow clone via http
receive-pack: support pushing to a shallow clone via http
smart-http: support shallow fetch/clone
remote-curl: pass ref SHA-1 to fetch-pack as well
send-pack: support pushing to a shallow clone
receive-pack: allow pushes that update .git/shallow
connected.c: add new variant that runs with --shallow-file
add GIT_SHALLOW_FILE to propagate --shallow-file to subprocesses
receive/send-pack: support pushing from a shallow clone
receive-pack: reorder some code in unpack()
fetch: add --update-shallow to accept refs that update .git/shallow
upload-pack: make sure deepening preserves shallow roots
fetch: support fetching from a shallow repository
clone: support remote shallow repository
...
Remove a few duplicate implementations of prefix/suffix comparison
functions, and rename them to starts_with and ends_with.
* cc/starts-n-ends-with:
replace {pre,suf}fixcmp() with {starts,ends}_with()
strbuf: introduce starts_with() and ends_with()
builtin/remote: remove postfixcmp() and use suffixcmp() instead
environment: normalize use of prefixcmp() by removing " != 0"
When "fetch --depth=N" where N exceeds the longest chain of history in
the source repo, usually we just send an "unshallow" line to the
client so full history is obtained.
When the source repo is shallow we need to make sure to "unshallow"
the current shallow point _and_ "shallow" again when the commit
reaches its shallow bottom in the source repo.
This should fix both cases: large <N> and --unshallow.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If either receive-pack or upload-pack is called on a shallow
repository, shallow commits (*) will be sent after the ref
advertisement (but before the packet flush), so that the receiver has
the full "shape" of the sender's commit graph. This will be needed for
the receiver to update its .git/shallow if necessary.
This breaks the protocol for all clients trying to push to a shallow
repo, or fetch from one. Which is basically the same end result as
today's "is_repository_shallow() && die()" in receive-pack and
upload-pack. New clients will be made aware of shallow upstream and
can make use of this information.
The sender must send all shallow commits that are sent in the
following pack. It may send more shallow commits than necessary.
upload-pack for example may choose to advertise no shallow commits if
it knows in advance that the pack it's going to send contains no
shallow commits. But upload-pack is the server, so we choose the
cheaper way, send full .git/shallow and let the client deal with it.
Smart HTTP is not affected by this patch. Shallow support on
smart-http comes later separately.
(*) A shallow commit is a commit that terminates the revision
walker. It is usually put in .git/shallow in order to keep the
revision walker from going out of bound because there is no
guarantee that objects behind this commit is available.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Leaving only the function definitions and declarations so that any
new topic in flight can still make use of the old functions, replace
existing uses of the prefixcmp() and suffixcmp() with new API
functions.
The change can be recreated by mechanically applying this:
$ git grep -l -e prefixcmp -e suffixcmp -- \*.c |
grep -v strbuf\\.c |
xargs perl -pi -e '
s|!prefixcmp\(|starts_with\(|g;
s|prefixcmp\(|!starts_with\(|g;
s|!suffixcmp\(|ends_with\(|g;
s|suffixcmp\(|!ends_with\(|g;
'
on the result of preparatory changes in this series.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* jk/robustify-parse-commit:
checkout: do not die when leaving broken detached HEAD
use parse_commit_or_die instead of custom message
use parse_commit_or_die instead of segfaulting
assume parse_commit checks for NULL commit
assume parse_commit checks commit->object.parsed
log_tree_diff: die when we fail to parse a commit
Hotfix for recent regression while talking to upload-pack
in a repository with many symbolic refs.
* maint:
Revert "upload-pack: send non-HEAD symbolic refs"
This reverts commit 5e7dcad771cb873e278a0571b46910d7c32e2f6c; there
may be unbounded number of symbolic refs in the repository, but the
capability header line in the on-wire protocol has a rather low
length limit.
One long-standing flaw in the pack transfer protocol used by "git
clone" was that there was no way to tell the other end which branch
"HEAD" points at, and the receiving end needed to guess. A new
capability has been defined in the pack protocol to convey this
information so that cloning from a repository with more than one
branches pointing at the same commit where the HEAD is at now
reliably sets the initial branch in the resulting repository.
