Commit graph

403 commits

Author SHA1 Message Date
René Scharfe
bf73282c0b fetch-pack: factor out is_unmatched_ref()
Move the code to determine if a request is unmatched to its own little
helper.  This allows us to reuse it in a subsequent patch.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-04 11:12:13 -07:00
Jonathan Tan
4c7f9567ea fetch-pack: exclude blobs when lazy-fetching trees
A partial clone with missing trees can be obtained using "git clone
--filter=tree:none <repo>". In such a repository, when a tree needs to
be lazily fetched, any tree or blob it directly or indirectly references
is fetched as well, regardless of whether the original command required
those objects, or if the local repository already had some of them.

This is because the fetch protocol, which the lazy fetch uses, does not
allow clients to request that only the wanted objects be sent, which
would be the ideal solution. This patch implements a partial solution:
specify the "blob:none" filter, somewhat reducing the fetch payload.

This change has no effect when lazily fetching blobs (due to how filters
work). And if lazily fetching a commit (such repositories are difficult
to construct and is not a use case we support very well, but it is
possible), referenced commits and trees are still fetched - only the
blobs are not fetched.

The necessary code change is done in fetch_pack() instead of somewhere
closer to where the "filter" instruction is written to the wire so that
only one part of the code needs to be changed in order for users of all
protocol versions to benefit from this optimization.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-04 06:03:49 -07:00
Jonathan Tan
12f19a9825 fetch-pack: avoid object flags if no_dependents
When fetch_pack() is invoked as part of another Git command (due to a
lazy fetch from a partial clone, for example), it uses object flags that
may already be used by the outer Git command.

The commit that introduced the lazy fetch feature (88e2f9ed8e
("introduce fetch-object: fetch one promisor object", 2017-12-05)) tried
to avoid this overlap, but it did not avoid it totally. It was
successful in avoiding writing COMPLETE, but did not avoid reading
COMPLETE, and did not avoid writing and reading ALTERNATE.

Ensure that no flags are written or read by fetch_pack() in the case
where it is used to perform a lazy fetch. To do this, it is sufficient
to avoid checking completeness of wanted refs (unnecessary in the case
of lazy fetches), and to avoid negotiation-related work (in the current
implementation, already, no negotiation is performed). After that was
done, the lack of overlap was verified by checking all direct and
indirect usages of COMPLETE and ALTERNATE - that they are read or
written only if no_dependents is false.

There are other possible solutions to this issue:

 (1) Split fetch-pack.{c,h} into a flag-using part and a non-flag-using
     part, and whenever no_dependents is set, only use the
     non-flag-using part.
 (2) Make fetch_pack() be able to be used with arbitrary repository
     objects. fetch_pack() should then create its own repository object
     based on the given repository object, with its own object
     hashtable, so that the flags do not conflict.

(1) is possible but invasive - some functions would need to be split;
and such invasiveness would potentially be unnecessary if we ever were
to need (2) anyway. (2) would be useful if we were to support, say,
submodules that were partial clones themselves, but I don't know when or
if the Git project plans to support those.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-10-04 06:00:53 -07:00
Jeff King
9001dc2a74 convert "oidcmp() != 0" to "!oideq()"
This is the flip side of the previous two patches: checking
for a non-zero oidcmp() can be more strictly expressed as
inequality. Like those patches, we write "!= 0" in the
coccinelle transformation, which covers by isomorphism the
more common:

  if (oidcmp(E1, E2))

As with the previous two patches, this patch can be achieved
almost entirely by running "make coccicheck"; the only
differences are manual line-wrap fixes to match the original
code.

There is one thing to note for anybody replicating this,
though: coccinelle 1.0.4 seems to miss the case in
builtin/tag.c, even though it's basically the same as all
the others. Running with 1.0.7 does catch this, so
presumably it's just a coccinelle bug that was fixed in the
interim.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-29 11:32:49 -07:00
Junio C Hamano
f8ca71870a Merge branch 'ab/fsck-transfer-updates'
The test performed at the receiving end of "git push" to prevent
bad objects from entering repository can be customized via
receive.fsck.* configuration variables; we now have gained a
counterpart to do the same on the "git fetch" side, with
fetch.fsck.* configuration variables.

* ab/fsck-transfer-updates:
  fsck: test and document unknown fsck.<msg-id> values
  fsck: add stress tests for fsck.skipList
  fsck: test & document {fetch,receive}.fsck.* config fallback
  fetch: implement fetch.fsck.*
  transfer.fsckObjects tests: untangle confusing setup
  config doc: elaborate on fetch.fsckObjects security
  config doc: elaborate on what transfer.fsckObjects does
  config doc: unify the description of fsck.* and receive.fsck.*
  config doc: don't describe *.fetchObjects twice
  receive.fsck.<msg-id> tests: remove dead code
2018-08-17 13:09:54 -07:00
Junio C Hamano
b160b6e69d Merge branch 'jt/connectivity-check-after-unshallow'
"git fetch" sometimes failed to update the remote-tracking refs,
which has been corrected.

* jt/connectivity-check-after-unshallow:
  fetch-pack: unify ref in and out param
2018-08-15 15:08:28 -07:00
Junio C Hamano
ea30f539ef Merge branch 'bw/fetch-pack-i18n'
i18n updates.

* bw/fetch-pack-i18n:
  fetch-pack: mark die strings for translation
2018-08-15 15:08:20 -07:00
Junio C Hamano
7c85ee6c58 Merge branch 'jt/fetch-negotiator-skipping'
Add a server-side knob to skip commits in exponential/fibbonacci
stride in an attempt to cover wider swath of history with a smaller
number of iterations, potentially accepting a larger packfile
transfer, instead of going back one commit a time during common
ancestor discovery during the "git fetch" transaction.

* jt/fetch-negotiator-skipping:
  negotiator/skipping: skip commits during fetch
2018-08-02 15:30:46 -07:00
Junio C Hamano
30bf8d9f4f Merge branch 'jt/fetch-nego-tip'
"git fetch" learned a new option "--negotiation-tip" to limit the
set of commits it tells the other end as "have", to reduce wasted
bandwidth and cycles, which would be helpful when the receiving
repository has a lot of refs that have little to do with the
history at the remote it is fetching from.

* jt/fetch-nego-tip:
  fetch-pack: support negotiation tip whitelist
2018-08-02 15:30:43 -07:00
Junio C Hamano
3a2a1dc170 Merge branch 'sb/object-store-lookup'
lookup_commit_reference() and friends have been updated to find
in-core object for a specific in-core repository instance.

* sb/object-store-lookup: (32 commits)
  commit.c: allow lookup_commit_reference to handle arbitrary repositories
  commit.c: allow lookup_commit_reference_gently to handle arbitrary repositories
  tag.c: allow deref_tag to handle arbitrary repositories
  object.c: allow parse_object to handle arbitrary repositories
  object.c: allow parse_object_buffer to handle arbitrary repositories
  commit.c: allow get_cached_commit_buffer to handle arbitrary repositories
  commit.c: allow set_commit_buffer to handle arbitrary repositories
  commit.c: migrate the commit buffer to the parsed object store
  commit-slabs: remove realloc counter outside of slab struct
  commit.c: allow parse_commit_buffer to handle arbitrary repositories
  tag: allow parse_tag_buffer to handle arbitrary repositories
  tag: allow lookup_tag to handle arbitrary repositories
  commit: allow lookup_commit to handle arbitrary repositories
  tree: allow lookup_tree to handle arbitrary repositories
  blob: allow lookup_blob to handle arbitrary repositories
  object: allow lookup_object to handle arbitrary repositories
  object: allow object_as_type to handle arbitrary repositories
  tag: add repository argument to deref_tag
  tag: add repository argument to parse_tag_buffer
  tag: add repository argument to lookup_tag
  ...
2018-08-02 15:30:42 -07:00
Junio C Hamano
af8ac73801 Merge branch 'jt/fetch-pack-negotiator'
Code restructuring and a small fix to transport protocol v2 during
fetching.

* jt/fetch-pack-negotiator:
  fetch-pack: introduce negotiator API
  fetch-pack: move common check and marking together
  fetch-pack: make negotiation-related vars local
  fetch-pack: use ref adv. to prune "have" sent
  fetch-pack: directly end negotiation if ACK ready
  fetch-pack: clear marks before re-marking
  fetch-pack: split up everything_local()
2018-08-02 15:30:41 -07:00
Jonathan Tan
e2842b39f4 fetch-pack: unify ref in and out param
When a user fetches:
 - at least one up-to-date ref and at least one non-up-to-date ref,
 - using HTTP with protocol v0 (or something else that uses the fetch
   command of a remote helper)
some refs might not be updated after the fetch.

This bug was introduced in commit 989b8c4452 ("fetch-pack: put shallow
info in output parameter", 2018-06-28) which allowed transports to
report the refs that they have fetched in a new out-parameter
"fetched_refs". If they do so, transport_fetch_refs() makes this
information available to its caller.

Users of "fetched_refs" rely on the following 3 properties:
 (1) it is the complete list of refs that was passed to
     transport_fetch_refs(),
 (2) it has shallow information (REF_STATUS_REJECT_SHALLOW set if
     relevant), and
 (3) it has updated OIDs if ref-in-want was used (introduced after
     989b8c4452).

In an effort to satisfy (1), whenever transport_fetch_refs()
filters the refs sent to the transport, it re-adds the filtered refs to
whatever the transport supplies before returning it to the user.
However, the implementation in 989b8c4452 unconditionally re-adds the
filtered refs without checking if the transport refrained from reporting
anything in "fetched_refs" (which it is allowed to do), resulting in an
incomplete list, no longer satisfying (1).

An earlier effort to resolve this [1] solved the issue by readding the
filtered refs only if the transport did not refrain from reporting in
"fetched_refs", but after further discussion, it seems that the better
solution is to revert the API change that introduced "fetched_refs".
This API change was first suggested as part of a ref-in-want
implementation that allowed for ref patterns and, thus, there could be
drastic differences between the input refs and the refs actually fetched
[2]; we eventually decided to only allow exact ref names, but this API
change remained even though its necessity was decreased.

Therefore, revert this API change by reverting commit 989b8c4452, and
make receive_wanted_refs() update the OIDs in the sought array (like how
update_shallow() updates shallow information in the sought array)
instead. A test is also included to show that the user-visible bug
discussed at the beginning of this commit message no longer exists.

[1] https://public-inbox.org/git/20180801171806.GA122458@google.com/
[2] https://public-inbox.org/git/86a128c5fb710a41791e7183207c4d64889f9307.1485381677.git.jonathantanmy@google.com/

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-01 15:00:52 -07:00
Ævar Arnfjörð Bjarmason
1362df0d41 fetch: implement fetch.fsck.*
Implement support for fetch.fsck.* corresponding with the existing
receive.fsck.*. This allows for pedantically cloning repositories with
specific issues without turning off fetch.fsckObjects.

One such repository is https://github.com/robbyrussell/oh-my-zsh.git
which before this change will emit this error when cloned with
fetch.fsckObjects:

    error: object 2b7227859263b6aabcc28355b0b994995b7148b6: zeroPaddedFilemode: contains zero-padded file modes
    fatal: Error in object
    fatal: index-pack failed

Now with fetch.fsck.zeroPaddedFilemode=warn we'll warn about that
issue, but the clone will succeed:

    warning: object 2b7227859263b6aabcc28355b0b994995b7148b6: zeroPaddedFilemode: contains zero-padded file modes
    warning: object a18c4d13c2a5fa2d4ecd5346c50e119b999b807d: zeroPaddedFilemode: contains zero-padded file modes
    warning: object 84df066176c8da3fd59b13731a86d90f4f1e5c9d: zeroPaddedFilemode: contains zero-padded file modes

The motivation for this is to be able to turn on fetch.fsckObjects
globally across a fleet of computers but still be able to manually
clone various legacy repositories by either white-listing specific
issues, or better yet whitelist specific objects.

The use of --git-dir=* instead of -C in the tests could be considered
somewhat archaic, but the tests I'm adding here are duplicating the
corresponding receive.* tests with as few changes as possible.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-27 11:36:05 -07:00
Junio C Hamano
88df0fa659 Merge branch 'jt/connectivity-check-after-unshallow'
"git fetch" failed to correctly validate the set of objects it
received when making a shallow history deeper, which has been
corrected.

* jt/connectivity-check-after-unshallow:
  fetch-pack: write shallow, then check connectivity
  fetch-pack: implement ref-in-want
  fetch-pack: put shallow info in output parameter
  fetch: refactor to make function args narrower
  fetch: refactor fetch_refs into two functions
  fetch: refactor the population of peer ref OIDs
  upload-pack: test negotiation with changing repository
  upload-pack: implement ref-in-want
  test-pkt-line: add unpack-sideband subcommand
2018-07-24 14:50:44 -07:00
Brandon Williams
bbb19a8b06 fetch-pack: mark die strings for translation
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-23 15:59:40 -07:00
Junio C Hamano
00624d608c Merge branch 'sb/object-store-grafts'
The conversion to pass "the_repository" and then "a_repository"
throughout the object access API continues.

* sb/object-store-grafts:
  commit: allow lookup_commit_graft to handle arbitrary repositories
  commit: allow prepare_commit_graft to handle arbitrary repositories
  shallow: migrate shallow information into the object parser
  path.c: migrate global git_path_* to take a repository argument
  cache: convert get_graft_file to handle arbitrary repositories
  commit: convert read_graft_file to handle arbitrary repositories
  commit: convert register_commit_graft to handle arbitrary repositories
  commit: convert commit_graft_pos() to handle arbitrary repositories
  shallow: add repository argument to is_repository_shallow
  shallow: add repository argument to check_shallow_file_for_update
  shallow: add repository argument to register_shallow
  shallow: add repository argument to set_alternate_shallow_file
  commit: add repository argument to lookup_commit_graft
  commit: add repository argument to prepare_commit_graft
  commit: add repository argument to read_graft_file
  commit: add repository argument to register_commit_graft
  commit: add repository argument to commit_graft_pos
  object: move grafts to object parser
  object-store: move object access functions to object-store.h
2018-07-18 12:20:28 -07:00
Jonathan Tan
42cc7485a2 negotiator/skipping: skip commits during fetch
Introduce a new negotiation algorithm used during fetch that skips
commits in an effort to find common ancestors faster. The skips grow
similarly to the Fibonacci sequence as the commit walk proceeds further
away from the tips. The skips may cause unnecessary commits to be
included in the packfile, but the negotiation step typically ends more
quickly.

