Commit Graph

928 Commits

Author SHA1 Message Date
Michael Haggerty
3c0cb0cbae read_loose_refs(): read refs using resolve_ref_recursively()
There is no need to call read_ref_full() or resolve_gitlink_ref() from
read_loose_refs(), because we already have a ref_store object in hand.
So we can call resolve_ref_recursively() ourselves. Happily, this
unifies the code for the submodule vs. non-submodule cases.

This requires resolve_ref_recursively() to be exposed to the refs
subsystem, though not to non-refs code.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-02-13 15:14:15 -08:00
Michael Haggerty
fbfd0a2915 base_ref_store_init(): remove submodule argument
This is another step towards weakening the 1:1 relationship between
ref_stores and submodules.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-02-10 11:13:26 -08:00
Michael Haggerty
32c597e7b2 refs: push the submodule attribute down
Push the submodule attribute down from ref_store to files_ref_store.
This is another step towards loosening the 1:1 connection between
ref_stores and submodules.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-02-10 11:13:26 -08:00
Michael Haggerty
7d4558c462 refs: store submodule ref stores in a hashmap
Aside from scaling better, this means that the submodule name needn't be
stored in the ref_store instance anymore (which will be changed in a
moment). This, in turn, will help loosen the strict 1:1 relationship
between ref_stores and submodules.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-02-10 11:13:26 -08:00
Michael Haggerty
ba88add581 register_ref_store(): new function
Move the responsibility for registering the ref_store for a submodule
from base_ref_store_init() to a new function, register_ref_store(). Call
the latter from ref_store_init().

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-02-10 11:13:26 -08:00
Michael Haggerty
b4f540b6ce refs: remove some unnecessary handling of submodule == ""
The only external entry point to the ref_store lookup functions is
get_ref_store(), which ensures that submodule == "" is passed along as
NULL. So ref_store_init() and lookup_ref_store() don't have to handle
submodule being specified as the empty string.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-02-10 11:13:26 -08:00
Michael Haggerty
c468da4e27 refs: make some ref_store lookup functions private
The following functions currently don't need to be exposed:

* ref_store_init()
* lookup_ref_store()

That might change in the future, but for now make them private.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-02-10 11:13:26 -08:00
Michael Haggerty
620a66b9e2 refs: reorder some function definitions
This avoids the need to add forward declarations in the next step.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-02-10 11:13:25 -08:00
Cornelius Weig
341fb28621 refs: add option core.logAllRefUpdates = always
When core.logallrefupdates is true, we only create a new reflog for refs
that are under certain well-known hierarchies. The reason is that we
know that some hierarchies (like refs/tags) are not meant to change, and
that unknown hierarchies might not want reflogs at all (e.g., a
hypothetical refs/foo might be meant to change often and drop old
history immediately).

However, sometimes it is useful to override this decision and simply log
for all refs, because the safety and audit trail is more important than
the performance implications of keeping the log around.

This patch introduces a new "always" mode for the core.logallrefupdates
option which will log updates to everything under refs/, regardless
where in the hierarchy it is (we still will not log things like
ORIG_HEAD and FETCH_HEAD, which are known to be transient).

Based-on-patch-by: Jeff King <peff@peff.net>
Signed-off-by: Cornelius Weig <cornelius.weig@tngtech.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-01-31 10:01:24 -08:00
Junio C Hamano
a03973893b Merge branch 'jc/cocci-xstrdup-or-null'
Code cleanup.

* jc/cocci-xstrdup-or-null:
  cocci: refactor common patterns to use xstrdup_or_null()
2016-10-26 13:14:45 -07:00
Junio C Hamano
13092a916d cocci: refactor common patterns to use xstrdup_or_null()
d64ea0f83b ("git-compat-util: add xstrdup_or_null helper",
2015-01-12) added a handy wrapper that allows us to get a duplicate
of a string or NULL if the original is NULL, but a handful of
codepath predate its introduction or just weren't aware of it.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-10-12 11:22:10 -07:00
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
4af9a7d344 Merge branch 'bc/object-id'
The "unsigned char sha1[20]" to "struct object_id" conversion
continues.  Notable changes in this round includes that ce->sha1,
i.e. the object name recorded in the cache_entry, turns into an
object_id.

It had merge conflicts with a few topics in flight (Christian's
"apply.c split", Dscho's "cat-file --filters" and Jeff Hostetler's
"status --porcelain-v2").  Extra sets of eyes double-checking for
mismerges are highly appreciated.

* bc/object-id:
  builtin/reset: convert to use struct object_id
  builtin/commit-tree: convert to struct object_id
  builtin/am: convert to struct object_id
  refs: add an update_ref_oid function.
  sha1_name: convert get_sha1_mb to struct object_id
  builtin/update-index: convert file to struct object_id
  notes: convert init_notes to use struct object_id
  builtin/rm: convert to use struct object_id
  builtin/blame: convert file to use struct object_id
  Convert read_mmblob to take struct object_id.
  notes-merge: convert struct notes_merge_pair to struct object_id
  builtin/checkout: convert some static functions to struct object_id
  streaming: make stream_blob_to_fd take struct object_id
  builtin: convert textconv_object to use struct object_id
  builtin/cat-file: convert some static functions to struct object_id
  builtin/cat-file: convert struct expand_data to use struct object_id
  builtin/log: convert some static functions to use struct object_id
  builtin/blame: convert struct origin to use struct object_id
  builtin/apply: convert static functions to struct object_id
  cache: convert struct cache_entry to use struct object_id
2016-09-19 13:47:19 -07:00
Junio C Hamano
4322f3848a Merge branch 'mh/ref-store'
The ref-store abstraction was introduced to the refs API so that we
can plug in different backends to store references.

* mh/ref-store: (38 commits)
  refs: implement iteration over only per-worktree refs
  refs: make lock generic
  refs: add method to rename refs
  refs: add methods to init refs db
  refs: make delete_refs() virtual
  refs: add method for initial ref transaction commit
  refs: add methods for reflog
  refs: add method iterator_begin
  files_ref_iterator_begin(): take a ref_store argument
  split_symref_update(): add a files_ref_store argument
  lock_ref_sha1_basic(): add a files_ref_store argument
  lock_ref_for_update(): add a files_ref_store argument
  commit_ref_update(): add a files_ref_store argument
  lock_raw_ref(): add a files_ref_store argument
  repack_without_refs(): add a files_ref_store argument
  refs: make peel_ref() virtual
  refs: make create_symref() virtual
  refs: make pack_refs() virtual
  refs: make verify_refname_available() virtual
  refs: make read_raw_ref() virtual
  ...
2016-09-19 13:47:19 -07:00
David Turner
9b6b40d93a refs: add method to rename refs
This removes the last caller of function get_files_ref_store(), so
remove it.

Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-09 15:28:14 -07:00
David Turner
6fb5acfd8f refs: add methods to init refs db
Alternate refs backends might not need the refs/heads directory and so
on, so we make ref db initialization part of the backend.

Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-09 15:28:14 -07:00
David Turner
a27dcf89b6 refs: make delete_refs() virtual
In the file-based backend, delete_refs has some special optimization
to deal with packed refs.  In other backends, we might be able to make
ref deletion faster by putting all deletions into a single
transaction.  So we need a special backend function for this.

Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-09 15:28:14 -07:00
David Turner
fc6814637d refs: add method for initial ref transaction commit
Signed-off-by: Ronnie Sahlberg <rsahlberg@google.com>
Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-09 15:28:14 -07:00
David Turner
e3688bd6cf refs: add methods for reflog
In the file-based backend, the reflog piggybacks on the ref lock.
Since other backends won't have the same sort of ref lock, ref backends
must also handle reflogs.

Signed-off-by: Ronnie Sahlberg <rsahlberg@google.com>
Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-09 15:28:13 -07:00
Michael Haggerty
1a769003c1 refs: add method iterator_begin
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-09 15:28:13 -07:00
Michael Haggerty
37b6f6d5f4 files_ref_iterator_begin(): take a ref_store argument
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-09 15:28:13 -07:00
Michael Haggerty
bd427cf27f refs: make peel_ref() virtual
For now it only supports the main reference store.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-09 15:28:13 -07:00
Michael Haggerty
284689ba0f refs: make create_symref() virtual
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-09 15:28:13 -07:00
Michael Haggerty
8231527e15 refs: make pack_refs() virtual
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-09 15:28:13 -07:00
Michael Haggerty
62665823d2 refs: make verify_refname_available() virtual
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-09 15:28:13 -07:00
Michael Haggerty
e1e33b722c refs: make read_raw_ref() virtual
Reference backends will be able to customize this function to implement
reference reading.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-09 15:28:13 -07:00
Michael Haggerty
a8355bb717 resolve_gitlink_ref(): rename path parameter to submodule
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-09 15:28:13 -07:00
Michael Haggerty
48a8475fd3 resolve_gitlink_ref(): avoid memory allocation in many cases
If we don't have to strip trailing '/' from the submodule path, then
don't allocate and copy the submodule name.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-09 15:28:13 -07:00
Michael Haggerty
424dcc7683 resolve_gitlink_ref(): implement using resolve_ref_recursively()
resolve_ref_recursively() can handle references in arbitrary files
reference stores, so use it to resolve "gitlink" (i.e., submodule)
references. Aside from removing redundant code, this allows submodule
lookups to benefit from the much more robust code that we use for
reading non-submodule references. And, since the code is now agnostic
about reference backends, it will work for any future references
backend (so move its definition to refs.c).