* jc/upload-pack-send-symref:
t5570: Update for clone-progress-to-stderr branch
t5570: Update for symref capability
clone: test the new HEAD detection logic
connect: annotate refs with their symref information in get_remote_head()
connect.c: make parse_feature_value() static
upload-pack: send non-HEAD symbolic refs
upload-pack: send symbolic ref information as capability
upload-pack.c: do not pass confusing cb_data to mark_our_ref()
t5505: fix "set-head --auto with ambiguous HEAD" test
One long-standing flaw in the pack transfer protocol used by "git
clone" was that there was no way to tell the other end which branch
"HEAD" points at, and the receiving end needed to guess. A new
capability has been defined in the pack protocol to convey this
information so that cloning from a repository with more than one
branches pointing at the same commit where the HEAD is at now
reliably sets the initial branch in the resulting repository.
* jc/upload-pack-send-symref:
t5570: Update for clone-progress-to-stderr branch
t5570: Update for symref capability
clone: test the new HEAD detection logic
connect: annotate refs with their symref information in get_remote_head()
connect.c: make parse_feature_value() static
upload-pack: send non-HEAD symbolic refs
upload-pack: send symbolic ref information as capability
upload-pack.c: do not pass confusing cb_data to mark_our_ref()
t5505: fix "set-head --auto with ambiguous HEAD" test
Many calls to parse_commit detect errors and die. In some
cases, the custom error messages are more useful than what
parse_commit_or_die could produce, because they give some
context, like which ref the commit came from. Some, however,
just say "invalid commit". Let's convert the latter to use
parse_commit_or_die; its message is slightly more informative,
and it makes the error more consistent throughout git.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When there is no sufficient overlap between old and new history
during a "git fetch" into a shallow repository, objects that the
sending side knows the receiving end has were unnecessarily sent.
* nd/fetch-into-shallow:
Add testcase for needless objects during a shallow fetch
list-objects: mark more commits as edges in mark_edges_uninteresting
list-objects: reduce one argument in mark_edges_uninteresting
upload-pack: delegate rev walking in shallow fetch to pack-objects
shallow: add setup_temporary_shallow()
shallow: only add shallow graft points to new shallow file
move setup_alternate_shallow and write_shallow_commits to shallow.c
When running "fetch -q", a long silence while the sender side
computes the set of objects to send can be mistaken by proxies as
dropped connection. The server side has been taught to send a small
empty messages to keep the connection alive.
* jk/upload-pack-keepalive:
upload-pack: bump keepalive default to 5 seconds
upload-pack: send keepalive packets during pack computation
When there is no sufficient overlap between old and new history
during a fetch into a shallow repository, we unnecessarily sent
objects the sending side knows the receiving end has.
* nd/fetch-into-shallow:
Add testcase for needless objects during a shallow fetch
list-objects: mark more commits as edges in mark_edges_uninteresting
list-objects: reduce one argument in mark_edges_uninteresting
upload-pack: delegate rev walking in shallow fetch to pack-objects
shallow: add setup_temporary_shallow()
shallow: only add shallow graft points to new shallow file
move setup_alternate_shallow and write_shallow_commits to shallow.c
With the same mechanism as used to tell where "HEAD" points at to
the other end, we can tell the target of other symbolic refs as
well.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
One long-standing flaw in the pack transfer protocol was that there
was no way to tell the other end which branch "HEAD" points at.
With a capability "symref=HEAD:refs/heads/master", let the sender to
tell the receiver what symbolic ref points at what ref.
This capability can be repeated more than once to represent symbolic
refs other than HEAD, such as "refs/remotes/origin/HEAD").
Add an infrastructure to collect symbolic refs, format them as extra
capabilities and put it on the wire. For now, just send information
on the "HEAD" and nothing else.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The callee does not use cb_data, and the caller is an intermediate
function in a callchain that later wants to use the cb_data for its
own use. Clarify the code by breaking the dataflow explicitly by
not passing cb_data down to mark_our_ref().
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There is no reason not to turn on keepalives by default.