Usage of this algorithm is guarded behind the configuration flag
fetch.negotiationAlgorithm.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-16 14:51:12 -07:00
Jonathan Tan
3390e42adb fetch-pack: support negotiation tip whitelist
During negotiation, fetch-pack eventually reports as "have" lines all
commits reachable from all refs. Allow the user to restrict the commits
sent in this way by providing a whitelist of tips; only the tips
themselves and their ancestors will be sent.

Both globs and single objects are supported.

This feature is only supported for protocols that support connect or
stateless-connect (such as HTTP with protocol v2).

This will speed up negotiation when the repository has multiple
relatively independent branches (for example, when a repository
interacts with multiple repositories, such as with linux-next [1] and
torvalds/linux [2]), and the user knows which local branch is likely to
have commits in common with the upstream branch they are fetching.

[1] https://kernel.googlesource.com/pub/scm/linux/kernel/git/next/linux-next/
[2] https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux/

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-03 15:00:41 -07:00
Jonathan Tan
cf1e7c0770 fetch-pack: write shallow, then check connectivity
When fetching, connectivity is checked after the shallow file is
updated. There are 2 issues with this: (1) the connectivity check is
only performed up to ancestors of existing refs (which is not thorough
enough if we were deepening an existing ref in the first place), and (2)
there is no rollback of the shallow file if the connectivity check
fails.

To solve (1), update the connectivity check to check the ancestry chain
completely in the case of a deepening fetch by refraining from passing
"--not --all" when invoking rev-list in connected.c.

To solve (2), have fetch_pack() perform its own connectivity check
before updating the shallow file. To support existing use cases in which
"git fetch-pack" is used to download objects without much regard as to
the connectivity of the resulting objects with respect to the existing
repository, the connectivity check is only done if necessary (that is,
the fetch is not a clone, and the fetch involves shallow/deepen
functionality). "git fetch" still performs its own connectivity check,
preserving correctness but sometimes performing redundant work. This
redundancy is mitigated by the fact that fetch_pack() reports if it has
performed a connectivity check itself, and if the transport supports
connect or stateless-connect, it will bubble up that report so that "git
fetch" knows not to perform the connectivity check in such a case.

This was noticed when a user tried to deepen an existing repository by
fetching with --no-shallow from a server that did not send all necessary
objects - the connectivity check as run by "git fetch" succeeded, but a
subsequent "git fsck" failed.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-03 14:57:44 -07:00
Stefan Beller
a74093da5e tag: add repository argument to deref_tag
Add a repository argument to allow the callers of deref_tag
to be more specific about which repository to act on. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.

As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-29 10:43:39 -07:00
Stefan Beller
c1f5eb4962 commit: add repository argument to lookup_commit
Add a repository argument to allow callers of lookup_commit to be more
specific about which repository to handle. This is a small mechanical
change; it doesn't change the implementation to handle repositories
other than the_repository yet.

As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-29 10:43:39 -07:00
Stefan Beller
5abddd1eb7 object: add repository argument to lookup_object
Add a repository argument to allow callers of lookup_object to be more
specific about which repository to handle. This is a small mechanical
change; it doesn't change the implementation to handle repositories
other than the_repository yet.

As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-29 10:43:38 -07:00
Stefan Beller
109cd76dd3 object: add repository argument to parse_object
Add a repository argument to allow the callers of parse_object
to be more specific about which repository to act on. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.

As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-29 10:43:38 -07:00
Junio C Hamano
b16b60f71b Merge branch 'sb/object-store-grafts' into sb/object-store-lookup
* sb/object-store-grafts:
  commit: allow lookup_commit_graft to handle arbitrary repositories
  commit: allow prepare_commit_graft to handle arbitrary repositories
  shallow: migrate shallow information into the object parser
  path.c: migrate global git_path_* to take a repository argument
  cache: convert get_graft_file to handle arbitrary repositories
  commit: convert read_graft_file to handle arbitrary repositories
  commit: convert register_commit_graft to handle arbitrary repositories
  commit: convert commit_graft_pos() to handle arbitrary repositories
  shallow: add repository argument to is_repository_shallow
  shallow: add repository argument to check_shallow_file_for_update
  shallow: add repository argument to register_shallow
  shallow: add repository argument to set_alternate_shallow_file
  commit: add repository argument to lookup_commit_graft
  commit: add repository argument to prepare_commit_graft
  commit: add repository argument to read_graft_file
  commit: add repository argument to register_commit_graft
  commit: add repository argument to commit_graft_pos
  object: move grafts to object parser
  object-store: move object access functions to object-store.h
2018-06-29 10:43:28 -07:00
Junio C Hamano
0079732e96 Merge branch 'jk/fetch-all-peeled-fix'
"git fetch-pack --all" used to unnecessarily fail upon seeing an
annotated tag that points at an object other than a commit.

* jk/fetch-all-peeled-fix:
  fetch-pack: test explicitly that --all can fetch tag references pointing to non-commits
  fetch-pack: don't try to fetch peel values with --all
2018-06-28 12:53:32 -07:00
Brandon Williams
733020517a fetch-pack: implement ref-in-want
Implement ref-in-want on the client side so that when a server supports
the "ref-in-want" feature, a client will send "want-ref" lines for each
reference the client wants to fetch.  This feature allows clients to
tolerate inconsistencies that exist when a remote repository's refs
change during the course of negotiation.

This allows a client to request to request a particular ref without
specifying the OID of the ref.  This means that instead of hitting an
error when a ref no longer points at the OID it did at the beginning of
negotiation, negotiation can continue and the value of that ref will be
sent at the termination of negotiation, just before a packfile is sent.

More information on the ref-in-want feature can be found in
Documentation/technical/protocol-v2.txt.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-28 09:33:30 -07:00
Brandon Williams
989b8c4452 fetch-pack: put shallow info in output parameter
Expand the transport fetch method signature, by adding an output
parameter, to allow transports to return information about the refs they
have fetched.  Then communicate shallow status information through this
mechanism instead of by modifying the input list of refs.

This does require clients to sometimes generate the ref map twice: once
from the list of refs provided by the remote (as is currently done) and
potentially once from the new list of refs that the fetch mechanism
provides.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-28 09:33:29 -07:00
Jonathan Tan
ec06283844 fetch-pack: introduce negotiator API
Introduce the new files fetch-negotiator.{h,c}, which contains an API
behind which the details of negotiation are abstracted. Currently, only
one algorithm is available: the existing one.

This patch is written to be easily reviewed: static functions are
moved verbatim from fetch-pack.c to negotiator/default.c, and it can be
seen that the lines replaced by negotiator->X() calls are present in the
X() functions respectively.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-15 08:44:24 -07:00
Jonathan Tan
d093bc7582 fetch-pack: move common check and marking together
When receiving 'ACK <object-id> continue' for a common commit, check if
the commit was already known to be common and mark it as such if not up
front. This should make future refactoring of how the information about
common commits is stored more straightforward.

No visible change intended.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-15 08:44:24 -07:00
Jonathan Tan
d30fe89c37 fetch-pack: make negotiation-related vars local
Reduce the number of global variables by making the priority queue and
the count of non-common commits in it local, passing them as a struct to
various functions where necessary.

This also helps in the case that fetch_pack() is invoked twice in the
same process (when tag following is required when using a transport that
does not support tag following), in that different priority queues will
now be used in each invocation, instead of reusing the possibly
non-empty one.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-15 08:44:23 -07:00
Jonathan Tan
af1c90d13e fetch-pack: use ref adv. to prune "have" sent
In negotiation using protocol v2, fetch-pack sometimes does not make
full use of the information obtained in the ref advertisement:
specifically, that if the server advertises a commit that the client
also has, the client never needs to inform the server that it has the
commit's parents, since it can just tell the server that it has the
advertised commit and it knows that the server can and will infer the
rest.

This is because, in do_fetch_pack_v2(), rev_list_insert_ref_oid() is
invoked before mark_complete_and_common_ref(). This means that if we
have a commit that is both our ref and their ref, it would be enqueued
by rev_list_insert_ref_oid() as SEEN, and since it is thus already SEEN,
mark_complete_and_common_ref() would not enqueue it.

If mark_complete_and_common_ref() were invoked first, as it is in
do_fetch_pack() for protocol v0, then mark_complete_and_common_ref()
would enqueue it with COMMON_REF | SEEN. The addition of COMMON_REF
ensures that its parents are not sent as "have" lines.

Change the order in do_fetch_pack_v2() to be consistent with
do_fetch_pack(), and to avoid sending unnecessary "have" lines.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-15 08:44:23 -07:00
Jonathan Tan
21bcf6e429 fetch-pack: directly end negotiation if ACK ready
When "ACK %s ready" is received, find_common() clears rev_list in an
attempt to stop further "have" lines from being sent [1]. It is much
more readable to explicitly break from the loop instead.

So explicitly break from the loop, and make the clearing of the rev_list
happen unconditionally.

[1] The rationale is further described in the originating commit
f2cba9299b ("fetch-pack: Finish negotation if remote replies "ACK %s
ready"", 2011-03-14).

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-15 08:44:23 -07:00
Jonathan Tan
af008558cc fetch-pack: clear marks before re-marking
If tag following is required when using a transport that does not
support tag following, fetch_pack() will be invoked twice in the same
process, necessitating a clearing of the object flags used by
fetch_pack() sometime during the second invocation. This is currently
done in find_common(), which means that the invocation of
mark_complete_and_common_ref() in do_fetch_pack() is useless.

(This cannot be reproduced with Git alone, because all transports that
come with Git support tag following.)

Therefore, move this clearing from find_common() to its
parent function do_fetch_pack(), right before it calls
mark_complete_and_common_ref().

This has been occurring since the commit that introduced the clearing of
marks, 420e9af498 ("Fix tag following", 2008-03-19).

The corresponding code for protocol v2 in do_fetch_pack_v2() does not
have this problem, as the clearing of flags is done before any marking
(whether by rev_list_insert_ref_oid() or
mark_complete_and_common_ref()).

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-14 11:31:24 -07:00
Jonathan Tan
34c2903456 fetch-pack: split up everything_local()
The function everything_local(), despite its name, also (1) marks
commits as COMPLETE and COMMON_REF and (2) invokes filter_refs() as
important side effects. Extract (1) into its own function
(mark_complete_and_common_ref()) and remove
(2).

The restoring of save_commit_buffer, which was introduced in a1c6d7c1a7
("fetch-pack: restore save_commit_buffer after use", 2017-12-08), is a
concern of the parse_object() call in mark_complete_and_common_ref(), so
it has been moved from the end of everything_local() to the end of
mark_complete_and_common_ref().

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-14 11:31:24 -07:00
Jeff King
e9502c0a7f fetch-pack: don't try to fetch peel values with --all
When "fetch-pack --all" sees a tag-to-blob on the remote, it
tries to fetch both the tag itself ("refs/tags/foo") and the
peeled value that the remote advertises ("refs/tags/foo^{}").
Asking for the object pointed to by the latter can cause
upload-pack to complain with "not our ref", since it does
not mark the peeled objects with the OUR_REF (unless they
were at the tip of some other ref).

Arguably upload-pack _should_ be marking those peeled
objects. But it never has in the past, since clients would
generally just ask for the tag and expect to get the peeled
value along with it. And that's how "git fetch" works, as
well as older versions of "fetch-pack --all".

The problem was introduced by 5f0fc64513 (fetch-pack:
eliminate spurious error messages, 2012-09-09). Before then,
the matching logic was something like:

  if (refname is ill-formed)
     do nothing
  else if (doing --all)
     always consider it matched
  else
     look through list of sought refs for a match

That commit wanted to flip the order of the second two arms
of that conditional. But we ended up with:

  if (refname is ill-formed)
    do nothing
  else
    look through list of sought refs for a match

  if (--all and no match so far)
    always consider it matched

That means tha an ill-formed ref will trigger the --all
conditional block, even though we should just be ignoring
it. We can fix that by having a single "else" with all of
the well-formed logic, that checks the sought refs and
"--all" in the correct order.

Reported-by: Kirill Smelkov <kirr@nexedi.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-11 12:50:58 -07:00
Junio C Hamano
54db5c0e1e Merge branch 'jt/partial-clone-proto-v2'
Transfer protocol v2 learned to support the partial clone.

* jt/partial-clone-proto-v2:
  {fetch,upload}-pack: support filter in protocol v2
  upload-pack: read config when serving protocol v2
  upload-pack: fix error message typo
2018-05-30 14:04:10 +09:00
Junio C Hamano
41267e9697 Merge branch 'bw/server-options'
The transport protocol v2 is getting updated further.

* bw/server-options:
  fetch: send server options when using protocol v2
  ls-remote: send server options when using protocol v2
  serve: introduce the server-option capability
2018-05-23 14:38:15 +09:00
Stefan Beller
102de880d2 path.c: migrate global git_path_* to take a repository argument
Migrate all git_path_* functions that are defined in path.c to take a
repository argument. Unlike other patches in this series, do not use the
 #define trick, as we rewrite the whole function, which is rather small.

This doesn't migrate all the functions, as other builtins have their own
local path functions defined using GIT_PATH_FUNC. So keep that macro
around to serve the other locations.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-18 08:13:10 +09:00
Stefan Beller
c88134870e shallow: add repository argument to is_repository_shallow
Add a repository argument to allow callers of is_repository_shallow
to be more specific about which repository to handle. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.