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-09 15:28:13 -07:00
Michael Haggerty
bd40dcda27 resolve_ref_recursively(): new function
Add a new function, resolve_ref_recursively(), which is basically like
the old resolve_ref_unsafe() except that it takes a (ref_store *)
argument and also works for submodules.

Re-implement resolve_ref_unsafe() as a thin wrapper around
resolve_ref_recursively().

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-09 15:28:13 -07:00
Michael Haggerty
34c7ad8ffc read_raw_ref(): take a (struct ref_store *) argument
And make the function work for submodules.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-09 15:28:12 -07:00
Ronnie Sahlberg
127b42a186 refs: add a transaction_commit() method
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-09 15:28:12 -07:00
Michael Haggerty
00eebe351c refs: create a base class "ref_store" for files_ref_store
We want ref_stores to be polymorphic, so invent a base class of which
files_ref_store is a derived class. For now there is exactly one
ref_store for the main repository and one for any submodules whose
references have been accessed.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-09 15:28:12 -07:00
Ronnie Sahlberg
3dce444f17 refs: add a backend method structure
Add a `struct ref_storage_be` to represent types of reference stores. In
OO notation, this is the class, and will soon hold some class
methods (e.g., a factory to create new ref_store instances) and will
also serve as the vtable for ref_store instances of that type.

As yet, the backends cannot do anything.

Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-09 15:28:12 -07:00
David Turner
ff3a299c45 rename_ref_available(): add docstring
And improve the internal variable names.

Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-09 15:28:12 -07:00
brian m. carlson
8f6dc7e32e refs: add an update_ref_oid function.
Several places around the codebase want to pass update_ref data from
struct object_id, but update_ref may also be passed NULL pointers.
Instead of checking and dereferencing in every caller, create an
update_ref_oid which wraps update_ref and provides this functionality.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:59:43 -07:00
René Scharfe
50492f7b38 pass constants as first argument to st_mult()
The result of st_mult() is the same no matter the order of its
arguments.  It invokes the macro unsigned_mult_overflows(), which
divides the second parameter by the first one.  Pass constants
first to allow that division to be done already at compile time.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-08-01 14:01:03 -07:00
Michael Haggerty
4c4de89573 do_for_each_ref(): reimplement using reference iteration
Use the reference iterator interface to implement do_for_each_ref().
Delete a bunch of code supporting the old for_each_ref() implementation.
And now that do_for_each_ref() is generic code (it is no longer tied to
the files backend), move it to refs.c.

The implementation is via a new function, do_for_each_ref_iterator(),
which takes a reference iterator as argument and calls a callback
function for each of the references in the iterator.

This change requires the current_ref performance hack for peel_ref() to
be implemented via ref_iterator_peel() rather than peel_entry() because
we don't have a ref_entry handy (it is hidden under three layers:
file_ref_iterator, merge_ref_iterator, and cache_ref_iterator). So:

* do_for_each_ref_iterator() records the active iterator in
  current_ref_iter while it is running.

* peel_ref() checks whether current_ref_iter is pointing at the
  requested reference. If so, it asks the iterator to peel the
  reference (which it can do efficiently via its "peel" virtual
  function). For extra safety, we do the optimization only if the
  refname *addresses* are the same, not only if the refname *strings*
  are the same, to forestall possible mixups between refnames that come
  from different ref_iterators.

Please note that this optimization of peel_ref() is only available when
iterating via do_for_each_ref_iterator() (including all of the
for_each_ref() functions, which call it indirectly). It would be
complicated to implement a similar optimization when iterating directly
using a reference iterator, because multiple reference iterators can be
in use at the same time, with interleaved calls to
ref_iterator_advance(). (In fact we do exactly that in
merge_ref_iterator.)

But that is not necessary. peel_ref() is only called while iterating
over references. Callers who iterate using the for_each_ref() functions
benefit from the optimization described above. Callers who iterate using
reference iterators directly have access to the ref_iterator, so they
can call ref_iterator_peel() themselves to get an analogous optimization
in a more straightforward manner.

If we rewrite all callers to use the reference iteration API, then we
can remove the current_ref_iter hack permanently.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-06-20 11:38:20 -07:00
Nguyễn Thái Ngọc Duy
41da7111f2 refs: add expand_ref()
This is basically dwim_ref() without @{} support. To be used on the
server side where we want to expand abbreviated to full ref names and
nothing else. The first user is "git clone/fetch --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
Michael Haggerty
8a679de6f1 ref_transaction_update(): check refname_is_safe() at a minimum
If the user has asked that a new value be set for a reference, we use
check_refname_format() to verify that the reference name satisfies all
of the rules. But in other cases, at least check that refname_is_safe().

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
2016-06-13 11:23:50 +02:00
Michael Haggerty
71564516de add_update(): initialize the whole ref_update
Change add_update() to initialize all of the fields in the new
ref_update object. Rename the function to ref_transaction_add_update(),
and increase its visibility to all of the refs-related code.

All of this makes the function more useful for other future callers.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
2016-06-13 11:23:49 +02:00
Michael Haggerty
c52ce248d6 ref_transaction_create(): disallow recursive pruning
It is nonsensical (and a little bit dangerous) to use REF_ISPRUNING
without REF_NODEREF. Forbid it explicitly. Change the one REF_ISPRUNING
caller to pass REF_NODEREF too.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
2016-06-13 11:23:49 +02:00
Michael Haggerty
0568c8e9dc refs: make error messages more consistent
* Always start error messages with a lower-case letter.

* Always enclose reference names in single quotes.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
2016-06-13 11:23:49 +02:00
Michael Haggerty
e40f3557f7 refname_is_safe(): insist that the refname already be normalized
The reference name is going to be compared to other reference names, so
it should be in its normalized form.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
2016-05-05 16:37:30 +02:00
Michael Haggerty
35db25c65f refname_is_safe(): don't allow the empty string
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
2016-05-05 16:37:30 +02:00
Michael Haggerty
39950fef8b refname_is_safe(): use skip_prefix()
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
2016-05-05 16:37:30 +02:00
David Turner
2d0663b216 refs: move resolve_ref_unsafe into common code
Now that resolve_ref_unsafe's only interaction with the backend is
through read_raw_ref, we can move it into the common code. Later,
we'll replace read_raw_ref with a backend function.

Signed-off-by: David Turner <dturner@twopensource.com>
Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-04-10 11:35:41 -07:00
David Turner
937705901b refs: move for_each_*ref* functions into common code
Make do_for_each_ref take a submodule as an argument instead of a
ref_cache.  Since all for_each_*ref* functions are defined in terms of
do_for_each_ref, we can then move them into the common code.

Later, we can simply make do_for_each_ref into a backend function.

Signed-off-by: David Turner <dturner@twopensource.com>
Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-04-10 11:34:55 -07:00
David Turner
2bf68ed5aa refs: move head_ref{,_submodule} to the common code
These don't use any backend-specific functions.  These were previously
defined in terms of the do_head_ref helper function, but since they
are otherwise identical, we don't need that function.

Signed-off-by: David Turner <dturner@twopensource.com>
Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-04-10 11:34:41 -07:00
Jeff King
50a6c8efa2 use st_add and st_mult for allocation size computation
If our size computation overflows size_t, we may allocate a
much smaller buffer than we expected and overflow it. It's
probably impossible to trigger an overflow in most of these
sites in practice, but it is easy enough convert their
additions and multiplications into overflow-checking
variants. This may be fixing real bugs, and it makes
auditing the code easier.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-02-22 14:51:09 -08:00
Jeff King
96ffc06f72 convert trivial cases to FLEX_ARRAY macros
Using FLEX_ARRAY macros reduces the amount of manual
computation size we have to do. It also ensures we don't
overflow size_t, and it makes sure we write the same number
of bytes that we allocated.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-02-22 14:51:09 -08:00
Jeff King
3733e69464 use xmallocz to avoid size arithmetic
We frequently allocate strings as xmalloc(len + 1), where
the extra 1 is for the NUL terminator. This can be done more
simply with xmallocz, which also checks for integer
overflow.

There's no case where switching xmalloc(n+1) to xmallocz(n)
is wrong; the result is the same length, and malloc made no
guarantees about what was in the buffer anyway. But in some
cases, we can stop manually placing NUL at the end of the
allocated buffer. But that's only safe if it's clear that
the contents will always fill the buffer.

In each case where this patch does so, I manually examined
the control flow, and I tried to err on the side of caution.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-02-22 14:51:09 -08:00
Junio C Hamano
844a9ce472 Merge branch 'bc/object-id'
More transition from "unsigned char[40]" to "struct object_id".

This needed a few merge fixups, but is mostly disentangled from other
topics.