They take very little bandwidth, and significantly less than
the progress reporting they are replacing. And in the case
that progress reporting is on, we should never need to send
a keepalive anyway, as we will constantly be showing
progress and resetting the keepalive timer.
We do not necessarily know what the client's idea of a
reasonable timeout is, so let's keep this on the low side of
5 seconds. That is high enough that we will always prefer
our normal 1-second progress reports to sending a keepalive
packet, but low enough that no sane client should consider
the connection hung.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When upload-pack has started pack-objects, there may be a quiet
period while pack-objects prepares the pack (i.e., counting objects
and delta compression). Normally we would see (and send to the
client) progress information, but if "--quiet" is in effect,
pack-objects will produce nothing at all until the pack data is
ready. On a large repository, this can take tens of seconds (or even
minutes if the system is loaded or the repository is badly packed).
Clients or intermediate proxies can sometimes give up in this
situation, assuming that the server or connection has hung.
This patch introduces a "keepalive" option; if upload-pack sees no
data from pack-objects for a certain number of seconds, it will send
an empty sideband data packet to let the other side know that we are
still working on it.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
upload-pack has a special revision walking code for shallow
recipients. It works almost like the similar code in pack-objects
except:
1. in upload-pack, graft points could be added for deepening;
2. also when the repository is deepened, the shallow point will be
moved further away from the tip, but the old shallow point will be
marked as edge to produce more efficient packs. See 6523078 (make
shallow repository deepening more network efficient - 2009-09-03).
Pass the file to pack-objects via --shallow-file. This will override
$GIT_DIR/shallow and give pack-objects the exact repository shape
that upload-pack has.
mark edge commits by revision command arguments. Even if old shallow
points are passed as "--not" revisions as in this patch, they will not
be picked up by mark_edges_uninteresting() because this function looks
up to parents for edges, while in this case the edge is the children,
in the opposite direction. This will be fixed in an later patch when
all given uninteresting commits are marked as edges.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The definition of "struct ref" in "cache.h", a header file so
central to the system, always confused me. This structure is not
about the local ref used by sha1-name API to name local objects.
It is what refspecs are expanded into, after finding out what refs
the other side has, to define what refs are updated after object
transfer succeeds to what values. It belongs to "remote.h" together
with "struct refspec".
While we are at it, also move the types and functions related to the
Git transport connection to a new header file connect.h
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When the client sends a 'shallow' line for an object that the server does
not have, the server currently dies with the error: "did not find object
for shallow <obj-id>". The client may have truncated the history at
the commit by fetching shallowly from a different server, or the commit
may have been garbage collected by the server. In either case, this
unknown commit is not relevant for calculating the pack that is to be
sent and can be safely ignored, and it is not used when recomputing where
the updated history of the client is cauterised.
The documentation in technical/pack-protocol.txt has been updated to
remove the restriction that "Clients MUST NOT mention an obj-id which it
does not know exists on the server". This requirement is not realistic
because clients cannot know whether an object has been garbage collected
by the server.
Signed-off-by: Michael Heemskerk <mheemskerk@atlassian.com>
Reviewed-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Clean up pkt-line API, implementation and its callers to make them
more robust.
* jk/pkt-line-cleanup:
do not use GIT_TRACE_PACKET=3 in tests
remote-curl: always parse incoming refs
remote-curl: move ref-parsing code up in file
remote-curl: pass buffer straight to get_remote_heads
teach get_remote_heads to read from a memory buffer
pkt-line: share buffer/descriptor reading implementation
pkt-line: provide a LARGE_PACKET_MAX static buffer
pkt-line: move LARGE_PACKET_MAX definition from sideband
pkt-line: teach packet_read_line to chomp newlines
pkt-line: provide a generic reading function with options
pkt-line: drop safe_write function
pkt-line: move a misplaced comment
write_or_die: raise SIGPIPE when we get EPIPE
upload-archive: use argv_array to store client arguments
upload-archive: do not copy repo name
send-pack: prefer prefixcmp over memcmp in receive_status
fetch-pack: fix out-of-bounds buffer offset in get_ack
upload-pack: remove packet debugging harness
upload-pack: do not add duplicate objects to shallow list
upload-pack: use get_sha1_hex to parse "shallow" lines
Recent optimization broke shallow clones.