As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-18 08:13:10 +09:00
Stefan Beller
19143f139d shallow: add repository argument to register_shallow
Add a repository argument to allow callers of register_shallow
to be more specific about which repository to handle. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.

As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-18 08:13:10 +09:00
Stefan Beller
cbd53a2193 object-store: move object access functions to object-store.h
This should make these functions easier to find and cache.h less
overwhelming to read.

In particular, this moves:
- read_object_file
- oid_object_info
- write_object_file

As a result, most of the codebase needs to #include object-store.h.
In this patch the #include is only added to files that would fail to
compile otherwise.  It would be better to #include wherever
identifiers from the header are used.  That can happen later
when we have better tooling for it.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-16 11:42:03 +09:00
Junio C Hamano
9bfa0f9be3 Merge branch 'bw/protocol-v2'
The beginning of the next-gen transfer protocol.

* bw/protocol-v2: (35 commits)
  remote-curl: don't request v2 when pushing
  remote-curl: implement stateless-connect command
  http: eliminate "# service" line when using protocol v2
  http: don't always add Git-Protocol header
  http: allow providing extra headers for http requests
  remote-curl: store the protocol version the server responded with
  remote-curl: create copy of the service name
  pkt-line: add packet_buf_write_len function
  transport-helper: introduce stateless-connect
  transport-helper: refactor process_connect_service
  transport-helper: remove name parameter
  connect: don't request v2 when pushing
  connect: refactor git_connect to only get the protocol version once
  fetch-pack: support shallow requests
  fetch-pack: perform a fetch using v2
  upload-pack: introduce fetch server command
  push: pass ref prefixes when pushing
  fetch: pass ref prefixes when fetching
  ls-remote: pass ref prefixes when requesting a remote's refs
  transport: convert transport_get_remote_refs to take a list of ref prefixes
  ...
2018-05-08 15:59:16 +09:00
Jonathan Tan
ba95710a3b {fetch,upload}-pack: support filter in protocol v2
The fetch-pack/upload-pack protocol v2 was developed independently of
the filter parameter (used in partial fetches), thus it did not include
support for it. Add support for the filter parameter.

Like in the legacy protocol, the server advertises and supports "filter"
only if uploadpack.allowfilter is configured.

Like in the legacy protocol, the client continues with a warning if
"--filter" is specified, but the server does not advertise it.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-05-06 13:17:19 +09:00
Junio C Hamano
ea44c0a594 Merge branch 'bw/protocol-v2' into jt/partial-clone-proto-v2
The beginning of the next-gen transfer protocol.

* bw/protocol-v2: (35 commits)
  remote-curl: don't request v2 when pushing
  remote-curl: implement stateless-connect command
  http: eliminate "# service" line when using protocol v2
  http: don't always add Git-Protocol header
  http: allow providing extra headers for http requests
  remote-curl: store the protocol version the server responded with
  remote-curl: create copy of the service name
  pkt-line: add packet_buf_write_len function
  transport-helper: introduce stateless-connect
  transport-helper: refactor process_connect_service
  transport-helper: remove name parameter
  connect: don't request v2 when pushing
  connect: refactor git_connect to only get the protocol version once
  fetch-pack: support shallow requests
  fetch-pack: perform a fetch using v2
  upload-pack: introduce fetch server command
  push: pass ref prefixes when pushing
  fetch: pass ref prefixes when fetching
  ls-remote: pass ref prefixes when requesting a remote's refs
  transport: convert transport_get_remote_refs to take a list of ref prefixes
  ...
2018-05-02 18:54:10 +09:00
Brandon Williams
5e3548ef16 fetch: send server options when using protocol v2
Teach fetch to optionally accept server options by specifying them on
the cmdline via '-o' or '--server-option'.  These server options are
sent to the remote end when performing a fetch communicating using
protocol version 2.

If communicating using a protocol other than v2 the provided options are
ignored and not sent to the remote end.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-24 11:24:40 +09:00
Junio C Hamano
bbc39d4020 Merge branch 'bw/protocol-v2' into HEAD
* bw/protocol-v2: (35 commits)
  remote-curl: don't request v2 when pushing
  remote-curl: implement stateless-connect command
  http: eliminate "# service" line when using protocol v2
  http: don't always add Git-Protocol header
  http: allow providing extra headers for http requests
  remote-curl: store the protocol version the server responded with
  remote-curl: create copy of the service name
  pkt-line: add packet_buf_write_len function
  transport-helper: introduce stateless-connect
  transport-helper: refactor process_connect_service
  transport-helper: remove name parameter
  connect: don't request v2 when pushing
  connect: refactor git_connect to only get the protocol version once
  fetch-pack: support shallow requests
  fetch-pack: perform a fetch using v2
  upload-pack: introduce fetch server command
  push: pass ref prefixes when pushing
  fetch: pass ref prefixes when fetching
  ls-remote: pass ref prefixes when requesting a remote's refs
  transport: convert transport_get_remote_refs to take a list of ref prefixes
  ...
2018-04-24 11:24:22 +09:00
Stefan Beller
d807c4a01d exec_cmd: rename to use dash in file name
This is more consistent with the project style. The majority of Git's
source files use dashes in preference to underscores in their file names.

Signed-off-by: Stefan Beller <sbeller@google.com>
2018-04-11 18:11:00 +09:00
Junio C Hamano
3a1ec60c43 Merge branch 'sb/packfiles-in-repository'
Refactoring of the internal global data structure continues.

* sb/packfiles-in-repository:
  packfile: keep prepare_packed_git() private
  packfile: allow find_pack_entry to handle arbitrary repositories
  packfile: add repository argument to find_pack_entry
  packfile: allow reprepare_packed_git to handle arbitrary repositories
  packfile: allow prepare_packed_git to handle arbitrary repositories
  packfile: allow prepare_packed_git_one to handle arbitrary repositories
  packfile: add repository argument to reprepare_packed_git
  packfile: add repository argument to prepare_packed_git
  packfile: add repository argument to prepare_packed_git_one
  packfile: allow install_packed_git to handle arbitrary repositories
  packfile: allow rearrange_packed_git to handle arbitrary repositories
  packfile: allow prepare_packed_git_mru to handle arbitrary repositories
2018-04-11 13:09:55 +09:00
Junio C Hamano
5d806b74d5 Merge branch 'ti/fetch-everything-local-optim'
A "git fetch" from a repository with insane number of refs into a
repository that is already up-to-date still wasted too many cycles
making many lstat(2) calls to see if these objects at the tips
exist as loose objects locally.  These lstat(2) calls are optimized
away by enumerating all loose objects beforehand.

It is unknown if the new strategy negatively affects existing use
cases, fetching into a repository with many loose objects from a
repository with small number of refs.

* ti/fetch-everything-local-optim:
  fetch-pack.c: use oidset to check existence of loose object
2018-04-10 08:25:43 +09:00
Stefan Beller
a49d283435 packfile: add repository argument to reprepare_packed_git
See previous patch for explanation.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-26 10:07:43 -07:00
Brandon Williams
f7e2050105 fetch-pack: support shallow requests
Enable shallow clones and deepen requests using protocol version 2 if
the server 'fetch' command supports the 'shallow' feature.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-15 12:01:09 -07:00
Brandon Williams
685fbd3291 fetch-pack: perform a fetch using v2
When communicating with a v2 server, perform a fetch by requesting the
'fetch' command.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-15 12:01:08 -07:00
Jonathan Tan
98a2ea46c2 fetch-pack: do not check links for partial fetch
When doing a partial clone or fetch with transfer.fsckobjects=1, use the
--fsck-objects instead of the --strict flag when invoking index-pack so
that links are not checked, only objects. This is because incomplete
links are expected when doing a partial clone or fetch.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-15 10:16:27 -07:00
Takuto Ikuta
024aa4696c fetch-pack.c: use oidset to check existence of loose object
When fetching from a repository with large number of refs, because to
check existence of each refs in local repository to packed and loose
objects, 'git fetch' ends up doing a lot of lstat(2) to non-existing
loose form, which makes it slow.

Instead of making as many lstat(2) calls as the refs the remote side
advertised to see if these objects exist in the loose form, first
enumerate all the existing loose objects in hashmap beforehand and use
it to check existence of them if the number of refs is larger than the
number of loose objects.

With this patch, the number of lstat(2) calls in `git fetch` is reduced
from 411412 to 13794 for chromium repository, it has more than 480000
remote refs.

I took time stat of `git fetch` when fetch-pack happens for chromium
repository 3 times on linux with SSD.
* with this patch
8.105s
8.309s
7.640s
avg: 8.018s

* master
12.287s
11.175s
12.227s
avg: 11.896s

On my MacBook Air which has slower lstat(2).
* with this patch
14.501s

* master
1m16.027s

`git fetch` on slow disk will be improved largely.

Signed-off-by: Takuto Ikuta <tikuta@chromium.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-03-14 11:17:26 -07:00
Junio C Hamano
2fb346c06a Merge branch 'js/packet-read-line-check-null'
Some low level protocol codepath could crash when they get an
unexpected flush packet, which is now fixed.

* js/packet-read-line-check-null:
  always check for NULL return from packet_read_line()
  correct error messages for NULL packet_read_line()
2018-02-27 10:33:55 -08:00
Junio C Hamano
6bed209a20 Merge branch 'jh/partial-clone'
The machinery to clone & fetch, which in turn involves packing and
unpacking objects, have been told how to omit certain objects using
the filtering mechanism introduced by the jh/object-filtering
topic, and also mark the resulting pack as a promisor pack to
tolerate missing objects, taking advantage of the mechanism
introduced by the jh/fsck-promisors topic.

* jh/partial-clone:
  t5616: test bulk prefetch after partial fetch
  fetch: inherit filter-spec from partial clone
  t5616: end-to-end tests for partial clone
  fetch-pack: restore save_commit_buffer after use
  unpack-trees: batch fetching of missing blobs
  clone: partial clone
  partial-clone: define partial clone settings in config
  fetch: support filters
  fetch: refactor calculation of remote list
  fetch-pack: test support excluding large blobs
  fetch-pack: add --no-filter
  fetch-pack, index-pack, transport: partial clone
  upload-pack: add object filtering for partial clone
2018-02-13 13:39:04 -08:00
Junio C Hamano
f3d618d2bf Merge branch 'jh/fsck-promisors'
In preparation for implementing narrow/partial clone, the machinery
for checking object connectivity used by gc and fsck has been
taught that a missing object is OK when it is referenced by a
packfile specially marked as coming from trusted repository that
promises to make them available on-demand and lazily.

* jh/fsck-promisors:
  gc: do not repack promisor packfiles
  rev-list: support termination at promisor objects
  sha1_file: support lazily fetching missing objects
  introduce fetch-object: fetch one promisor object
  index-pack: refactor writing of .keep files
  fsck: support promisor objects as CLI argument
  fsck: support referenced promisor objects
  fsck: support refs pointing to promisor objects
  fsck: introduce partialclone extension
  extension.partialclone: introduce partial clone extension
2018-02-13 13:39:03 -08:00
Jeff King
bc9d4dc5b0 correct error messages for NULL packet_read_line()
The packet_read_line() function dies if it gets an
unexpected EOF. It only returns NULL if we get a flush
packet (or technically, a zero-length "0004" packet, but
nobody is supposed to send those, and they are
indistinguishable from a flush in this interface).

Let's correct error messages which claim an unexpected EOF;
it's really an unexpected flush packet.

While we're here, let's also check "!line" instead of
"!len" in the second case. The two events should always
coincide, but checking "!line" makes it more obvious that we
are not about to dereference NULL.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-08 12:37:30 -08:00
Jonathan Tan
a1c6d7c1a7 fetch-pack: restore save_commit_buffer after use
In fetch-pack, the global variable save_commit_buffer is set to 0, but
not restored to its original value after use.

In particular, if show_log() (in log-tree.c) is invoked after
fetch_pack() in the same process, show_log() will return before printing
out the commit message (because the invocation to
get_cached_commit_buffer() returns NULL, because the commit buffer was
not saved). I discovered this when attempting to run "git log -S" in a
partial clone, triggering the case where revision walking lazily loads
missing objects.

Therefore, restore save_commit_buffer to its original value after use.

An alternative to solve the problem I had is to replace
get_cached_commit_buffer() with get_commit_buffer(). That invocation was
introduced in commit a97934d ("use get_cached_commit_buffer where
appropriate", 2014-06-13) to replace "commit->buffer" introduced in
commit 3131b71 ("Add "--show-all" revision walker flag for debugging",
2008-02-13). In the latter commit, the commit author seems to be
deciding between not showing an unparsed commit at all and showing an
unparsed commit without the message (which is what the commit does), and
did not mention parsing the unparsed commit, so I prefer to preserve the
existing behavior.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-12-08 09:58:52 -08:00
Jeff Hostetler
640d8b72fe fetch-pack, index-pack, transport: partial clone
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-12-08 09:58:51 -08:00
Junio C Hamano
79bafd23a8 Merge branch 'jk/fewer-pack-rescan'
Internaly we use 0{40} as a placeholder object name to signal the
codepath that there is no such object (e.g. the fast-forward check
while "git fetch" stores a new remote-tracking ref says "we know
there is no 'old' thing pointed at by the ref, as we are creating
it anew" by passing 0{40} for the 'old' side), and expect that a
codepath to locate an in-core object to return NULL as a sign that
the object does not exist.  A look-up for an object that does not
exist however is quite costly with a repository with large number
of packfiles.  This access pattern has been optimized.

* jk/fewer-pack-rescan:
  sha1_file: fast-path null sha1 as a missing object
  everything_local: use "quick" object existence check
  p5551: add a script to test fetch pack-dir rescans
  t/perf/lib-pack: use fast-import checkpoint to create packs
  p5550: factor out nonsense-pack creation
2017-12-06 09:23:42 -08:00
Jonathan Tan
88e2f9ed8e introduce fetch-object: fetch one promisor object
Introduce fetch-object, providing the ability to fetch one object from a
promisor remote.