* bc/object-id:
  remote: convert functions to struct object_id
  Remove get_object_hash.
  Convert struct object to object_id
  Add several uses of get_object_hash.
  object: introduce get_object_hash macro.
  ref_newer: convert to use struct object_id
  push_refs_with_export: convert to struct object_id
  get_remote_heads: convert to struct object_id
  parse_fetch: convert to use struct object_id
  add_sought_entry_mem: convert to struct object_id
  Convert struct ref to use object_id.
  sha1_file: introduce has_object_file helper.
2015-12-10 12:36:13 -08:00
Junio C Hamano
b1cda70fff Merge branch 'dt/refs-backend-pre-vtable'
Code preparation for pluggable ref backends.

* dt/refs-backend-pre-vtable:
  refs: break out ref conflict checks
  files_log_ref_write: new function
  initdb: make safe_create_dir public
  refs: split filesystem-based refs code into a new file
  refs/refs-internal.h: new header file
  refname_is_safe(): improve docstring
  pack_if_possible_fn(): use ref_type() instead of is_per_worktree_ref()
  copy_msg(): rename to copy_reflog_msg()
  verify_refname_available(): new function
  verify_refname_available(): rename function
2015-12-08 14:14:49 -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
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
David Turner
0845122c39 refs: break out ref conflict checks
Create new function find_descendant_ref, to hold one of the ref
conflict checks used in verify_refname_available. Multiple backends
will need this function, so move it to the common code.

Also move rename_ref_available to the common code, because alternate
backends might need it and it has no files-backend-specific code.

Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>
2015-11-20 04:52:01 -05:00
Michael Haggerty
7bd9bcf372 refs: split filesystem-based refs code into a new file
As another step in the move to pluggable reference backends, move the
code that is specific to the filesystem-based reference backend (i.e.,
the current system of storing references as loose and packed files) into
a separate file, refs/files-backend.c.

Aside from a tiny bit of file header boilerplate, this commit only moves
a subset of the code verbatim from refs.c to the new file, as can easily
be verified using patience diff:

    git diff --patience $commit^:refs.c $commit:refs.c
    git diff --patience $commit^:refs.c $commit:refs/files-backend.c

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>
2015-11-20 04:52:01 -05:00
Michael Haggerty
4cb77009e1 refs/refs-internal.h: new header file
There are a number of constants, structs, and static functions defined
in refs.c and treated as private to the references module. But we want
to support multiple reference backends within the reference module,
and those backends will need access to some heretofore private
declarations.

We don't want those declarations to be visible to non-refs code, so we
don't want to move them to refs.h. Instead, add a new header file,
refs/refs-internal.h, that is intended to be included only from within
the refs module. Make some functions non-static and move some
declarations (and their corresponding docstrings) from refs.c to this
file.

In a moment we will add more content to the "refs" subdirectory.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>
2015-11-20 04:52:01 -05:00
Michael Haggerty
03b32623d8 refname_is_safe(): improve docstring
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>
2015-11-20 04:52:01 -05:00
Michael Haggerty
a935ebd4a7 pack_if_possible_fn(): use ref_type() instead of is_per_worktree_ref()
is_per_worktree_ref() will soon be made private, so use the public
interface, ref_type(), in its place. And now that we're using
ref_type(), we can make it clear that we won't pack pseudorefs. This was
the case before, but due to the not-so-obvious reason that this function
is applied to references via the loose reference cache, which only
includes references that live inside "refs/".

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>
2015-11-20 04:52:01 -05:00
David Turner
f4a5721ccb copy_msg(): rename to copy_reflog_msg()
We will soon increase the visibility of this function, so make its name
more distinctive.

Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>
2015-11-20 04:52:01 -05:00
Ronnie Sahlberg
d336123160 verify_refname_available(): new function
Add a new verify_refname_available() function, which checks whether the
refname is available for use, taking all references (both packed and
loose) into account. This function, unlike the old
verify_refname_available(), has semantics independent of the choice of
reference storage, and can therefore be implemented by alternative
reference backends.

Use the new function in a couple of places.

Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>
2015-11-20 04:52:01 -05:00
Ronnie Sahlberg
7003b3ce21 verify_refname_available(): rename function
Rename verify_refname_available() to verify_refname_available_dir() to
make the old name available for a more general purpose.

Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>
2015-11-20 04:52:01 -05:00
Lukas Fleischer
78a766ab6e hideRefs: add support for matching full refs
In addition to matching stripped refs, one can now add hideRefs
patterns that the full (unstripped) ref is matched against. To
distinguish between stripped and full matches, those new patterns
must be prefixed with a circumflex (^).

This commit also removes support for the undocumented and unintended
hideRefs settings ".have" (suppressing all "have" lines) and
"capabilities^{}" (suppressing the capabilities line).

Signed-off-by: Lukas Fleischer <lfleischer@lfos.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-11-05 11:25:02 -08:00
Junio C Hamano
78891795df Merge branch 'jk/war-on-sprintf'
Many allocations that is manually counted (correctly) that are
followed by strcpy/sprintf have been replaced with a less error
prone constructs such as xstrfmt.

Macintosh-specific breakage was noticed and corrected in this
reroll.

* jk/war-on-sprintf: (70 commits)
  name-rev: use strip_suffix to avoid magic numbers
  use strbuf_complete to conditionally append slash
  fsck: use for_each_loose_file_in_objdir
  Makefile: drop D_INO_IN_DIRENT build knob
  fsck: drop inode-sorting code
  convert strncpy to memcpy
  notes: document length of fanout path with a constant
  color: add color_set helper for copying raw colors
  prefer memcpy to strcpy
  help: clean up kfmclient munging
  receive-pack: simplify keep_arg computation
  avoid sprintf and strcpy with flex arrays
  use alloc_ref rather than hand-allocating "struct ref"
  color: add overflow checks for parsing colors
  drop strcpy in favor of raw sha1_to_hex
  use sha1_to_hex_r() instead of strcpy
  daemon: use cld->env_array when re-spawning
  stat_tracking_info: convert to argv_array
  http-push: use an argv_array for setup_revisions
  fetch-pack: use argv_array for index-pack / unpack-objects
  ...
2015-10-20 15:24:01 -07:00
Junio C Hamano
8a54523f0f Merge branch 'kn/for-each-tag'
The "ref-filter" code was taught about many parts of what "tag -l"
does and then "tag -l" is being reimplemented in terms of "ref-filter".

* kn/for-each-tag:
  tag.c: implement '--merged' and '--no-merged' options
  tag.c: implement '--format' option
  tag.c: use 'ref-filter' APIs
  tag.c: use 'ref-filter' data structures
  ref-filter: add option to match literal pattern
  ref-filter: add support to sort by version
  ref-filter: add support for %(contents:lines=X)
  ref-filter: add option to filter out tags, branches and remotes
  ref-filter: implement an `align` atom
  ref-filter: introduce match_atom_name()
  ref-filter: introduce handler function for each atom
  utf8: add function to align a string into given strbuf
  ref-filter: introduce ref_formatting_state and ref_formatting_stack
  ref-filter: move `struct atom_value` to ref-filter.c
  strtoul_ui: reject negative values
2015-10-05 12:30:18 -07:00
Jeff King
00b6c178c3 use strbuf_complete to conditionally append slash
When working with paths in strbufs, we frequently want to
ensure that a directory contains a trailing slash before
appending to it. We can shorten this code (and make the
intent more obvious) by calling strbuf_complete.

Most of these cases are trivially identical conversions, but
there are two things to note:

  - in a few cases we did not check that the strbuf is
    non-empty (which would lead to an out-of-bounds memory
    access). These were generally not triggerable in
    practice, either from earlier assertions, or typically
    because we would have just fed the strbuf to opendir(),
    which would choke on an empty path.

  - in a few cases we indexed the buffer with "original_len"
    or similar, rather than the current sb->len, and it is
    not immediately obvious from the diff that they are the
    same. In all of these cases, I manually verified that
    the strbuf does not change between the assignment and
    the strbuf_complete call.

This does not convert cases which look like:

  if (sb->len && !is_dir_sep(sb->buf[sb->len - 1]))
	  strbuf_addch(sb, '/');

as those are obviously semantically different. Some of these
cases arguably should be doing that, but that is out of
scope for this change, which aims purely for cleanup with no
behavior change (and at least it will make such sites easier
to find and examine in the future, as we can grep for
strbuf_complete).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-10-05 11:08:06 -07:00
Jeff King
c7ab0ba340 avoid sprintf and strcpy with flex arrays
When we are allocating a struct with a FLEX_ARRAY member, we
generally compute the size of the array and then sprintf or
strcpy into it. Normally we could improve a dynamic allocation
like this by using xstrfmt, but it doesn't work here; we
have to account for the size of the rest of the struct.

But we can improve things a bit by storing the length that
we use for the allocation, and then feeding it to xsnprintf
or memcpy, which makes it more obvious that we are not
writing more than the allocated number of bytes.

It would be nice if we had some kind of helper for
allocating generic flex arrays, but it doesn't work that
well:

 - the call signature is a little bit unwieldy:

      d = flex_struct(sizeof(*d), offsetof(d, path), fmt, ...);

   You need offsetof here instead of just writing to the
   end of the base size, because we don't know how the
   struct is packed (partially this is because FLEX_ARRAY
   might not be zero, though we can account for that; but
   the size of the struct may actually be rounded up for
   alignment, and we can't know that).