* jk/peel-ref:
upload-pack: load non-tip "want" objects from disk
upload-pack: make sure "want" objects are parsed
upload-pack: drop lookup-before-parse optimization
Allows requests to fetch objects at any tip of refs (including
hidden ones). It seems that there may be use cases even outside
Gerrit (e.g. $gmane/215701).
* jc/fetch-raw-sha1:
fetch: fetch objects by their exact SHA-1 object names
upload-pack: optionally allow fetching from the tips of hidden refs
fetch: use struct ref to represent refs to be fetched
parse_fetch_refspec(): clarify the codeflow a bit
It is a long-time security feature that upload-pack will not
serve any "want" lines that do not correspond to the tip of
one of our refs. Traditionally, this was enforced by
checking the objects in the in-memory hash; they should have
been loaded and received the OUR_REF flag during the
advertisement.
The stateless-rpc mode, however, has a race condition here:
one process advertises, and another receives the want lines,
so the refs may have changed in the interim. To address
this, commit 051e400 added a new verification mode; if the
object is not OUR_REF, we set a "has_non_tip" flag, and then
later verify that the requested objects are reachable from
our current tips.
However, we still die immediately when the object is not in
our in-memory hash, and at this point we should only have
loaded our tip objects. So the check_non_tip code path does
not ever actually trigger, as any non-tip objects would
have already caused us to die.
We can fix that by using parse_object instead of
lookup_object, which will load the object from disk if it
has not already been loaded.
We still need to check that parse_object does not return
NULL, though, as it is possible we do not have the object
at all. A more appropriate error message would be "no such
object" rather than "not our ref"; however, we do not want
to leak information about what objects are or are not in
the object database, so we continue to use the same "not
our ref" message that would be produced by an unreachable
object.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When upload-pack receives a "want" line from the client, it
adds it to an object array. We call lookup_object to find
the actual object, which will only check for objects already
in memory. This works because we are expecting to find
objects that we already loaded during the ref advertisement.
We use the resulting object structs for a variety of
purposes. Some of them care only about the object flags, but
others care about the type of the object (e.g.,
ok_to_give_up), or even feed them to the revision parser
(when --depth is used), which assumes that objects it
receives are fully parsed.
Once upon a time, this was OK; any object we loaded into
memory would also have been parsed. But since 435c833
(upload-pack: use peel_ref for ref advertisements,
2012-10-04), we try to avoid parsing objects during the ref
advertisement. This means that lookup_object may return an
object with a type of OBJ_NONE. The resulting mess depends
on the exact set of objects, but can include the revision
parser barfing, or the shallow code sending the wrong set of
objects.
This patch teaches upload-pack to parse each "want" object
as we receive it. We do not replace the lookup_object call
with parse_object, as the current code is careful not to let
just any object appear on a "want" line, but rather only one
we have previously advertised (whereas parse_object would
actually load any arbitrary object from disk).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we receive a "have" line from the client, we want to
load the object pointed to by the sha1. However, we are
careful to do:
o = lookup_object(sha1);
if (!o || !o->parsed)
o = parse_object(sha1);
to avoid loading the object from disk if we have already
seen it. However, since ccdc603 (parse_object: try internal
cache before reading object db), parse_object already does
this optimization internally. We can just call parse_object
directly.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Most of the callers of packet_read_line just read into a
static 1000-byte buffer (callers which handle arbitrary
binary data already use LARGE_PACKET_MAX). This works fine
in practice, because:
1. The only variable-sized data in these lines is a ref
name, and refs tend to be a lot shorter than 1000
characters.
2. When sending ref lines, git-core always limits itself
to 1000 byte packets.
However, the only limit given in the protocol specification
in Documentation/technical/protocol-common.txt is
LARGE_PACKET_MAX; the 1000 byte limit is mentioned only in
pack-protocol.txt, and then only describing what we write,
not as a specific limit for readers.
This patch lets us bump the 1000-byte limit to
LARGE_PACKET_MAX. Even though git-core will never write a
packet where this makes a difference, there are two good
reasons to do this:
1. Other git implementations may have followed
protocol-common.txt and used a larger maximum size. We
don't bump into it in practice because it would involve
very long ref names.