This uses fetch-pack. To do this, the transport mechanism has been
updated with 2 flags, "from-promisor" to indicate that the resulting
pack comes from a promisor remote (and thus should be annotated as such
by index-pack), and "no-dependents" to indicate that only the objects
themselves need to be fetched (but fetching additional objects is
nevertheless safe).

Whenever "no-dependents" is used, fetch-pack will refrain from using any
object flags, because it is most likely invoked as part of a dynamic
object fetch by another Git command (which may itself use object flags).
An alternative to this is to leave fetch-pack alone, and instead update
the allocation of flags so that fetch-pack's flags never overlap with
any others, but this will end up shrinking the number of flags available
to nearly every other Git command (that is, every Git command that
accesses objects), so the approach in this commit was used instead.

This will be tested in a subsequent commit.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-12-05 09:46:05 -08:00
Jeff King
c291293b2e everything_local: use "quick" object existence check
In b495697b82 (fetch-pack: avoid repeatedly re-scanning pack
directory, 2013-01-26), we noticed that everything_local()
could waste time trying to find and parse objects which we
_expect_ to be missing. The solution was to put
has_sha1_file() in front of parse_object() to skip the
more-expensive parse attempt.

That optimization was negated later when has_sha1_file()
learned to do the same re-scan in 45e8a74873 (has_sha1_file:
re-check pack directory before giving up, 2013-08-30).

We can restore it by using the "quick" flag to tell
has_sha1_file (actually has_object_file these days) that we
prefer speed to thoroughness for this call.  See also the
fixes in 5827a0354 and 0eeb077be7 for prior art and
discussion on using the "quick" flag for these cases.

The recently-added performance regression test in p5551
demonstrates the problem. You can see the original fix:

  Test            b495697b82^       b495697b82
  --------------------------------------------------------
  5551.4: fetch   1.68(1.33+0.35)   0.87(0.69+0.18) -48.2%

and then the regression:

  Test            45e8a74873^       45e8a74873
  ---------------------------------------------------------
  5551.4: fetch   0.96(0.77+0.19)   2.55(2.04+0.50) +165.6%

and now our fix:

  Test            HEAD^             HEAD
  --------------------------------------------------------
  5551.4: fetch   7.21(6.58+0.63)   5.47(5.04+0.43) -24.1%

You can also see that other things have gotten a lot slower
since 2013. We'll deal with those in separate patches.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-11-21 11:30:41 +09:00
Jonathan Tan
9e6fabde82 oidmap: map with OID as key
This is similar to using the hashmap in hashmap.c, but with an
easier-to-use API. In particular, custom entry comparisons no longer
need to be written, and lookups can be done without constructing a
temporary entry structure.

This is implemented as a thin wrapper over the hashmap API. In
particular, this means that there is an additional 4-byte overhead due
to the fact that the first 4 bytes of the hash is redundantly stored.
For now, I'm taking the simpler approach, but if need be, we can
reimplement oidmap without affecting the callers significantly.

oidset has been updated to use oidmap.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-10-01 17:18:03 +09:00
Jonathan Tan
0abe14f6a5 pack: move {,re}prepare_packed_git and approximate_object_count
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-08-23 15:12:07 -07:00
Junio C Hamano
f31d23a399 Merge branch 'bw/config-h'
Fix configuration codepath to pay proper attention to commondir
that is used in multi-worktree situation, and isolate config API
into its own header file.

* bw/config-h:
  config: don't implicitly use gitdir or commondir
  config: respect commondir
  setup: teach discover_git_directory to respect the commondir
  config: don't include config.h by default
  config: remove git_config_iter
  config: create config.h
2017-06-24 14:28:41 -07:00
Brandon Williams
b2141fc1d2 config: don't include config.h by default
Stop including config.h by default in cache.h.  Instead only include
config.h in those files which require use of the config system.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-15 12:56:22 -07:00
Junio C Hamano
02c531eba2 Merge branch 'jt/fetch-allow-tip-sha1-implicitly'
There is no good reason why "git fetch $there $sha1" should fail
when the $sha1 names an object at the tip of an advertised ref,
even when the other side hasn't enabled allowTipSHA1InWant.

* jt/fetch-allow-tip-sha1-implicitly:
  fetch-pack: always allow fetching of literal SHA1s
2017-05-30 11:16:43 +09:00
Junio C Hamano
6b526ced6f Merge branch 'bc/object-id'
Conversion from uchar[20] to struct object_id continues.

* bc/object-id: (53 commits)
  object: convert parse_object* to take struct object_id
  tree: convert parse_tree_indirect to struct object_id
  sequencer: convert do_recursive_merge to struct object_id
  diff-lib: convert do_diff_cache to struct object_id
  builtin/ls-tree: convert to struct object_id
  merge: convert checkout_fast_forward to struct object_id
  sequencer: convert fast_forward_to to struct object_id
  builtin/ls-files: convert overlay_tree_on_cache to object_id
  builtin/read-tree: convert to struct object_id
  sha1_name: convert internals of peel_onion to object_id
  upload-pack: convert remaining parse_object callers to object_id
  revision: convert remaining parse_object callers to object_id
  revision: rename add_pending_sha1 to add_pending_oid
  http-push: convert process_ls_object and descendants to object_id
  refs/files-backend: convert many internals to struct object_id
  refs: convert struct ref_update to use struct object_id
  ref-filter: convert some static functions to struct object_id
  Convert struct ref_array_item to struct object_id
  Convert the verify_pack callback to struct object_id
  Convert lookup_tag to struct object_id
  ...
2017-05-29 12:34:43 +09:00
Junio C Hamano
b15667bbdc Merge branch 'js/larger-timestamps'
Some platforms have ulong that is smaller than time_t, and our
historical use of ulong for timestamp would mean they cannot
represent some timestamp that the platform allows.  Invent a
separate and dedicated timestamp_t (so that we can distingiuish
timestamps and a vanilla ulongs, which along is already a good
move), and then declare uintmax_t is the type to be used as the
timestamp_t.

* js/larger-timestamps:
  archive-tar: fix a sparse 'constant too large' warning
  use uintmax_t for timestamps
  date.c: abort if the system time cannot handle one of our timestamps
  timestamp_t: a new data type for timestamps
  PRItime: introduce a new "printf format" for timestamps
  parse_timestamp(): specify explicitly where we parse timestamps
  t0006 & t5000: skip "far in the future" test when time_t is too limited
  t0006 & t5000: prepare for 64-bit timestamps
  ref-filter: avoid using `unsigned long` for catch-all data type
2017-05-16 11:51:59 +09:00
Jonathan Tan
fdb69d33c4 fetch-pack: always allow fetching of literal SHA1s
fetch-pack, when fetching a literal SHA-1 from a server that is not
configured with uploadpack.allowtipsha1inwant (or similar), always
returns an error message of the form "Server does not allow request for
unadvertised object %s". However, it is sometimes the case that such
object is advertised. This situation would occur, for example, if a user
or a script was provided a SHA-1 instead of a branch or tag name for
fetching, and wanted to invoke "git fetch" or "git fetch-pack" using
that SHA-1.

Teach fetch-pack to also check the SHA-1s of the refs in the received
ref advertisement if a literal SHA-1 was given by the user.

Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-16 10:17:05 +09:00
brian m. carlson
c251c83df2 object: convert parse_object* to take struct object_id
Make parse_object, parse_object_or_die, and parse_object_buffer take a
pointer to struct object_id.  Remove the temporary variables inserted
earlier, since they are no longer necessary.  Transform all of the
callers using the following semantic patch:

@@
expression E1;
@@
- parse_object(E1.hash)
+ parse_object(&E1)

@@
expression E1;
@@
- parse_object(E1->hash)
+ parse_object(E1)

@@
expression E1, E2;
@@
- parse_object_or_die(E1.hash, E2)
+ parse_object_or_die(&E1, E2)

@@
expression E1, E2;
@@
- parse_object_or_die(E1->hash, E2)
+ parse_object_or_die(E1, E2)

@@
expression E1, E2, E3, E4, E5;
@@
- parse_object_buffer(E1.hash, E2, E3, E4, E5)
+ parse_object_buffer(&E1, E2, E3, E4, E5)

@@
expression E1, E2, E3, E4, E5;
@@
- parse_object_buffer(E1->hash, E2, E3, E4, E5)
+ parse_object_buffer(E1, E2, E3, E4, E5)

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-08 15:12:58 +09:00
brian m. carlson
bc83266abe Convert lookup_commit* to struct object_id
Convert lookup_commit, lookup_commit_or_die,
lookup_commit_reference, and lookup_commit_reference_gently to take
struct object_id arguments.

Introduce a temporary in parse_object buffer in order to convert this
function.  This is required since in order to convert parse_object and
parse_object_buffer, lookup_commit_reference_gently and
lookup_commit_or_die would need to be converted.  Not introducing a
temporary would therefore require that lookup_commit_or_die take a
struct object_id *, but lookup_commit would take unsigned char *,
leaving a confusing and hard-to-use interface.

parse_object_buffer will lose this temporary in a later patch.

This commit was created with manual changes to commit.c, commit.h, and
object.c, plus the following semantic patch:

@@
expression E1, E2;
@@
- lookup_commit_reference_gently(E1.hash, E2)
+ lookup_commit_reference_gently(&E1, E2)

@@
expression E1, E2;
@@
- lookup_commit_reference_gently(E1->hash, E2)
+ lookup_commit_reference_gently(E1, E2)

@@
expression E1;
@@
- lookup_commit_reference(E1.hash)
+ lookup_commit_reference(&E1)

@@
expression E1;
@@
- lookup_commit_reference(E1->hash)
+ lookup_commit_reference(E1)

@@
expression E1;
@@
- lookup_commit(E1.hash)
+ lookup_commit(&E1)

@@
expression E1;
@@
- lookup_commit(E1->hash)
+ lookup_commit(E1)

@@
expression E1, E2;
@@
- lookup_commit_or_die(E1.hash, E2)
+ lookup_commit_or_die(&E1, E2)

@@
expression E1, E2;
@@
- lookup_commit_or_die(E1->hash, E2)
+ lookup_commit_or_die(E1, E2)

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-08 15:12:57 +09:00
brian m. carlson
e92b848cb6 shallow: convert shallow registration functions to object_id
Convert register_shallow and unregister_shallow to take struct
object_id.  register_shallow is a caller of lookup_commit, which we will
convert later.  It doesn't make sense for the registration and
unregistration functions to have incompatible interfaces, so convert
them both.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-08 15:12:57 +09:00
brian m. carlson
1b283377b1 fetch-pack: convert to struct object_id
Convert all uses of unsigned char [20] to struct object_id.  Switch one
use of get_sha1_hex to parse_oid_hex to avoid the need for a constant.
This change is necessary in order to convert parse_object.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-02 10:46:41 +09:00
Johannes Schindelin
dddbad728c timestamp_t: a new data type for timestamps
Git's source code assumes that unsigned long is at least as precise as
time_t. Which is incorrect, and causes a lot of problems, in particular
where unsigned long is only 32-bit (notably on Windows, even in 64-bit
versions).

So let's just use a more appropriate data type instead. In preparation
for this, we introduce the new `timestamp_t` data type.

By necessity, this is a very, very large patch, as it has to replace all
timestamps' data type in one go.

As we will use a data type that is not necessarily identical to `time_t`,
we need to be very careful to use `time_t` whenever we interact with the
system functions, and `timestamp_t` everywhere else.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-27 13:07:39 +09:00
Junio C Hamano
5938454cbc Merge branch 'dt/xgethostname-nul-termination'
gethostname(2) may not NUL terminate the buffer if hostname does
not fit; unfortunately there is no easy way to see if our buffer
was too small, but at least this will make sure we will not end up
using garbage past the end of the buffer.

* dt/xgethostname-nul-termination:
  xgethostname: handle long hostnames
  use HOST_NAME_MAX to size buffers for gethostname(2)
2017-04-23 22:07:57 -07:00
Junio C Hamano
d2617eb984 Merge branch 'jt/fetch-pack-error-reporting'
"git fetch-pack" was not prepared to accept ERR packet that the
upload-pack can send with a human-readable error message.  It
showed the packet contents with ERR prefix, so there was no data
loss, but it was redundant to say "ERR" in an error message.

* jt/fetch-pack-error-reporting:
  fetch-pack: show clearer error message upon ERR
2017-04-23 22:07:53 -07:00
Johannes Schindelin
cb71f8bdb5 PRItime: introduce a new "printf format" for timestamps
Currently, Git's source code treats all timestamps as if they were
unsigned longs. Therefore, it is okay to write "%lu" when printing them.

There is a substantial problem with that, though: at least on Windows,
time_t is *larger* than unsigned long, and hence we will want to switch
away from the ill-specified `unsigned long` data type.

So let's introduce the pseudo format "PRItime" (currently simply being
defined to "lu") to make it easier to change the data type used for
timestamps.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-23 20:19:15 -07:00
David Turner
5781a9a270 xgethostname: handle long hostnames
If the full hostname doesn't fit in the buffer supplied to
gethostname, POSIX does not specify whether the buffer will be
null-terminated, so to be safe, we should do it ourselves.  Introduce
new function, xgethostname, which ensures that there is always a \0
at the end of the buffer.

Signed-off-by: David Turner <dturner@twosigma.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-18 19:58:04 -07:00
René Scharfe
da25bdb776 use HOST_NAME_MAX to size buffers for gethostname(2)
POSIX limits the length of host names to HOST_NAME_MAX.  Export the
fallback definition from daemon.c and use this constant to make all
buffers used with gethostname(2) big enough for any possible result
and a terminating NUL.

Inspired-by: David Turner <dturner@twosigma.com>
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: David Turner <dturner@twosigma.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-18 19:57:41 -07:00
Jonathan Tan
8e2c7bef03 fetch-pack: show clearer error message upon ERR
Currently, fetch-pack prints a confusing error message ("expected
ACK/NAK") when the server it's communicating with sends a pkt-line
starting with "ERR".  Replace it with a less confusing error message.