 - some sites do clever things, like over-allocating because
   they know they will write larger things into the buffer
   later (e.g., struct packed_git here).

So we're better off to just write out each allocation (or
add type-specific helpers, though many of these are one-off
allocations anyway).

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
495127dbcb resolve_ref: use strbufs for internal buffers
resolve_ref already uses a strbuf internally when generating
pathnames, but it uses fixed-size buffers for storing the
refname and symbolic refs. This means that you cannot
actually point HEAD to a ref that is larger than 256 bytes.

We can lift this limit by using strbufs here, too. Like
sb_path, we pass the the buffers into our helper function,
so that we can easily clean up all output paths. We can also
drop the "unsafe" name from our helper function, as it no
longer uses a single static buffer (but of course
resolve_ref_unsafe is still unsafe, because the static
buffers moved there).

As a bonus, we also get to drop some strcpy calls between
the two fixed buffers (that cannot currently overflow
because the two buffers are sized identically).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-09-25 10:18:18 -07:00
Jeff King
5096d4909f convert trivial sprintf / strcpy calls to xsnprintf
We sometimes sprintf into fixed-size buffers when we know
that the buffer is large enough to fit the input (either
because it's a constant, or because it's numeric input that
is bounded in size). Likewise with strcpy of constant
strings.

However, these sites make it hard to audit sprintf and
strcpy calls for buffer overflows, as a reader has to
cross-reference the size of the array with the input. Let's
use xsnprintf instead, which communicates to a reader that
we don't expect this to overflow (and catches the mistake in
case we do).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-09-25 10:18:18 -07:00
Karthik Nayak
5b4f28510f ref-filter: add option to filter out tags, branches and remotes
Add a function called 'for_each_fullref_in()' to refs.{c,h} which
iterates through each ref for the given path without trimming the path
and also accounting for broken refs, if mentioned.

Add 'filter_ref_kind()' in ref-filter.c to check the kind of ref being
handled and return the kind to 'ref_filter_handler()', where we
discard refs which we do not need and assign the kind to needed refs.

Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Matthieu Moy <matthieu.moy@grenoble-inp.fr>
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-09-17 10:02:48 -07:00
David Turner
ce414b33ec refs: make refs/bisect/* per-worktree
We need the place we stick refs for bisects in progress to not be
shared between worktrees.  So we make the refs/bisect/ hierarchy
per-worktree.

The is_per_worktree_ref function and associated docs learn that
refs/bisect/ is per-worktree, as does the git_path code in path.c

The ref-packing functions learn that per-worktree refs should not be
packed (since packed-refs is common rather than per-worktree).

Since refs/bisect is per-worktree, logs/refs/bisect should be too.

Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-09-01 10:37:39 -07:00
Junio C Hamano
db86e61cbb Merge branch 'mh/tempfile'
The "lockfile" API has been rebuilt on top of a new "tempfile" API.

* mh/tempfile:
  credential-cache--daemon: use tempfile module
  credential-cache--daemon: delete socket from main()
  gc: use tempfile module to handle gc.pid file
  lock_repo_for_gc(): compute the path to "gc.pid" only once
  diff: use tempfile module
  setup_temporary_shallow(): use tempfile module
  write_shared_index(): use tempfile module
  register_tempfile(): new function to handle an existing temporary file
  tempfile: add several functions for creating temporary files
  prepare_tempfile_object(): new function, extracted from create_tempfile()
  tempfile: a new module for handling temporary files
  commit_lock_file(): use get_locked_file_path()
  lockfile: add accessor get_lock_file_path()
  lockfile: add accessors get_lock_file_fd() and get_lock_file_fp()
  create_bundle(): duplicate file descriptor to avoid closing it twice
  lockfile: move documentation to lockfile.h and lockfile.c
2015-08-25 14:57:09 -07:00
Junio C Hamano
080cc64663 Merge branch 'dt/refs-pseudo'
To prepare for allowing a different "ref" backend to be plugged in
to the system, update_ref()/delete_ref() have been taught about
ref-like things like MERGE_HEAD that are per-worktree (they will
always be written to the filesystem inside $GIT_DIR).

* dt/refs-pseudo:
  pseudoref: check return values from read_ref()
  sequencer: replace write_cherry_pick_head with update_ref
  bisect: use update_ref
  pseudorefs: create and use pseudoref update and delete functions
  refs: add ref_type function
  refs: introduce pseudoref and per-worktree ref concepts
2015-08-25 14:57:08 -07:00
Junio C Hamano
8c9155e031 Merge branch 'jk/git-path'
git_path() and mkpath() are handy helper functions but it is easy
to misuse, as the callers need to be careful to keep the number of
active results below 4.  Their uses have been reduced.

* jk/git-path:
  memoize common git-path "constant" files
  get_repo_path: refactor path-allocation
  find_hook: keep our own static buffer
  refs.c: remove_empty_directories can take a strbuf
  refs.c: avoid git_path assignment in lock_ref_sha1_basic
  refs.c: avoid repeated git_path calls in rename_tmp_log
  refs.c: simplify strbufs in reflog setup and writing
  path.c: drop git_path_submodule
  refs.c: remove extra git_path calls from read_loose_refs
  remote.c: drop extraneous local variable from migrate_file
  prefer mkpathdup to mkpath in assignments
  prefer git_pathdup to git_path in some possibly-dangerous cases
  add_to_alternates_file: don't add duplicate entries
  t5700: modernize style
  cache.h: complete set of git_path_submodule helpers
  cache.h: clarify documentation for git_path, et al
2015-08-19 14:48:56 -07:00
Junio C Hamano
824a0be6be Merge branch 'jk/negative-hiderefs'
A negative !ref entry in multi-value transfer.hideRefs
configuration can be used to say "don't hide this one".

* jk/negative-hiderefs:
  refs: support negative transfer.hideRefs
  docs/config.txt: reorder hideRefs config
2015-08-19 14:48:54 -07:00
David Turner
2c3aed1381 pseudoref: check return values from read_ref()
These codepaths attempt to compare the "expected" current value with
the actual current value, but did not check if we successfully read
the current value before comparison.

Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-08-11 15:52:20 -07:00
Jeff King
470e28d4e1 refs.c: remove_empty_directories can take a strbuf
The first thing we do in this function is copy the input
into a strbuf. Of the 4 callers, 3 of them already have a
strbuf we could use. Let's just take the strbuf, and convert
the remaining caller to use a strbuf, rather than a raw
git_path. This is safer, anyway, as remove_dir_recursively
is a non-trivial function that might use the pathname
buffers itself (this is _probably_ OK, as the likely culprit
would be calling resolve_gitlink_ref, but we do not pass the
proper flags to ask it to avoid blowing away gitlinks).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-08-10 15:37:13 -07:00
Jeff King
5f8ef5b848 refs.c: avoid git_path assignment in lock_ref_sha1_basic
Assigning the result of git_path is a bad pattern, because
it's not immediately obvious how long you expect the content
to stay valid (and it may be overwritten by subsequent
calls). Let's use a function-local strbuf here instead,
which we know is safe (we just have to remember to free it
in all code paths).

As a bonus, we get rid of a confusing variable-reuse
("ref_file" is used for two distinct purposes).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-08-10 15:37:13 -07:00
Jeff King
d6549f3655 refs.c: avoid repeated git_path calls in rename_tmp_log
Because it's not safe to store the static-buffer results of
git_path for a long time, we end up formatting the same
filename over and over. We can fix this by using a
function-local strbuf to store the formatted pathname and
avoid repeating ourselves.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-08-10 15:37:13 -07:00
Jeff King
54b418f698 refs.c: simplify strbufs in reflog setup and writing
Commit 1a83c24 (git_snpath(): retire and replace with
strbuf_git_path(), 2014-11-30) taught log_ref_setup and
log_ref_write_1 to take a strbuf parameter, rather than a
bare string. It then makes an alias to the strbuf's "buf"
field under the original name.

This made the original diff much shorter, but the resulting
code is more complicated that it needs to be. Since we've
aliased the pointer, we drop our reference to the strbuf to
ensure we don't accidentally change it. But if we simply
drop our alias and use "logfile.buf" directly, we do not
have to worry about this aliasing. It's a larger diff, but
the resulting code is simpler.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-08-10 15:37:13 -07:00
Jeff King
f5b2dec165 refs.c: remove extra git_path calls from read_loose_refs
In iterating over the loose refs in "refs/foo/", we keep a
running strbuf with "refs/foo/one", "refs/foo/two", etc. But
we also need to access these files in the filesystem, as
".git/refs/foo/one", etc. For this latter purpose, we make a
series of independent calls to git_path(). These are safe
(we only use the result to call stat()), but assigning the
result of git_path is a suspicious pattern that we'd rather
avoid.

This patch keeps a running buffer with ".git/refs/foo/", and
we can just append/reset each directory element as we loop.
This matches how we handle the refnames. It should also be
more efficient, as we do not keep formatting the same
".git/refs/foo" prefix (which can be arbitrarily deep).

Technically we are dropping a call to strbuf_cleanup() on
each generated filename, but that's OK; it wasn't doing
anything, as we are putting in single-level names we read
from the filesystem (so it could not possibly be cleaning up
cruft like "./" in this instance).