2. We may want to increase the 1000-byte limit one day.
Since packets are transferred before any capabilities,
it's difficult to do this in a backwards-compatible
way. But if we bump the size of buffer the readers can
handle, eventually older versions of git will be
obsolete enough that we can justify bumping the
writers, as well. We don't have plans to do this
anytime soon, but there is no reason not to start the
clock ticking now.
Just bumping all of the reading bufs to LARGE_PACKET_MAX
would waste memory. Instead, since most readers just read
into a temporary buffer anyway, let's provide a single
static buffer that all callers can use. We can further wrap
this detail away by having the packet_read_line wrapper just
use the buffer transparently and return a pointer to the
static storage. That covers most of the cases, and the
remaining ones already read into their own LARGE_PACKET_MAX
buffers.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The packets sent during ref negotiation are all terminated
by newline; even though the code to chomp these newlines is
short, we end up doing it in a lot of places.
This patch teaches packet_read_line to auto-chomp the
trailing newline; this lets us get rid of a lot of inline
chomping code.
As a result, some call-sites which are not reading
line-oriented data (e.g., when reading chunks of packfiles
alongside sideband) transition away from packet_read_line to
the generic packet_read interface. This patch converts all
of the existing callsites.
Since the function signature of packet_read_line does not
change (but its behavior does), there is a possibility of
new callsites being introduced in later commits, silently
introducing an incompatibility. However, since a later
patch in this series will change the signature, such a
commit would have to be merged directly into this commit,
not to the tip of the series; we can therefore ignore the
issue.
This is an internal cleanup and should produce no change of
behavior in the normal case. However, there is one corner
case to note. Callers of packet_read_line have never been
able to tell the difference between a flush packet ("0000")
and an empty packet ("0004"), as both cause packet_read_line
to return a length of 0. Readers treat them identically,
even though Documentation/technical/protocol-common.txt says
we must not; it also says that implementations should not
send an empty pkt-line.
By stripping out the newline before the result gets to the
caller, we will now treat the newline-only packet ("0005\n")
the same as an empty packet, which in turn gets treated like
a flush packet. In practice this doesn't matter, as neither
empty nor newline-only packets are part of git's protocols
(at least not for the line-oriented bits, and readers who
are not expecting line-oriented packets will be calling
packet_read directly, anyway). But even if we do decide to
care about the distinction later, it is orthogonal to this
patch. The right place to tighten would be to stop treating
empty packets as flush packets, and this change does not
make doing so any harder.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is just write_or_die by another name. The one
distinction is that write_or_die will treat EPIPE specially
by suppressing error messages. That's fine, as we die by
SIGPIPE anyway (and in the off chance that it is disabled,
write_or_die will simulate it).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If you set the GIT_DEBUG_SEND_PACK environment variable,
upload-pack will dump lines it receives in the receive_needs
phase to a descriptor. This debugging harness is a strict
subset of what GIT_TRACE_PACKET can do. Let's just drop it
in favor of that.
A few tests used GIT_DEBUG_SEND_PACK to confirm which
objects get sent; we have to adapt them to the new output
format.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When the client tells us it has a shallow object via
"shallow <sha1>", we make sure we have the object, mark it
with a flag, then add it to a dynamic array of shallow
objects. This means that a client can get us to allocate
arbitrary amounts of memory just by flooding us with shallow
lines (whether they have the objects or not). You can
demonstrate it easily with:
yes '0035shallow e83c5163316f89bfbde7d9ab23ca2e25604af290' |
git-upload-pack git.git
We already protect against duplicates in want lines by
checking if our flag is already set; let's do the same thing
here. Note that a client can still get us to allocate some
amount of memory by marking every object in the repo as
"shallow" (or "want"). But this at least bounds it with the
number of objects in the repository, which is not under the
control of an upload-pack client.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we receive a line like "shallow <sha1>" from the
client, we feed the <sha1> part to get_sha1. This is a
mistake, as the argument on a shallow line is defined by
Documentation/technical/pack-protocol.txt to contain an
"obj-id". This is never defined in the BNF, but it is clear
from the text and from the other uses that it is meant to be
a hex sha1, not an arbitrary identifier (and that is what
fetch-pack has always sent).