Also update the documentation describing the fetch-pack/upload-pack
protocol (pack-protocol.txt) to indicate that "ERR" can be sent in the
place of "ACK" or "NAK". In practice, this has been done for quite some
time by other Git implementations (e.g. JGit sends "want $id not valid")
and by Git itself (since commit bdb31ea: "upload-pack: report "not our
ref" to client", 2017-02-23) whenever a "want" line references an object
that it does not have. (This is uncommon, but can happen if a repository
is garbage-collected during a negotiation.)

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-17 18:51:28 -07:00
brian m. carlson
910650d2f8 Rename sha1_array to oid_array
Since this structure handles an array of object IDs, rename it to struct
oid_array.  Also rename the accessor functions and the initialization
constant.

This commit was produced mechanically by providing non-Documentation
files to the following Perl one-liners:

    perl -pi -E 's/struct sha1_array/struct oid_array/g'
    perl -pi -E 's/\bsha1_array_/oid_array_/g'
    perl -pi -E 's/SHA1_ARRAY_INIT/OID_ARRAY_INIT/g'

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-31 08:33:56 -07:00
brian m. carlson
98a72ddc12 Make sha1_array_append take a struct object_id *
Convert the callers to pass struct object_id by changing the function
declaration and definition and applying the following semantic patch:

@@
expression E1, E2;
@@
- sha1_array_append(E1, E2.hash)
+ sha1_array_append(E1, &E2)

@@
expression E1, E2;
@@
- sha1_array_append(E1, E2->hash)
+ sha1_array_append(E1, E2)

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-31 08:33:55 -07:00
brian m. carlson
ee3051bd23 sha1-array: convert internal storage for struct sha1_array to object_id
Make the internal storage for struct sha1_array use an array of struct
object_id internally.  Update the users of this struct which inspect its
internals.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-28 09:59:34 -07:00
Junio C Hamano
07198afbd1 Merge branch 'mm/fetch-show-error-message-on-unadvertised-object'
"git fetch" that requests a commit by object name, when the other
side does not allow such an request, failed without much
explanation.

* mm/fetch-show-error-message-on-unadvertised-object:
  fetch-pack: add specific error for fetching an unadvertised object
  fetch_refs_via_pack: call report_unmatched_refs
  fetch-pack: move code to report unmatched refs to a function
2017-03-14 15:23:18 -07:00
Matt McCutchen
d56583ded6 fetch-pack: add specific error for fetching an unadvertised object
Enhance filter_refs (which decides whether a request for an unadvertised
object should be sent to the server) to record a new match status on the
"struct ref" when a request is not allowed, and have
report_unmatched_refs check for this status and print a special error
message, "Server does not allow request for unadvertised object".

Signed-off-by: Matt McCutchen <matt@mattmccutchen.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-02 11:12:53 -08:00
Matt McCutchen
e860d96bf8 fetch-pack: move code to report unmatched refs to a function
Prepare to reuse this code in transport.c for "git fetch".

While we're here, internationalize the existing error message.

Signed-off-by: Matt McCutchen <matt@mattmccutchen.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-02 11:12:53 -08:00
Jeff King
41a078c60b fetch-pack: cache results of for_each_alternate_ref
We may run for_each_alternate_ref() twice, once in
find_common() and once in everything_local(). This operation
can be expensive, because it involves running a sub-process
which must freshly load all of the alternate's refs from
disk.

Let's cache and reuse the results between the two calls. We
can make some optimizations based on the particular use
pattern in fetch-pack to keep our memory usage down.

The first is that we only care about the sha1s, not the refs
themselves. So it's OK to store only the sha1s, and to
suppress duplicates. The natural fit would therefore be a
sha1_array.

However, sha1_array's de-duplication happens only after it
has read and sorted all entries. It still stores each
duplicate. For an alternate with a large number of refs
pointing to the same commits, this is a needless expense.

Instead, we'd prefer to eliminate duplicates before putting
them in the cache, which implies using a hash. We can
further note that fetch-pack will call parse_object() on
each alternate sha1. We can therefore keep our cache as a
set of pointers to "struct object". That gives us a place to
put our "already seen" bit with an optimized hash lookup.
And as a bonus, the object stores the sha1 for us, so
pointer-to-object is all we need.

There are two extra optimizations I didn't do here:

  - we actually store an array of pointer-to-object.
    Technically we could just walk the obj_hash table
    looking for entries with the ALTERNATE flag set (because
    our use case doesn't care about the order here).

    But that hash table may be mostly composed of
    non-ALTERNATE entries, so we'd waste time walking over
    them. So it would be a slight win in memory use, but a
    loss in CPU.

  - the items we pull out of the cache are actual "struct
    object"s, but then we feed "obj->sha1" to our
    sub-functions, which promptly call parse_object().

    This second parse is cheap, because it starts with
    lookup_object() and will bail immediately when it sees
    we've already parsed the object. We could save the extra
    hash lookup, but it would involve refactoring the
    functions we call. It may or may not be worth the
    trouble.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-02-08 15:39:55 -08:00
Jeff King
2429d63a46 for_each_alternate_ref: pass name/oid instead of ref struct
Breaking down the fields in the interface makes it easier to
change the backend of for_each_alternate_ref to something
that doesn't use "struct ref" internally.

The only field that callers actually look at is the oid,
anyway. The refname is kept in the interface as a plausible
thing for future code to want.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-02-08 15:39:55 -08:00
Ralf Thielow
dfbfb9f377 fetch-pack.c: correct command at the beginning of an error message
One error message in fetch-pack.c uses 'git fetch_pack' at the beginning
which is not a git command.  Use 'git fetch-pack' instead.

Signed-off-by: Ralf Thielow <ralf.thielow@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-11-11 13:28:39 -08:00
Junio C Hamano
a460ea4a3c Merge branch 'nd/shallow-deepen'
The existing "git fetch --depth=<n>" option was hard to use
correctly when making the history of an existing shallow clone
deeper.  A new option, "--deepen=<n>", has been added to make this
easier to use.  "git clone" also learned "--shallow-since=<date>"
and "--shallow-exclude=<tag>" options to make it easier to specify
"I am interested only in the recent N months worth of history" and
"Give me only the history since that version".

* nd/shallow-deepen: (27 commits)
  fetch, upload-pack: --deepen=N extends shallow boundary by N commits
  upload-pack: add get_reachable_list()
  upload-pack: split check_unreachable() in two, prep for get_reachable_list()
  t5500, t5539: tests for shallow depth excluding a ref
  clone: define shallow clone boundary with --shallow-exclude
  fetch: define shallow boundary with --shallow-exclude
  upload-pack: support define shallow boundary by excluding revisions
  refs: add expand_ref()
  t5500, t5539: tests for shallow depth since a specific date
  clone: define shallow clone boundary based on time with --shallow-since
  fetch: define shallow boundary with --shallow-since
  upload-pack: add deepen-since to cut shallow repos based on time
  shallow.c: implement a generic shallow boundary finder based on rev-list
  fetch-pack: use a separate flag for fetch in deepening mode
  fetch-pack.c: mark strings for translating
  fetch-pack: use a common function for verbose printing
  fetch-pack: use skip_prefix() instead of starts_with()
  upload-pack: move rev-list code out of check_non_tip()
  upload-pack: make check_non_tip() clean things up on error
  upload-pack: tighten number parsing at "deepen" lines
  ...
2016-10-10 14:03:50 -07:00
Junio C Hamano
b8688adb12 Merge branch 'rs/qsort'
We call "qsort(array, nelem, sizeof(array[0]), fn)", and most of
the time third parameter is redundant.  A new QSORT() macro lets us
omit it.

* rs/qsort:
  show-branch: use QSORT
  use QSORT, part 2
  coccicheck: use --all-includes by default
  remove unnecessary check before QSORT
  use QSORT
  add QSORT
2016-10-10 14:03:46 -07:00
René Scharfe
9ed0d8d6e6 use QSORT
Apply the semantic patch contrib/coccinelle/qsort.cocci to the code
base, replacing calls of qsort(3) with QSORT.  The resulting code is
shorter and supports empty arrays with NULL pointers.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-29 15:42:18 -07:00
Jonathan Tan
06b3d386e0 fetch-pack: do not reset in_vain on non-novel acks
The MAX_IN_VAIN mechanism was introduced in commit f061e5f ("fetch-pack:
give up after getting too many "ack continue"", 2006-05-24) to stop ref
negotiation if a number of consecutive "have"s have been sent with no
corresponding new acks. This is to stop the client from digging too deep
in an irrelevant side branch in vain without ever finding a common
ancestor. A use case (as described in that commit) is the scenario in
which the local repository has more roots than the remote repository.

However, during a negotiation in which stateless RPCs are used,
MAX_IN_VAIN will (almost) never trigger (in the more-roots scenario
above and others) because in each new request, the client has to inform
the server of objects it already has and knows the server has (to remind
the server of the state), which the server then acks.

Make fetch-pack only consider, as new acks for the purpose of
MAX_IN_VAIN, acks for objects for which the client has never received an
ack before in this session.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-23 12:37:45 -07:00
Jonathan Tan
da470981de fetch-pack: grow stateless RPC windows exponentially
When updating large repositories, the LARGE_FLUSH limit (that is, the
limit at which the window growth strategy switches from exponential to
linear) is reached quite quickly. Use a conservative exponential growth
strategy when that limit is reached instead (and increase LARGE_FLUSH so
that there is no regression in window size).

This optimization is only applied during stateless RPCs to avoid the
issue raised and fixed in commit 44d8dc54 (Fix potential local
deadlock during fetch-pack, 2011-03-29).

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-19 13:27:22 -07:00
Nguyễn Thái Ngọc Duy
cccf74e2da fetch, upload-pack: --deepen=N extends shallow boundary by N commits
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>
2016-06-13 14:38:16 -07:00
Nguyễn Thái Ngọc Duy
a45a260086 fetch: define shallow boundary with --shallow-exclude
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-06-13 14:38:16 -07:00
Nguyễn Thái Ngọc Duy
508ea88226 fetch: define shallow boundary with --shallow-since
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-06-13 14:38:16 -07:00
Nguyễn Thái Ngọc Duy
79891cb90a fetch-pack: use a separate flag for fetch in deepening mode
The shallow repo could be deepened or shortened when then user gives
--depth. But in future that won't be the only way to deepen/shorten a
repo. Stop relying on args->depth in this mode. Future deepening
methods can simply set this flag on instead of updating all these if
expressions.

The new name "deepen" was chosen after the command to define shallow
boundary in pack protocol. New commands also follow this tradition.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-06-13 14:38:16 -07:00
Nguyễn Thái Ngọc Duy
1dd73e20d7 fetch-pack.c: mark strings for translating
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-06-13 14:38:16 -07:00
Nguyễn Thái Ngọc Duy
0d789a5bc1 fetch-pack: use a common function for verbose printing
This reduces the number of "if (verbose)" which makes it a bit easier
to read imo. It also makes it easier to redirect all these printouts,
to a file for example.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-06-13 14:38:16 -07:00
Jeff King
df85757244 fetch-pack: isolate sigpipe in demuxer thread
In commit 9ff18fa (fetch-pack: ignore SIGPIPE in sideband
demuxer, 2016-02-24), we started using sigchain_push() to
ignore SIGPIPE in the async demuxer thread. However, this is
rather clumsy, as it ignores SIGPIPE for the entire process,
including the main thread. At the time we didn't have any
per-thread signal support, but we now we do. Let's use it.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-04-20 13:33:56 -07:00
Jeff King
9ff18faf2f fetch-pack: ignore SIGPIPE in sideband demuxer
If the other side feeds us a bogus pack, index-pack (or
unpack-objects) may die early, before consuming all of its
input. As a result, the sideband demuxer may get SIGPIPE
(racily, depending on whether our data made it into the pipe
buffer or not). If this happens and we are compiled with
pthread support, it will take down the main thread, too.

This isn't the end of the world, as the main process will
just die() anyway when it sees index-pack failed. But it
does mean we don't get a chance to say "fatal: index-pack
failed" or similar. And it also means that we racily fail
t5504, as we sometimes die() and sometimes are killed by
SIGPIPE.

So let's ignore SIGPIPE while demuxing the sideband. We are
already careful to check the return value of write(), so we
won't waste time writing to a broken pipe. The caller will
notice the error return from the async thread, though in
practice we don't even get that far, as we die() as soon as
we see that index-pack failed.

The non-sideband case is already fine; we let index-pack
read straight from the socket, so there is no SIGPIPE at
all. Technically the non-threaded async case is also OK
without this (the forked async process gets SIGPIPE), but
it's not worth distinguishing from the threaded case here.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-02-25 13:51:47 -08:00
brian m. carlson
ed1c9977cb Remove get_object_hash.
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>
2015-11-20 08:02:05 -05:00
brian m. carlson
f2fd0760f6 Convert struct object to object_id
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>
2015-11-20 08:02:05 -05:00
brian m. carlson
7999b2cf77 Add several uses of get_object_hash.
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>
2015-11-20 08:02:05 -05:00
brian m. carlson
f4e54d02b8 Convert struct ref to use object_id.
Use struct object_id in three fields in struct ref and convert all the
necessary places that use it.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Jeff King <peff@peff.net>
2015-11-20 08:02:05 -05:00
Jeff King
984a43b902 fetch-pack: use argv_array for index-pack / unpack-objects
This cleans up a magic number that must be kept in sync with
the rest of the code (the number of argv slots). It also
lets us drop some fixed buffers and an sprintf (since we
can now use argv_array_pushf).

We do still have to keep one fixed buffer for calling
gethostname, but at least now the size computations for it
are much simpler.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-10-05 11:08:05 -07:00
Jeff King
f932729cc7 memoize common git-path "constant" files
One of the most common uses of git_path() is to pass a
constant, like git_path("MERGE_MSG"). This has two
drawbacks:

  1. The return value is a static buffer, and the lifetime
     is dependent on other calls to git_path, etc.

  2. There's no compile-time checking of the pathname. This
     is OK for a one-off (after all, we have to spell it
     correctly at least once), but many of these constant
     strings appear throughout the code.