A clever reader may also note that the running refname
buffer ("refs/foo/") is actually a subset of the filesystem
path buffer (".git/refs/foo/"). We could get by with one
buffer, indexing the length of $GIT_DIR when we want the
refname. However, having tried this, the resulting code
actually ends up a little more confusing, and the efficiency
improvement is tiny (and almost certainly dwarfed by the
system calls we are making).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-08-10 15:37:13 -07:00
Jeff King
e3cf230324 prefer mkpathdup to mkpath in assignments
As with the previous commit to git_path, assigning the
result of mkpath is suspicious, since it is not clear
whether we will still depend on the value after it may have
been overwritten by subsequent calls. This patch converts
low-hanging fruit to use mkpathdup instead of mkpath (with
the downside that we must remember to free the result).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-08-10 15:37:12 -07:00
Jeff King
fcd12db6af prefer git_pathdup to git_path in some possibly-dangerous cases
Because git_path uses a static buffer that is shared with
calls to git_path, mkpath, etc, it can be dangerous to
assign the result to a variable or pass it to a non-trivial
function. The value may change unexpectedly due to other
calls.

None of the cases changed here has a known bug, but they're
worth converting away from git_path because:

  1. It's easy to use git_pathdup in these cases.

  2. They use constructs (like assignment) that make it
     hard to tell whether they're safe or not.

The extra malloc overhead should be trivial, as an
allocation should be an order of magnitude cheaper than a
system call (which we are clearly about to make, since we
are constructing a filename). The real cost is that we must
remember to free the result.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-08-10 15:37:12 -07:00
Michael Haggerty
b4fb09e4da lockfile: add accessor get_lock_file_path()
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-08-10 12:57:14 -07:00
Michael Haggerty
c99a4c2db3 lockfile: add accessors get_lock_file_fd() and get_lock_file_fp()
We are about to move those members, so change client code to read them
through accessor functions.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-08-10 12:57:14 -07:00
Jeff King
2bc31d1631 refs: support negative transfer.hideRefs
If you hide a hierarchy of refs using the transfer.hideRefs
config, there is no way to later override that config to
"unhide" it. This patch implements a "negative" hide which
causes matches to immediately be marked as unhidden, even if
another match would hide it. We take care to apply the
matches in reverse-order from how they are fed to us by the
config machinery, as that lets our usual "last one wins"
config precedence work (and entries in .git/config, for
example, will override /etc/gitconfig).

So you can now do:

  $ git config --system transfer.hideRefs refs/secret
  $ git config transfer.hideRefs '!refs/secret/not-so-secret'

to hide refs/secret in all repos, except for one public bit
in one specific repo. Or you can even do:

  $ git clone \
      -u "git -c transfer.hiderefs="!refs/foo" upload-pack" \
      remote:repo.git

to clone remote:repo.git, overriding any hiding it has
configured.

There are two alternatives that were considered and
rejected:

  1. A generic config mechanism for removing an item from a
     list. E.g.: (e.g., "[transfer] hideRefs -= refs/foo").

     This is nice because it could apply to other
     multi-valued config, as well. But it is not nearly as
     flexible. There is no way to say:

       [transfer]
       hideRefs = refs/secret
       hideRefs = refs/secret/not-so-secret

     Having explicit negative specifications means we can
     override previous entries, even if they are not the
     same literal string.

  2. Adding another variable to override some parts of
     hideRefs (e.g., "exposeRefs").

     This solves the problem from alternative (1), but it
     cannot easily obey the normal config precedence,
     because it would use two separate lists. For example:

       [transfer]
       hideRefs = refs/secret
       exposeRefs = refs/secret/not-so-secret
       hideRefs = refs/secret/not-so-secret/no-really-its-secret

     With two lists, we have to apply the "expose" rules
     first, and only then apply the "hide" rules. But that
     does not match what the above config intends.

     Of course we could internally parse that to a single
     list, respecting the ordering, which saves us having to
     invent the new "!" syntax. But using a single name
     communicates to the user that the ordering _is_
     important. And "!" is well-known for negation, and
     should not appear at the beginning of a ref (it is
     actually valid in a ref-name, but all entries here
     should be fully-qualified, starting with "refs/").

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-08-07 11:47:36 -07:00
Junio C Hamano
8d3981ccbe Merge branch 'jk/refspec-parse-wildcard'
Allow an asterisk as a substring (as opposed to the entirety) of
a path component for both side of a refspec, e.g.
"refs/heads/o*:refs/remotes/heads/i*".

* jk/refspec-parse-wildcard:
  refs: loosen restriction on wildcard "*" refspecs
  refs: cleanup comments regarding check_refname_component()
2015-08-03 11:01:31 -07:00
Junio C Hamano
b6d323f164 Merge branch 'dt/refs-backend-preamble'
In preparation for allowing different "backends" to store the refs
in a way different from the traditional "one ref per file in $GIT_DIR
or in a $GIT_DIR/packed-refs file" filesystem storage, reduce
direct filesystem access to ref-like things like CHERRY_PICK_HEAD
from scripts and programs.

* dt/refs-backend-preamble:
  git-stash: use update-ref --create-reflog instead of creating files
  update-ref and tag: add --create-reflog arg
  refs: add REF_FORCE_CREATE_REFLOG flag
  git-reflog: add exists command
  refs: new public ref function: safe_create_reflog
  refs: break out check for reflog autocreation
  refs.c: add err arguments to reflog functions
2015-08-03 11:01:29 -07:00
Junio C Hamano
d939af12bd Merge branch 'jk/date-mode-format'
Teach "git log" and friends a new "--date=format:..." option to
format timestamps using system's strftime(3).

* jk/date-mode-format:
  strbuf: make strbuf_addftime more robust
  introduce "format" date-mode
  convert "enum date_mode" into a struct
  show-branch: use DATE_RELATIVE instead of magic number
2015-08-03 11:01:27 -07:00
Junio C Hamano
be9cb560e3 Merge branch 'mh/init-delete-refs-api'
Clean up refs API and make "git clone" less intimate with the
implementation detail.

* mh/init-delete-refs-api:
  delete_ref(): use the usual convention for old_sha1
  cmd_update_ref(): make logic more straightforward
  update_ref(): don't read old reference value before delete
  check_branch_commit(): make first parameter const
  refs.h: add some parameter names to function declarations
  refs: move the remaining ref module declarations to refs.h
  initial_ref_transaction_commit(): check for ref D/F conflicts
  initial_ref_transaction_commit(): check for duplicate refs
  refs: remove some functions from the module's public interface
  initial_ref_transaction_commit(): function for initial ref creation
  repack_without_refs(): make function private
  prune_refs(): use delete_refs()
  prune_remote(): use delete_refs()
  delete_refs(): bail early if the packed-refs file cannot be rewritten
  delete_refs(): make error message more generic
  delete_refs(): new function for the refs API
  delete_ref(): handle special case more explicitly
  remove_branches(): remove temporary
  delete_ref(): move declaration to refs.h
2015-08-03 11:01:17 -07:00
Junio C Hamano
31a0ad5456 Merge branch 'mh/replace-refs'
Add an environment variable to tell Git to look into refs hierarchy
other than refs/replace/ for the object replacement data.

* mh/replace-refs:
  Allow to control where the replace refs are looked for
2015-08-03 11:01:10 -07:00
David Turner
74ec19d4be pseudorefs: create and use pseudoref update and delete functions
Pseudorefs should not be updated through the ref transaction
API, because alternate ref backends still need to store pseudorefs
in GIT_DIR (instead of wherever they store refs).  Instead,
change update_ref and delete_ref to call pseudoref-specific
functions.

Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-07-31 10:39:38 -07:00
David Turner
266b18273a refs: add ref_type function
Add a function ref_type, which categorizes refs as per-worktree,
pseudoref, or normal ref.

Later, we will use this in refs.c to treat pseudorefs specially.
Alternate ref backends may use it to treat both pseudorefs and
per-worktree refs differently.

Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-07-31 10:39:04 -07:00
Jacob Keller
cd377f45c9 refs: loosen restriction on wildcard "*" refspecs
Loosen restrictions on refspecs by allowing patterns that have a "*"
within a component instead of only as the whole component.

Remove the logic to accept a single "*" as a whole component from
check_refname_format(), and implement an extended form of that logic
in check_refname_component().  Pass the pointer to the flags argument
to the latter, as it has to clear REFNAME_REFSPEC_PATTERN bit when
it sees "*".

Teach check_refname_component() function to allow an asterisk "*"
only when REFNAME_REFSPEC_PATTERN is set in the flags, and drop the
bit after seeing a "*", to ensure that one side of a refspec
contains at most one asterisk.

This will allow us to accept refspecs such as `for/bar*:foo/baz*`.
Any refspec which functioned before shall continue functioning with
the new logic.

Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-07-27 09:21:31 -07:00
Jacob Keller
53a8555ee4 refs: cleanup comments regarding check_refname_component()
Correctly specify all characters which are rejected under the '4: a
bad character' disposition, which did not list all characters that
are treated as such.

Cleanup comment style for rejected refs by inserting a ", or" at the
end of each statement.