We should be using get_sha1_hex instead, which doesn't allow
the client to request arbitrary junk like "HEAD@{yesterday}".
Because this is just marking shallow objects, the client
couldn't actually do anything interesting (like fetching
objects from unreachable reflog entries), but we should keep
our parsing tight to be on the safe side.
Because get_sha1 is for the most part a superset of
get_sha1_hex, in theory the only behavior change should be
disallowing non-hex object references. However, there is
one interesting exception: get_sha1 will only parse
a 40-character hex sha1 if the string has exactly 40
characters, whereas get_sha1_hex will just eat the first 40
characters, leaving the rest. That means that current
versions of git-upload-pack will not accept a "shallow"
packet that has a trailing newline, even though the protocol
documentation is clear that newlines are allowed (even
encouraged) in non-binary parts of the protocol.
This never mattered in practice, though, because fetch-pack,
contrary to the protocol documentation, does not include a
newline in its shallow lines. JGit follows its lead (though
it correctly is strict on the parsing end about wanting a
hex object id).
We do not adjust fetch-pack to send newlines here, as it
would break communication with older versions of git (and
there is no actual benefit to doing so, except for
consistency with other parts of the protocol).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Allow the server side to redact the refs/ namespace it shows to the
client.
Will merge to 'master'.
* jc/hidden-refs:
upload/receive-pack: allow hiding ref hierarchies
upload-pack: simplify request validation
upload-pack: share more code
With uploadpack.allowtipsha1inwant configuration option set, future
versions of "git fetch" that allow an exact object name (likely to
have been obtained out of band) on the LHS of the fetch refspec can
make a request with a "want" line that names an object that may not
have been advertised due to transfer.hiderefs configuration.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A repository may have refs that are only used for its internal
bookkeeping purposes that should not be exposed to the others that
come over the network.
Teach upload-pack to omit some refs from its initial advertisement
by paying attention to the uploadpack.hiderefs multi-valued
configuration variable. Do the same to receive-pack via the
receive.hiderefs variable. As a convenient short-hand, allow using
transfer.hiderefs to set the value to both of these variables.
Any ref that is under the hierarchies listed on the value of these
variable is excluded from responses to requests made by "ls-remote",
"fetch", etc. (for upload-pack) and "push" (for receive-pack).
Because these hidden refs do not count as OUR_REF, an attempt to
fetch objects at the tip of them will be rejected, and because these
refs do not get advertised, "git push :" will not see local branches
that have the same name as them as "matching" ones to be sent.
An attempt to update/delete these hidden refs with an explicit
refspec, e.g. "git push origin :refs/hidden/22", is rejected. This
is not a new restriction. To the pusher, it would appear that there
is no such ref, so its push request will conclude with "Now that I
sent you all the data, it is time for you to update the refs. I saw
that the ref did not exist when I started pushing, and I want the
result to point at this commit". The receiving end will apply the
compare-and-swap rule to this request and rejects the push with
"Well, your update request conflicts with somebody else; I see there
is such a ref.", which is the right thing to do. Otherwise a push to
a hidden ref will always be "the last one wins", which is not a good
default.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git fetch --depth" was broken in at least three ways. The
resulting history was deeper than specified by one commit, it was
unclear how to wipe the shallowness of the repository with the
command, and documentation was misleading.
* nd/fetch-depth-is-broken:
fetch: elaborate --depth action
upload-pack: fix off-by-one depth calculation in shallow clone
fetch: add --unshallow for turning shallow repo into complete one
Long time ago, we used to punt on a large (read: asking for more
than 256 refs) fetch request and instead sent a full pack, because
we couldn't fit many refs on the command line of rev-list we run
internally to enumerate the objects to be sent. To fix this,
565ebbf (upload-pack: tighten request validation., 2005-10-24),
added a check to count the number of refs in the request and matched
with the number of refs we advertised, and changed the invocation of
rev-list to pass "--all" to it, still keeping us under the command
line argument limit.