This patch introduces a series of functions to "memoize"
these strings, which are essentially globals for the
lifetime of the program. We compute the value once, take
ownership of the buffer, and return the cached value for
subsequent calls.  cache.h provides a helper macro for
defining these functions as one-liners, and defines a few
common ones for global use.

Using a macro is a little bit gross, but it does nicely
document the purpose of the functions. If we need to touch
them all later (e.g., because we learned how to change the
git_dir variable at runtime, and need to invalidate all of
the stored values), it will be much easier to have the
complete list.

Note that the shared-global functions have separate, manual
declarations. We could do something clever with the macros
(e.g., expand it to a declaration in some places, and a
declaration _and_ a definition in path.c). But there aren't
that many, and it's probably better to stay away from
too-magical macros.

Likewise, if we abandon the C preprocessor in favor of
generating these with a script, we could get much fancier.
E.g., normalizing "FOO/BAR-BAZ" into "git_path_foo_bar_baz".
But the small amount of saved typing is probably not worth
the resulting confusion to readers who want to grep for the
function's definition.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-08-10 15:37:14 -07:00
Junio C Hamano
58eb0122f3 Merge branch 'me/fetch-into-shallow-safety'
"git fetch --depth=<depth>" and "git clone --depth=<depth>" issued
a shallow transfer request even to an upload-pack that does not
support the capability.

* me/fetch-into-shallow-safety:
  fetch-pack: check for shallow if depth given
2015-07-01 14:02:33 -07:00
Mike Edgar
eb86a507a1 fetch-pack: check for shallow if depth given
When a repository is first fetched as a shallow clone, either by
git-clone or by fetching into an empty repo, the server's capabilities
are not currently consulted. The client will send shallow requests even
if the server does not understand them, and the resulting error may be
unhelpful to the user. This change pre-emptively checks so we can exit
with a helpful error if necessary.

Signed-off-by: Mike Edgar <adgar@google.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-17 12:03:58 -07:00
Junio C Hamano
5455ee0573 Merge branch 'bc/object-id'
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
  ...
2015-06-05 12:17:37 -07:00
Michael Haggerty
c38cd1c89d rev_list_insert_ref(): remove unneeded arguments
Now that the function is not being used as an each_ref_sha1_fn, we can
delete the unused arguments in its signature.

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>
2015-05-25 12:19:39 -07:00
Michael Haggerty
b1b49c6eb6 rev_list_insert_ref_oid(): new function, taking an object_oid
This function can be used with for_each_ref() without having to be
wrapped.

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>
2015-05-25 12:19:39 -07:00
Michael Haggerty
6e20a51a80 mark_complete(): remove unneeded arguments
Now that the function is not being used as an each_ref_sha1_fn, we can
delete the unused arguments in its signature.

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>
2015-05-25 12:19:38 -07:00
Michael Haggerty
f8ee4d8522 mark_complete_oid(): new function, taking an object_oid
This function can be used with for_each_ref() without having to be
wrapped.

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>
2015-05-25 12:19:38 -07:00
Michael Haggerty
c50fb6cee6 clear_marks(): rewrite to take an object_id argument
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>
2015-05-25 12:19:38 -07:00
Michael Haggerty
2b2a5be394 each_ref_fn: change to take an object_id parameter
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>
2015-05-25 12:19:27 -07:00
Fredrik Medley
68ee628932 upload-pack: optionally allow fetching reachable sha1
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>
2015-05-22 18:25:36 -07:00
Fredrik Medley
7199c093ad upload-pack: prepare to extend allow-tip-sha1-in-want
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>
2015-05-22 18:25:35 -07:00
Jeff King
32d0462f8d fetch-pack: remove dead assignment to ref->new_sha1
In everything_local(), we used to assign the current ref's value
found in ref->old_sha1 to ref->new_sha1 when we already have all the
necessary objects to complete the history leading to that
commit.  This copying was broken at 49bb805e (Do not ask for
objects known to be complete., 2005-10-19) and ever since we
instead stuffed a random bytes in ref->new_sha1 here.  No
code complained or failed due to this breakage.

It turns out that no code path that comes after this
assignment even looks at ref->new_sha1 at all.

 - The only caller of everything_local(), do_fetch_pack(),
   returns this list of refs, whose element has bogus
   new_sha1 values, to its caller.  It does not look at the
   elements itself, but does pass them to find_common, which
   looks only at the name and old_sha1 fields.

 - The only caller of do_fetch_pack(), fetch_pack(), returns this
   list to its caller.  It does not look at the elements nor act on
   them.

 - One of the two callers of fetch_pack() is cmd_fetch_pack(), the
   top-level that implements "git fetch-pack".  The only thing it
   looks at in the elements of the returned ref list is the old_sha1
   and name fields.

 - The other caller of fetch_pack() is fetch_refs_via_pack() in the
   transport layer, which is a helper that implements "git fetch".
   It only cares about whether the returned list is empty (i.e.
   failed to fetch anything).

Just drop the bogus assignment, that is not even necessary.  The
remote-tracking refs are updated based on a different list and not
using the ref list being manipulated by this code path; the caller
do_fetch_pack() created a copy of that real ref list and passed the
copy down to this function, and modifying the elements here does not
affect anything.

Noticed-by: Kyle J. McKay <mackyle@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-19 14:11:52 -07:00
Jeff King
c3c17bf107 filter_ref: make a copy of extra "sought" entries
If the server supports allow_tip_sha1_in_want, we add any
unmatched raw-sha1 entries in our "sought" list of refs to
the list of refs we will ask the other side for. We do so by
inserting the original "struct ref" directly into our list,
rather than making a copy. This has several problems.

The most minor problem is that one cannot ever free the
resulting list; it contains structs that are copies of the
remote refs (made earlier by fetch_pack) along with sought
refs that are referenced elsewhere.

But more importantly that we set the ref->next pointer to
NULL, chopping off the remainder of any existing list that
the ref was a part of. We get the set of "sought" refs in
an array rather than a linked list, but that array is often
in turn generated from a list.  The test modification in
t5516 demonstrates this. Rather than fetching just an exact
sha1, we fetch that sha1 plus another ref:

  - we build a linked list of refs to fetch when do_fetch
    calls get_ref_map; the exact sha1 is first, followed by
    the named ref ("refs/heads/extra" in this case).

  - we pass that linked list to transport_fetch_ref, which
    squashes it into an array of pointers

  - that array goes to fetch_pack, which calls filter_ref.
    There we generate the want list from a mix of what the
    remote side has advertised, and the "sought" entry for
    the exact sha1. We set the sought entry's "next" pointer
    to NULL.

  - after we return from transport_fetch_refs, we then try
    to update the refs by following the linked list. But our
    list is now truncated, and we do not update
    refs/heads/extra at all.

We can fix this by making a copy of the ref. There's nothing
that fetch_pack does to it that must be reflected in the
original "sought" list (and indeed, if that were the case we
would have a serious bug, because it is only exact-sha1
entries which are treated this way).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-19 14:11:11 -07:00
Jeff King
b7916422c7 filter_ref: avoid overwriting ref->old_sha1 with garbage
If the server supports allow_tip_sha1_in_want, then
fetch-pack's filter_refs function tries to check whether a
ref is a request for a straight sha1 by running:

  if (get_sha1_hex(ref->name, ref->old_sha1))
	  ...

I.e., we are using get_sha1_hex to ask "is this ref name a
sha1?". If it is true, then the contents of ref->old_sha1
will end up unchanged. But if it is false, then get_sha1_hex
makes no guarantees about what it has written. With a ref
name like "abcdefoo", we would overwrite 3 bytes of
ref->old_sha1 before realizing that it was not a sha1.

This is likely not a problem in practice, as anything in
refs->name (besides a sha1) will start with "refs/", meaning
that we would notice on the first character that there is a
problem. Still, we are making assumptions about the state
left in the output when get_sha1_hex returns an error (e.g.,
it could start from the end of the string, or error check
the values only once they were placed in the output). It's
better to be defensive.

We could just check that we have exactly 40 characters of
sha1. But let's be even more careful and make sure that we
have a 40-char hex refname that matches what is in old_sha1.
This is perhaps overly defensive, but spells out our
assumptions clearly.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-19 13:52:54 -07:00
Michael Haggerty
697cc8efd9 lockfile.h: extract new header file for the functions in lockfile.c
Move the interface declaration for the functions in lockfile.c from
cache.h to a new file, lockfile.h. Add #includes where necessary (and
remove some redundant includes of cache.h by files that already
include builtin.h).

Move the documentation of the lock_file state diagram from lockfile.c
to the new header file.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-10-01 13:56:14 -07:00
Junio C Hamano
825fd93767 Merge branch 'rs/child-process-init'
Code clean-up.

* rs/child-process-init:
  run-command: inline prepare_run_command_v_opt()
  run-command: call run_command_v_opt_cd_env() instead of duplicating it
  run-command: introduce child_process_init()
  run-command: introduce CHILD_PROCESS_INIT
2014-09-11 10:33:27 -07:00
René Scharfe
d318027932 run-command: introduce CHILD_PROCESS_INIT
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>
2014-08-20 09:53:37 -07:00
Tanay Abhra
f44af51d13 fetchpack.c: replace git_config() with git_config_get_*() family
Use `git_config_get_*()` family instead of `git_config()` to take advantage of
the config-set API which provides a cleaner control flow.

Signed-off-by: Tanay Abhra <tanayabh@gmail.com>
Reviewed-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-08-07 13:33:27 -07:00
Junio C Hamano
e91ae32a01 Merge branch 'jk/skip-prefix'
* jk/skip-prefix:
  http-push: refactor parsing of remote object names
  imap-send: use skip_prefix instead of using magic numbers
  use skip_prefix to avoid repeated calculations
  git: avoid magic number with skip_prefix
  fetch-pack: refactor parsing in get_ack
  fast-import: refactor parsing of spaces
  stat_opt: check extra strlen call
  daemon: use skip_prefix to avoid magic numbers
  fast-import: use skip_prefix for parsing input
  use skip_prefix to avoid repeating strings
  use skip_prefix to avoid magic numbers
  transport-helper: avoid reading past end-of-string
  fast-import: fix read of uninitialized argv memory
  apply: use skip_prefix instead of raw addition
  refactor skip_prefix to return a boolean
  avoid using skip_prefix as a boolean
  daemon: mark some strings as const
  parse_diff_color_slot: drop ofs parameter
2014-07-09 11:33:28 -07:00
Jeff King
82e56767aa fetch-pack: refactor parsing in get_ack
There are several uses of the magic number "line+45" when
parsing ACK lines from the server, and it's rather unclear
why 45 is the correct number. We can make this more clear by
keeping a running pointer as we parse, using skip_prefix to
jump past the first "ACK ", then adding 40 to jump past
get_sha1_hex (which is still magical, but hopefully 40 is
less magical to readers of git code).

Note that this actually puts us at line+44. The original
required some character between the sha1 and further ACK
flags (it is supposed to be a space, but we never enforced
that). We start our search for flags at line+44, which
meanas we are slightly more liberal than the old code.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-20 10:45:19 -07:00
Jeff King
ae021d8791 use skip_prefix to avoid magic numbers
It's a common idiom to match a prefix and then skip past it
with a magic number, like:

  if (starts_with(foo, "bar"))
	  foo += 3;

This is easy to get wrong, since you have to count the
prefix string yourself, and there's no compiler check if the
string changes.  We can use skip_prefix to avoid the magic
numbers here.

Note that some of these conversions could be much shorter.
For example:

  if (starts_with(arg, "--foo=")) {
	  bar = arg + 6;
	  continue;
  }

could become:

  if (skip_prefix(arg, "--foo=", &bar))
	  continue;

However, I have left it as:

  if (skip_prefix(arg, "--foo=", &v)) {
	  bar = v;
	  continue;
  }

to visually match nearby cases which need to actually
process the string. Like:

  if (skip_prefix(arg, "--foo=", &v)) {
	  bar = atoi(v);
	  continue;
  }

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-20 10:44:45 -07:00
René Scharfe
50e19a8358 Use starts_with() for C strings instead of memcmp()
Convert three cases of checking for a constant prefix using memcmp() to
starts_with().  This way there is no need for magic string length
constants and we avoid running over the end of the string should it be
shorter than the prefix.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-06-09 14:38:12 -07:00
Junio C Hamano
b407d40933 Merge branch 'nd/log-show-linear-break'
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
2014-04-03 12:38:11 -07:00
Nguyễn Thái Ngọc Duy
208acbfb82 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>
2014-03-25 15:09:24 -07:00
Junio C Hamano
3e14384b12 Merge branch 'jk/shallow-update-fix'
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
2014-03-21 12:33:29 -07:00
Jeff King
0179c945fc shallow: automatically clean up shallow tempfiles
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>
2014-02-27 12:07:13 -08:00
Nguyễn Thái Ngọc Duy
ff62eca7d1 fetch-pack: fix deepen shallow over smart http with no-done cap
In smart http, upload-pack adds new shallow lines at the beginning of
each rpc response. Only shallow lines from the first rpc call are
useful. After that they are thrown away. It's designed this way
because upload-pack is stateless and has no idea when its shallow
lines are helpful or not.

So after refs are negotiated with multi_ack_detailed and the server
thinks it learned enough, it sends "ACK obj-id ready", terminates the
rpc call and waits for the final rpc round. The client sends "done".
The server sends another response, which also has shallow lines at
the beginning, and the last "ACK obj-id" line.

When no-done is active, the last round is cut out, the server sends
"ACK obj-id ready" and "ACK obj-id" in the same rpc
response. fetch-pack is updated to recognize this and not send
"done". However it still tries to consume shallow lines, which are
never sent.

Update the code, make sure to skip consuming shallow lines when
no-done is enabled.