Signed-off-by: Jacob Keller <jacob.keller@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-07-27 09:21:15 -07:00
David Turner
0f2a71d992 refs: add REF_FORCE_CREATE_REFLOG flag
Add a flag to allow forcing the creation of a reflog even if the ref
name and core.logAllRefUpdates setting would not ordinarily cause ref
creation.

In a moment, we will use this to add options to git tag and git
update-ref to force reflog creation.

Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-07-21 14:08:26 -07:00
David Turner
abd0cd3a30 refs: new public ref function: safe_create_reflog
The safe_create_reflog function creates a reflog, if it does not
already exist.

The log_ref_setup function becomes private and gains a force_create
parameter to force the creation of a reflog even if log_all_ref_updates
is false or the refname is not one of the special refnames.

The new parameter also reduces the need to store, modify, and restore
the log_all_ref_updates global before reflog creation.

In a moment, we will use this to add reflog creation commands to
git-reflog.

Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-07-21 14:07:59 -07:00
David Turner
4e2bef57c9 refs: break out check for reflog autocreation
This is just for clarity.

Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-07-21 14:07:54 -07:00
David Turner
a4c653dfcd refs.c: add err arguments to reflog functions
Add an err argument to log_ref_setup that can explain the reason
for a failure. This then eliminates the need to manage errno through
this function since we can just add strerror(errno) to the err string
when meaningful. No callers relied on errno from this function for
anything else than the error message.

Also add err arguments to private functions write_ref_to_lockfile,
log_ref_write_1, commit_ref_update. This again eliminates the need to
manage errno in these functions.

Some error messages are slightly reordered.

Update of a patch by Ronnie Sahlberg.

Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-07-21 14:07:28 -07:00
Jeff King
a5481a6c94 convert "enum date_mode" into a struct
In preparation for adding date modes that may carry extra
information beyond the mode itself, this patch converts the
date_mode enum into a struct.

Most of the conversion is fairly straightforward; we pass
the struct as a pointer and dereference the type field where
necessary. Locations that declare a date_mode can use a "{}"
constructor.  However, the tricky case is where we use the
enum labels as constants, like:

  show_date(t, tz, DATE_NORMAL);

Ideally we could say:

  show_date(t, tz, &{ DATE_NORMAL });

but of course C does not allow that. Likewise, we cannot
cast the constant to a struct, because we need to pass an
actual address. Our options are basically:

  1. Manually add a "struct date_mode d = { DATE_NORMAL }"
     definition to each caller, and pass "&d". This makes
     the callers uglier, because they sometimes do not even
     have their own scope (e.g., they are inside a switch
     statement).

  2. Provide a pre-made global "date_normal" struct that can
     be passed by address. We'd also need "date_rfc2822",
     "date_iso8601", and so forth. But at least the ugliness
     is defined in one place.

  3. Provide a wrapper that generates the correct struct on
     the fly. The big downside is that we end up pointing to
     a single global, which makes our wrapper non-reentrant.
     But show_date is already not reentrant, so it does not
     matter.

This patch implements 3, along with a minor macro to keep
the size of the callers sane.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-29 11:39:07 -07:00
Junio C Hamano
9d71c5f408 Merge branch 'mh/reporting-broken-refs-from-for-each-ref'
"git for-each-ref" reported "missing object" for 0{40} when it
encounters a broken ref.  The lack of object whose name is 0{40} is
not the problem; the ref being broken is.

* mh/reporting-broken-refs-from-for-each-ref:
  read_loose_refs(): treat NULL_SHA1 loose references as broken
  read_loose_refs(): simplify function logic
  for-each-ref: report broken references correctly
  t6301: new tests of for-each-ref error handling
2015-06-24 12:21:52 -07:00
Michael Haggerty
1c03c4d347 delete_ref(): use the usual convention for old_sha1
The ref_transaction_update() family of functions use the following
convention for their old_sha1 parameters:

* old_sha1 == NULL: Don't check the old value at all.
* is_null_sha1(old_sha1): Ensure that the reference didn't exist
  before the transaction.
* otherwise: Ensure that the reference had the specified value before
  the transaction.

delete_ref() had a different convention, namely treating
is_null_sha1(old_sha1) as "don't care". Change it to adhere to the
standard convention to reduce the scope for confusion.

Please note that it is now a bug to pass old_sha1=NULL_SHA1 to
delete_ref() (because it doesn't make sense to delete a reference that
you already know doesn't exist). This is consistent with the behavior
of ref_transaction_delete().

Most of the callers of delete_ref() never pass old_sha1=NULL_SHA1 to
delete_ref(), and are therefore unaffected by this change. The
two exceptions are:

* The call in cmd_update_ref(), which passed NULL_SHA1 if the old
  value passed in on the command line was 0{40} or the empty string.
  Change that caller to pass NULL in those cases.

  Arguably, it should be an error to call "update-ref -d" with the old
  value set to "does not exist", just as it is for the `--stdin`
  command "delete". But since this usage was accepted until now,
  continue to accept it.

* The call in delete_branches(), which could pass NULL_SHA1 if
  deleting a broken or symbolic ref. Change it to pass NULL in these
  cases.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-22 13:17:14 -07:00
Michael Haggerty
fb58c8d507 refs: move the remaining ref module declarations to refs.h
Some functions from the refs module were still declared in cache.h.
Move them to refs.h.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-22 13:17:12 -07:00
Michael Haggerty
e426ff4222 initial_ref_transaction_commit(): check for ref D/F conflicts
In initial_ref_transaction_commit(), check for D/F conflicts (i.e.,
the type of conflict that exists between "refs/foo" and
"refs/foo/bar") among the references being created and between the
references being created and any hypothetical existing references.

Ideally, there shouldn't *be* any existing references when this
function is called. But, at least in the case of the "testgit" remote
helper, "clone" can be called after the remote-tracking "HEAD" and
"master" branches have already been created. So let's just do the
full-blown check.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-22 13:17:12 -07:00
Michael Haggerty
fb802b3129 initial_ref_transaction_commit(): check for duplicate refs
Error out if the ref_transaction includes more than one update for any
refname.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-22 13:17:11 -07:00
Michael Haggerty
0a4b24ff14 refs: remove some functions from the module's public interface
The following functions are no longer used from outside the refs
module:

* lock_packed_refs()
* add_packed_ref()
* commit_packed_refs()
* rollback_packed_refs()

So make these functions private.

This is an important step, because it means that nobody outside of the
refs module needs to know the difference between loose and packed
references.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-22 13:17:11 -07:00
Michael Haggerty
58f233ce1e initial_ref_transaction_commit(): function for initial ref creation
"git clone" uses shortcuts when creating the initial set of
references:

* It writes them directly to packed-refs.

* It doesn't lock the individual references (though it does lock the
  packed-refs file).

* It doesn't check for refname conflicts between two new references or
  between one new reference and any hypothetical old ones.

* It doesn't create reflog entries for the reference creations.

This functionality was implemented in builtin/clone.c. But really that
file shouldn't have such intimate knowledge of how references are
stored. So provide a new function in the refs API,
initial_ref_transaction_commit(), which can be used for initial
reference creation. The new function is based on the ref_transaction
interface.

This means that we can make some other functions private to the refs
module. That will be done in a followup commit.

It would seem to make sense to add a test here that there are no
existing references, because that is how the function *should* be
used. But in fact, the "testgit" remote helper appears to call it
*after* having set up refs/remotes/<name>/HEAD and
refs/remotes/<name>/master, so we can't be so strict. For now, the
function trusts its caller to only call it when it makes sense. Future
commits will add some more limited sanity checks.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-22 13:17:11 -07:00
Michael Haggerty
79e4d8a9b8 repack_without_refs(): make function private
It is no longer called from outside of the refs module. Also move its
docstring and change it to imperative voice.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-22 13:17:11 -07:00
Michael Haggerty
7fa7dc8904 delete_refs(): bail early if the packed-refs file cannot be rewritten
If we fail to delete the doomed references from the packed-refs file,
then it is unsafe to delete their loose references, because doing so
might expose a value from the packed-refs file that is obsolete and
perhaps even points at an object that has been garbage collected.

So if repack_without_refs() fails, emit a more explicit error message
and bail.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-22 13:17:10 -07:00
Michael Haggerty
5d97861b9b delete_refs(): make error message more generic
Change the error message from

    Could not remove branch %s

to

    could not remove reference %s

First of all, the old error message referred to "branch
refs/remotes/origin/foo", which was awkward even for the existing
caller. Normally we would refer to a reference like that as either
"remote-tracking branch origin/foo" or "reference
refs/remotes/origin/foo". Here I take the lazier alternative.

Moreover, now that this function is part of the refs API, it might be
called for refs that are neither branches nor remote-tracking
branches.