However, these days we feed the list of objects requested and the
list of objects the other end is known to have via standard input,
so there is no longer a valid reason to special case a full clone
request. Remove the code associated with "create_full_pack" to
simplify the logic.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We mark the objects pointed at our refs with "OUR_REF" flag in two
functions (mark_our_ref() and send_ref()), but we can just use the
former as a helper for the latter.
Update the way mark_our_ref() prepares in-core object to use
lookup_unknown_object() to delay reading the actual object data,
just like we did in 435c833 (upload-pack: use peel_ref for ref
advertisements, 2012-10-04).
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A minor consistency check patch that does not have much relevance
to the real world.
* nd/upload-pack-shallow-must-be-commit:
upload-pack: only accept commits from "shallow" line
The user can do --depth=2147483647 (*) for restoring complete repo
now. But it's hard to remember. Any other numbers larger than the
longest commit chain in the repository would also do, but some
guessing may be involved. Make easy-to-remember --unshallow an alias
for --depth=2147483647.
Make upload-pack recognize this special number as infinite depth. The
effect is essentially the same as before, except that upload-pack is
more efficient because it does not have to traverse to the bottom
anymore.
The chance of a user actually wanting exactly 2147483647 commits
depth, not infinite, on a repository with a history that long, is
probably too small to consider. The client can learn to add or
subtract one commit to avoid the special treatment when that actually
happens.
(*) This is the largest positive number a 32-bit signed integer can
contain. JGit and older C Git store depth as "int" so both are OK
with this number. Dulwich does not support shallow clone.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We only allow cuts at commits, not arbitrary objects. upload-pack will
fail eventually in register_shallow if a non-commit is given with a
generic error "Object %s is a %s, not a commit". Check it early and
give a more accurate error.
This should never show up in an ordinary session. It's for buggy
clients, or when the user manually edits .git/shallow.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When upload-pack advertises refs, we attempt to peel tags
and advertise the peeled version. We currently hand-roll the
tag dereferencing, and use as many optimizations as we can
to avoid loading non-tag objects into memory.
Not only has peel_ref recently learned these optimizations,
too, but it also contains an even more important one: it
has access to the "peeled" data from the pack-refs file.
That means we can avoid not only loading annotated tags
entirely, but also avoid doing any kind of object lookup at
all.
This cut the CPU time to advertise refs by 50% in the
linux-2.6 repo, as measured by:
echo 0000 | git-upload-pack . >/dev/null
best-of-five, warm cache, objects and refs fully packed:
[before] [after]
real 0m0.026s real 0m0.013s
user 0m0.024s user 0m0.008s
sys 0m0.000s sys 0m0.000s
Those numbers are irrelevantly small compared to an actual
fetch. Here's a larger repo (400K refs, of which 12K are
unique, and of which only 107 are unique annotated tags):
[before] [after]
real 0m0.704s real 0m0.596s
user 0m0.600s user 0m0.496s
sys 0m0.096s sys 0m0.092s
This shows only a 15% speedup (mostly because it has fewer
actual tags to parse), but a larger absolute value (100ms,
which isn't a lot compared to a real fetch, but this
advertisement happens on every fetch, even if the client is
just finding out they are completely up to date).
In truly pathological cases, where you have a large number
of unique annotated tags, it can make an even bigger
difference. Here are the numbers for a linux-2.6 repository
that has had every seventh commit tagged (so about 50K
tags):
[before] [after]
real 0m0.443s real 0m0.097s
user 0m0.416s user 0m0.080s
sys 0m0.024s sys 0m0.012s
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Instead of having the client advertise a particular version
number in the git protocol, we have managed extensions and
backwards compatibility by having clients and servers
advertise capabilities that they support. This is far more
robust than having each side consult a table of
known versions, and provides sufficient information for the
protocol interaction to complete.
However, it does not allow servers to keep statistics on
which client versions are being used. This information is
not necessary to complete the network request (the
capabilities provide enough information for that), but it
may be helpful to conduct a general survey of client
versions in use.
We already send the client version in the user-agent header
for http requests; adding it here allows us to gather
similar statistics for non-http requests.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