Reported-by: Jeff King <peff@peff.net>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-02-10 10:21:33 -08:00
Junio C Hamano
f583ace157 Merge branch 'jk/allow-fetch-onelevel-refname'
"git clone" would fail to clone from a repository that has a ref
directly under "refs/", e.g. "refs/stash", because different
validation paths do different things on such a refname.  Loosen the
client side's validation to allow such a ref.

* jk/allow-fetch-onelevel-refname:
  fetch-pack: do not filter out one-level refs
2014-01-27 10:44:14 -08:00
Junio C Hamano
92251b1b5b Merge branch 'nd/shallow-clone'
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
  ...
2014-01-17 12:21:20 -08:00
Jeff King
4c22408111 fetch-pack: do not filter out one-level refs
Currently fetching a one-level ref like "refs/foo" does not
work consistently. The outer "git fetch" program filters the
list of refs, checking each against check_refname_format.
Then it feeds the result to do_fetch_pack to actually
negotiate the haves/wants and get the pack. The fetch-pack
code does its own filter, and it behaves differently.

The fetch-pack filter looks for refs in "refs/", and then
feeds everything _after_ the slash (i.e., just "foo") into
check_refname_format.  But check_refname_format is not
designed to look at a partial refname. It complains that the
ref has only one component, thinking it is at the root
(i.e., alongside "HEAD"), when in reality we just fed it a
partial refname.

As a result, we omit a ref like "refs/foo" from the pack
request, even though "git fetch" then tries to store the
resulting ref.  If we happen to get the object anyway (e.g.,
because the ref is contained in another ref we are
fetching), then the fetch succeeds. But if it is a unique
object, we fail when trying to update "refs/foo".

We can fix this by just passing the whole refname into
check_refname_format; we know the part we were omitting is
"refs/", which is acceptable in a refname. This at least
makes the checks consistent with each other.

This problem happens most commonly with "refs/stash", which
is the only one-level ref in wide use. However, our test
does not use "refs/stash", as we may later want to restrict
it specifically (not because it is one-level, but because
of the semantics of stashes).

We may also want to do away with the multiple levels of
filtering (which can cause problems when they are out of
sync), or even forbid one-level refs entirely. However,
those decisions can come later; this fixes the most
immediate problem, which is the mismatch between the two.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-01-15 12:37:24 -08:00
Ramsay Jones
feefdf62c1 shallow: remove unused code
Commit 58babfff ("shallow.c: the 8 steps to select new commits for
.git/shallow", 05-12-2013) added a function to implement step 5 of
the quoted eight steps, namely 'remove_nonexistent_ours_in_pack()'.
This function implements an optional optimization step in the new
shallow commit selection algorithm. However, this function has no
callers. (The commented out call sites would need to change, in
order to provide information required by the function.)

Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Acked-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-01-06 09:05:40 -08:00
Junio C Hamano
ad70448576 Merge branch 'cc/starts-n-ends-with'
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"
2013-12-17 12:02:44 -08:00
Nguyễn Thái Ngọc Duy
48d25cae22 fetch: add --update-shallow to accept refs that update .git/shallow
The same steps are done as in when --update-shallow is not given. The
only difference is we now add all shallow commits in "ours" and
"theirs" to .git/shallow (aka "step 8").

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-10 16:14:17 -08:00
Nguyễn Thái Ngọc Duy
4820a33baa fetch: support fetching from a shallow repository
This patch just put together pieces from the 8 steps patch. We stop at
step 7 and reject refs that require new shallow commits.

Note that, by rejecting refs that require new shallow commits, we
leave dangling objects in the repo, which become "object islands" by
the next "git fetch" of the same source.

If the first fetch our "ours" set is zero and we do practically
nothing at step 7, "ours" is full at the next fetch and we may need to
walk through commits for reachability test. Room for improvement.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-10 16:14:17 -08:00
Nguyễn Thái Ngọc Duy
beea4152d9 clone: support remote shallow repository
Cloning from a shallow repository does not follow the "8 steps for new
.git/shallow" because if it does we need to get through step 6 for all
refs. That means commit walking down to the bottom.

Instead the rule to create .git/shallow is simpler and, more
importantly, cheap: if a shallow commit is found in the pack, it's
probably used (i.e. reachable from some refs), so we add it. Others
are dropped.

One may notice this method seems flawed by the word "probably". A
shallow commit may not be reachable from any refs at all if it's
attached to an object island (a group of objects that are not
reachable by any refs).

If that object island is not complete, a new fetch request may send
more objects to connect it to some ref. At that time, because we
incorrectly installed the shallow commit in this island, the user will
not see anything after that commit (fsck is still ok). This is not
desired.

Given that object islands are rare (C Git never sends such islands for
security reasons) and do not really harm the repository integrity, a
tradeoff is made to surprise the user occasionally but work faster
everyday.

A new option --strict could be added later that follows exactly the 8
steps. "git prune" can also learn to remove dangling objects _and_ the
shallow commits that are attached to them from .git/shallow.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-10 16:14:17 -08:00
Nguyễn Thái Ngọc Duy
a796ccee51 fetch-pack.c: move shallow update code out of fetch_pack()
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-10 16:14:16 -08:00
Nguyễn Thái Ngọc Duy
1a30f5a2f2 shallow.c: extend setup_*_shallow() to accept extra shallow commits
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-10 16:14:16 -08:00
Christian Couder
5955654823 replace {pre,suf}fixcmp() with {starts,ends}_with()
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>
2013-12-05 14:13:21 -08:00
Junio C Hamano
5bb62059f2 Merge branch 'jk/robustify-parse-commit'
* 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
2013-12-05 12:54:01 -08:00
Junio C Hamano
832ee79ab8 Merge branch 'jl/pack-transfer-avoid-double-close'
The codepath that send_pack() calls pack_objects() mistakenly
closed the same file descriptor twice, leading to potentially
closing a wrong file descriptor that was opened in the meantime.

* jl/pack-transfer-avoid-double-close:
  Clear fd after closing to avoid double-close error
2013-10-30 12:10:45 -07:00
Jeff King
0064053bd7 assume parse_commit checks commit->object.parsed
The parse_commit function will check the "parsed" flag of
the object and do nothing if it is set. There is no need
for callers to check the flag themselves, and doing so only
clutters the code.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-10-24 15:43:50 -07:00
Junio C Hamano
6ba0d9551a Merge branch 'nd/fetch-into-shallow' into maint
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
2013-10-23 13:32:17 -07:00
Jens Lindstrom
37cb1dd671 Clear fd after closing to avoid double-close error
In send_pack(), clear the fd passed to pack_objects() by setting
it to -1, since pack_objects() closes the fd (via a call to
run_command()).  Likewise, in get_pack(), clear the fd passed to
run_command().

Not doing so risks having git_transport_push(), caller of
send_pack(), closing the fd again, possibly incorrectly closing
some other open file; or similarly with fetch_refs_from_pack(),
indirect caller of get_pack().

Signed-off-by: Jens Lindström <jl@opera.com>
Acked-by: Jeff King <peff@peff.net>
Acked-by: Duy Nguyen <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-10-23 09:07:09 -07:00
Jonathan Nieder
40b77322d2 Merge branch 'nd/fetch-pack-error-reporting-fix'
* nd/fetch-pack-error-reporting-fix:
  fetch-pack.c: show correct command name that fails
2013-09-24 23:27:02 -07:00
Junio C Hamano
238504b014 Merge branch 'nd/fetch-into-shallow'
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
2013-09-20 12:25:32 -07:00
Nguyễn Thái Ngọc Duy
4727f671b8 fetch-pack.c: show correct command name that fails
When --shallow-file is added to the command line, it has to be
before the subcommand name, the first argument won't be the command
name any more. Stop assuming that and keep track of the command name
explicitly.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-09-18 11:11:53 -07:00
Junio C Hamano
2233ad4534 Merge branch 'jc/push-cas'
Allow a safer "rewind of the remote tip" push than blind "--force",
by requiring that the overwritten remote ref to be unchanged since
the new history to replace it was prepared.

The machinery is more or less ready.  The "--force" option is again
the big red button to override any safety, thanks to J6t's sanity
(the original round allowed --lockref to defeat --force).

The logic to choose the default implemented here is fragile
(e.g. "git fetch" after seeing a failure will update the
remote-tracking branch and will make the next "push" pass,
defeating the safety pretty easily).  It is suitable only for the
simplest workflows, and it may hurt users more than it helps them.

* jc/push-cas:
  push: teach --force-with-lease to smart-http transport
  send-pack: fix parsing of --force-with-lease option
  t5540/5541: smart-http does not support "--force-with-lease"
  t5533: test "push --force-with-lease"
  push --force-with-lease: tie it all together
  push --force-with-lease: implement logic to populate old_sha1_expect[]
  remote.c: add command line option parser for "--force-with-lease"
  builtin/push.c: use OPT_BOOL, not OPT_BOOLEAN
  cache.h: move remote/connect API out of it
2013-09-09 14:30:29 -07:00
Junio C Hamano
2ea3df68e8 Merge branch 'nd/fetch-pack-shallow-fix' into maint
The recent "short-cut clone connectivity check" topic broke a shallow
repository when a fetch operation tries to auto-follow tags.

* nd/fetch-pack-shallow-fix:
  fetch-pack: do not remove .git/shallow file when --depth is not specified
2013-09-05 14:40:58 -07:00
Junio C Hamano
e250020cd0 Merge branch 'nd/fetch-pack-shallow-fix'
The recent "short-cut clone connectivity check" topic broke a
shallow repository when a fetch operation tries to auto-follow tags.

* nd/fetch-pack-shallow-fix:
  fetch-pack: do not remove .git/shallow file when --depth is not specified
2013-08-30 10:05:55 -07:00
Nguyễn Thái Ngọc Duy
6da8bdcbbf fetch-pack: do not remove .git/shallow file when --depth is not specified
fetch_pack() can remove .git/shallow file when a shallow repository
becomes a full one again. This behavior is triggered incorrectly when
tags are also fetched because fetch_pack() will be called twice. At
the first fetch_pack() call:

 - shallow_lock is set up
 - alternate_shallow_file points to shallow_lock.filename, which is
   "shallow.lock"
 - commit_lock_file is called, which sets shallow_lock.filename to "".
   alternate_shallow_file also becomes "" because it points to the
   same memory.

At the second call, setup_alternate_shallow() is not called and
alternate_shallow_file remains "". It's mistaken as unshallow case and
.git/shallow is removed. The end result is a broken repository.

Fix this by always initializing alternate_shallow_file when
fetch_pack() is called. As an extra measure, check if args->depth > 0
before commit/rollback shallow file.

Reported-by: Kacper Kornet <kornet@camk.edu.pl>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-08-25 22:56:03 -07:00
Nguyễn Thái Ngọc Duy
3125fe528b move setup_alternate_shallow and write_shallow_commits to shallow.c
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-08-18 13:00:17 -07:00
Junio C Hamano
47a5918536 cache.h: move remote/connect API out of it
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>
2013-07-08 14:34:24 -07:00
Jeff King
099327b552 fetch-pack: avoid quadratic behavior in rev_list_push
When we call find_common to start finding common ancestors
with the remote side of a fetch, the first thing we do is
insert the tip of each ref into our rev_list linked list. We
keep the list sorted the whole time with
commit_list_insert_by_date, which means our insertion ends
up doing O(n^2) timestamp comparisons.

We could teach rev_list_push to use an unsorted list, and
then sort it once after we have added each ref. However, in
get_rev, we process the list by popping commits off the
front and adding parents back in timestamp-sorted order. So
that procedure would still operate on the large list.

Instead, we can replace the linked list with a heap-based
priority queue, which can do O(log n) insertion, making the
whole insertion procedure O(n log n).

As a result of switching to the prio_queue struct, we fix
two minor bugs:

  1. When we "pop" a commit in get_rev, and when we clear
     the rev_list in find_common, we do not take care to
     free the "struct commit_list", and just leak its
     memory. With the prio_queue implementation, the memory
     management is handled for us.

  2. In get_rev, we look at the head commit of the list,
     possibly push its parents onto the list, and then "pop"
     the front of the list off, assuming it is the same
     element that we just peeked at. This is typically going
     to be the case, but would not be in the face of clock
     skew: the parents are inserted by date, and could
     potentially be inserted at the head of the list if they
     have a timestamp newer than their descendent. In this
     case, we would accidentally pop the parent, and never
     process it at all.

     The new implementation pulls the commit off of the
     queue as we examine it, and so does not suffer from
     this problem.

With this patch, a fetch of a single commit into a
repository with 50,000 refs went from:

  real    0m7.984s
  user    0m7.852s
  sys     0m0.120s

to:

  real    0m2.017s
  user    0m1.884s
  sys     0m0.124s

Before this patch, a larger case with 370K refs still had
not completed after tens of minutes; with this patch, it
completes in about 12 seconds.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-07-02 12:05:46 -07:00
Jeff King
16445242ed fetch-pack: avoid quadratic list insertion in mark_complete
We insert the commit pointed to by each ref one-by-one into
the "complete" commit_list using insert_by_date. Because
each insertion is O(n), we end up with O(n^2) behavior.

This typically doesn't matter, because the number of refs is
reasonably small. And even if there are a lot of refs, they
often point to a smaller set of objects (in which case the
optimization in commit ea5f220 keeps our "n" small).

However, in pathological repositories (hundreds of thousands
of refs, each pointing to a unique commit), this quadratic
behavior can make a difference. Since we do not care about
the list order until we have finished building it, we can
simply keep it unsorted during the insertion phase, then
sort it afterwards.

On a repository like the one described above, this dropped
the time to do a no-op fetch from 2.0s to 1.7s. On normal
repositories, it probably does not matter at all, but it
does not hurt to protect ourselves from pathological cases.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-07-02 12:03:34 -07:00
Nguyễn Thái Ngọc Duy
c6807a40dc clone: open a shortcut for connectivity check
In order to make sure the cloned repository is good, we run "rev-list
--objects --not --all $new_refs" on the repository. This is expensive
on large repositories. This patch attempts to mitigate the impact in
this special case.