While we're at it, convert the error message to lower case, as per our
usual convention.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-22 13:17:09 -07:00
Michael Haggerty
98ffd5ff67 delete_refs(): new function for the refs API
Move the function remove_branches() from builtin/remote.c to refs.c,
rename it to delete_refs(), and make it public.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-22 13:17:09 -07:00
Michael Haggerty
fc67a0825c delete_ref(): handle special case more explicitly
delete_ref() uses a different convention for its old_sha1 parameter
than, say, ref_transaction_delete(): NULL_SHA1 means not to check the
old value. Make this fact a little bit clearer in the code by handling
it in explicit, commented code rather than burying it in a conditional
expression.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-22 13:17:09 -07:00
Michael Haggerty
fc1c21689d delete_ref(): move declaration to refs.h
Also

* Add a docstring

* Rename the second parameter to "old_sha1", to be consistent with the
  convention used elsewhere in the refs module

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-22 13:17:08 -07:00
Mike Hommey
58d121b22b Allow to control where the replace refs are looked for
It can be useful to have grafts or replace refs for specific use-cases while
keeping the default "view" of the repository pristine (or with a different
set of grafts/replace refs).

It is possible to use a different graft file with GIT_GRAFT_FILE, but while
replace refs are more powerful, they don't have an equivalent override.

Add a GIT_REPLACE_REF_BASE environment variable to control where git is
going to look for replace refs.

Signed-off-by: Mike Hommey <mh@glandium.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-12 15:28:17 -07:00
Junio C Hamano
829f03e98c Merge branch 'mh/verify-lock-error-report'
Bring consistency to error reporting mechanism used in "refs" API.

* mh/verify-lock-error-report:
  ref_transaction_commit(): do not capitalize error messages
  verify_lock(): do not capitalize error messages
  verify_lock(): report errors via a strbuf
  verify_lock(): on errors, let the caller unlock the lock
  verify_lock(): return 0/-1 rather than struct ref_lock *
2015-06-11 09:29:54 -07:00
Michael Haggerty
501cf47cdd read_loose_refs(): treat NULL_SHA1 loose references as broken
NULL_SHA1 is used to indicate an "invalid object name" throughout our
code (and the code of other git implementations), so it is vastly more
likely that an on-disk reference was set to this value due to a
software bug than that NULL_SHA1 is the legitimate SHA-1 of an actual
object.  Therefore, if a loose reference has the value NULL_SHA1,
consider it to be broken.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-08 10:35:41 -07:00
Junio C Hamano
7c997bcbf6 Merge branch 'mh/write-refs-sooner-2.4' into maint
Multi-ref transaction support we merged a few releases ago
unnecessarily kept many file descriptors open, risking to fail with
resource exhaustion.  This is for 2.4.x track.

* mh/write-refs-sooner-2.4:
  ref_transaction_commit(): fix atomicity and avoid fd exhaustion
  ref_transaction_commit(): remove the local flags variable
  ref_transaction_commit(): inline call to write_ref_sha1()
  rename_ref(): inline calls to write_ref_sha1() from this function
  commit_ref_update(): new function, extracted from write_ref_sha1()
  write_ref_to_lockfile(): new function, extracted from write_ref_sha1()
  t7004: rename ULIMIT test prerequisite to ULIMIT_STACK_SIZE
  update-ref: test handling large transactions properly
  ref_transaction_commit(): fix atomicity and avoid fd exhaustion
  ref_transaction_commit(): remove the local flags variable
  ref_transaction_commit(): inline call to write_ref_sha1()
  rename_ref(): inline calls to write_ref_sha1() from this function
  commit_ref_update(): new function, extracted from write_ref_sha1()
  write_ref_to_lockfile(): new function, extracted from write_ref_sha1()
  t7004: rename ULIMIT test prerequisite to ULIMIT_STACK_SIZE
  update-ref: test handling large transactions properly
2015-06-05 12:00:17 -07:00
Michael Haggerty
f5517074f8 read_loose_refs(): simplify function logic
Make it clearer that there are two possible ways to read the
reference, but that we handle read errors uniformly regardless of
which way it was read.

This refactoring also makes the following change easier to implement.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-03 11:44:25 -07:00
Michael Haggerty
c2e0a718c6 ref_transaction_commit(): do not capitalize error messages
Our convention is for error messages to start with a lower-case
letter.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-27 15:58:42 -07:00
Michael Haggerty
000f0da57a verify_lock(): do not capitalize error messages
Our convention is for error messages to start with a lower-case
letter.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-27 15:58:42 -07:00
Michael Haggerty
33ffc176d6 verify_lock(): report errors via a strbuf
Instead of writing error messages directly to stderr, write them to
a "strbuf *err".  The caller, lock_ref_sha1_basic(), uses this error
reporting convention with all the other callees, and reports its
error this way to its callers.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-27 15:57:47 -07:00
Michael Haggerty
f41d632970 verify_lock(): on errors, let the caller unlock the lock
The caller already knows how to do it, so always do it in the same
place.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-27 12:40:29 -07:00
Michael Haggerty
a5e2499e54 verify_lock(): return 0/-1 rather than struct ref_lock *
Its return value wasn't conveying any extra information, but it made
the reader wonder whether the ref_lock that it returned might be
different than the one that was passed to it. So change the function
to the traditional "return 0 on success or a negative value on error".

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-27 12:39:41 -07:00
Michael Haggerty
5cb901a4b0 struct ref_lock: convert old_sha1 member to object_id
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 12:19:40 -07:00
Michael Haggerty
4e675d1732 warn_if_dangling_symref(): convert local variable "junk" to object_id
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
0a0c953217 each_ref_fn_adapter(): remove adapter
All of the callers of the for_each_ref family of functions have now
been rewritten to work with object_ids, so this adapter is no longer
needed.

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
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
brian m. carlson
8353847e85 refs: convert struct ref_entry to use struct object_id
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-25 12:19:27 -07:00
Junio C Hamano
fb257bfa17 Merge branch 'mh/lockfile-retry'
Instead of dying immediately upon failing to obtain a lock, retry
after a short while with backoff.

* mh/lockfile-retry:
  lock_packed_refs(): allow retries when acquiring the packed-refs lock
  lockfile: allow file locking to be retried with a timeout
2015-05-22 12:41:55 -07:00
Junio C Hamano
faa4b2ecbb Merge branch 'mh/ref-directory-file'
The ref API did not handle cases where 'refs/heads/xyzzy/frotz' is
removed at the same time as 'refs/heads/xyzzy' is added (or vice
versa) very well.

* mh/ref-directory-file:
  reflog_expire(): integrate lock_ref_sha1_basic() errors into ours
  ref_transaction_commit(): delete extra "the" from error message
  ref_transaction_commit(): provide better error messages
  rename_ref(): integrate lock_ref_sha1_basic() errors into ours
  lock_ref_sha1_basic(): improve diagnostics for ref D/F conflicts
  lock_ref_sha1_basic(): report errors via a "struct strbuf *err"
  verify_refname_available(): report errors via a "struct strbuf *err"
  verify_refname_available(): rename function
  refs: check for D/F conflicts among refs created in a transaction
  ref_transaction_commit(): use a string_list for detecting duplicates
  is_refname_available(): use dirname in first loop
  struct nonmatching_ref_data: store a refname instead of a ref_entry
  report_refname_conflict(): inline function
  entry_matches(): inline function
  is_refname_available(): convert local variable "dirname" to strbuf
  is_refname_available(): avoid shadowing "dir" variable
  is_refname_available(): revamp the comments
  t1404: new tests of ref D/F conflicts within transactions
2015-05-22 12:41:53 -07:00
Junio C Hamano
91c90876de Merge branch 'mh/write-refs-sooner-2.4'
Multi-ref transaction support we merged a few releases ago
unnecessarily kept many file descriptors open, risking to fail with
resource exhaustion.  This is for 2.4.x track.

* mh/write-refs-sooner-2.4:
  ref_transaction_commit(): fix atomicity and avoid fd exhaustion
  ref_transaction_commit(): remove the local flags variable
  ref_transaction_commit(): inline call to write_ref_sha1()
  rename_ref(): inline calls to write_ref_sha1() from this function
  commit_ref_update(): new function, extracted from write_ref_sha1()
  write_ref_to_lockfile(): new function, extracted from write_ref_sha1()
  t7004: rename ULIMIT test prerequisite to ULIMIT_STACK_SIZE
  update-ref: test handling large transactions properly
  ref_transaction_commit(): fix atomicity and avoid fd exhaustion
  ref_transaction_commit(): remove the local flags variable
  ref_transaction_commit(): inline call to write_ref_sha1()
  rename_ref(): inline calls to write_ref_sha1() from this function
  commit_ref_update(): new function, extracted from write_ref_sha1()
  write_ref_to_lockfile(): new function, extracted from write_ref_sha1()
  t7004: rename ULIMIT test prerequisite to ULIMIT_STACK_SIZE
  update-ref: test handling large transactions properly
2015-05-22 12:41:52 -07:00
Junio C Hamano
4295abc040 Merge branch 'sb/ref-lock-lose-lock-fd'
The refs API uses ref_lock struct which had its own "int fd", even
though the same file descriptor was in the lock struct it contains.
Clean-up the code to lose this redundant field.

* sb/ref-lock-lose-lock-fd:
  refs.c: remove lock_fd from struct ref_lock
2015-05-19 13:17:59 -07:00
Michael Haggerty
f4ab4f3ab1 lock_packed_refs(): allow retries when acquiring the packed-refs lock
Currently, there is only one attempt to acquire any lockfile, and if
the lock is held by another process, the locking attempt fails
immediately.