In the "good" clone case, we only have one pack. If all of the
following are met, we can be sure that all objects reachable from the
new refs exist, which is the intention of running "rev-list ...":

 - all refs point to an object in the pack
 - there are no dangling pointers in any object in the pack
 - no objects in the pack point to objects outside the pack

The second and third checks can be done with the help of index-pack as
a slight variation of --strict check (which introduces a new condition
for the shortcut: pack transfer must be used and the number of objects
large enough to call index-pack). The first is checked in
check_everything_connected after we get an "ok" from index-pack.

"index-pack + new checks" is still faster than the current "index-pack
+ rev-list", which is the whole point of this patch. If any of the
conditions fail, we fall back to the good old but expensive "rev-list
..". In that case it's even more expensive because we have to pay for
the new checks in index-pack. But that should only happen when the
other side is either buggy or malicious.

Cloning linux-2.6 over file://

        before         after
real    3m25.693s      2m53.050s
user    5m2.037s       4m42.396s
sys     0m13.750s      0m16.574s

A more realistic test with ssh:// over wireless

        before         after
real    11m26.629s     10m4.213s
user    5m43.196s      5m19.444s
sys     0m35.812s      0m37.630s

This shortcut is not applied to shallow clones, partly because shallow
clones should have no more objects than a usual fetch and the cost of
rev-list is acceptable, partly to avoid dealing with corner cases when
grafting is involved.

This shortcut does not apply to unpack-objects code path either
because the number of objects must be small in order to trigger that
code path.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-28 08:07:20 -07:00
Nguyễn Thái Ngọc Duy
6035d6aad8 fetch-pack: prepare updated shallow file before fetching the pack
index-pack --strict looks up and follows parent commits. If shallow
information is not ready by the time index-pack is run, index-pack may
be led to non-existent objects. Make fetch-pack save shallow file to
disk before invoking index-pack.

git learns new global option --shallow-file to pass on the alternate
shallow file path. Undocumented (and not even support --shallow-file=
syntax) because it's unlikely to be used again elsewhere.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-05-28 08:06:08 -07:00
Junio C Hamano
e013bdab0f Merge branch 'jk/pkt-line-cleanup'
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
2013-04-01 08:59:37 -07:00
Junio C Hamano
e4e1c54990 Merge branch 'jc/fetch-raw-sha1'
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
2013-03-21 14:02:27 -07:00
Jeff King
74543a0423 pkt-line: provide a LARGE_PACKET_MAX static buffer
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>
2013-02-20 13:42:22 -08:00
Jeff King
819b929d33 pkt-line: teach packet_read_line to chomp newlines
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>
2013-02-20 13:42:21 -08:00
Jeff King
cdf4fb8e33 pkt-line: drop safe_write function
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>
2013-02-20 13:42:21 -08:00
Jeff King
030e9dd64f fetch-pack: fix out-of-bounds buffer offset in get_ack
When we read acks from the remote, we expect either:

  ACK <sha1>

or

  ACK <sha1> <multi-ack-flag>

We parse the "ACK <sha1>" bit from the line, and then start
looking for the flag strings at "line+45"; if we don't have
them, we assume it's of the first type.  But if we do have
the first type, then line+45 is not necessarily inside our
string at all!

It turns out that this works most of the time due to the way
we parse the packets. They should come in with a newline,
and packet_read puts an extra NUL into the buffer, so we end
up with:

  ACK <sha1>\n\0

with the newline at offset 44 and the NUL at offset 45. We
then strip the newline, putting a NUL at offset 44. So
when we look at "line+45", we are looking past the end of
our string; but it's OK, because we hit the terminator from
the original string.

This breaks down, however, if the other side does not
terminate their packets with a newline. In that case, our
packet is one character shorter, and we start looking
through uninitialized memory for the flag. No known
implementation sends such a packet, so it has never come up
in practice.

This patch tightens the check by looking for a short,
flagless ACK before trying to parse the flag.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-20 13:42:21 -08:00
Junio C Hamano
6e7b66eebd fetch: fetch objects by their exact SHA-1 object names
Teach "git fetch" to accept an exact SHA-1 object name the user may
obtain out of band on the LHS of a pathspec, and send it on a "want"
message when the server side advertises the allow-tip-sha1-in-want
capability.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-07 14:07:53 -08:00
Junio C Hamano
f2db854d24 fetch: use struct ref to represent refs to be fetched
Even though "git fetch" has full infrastructure to parse refspecs to
be fetched and match them against the list of refs to come up with
the final list of refs to be fetched, the list of refs that are
requested to be fetched were internally converted to a plain list of
strings at the transport layer and then passed to the underlying
fetch-pack driver.

Stop this conversion and instead pass around an array of refs.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-02-07 13:53:59 -08:00
Junio C Hamano
4acfff9dda Merge branch 'jk/gc-auto-after-fetch'
Help "fetch only" repositories that do not trigger "gc --auto"
often enough.

* jk/gc-auto-after-fetch:
  fetch-pack: avoid repeatedly re-scanning pack directory
  fetch: run gc --auto after fetching
2013-02-01 12:40:16 -08:00
Junio C Hamano
012a1bb524 Merge branch 'jk/maint-gc-auto-after-fetch' into jk/gc-auto-after-fetch
* jk/maint-gc-auto-after-fetch:
  fetch-pack: avoid repeatedly re-scanning pack directory
  fetch: run gc --auto after fetching
2013-01-26 19:42:09 -08:00
Junio C Hamano
8cabd200d2 Merge branch 'mk/qnx'
Port to QNX.

* mk/qnx:
  Port to QNX
  Make lock local to fetch_pack
2013-01-03 10:28:33 -08:00
Nguyễn Thái Ngọc Duy
745f7a8cac fetch-pack: move core code to libgit.a
fetch_pack() is used by transport.c, part of libgit.a while it stays
in builtin/fetch-pack.c. Move it to fetch-pack.c so that we won't get
undefined reference if a program that uses libgit.a happens to pull it
in.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Jeff King <peff@peff.net>
2012-10-29 03:40:29 -04:00
Daniel Barkalow
2d4177c01c Make fetch-pack a builtin with an internal API
Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-09-19 03:22:30 -07:00
Junio C Hamano
a6080a0a44 War on whitespace
This uses "git-apply --whitespace=strip" to fix whitespace errors that have
crept in to our source files over time.  There are a few files that need
to have trailing whitespaces (most notably, test vectors).  The results
still passes the test, and build result in Documentation/ area is unchanged.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-06-07 00:04:01 -07:00
Michael S. Tsirkin
7841ce7985 connect: display connection progress
Make git notify the user about host resolution/connection attempts.
This is useful both as a progress indicator on slow links, and helps
reassure the user there are no firewall problems.

Signed-off-by: Michael S. Tsirkin <mst@dev.mellanox.co.il>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-05-16 12:48:18 -07:00
Junio C Hamano
3ddad98b74 Merge branch 'js/fetch-progress' (early part)
* 'js/fetch-progress' (early part):
  Fixup no-progress for fetch & clone
  fetch & clone: do not output progress when not on a tty

Conflicts:

	git-fetch.sh
2007-03-04 17:31:21 -08:00
Johannes Schindelin
b0e908977e Fixup no-progress for fetch & clone
The intent of the commit 'fetch & clone: do not output progress when
not on a tty' was to make fetching and cloning less chatty when
output was not redirected (such as in a cron job).

However, there was a serious thinko in that commit. It assumed that
the client _and_ the server got this update at the same time. But
this is obviously not the case, and therefore upload-pack died on
seeing the option "--no-progress".

This patch fixes that issue by making it a protocol option. So, until
your server is updated, you still see the progress, but once the
server has this patch, it will be quiet.

A minor issue was also fixed: when cloning, the checkout did not
heed no_progress.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-02-24 00:26:18 -08:00
Junio C Hamano
599065a3bb prefixcmp(): fix-up mechanical conversion.
Previous step converted use of strncmp() with literal string
mechanically even when the result is only used as a boolean:

    if (!strncmp("foo", arg, 3)) ==> if (!(-prefixcmp(arg, "foo")))

This step manually cleans them up to read:

    if (!prefixcmp(arg, "foo"))

Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-02-20 22:03:15 -08:00
Junio C Hamano
cc44c7655f Mechanical conversion to use prefixcmp()
This mechanically converts strncmp() to use prefixcmp(), but only when
the parameters match specific patterns, so that they can be verified
easily.  Leftover from this will be fixed in a separate step, including
idiotic conversions like

    if (!strncmp("foo", arg, 3))

  =>

    if (!(-prefixcmp(arg, "foo")))

This was done by using this script in px.perl

   #!/usr/bin/perl -i.bak -p
   if (/strncmp\(([^,]+), "([^\\"]*)", (\d+)\)/ && (length($2) == $3)) {
           s|strncmp\(([^,]+), "([^\\"]*)", (\d+)\)|prefixcmp($1, "$2")|;
   }
   if (/strncmp\("([^\\"]*)", ([^,]+), (\d+)\)/ && (length($1) == $3)) {
           s|strncmp\("([^\\"]*)", ([^,]+), (\d+)\)|(-prefixcmp($2, "$1"))|;
   }

and running:

   $ git grep -l strncmp -- '*.c' | xargs perl px.perl

Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-02-20 22:03:15 -08:00
Johannes Schindelin
83a5ad6126 fetch & clone: do not output progress when not on a tty
This adds the option "--no-progress" to fetch-pack and upload-pack,
and makes fetch and clone pass this option when stdout is not a tty.

While at documenting that option, also document --strict and --timeout
options for upload-pack.

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-02-19 19:20:05 -08:00
Junio C Hamano
01754769ab Don't force everybody to call setup_ident().
Back when only handful commands that created commit and tag were
the only users of committer identity information, it made sense
to explicitly call setup_ident() to pre-fill the default value
from the gecos information.  But it is much simpler for programs
to make the call automatic when get_ident() is called these days,
since many more programs want to use the information when updating
the reflog.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-01-28 01:58:50 -08:00
Junio C Hamano
e28714c527 Consolidate {receive,fetch}.unpackLimit
This allows transfer.unpackLimit to specify what these two
configuration variables want to set.

We would probably want to deprecate the two separate variables,
as I do not see much point in specifying them independently.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-01-24 18:08:02 -08:00
Junio C Hamano
af7cf268f0 fetch-pack: remove --keep-auto and make it the default.
This makes git-fetch over git native protocol to automatically
decide to keep the downloaded pack if the fetch results in more
than 100 objects, just like receive-pack invoked by git-push
does.  This logic is disabled when --keep is explicitly given
from the command line, so that a very small clone still keeps
the downloaded pack as before.

The 100 threshold can be adjusted with fetch.unpacklimit
configuration.  We might want to introduce transfer.unpacklimit
to consolidate the two unpacklimit variables, which will be a
topic for the next patch.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-01-24 18:08:02 -08:00
Junio C Hamano
9e10fd1ac0 Allow fetch-pack to decide keeping the fetched pack without exploding
With --keep-auto option, fetch-pack decides to keep the pack
without exploding it just like receive-pack does.

We may want to later make this the default.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-01-24 18:08:02 -08:00
Uwe Kleine-König
27dca07fb7 rename --exec to --upload-pack for fetch-pack and peek-remote
Just some option name disambiguation.  This is the counter part to
commit d23842fd which made a similar change for push and send-pack.

--exec continues to work.

Signed-off-by: Uwe Kleine-König <ukleinek@informatik.uni-freiburg.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-01-24 16:12:15 -08:00
Uwe Kleine-König
18bd8821ca Update documentation of fetch-pack, push and send-pack
add all supported options to Documentation/git-....txt and the usage strings.

Signed-off-by: Uwe Kleine-König <zeisberg@informatik.uni-freiburg.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-01-19 17:54:32 -08:00
Junio C Hamano
54b9e0225a fetch-pack: do not use lockfile structure on stack.
They are used in atexit() for clean-up, and you will be
accessing unallocated memory at that point.

See 31f584c2 for the fix for a similar problem.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-01-02 11:22:08 -08:00
Junio C Hamano
37818d7db0 Merge branch 'master' into js/shallow
This is to adjust to:

  count-objects -v: show number of packs as well.

which will break a test in this series.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-12-27 02:43:46 -08:00
Junio C Hamano
85023577a8 simplify inclusion of system header files.
This is a mechanical clean-up of the way *.c files include
system header files.

 (1) sources under compat/, platform sha-1 implementations, and
     xdelta code are exempt from the following rules;

 (2) the first #include must be "git-compat-util.h" or one of
     our own header file that includes it first (e.g. config.h,
     builtin.h, pkt-line.h);

 (3) system headers that are included in "git-compat-util.h"
     need not be included in individual C source files.

 (4) "git-compat-util.h" does not have to include subsystem
     specific header files (e.g. expat.h).

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-12-20 09:51:35 -08:00
Junio C Hamano
310b86d480 fetch-pack: do not barf when duplicate re patterns are given
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-11-25 01:33:06 -08:00
Alexandre Julliard
4bcb310c25 fetch-pack: Do not fetch tags for shallow clones.
A better fix may be to only fetch tags that point to commits that we
are downloading, but git-clone doesn't have support for following
tags. This will happen automatically on the next git-fetch though.

Signed-off-by: Alexandre Julliard <julliard@winehq.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-11-24 15:42:50 -08:00
Alexandre Julliard
d6491e3a21 fetch-pack: Properly remove the shallow file when it becomes empty.
The code was unlinking the lock file instead.

Signed-off-by: Alexandre Julliard <julliard@winehq.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-11-24 15:42:49 -08:00
Junio C Hamano
fcd1e31906 Why does it mean we do not have to register shallow if we have one? 2006-11-24 15:42:49 -08:00
Junio C Hamano
cf01bd52ef We should make sure that the protocol is still extensible.
This just reformats if .. else if .. else chain to make it clear we
are handling extended response from the other end.
2006-11-24 15:42:49 -08:00