This is not such a limitation for loose reference files. First, they
don't take long to rewrite. Second, most reference updates have a
known "old" value, so if another process is updating a reference at
the same moment that we are trying to lock it, then probably the
expected "old" value will not longer be valid, and the update will
fail anyway.

But these arguments do not hold for packed-refs:

* The packed-refs file can be large and take significant time to
  rewrite.

* Many references are stored in a single packed-refs file, so it could
  be that the other process was changing a different reference than
  the one that we are interested in.

Therefore, it is much more likely for there to be spurious lock
conflicts in connection to the packed-refs file, resulting in
unnecessary command failures.

So, if the first attempt to lock the packed-refs file fails, continue
retrying for a configurable length of time before giving up. The
default timeout is 1 second.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-14 14:51:51 -07:00
Michael Haggerty
cf018ee0cd ref_transaction_commit(): fix atomicity and avoid fd exhaustion
The old code was roughly

    for update in updates:
        acquire locks and check old_sha
    for update in updates:
        if changing value:
            write_ref_to_lockfile()
            commit_ref_update()
    for update in updates:
        if deleting value:
            unlink()
    rewrite packed-refs file
    for update in updates:
        if reference still locked:
            unlock_ref()

This has two problems.

Non-atomic updates
==================

The atomicity of the reference transaction depends on all pre-checks
being done in the first loop, before any changes have started being
committed in the second loop. The problem is that
write_ref_to_lockfile() (previously part of write_ref_sha1()), which
is called from the second loop, contains two more checks:

* It verifies that new_sha1 is a valid object

* If the reference being updated is a branch, it verifies that
  new_sha1 points at a commit object (as opposed to a tag, tree, or
  blob).

If either of these checks fails, the "transaction" is aborted during
the second loop. But this might happen after some reference updates
have already been permanently committed. In other words, the
all-or-nothing promise of "git update-ref --stdin" could be violated.

So these checks have to be moved to the first loop.

File descriptor exhaustion
==========================

The old code locked all of the references in the first loop, leaving
all of the lockfiles open until later loops. Since we might be
updating a lot of references, this could result in file descriptor
exhaustion.

The solution
============

After this patch, the code looks like

    for update in updates:
        acquire locks and check old_sha
        if changing value:
            write_ref_to_lockfile()
        else:
            close_ref()
    for update in updates:
        if changing value:
            commit_ref_update()
    for update in updates:
        if deleting value:
            unlink()
    rewrite packed-refs file
    for update in updates:
        if reference still locked:
            unlock_ref()

This fixes both problems:

1. The pre-checks in write_ref_to_lockfile() are now done in the first
   loop, before any changes have been committed. If any of the checks
   fails, the whole transaction can now be rolled back correctly.

2. All lockfiles are closed in the first loop immediately after they
   are created (either by write_ref_to_lockfile() or by close_ref()).
   This means that there is never more than one open lockfile at a
   time, preventing file descriptor exhaustion.

To simplify the bookkeeping across loops, add a new REF_NEEDS_COMMIT
bit to update->flags, which keeps track of whether the corresponding
lockfile needs to be committed, as opposed to just unlocked. (Since
"struct ref_update" is internal to the refs module, this change is not
visible to external callers.)

This change fixes two tests in t1400.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-12 21:28:03 -07:00
Michael Haggerty
cbf50f9e3d ref_transaction_commit(): remove the local flags variable
Instead, work directly with update->flags. This has the advantage that
the REF_DELETING bit, set in the first loop, can be read in the second
loop instead of having to be recomputed. Plus, it was potentially
confusing having both update->flags and flags, which sometimes had
different values.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-12 21:28:03 -07:00
Michael Haggerty
61e51e0000 ref_transaction_commit(): inline call to write_ref_sha1()
That was the last caller, so delete function write_ref_sha1().

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-12 21:28:03 -07:00
Michael Haggerty
ba43b7f29c rename_ref(): inline calls to write_ref_sha1() from this function
Most of what it does is unneeded from these call sites.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-12 21:28:02 -07:00
Michael Haggerty
ad4cd6c297 commit_ref_update(): new function, extracted from write_ref_sha1()
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-12 21:28:02 -07:00
Michael Haggerty
e6fd3c6730 write_ref_to_lockfile(): new function, extracted from write_ref_sha1()
This is the first step towards separating the checking and writing of
the new reference value to committing the change.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-12 21:28:02 -07:00
Junio C Hamano
6cc983d0ad Merge branch 'jk/reading-packed-refs'
An earlier rewrite to use strbuf_getwholeline() instead of fgets(3)
to read packed-refs file revealed that the former is unacceptably
inefficient.

* jk/reading-packed-refs:
  t1430: add another refs-escape test
  read_packed_refs: avoid double-checking sane refs
  strbuf_getwholeline: use getdelim if it is available
  strbuf_getwholeline: avoid calling strbuf_grow
  strbuf_addch: avoid calling strbuf_grow
  config: use getc_unlocked when reading from file
  strbuf_getwholeline: use getc_unlocked
  git-compat-util: add fallbacks for unlocked stdio
  strbuf_getwholeline: use getc macro
2015-05-11 14:23:42 -07:00
Junio C Hamano
68a2e6a2c8 Merge branch 'nd/multiple-work-trees'
A replacement for contrib/workdir/git-new-workdir that does not
rely on symbolic links and make sharing of objects and refs safer
by making the borrowee and borrowers aware of each other.

* nd/multiple-work-trees: (41 commits)
  prune --worktrees: fix expire vs worktree existence condition
  t1501: fix test with split index
  t2026: fix broken &&-chain
  t2026 needs procondition SANITY
  git-checkout.txt: a note about multiple checkout support for submodules
  checkout: add --ignore-other-wortrees
  checkout: pass whole struct to parse_branchname_arg instead of individual flags
  git-common-dir: make "modules/" per-working-directory directory
  checkout: do not fail if target is an empty directory
  t2025: add a test to make sure grafts is working from a linked checkout
  checkout: don't require a work tree when checking out into a new one
  git_path(): keep "info/sparse-checkout" per work-tree
  count-objects: report unused files in $GIT_DIR/worktrees/...
  gc: support prune --worktrees
  gc: factor out gc.pruneexpire parsing code
  gc: style change -- no SP before closing parenthesis
  checkout: clean up half-prepared directories in --to mode
  checkout: reject if the branch is already checked out elsewhere
  prune: strategies for linked checkouts
  checkout: support checking out into a new working directory
  ...
2015-05-11 14:23:39 -07:00
Michael Haggerty
c628edfddb reflog_expire(): integrate lock_ref_sha1_basic() errors into ours
Now that lock_ref_sha1_basic() gives us back its error messages via a
strbuf, incorporate its error message into our error message rather
than emitting two separate error messages.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
2015-05-11 11:50:20 -07:00
Michael Haggerty
3553944aa8 ref_transaction_commit(): delete extra "the" from error message
While we are in the area, let's remove a superfluous definite article
from the error message that is emitted when the reference cannot be
locked. This improves how it reads and makes it a bit shorter.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
2015-05-11 11:50:20 -07:00
Michael Haggerty
cbaabcbc6f ref_transaction_commit(): provide better error messages
Now that lock_ref_sha1_basic() gives us back its error messages via a
strbuf, incorporate its error message into our error message rather
than emitting one error messages to stderr immediately and returning a
second to our caller.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
2015-05-11 11:50:20 -07:00
Michael Haggerty
abeef9c856 rename_ref(): integrate lock_ref_sha1_basic() errors into ours
Now that lock_ref_sha1_basic() gives us back its error messages via a
strbuf, incorporate its error message into our error message rather
than emitting two separate error messages.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
2015-05-11 11:50:20 -07:00
Michael Haggerty
5b2d8d6f21 lock_ref_sha1_basic(): improve diagnostics for ref D/F conflicts
If there is a failure to lock a reference that is likely caused by a
D/F conflict (e.g., trying to lock "refs/foo/bar" when reference
"refs/foo" already exists), invoke verify_refname_available() to try
to generate a more helpful error message.

That function might not detect an error. For example, some
non-reference file might be blocking the deletion of an
otherwise-empty directory tree, or there might be a race with another
process that just deleted the offending reference. In such cases,
generate the strerror-based error message like before.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
2015-05-11 11:50:20 -07:00
Michael Haggerty
4a32b2e08b lock_ref_sha1_basic(): report errors via a "struct strbuf *err"
For now, change the callers to spew the error to stderr like before.
But soon we will change them to incorporate the reason for the failure
into their own error messages.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
2015-05-11 11:50:19 -07:00
Michael Haggerty
1146f17e2c verify_refname_available(): report errors via a "struct strbuf *err"
It shouldn't be spewing errors directly to stderr.

For now, change its callers to spew the errors to stderr.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
2015-05-11 11:50:19 -07:00
Michael Haggerty
5baf37d383 verify_refname_available(): rename function
Rename is_refname_available() to verify_refname_available() and change
its return value from 1 for success to 0 for success, to be consistent
with our error-handling convention. In a moment it will also get a
"struct strbuf *err" parameter.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
2015-05-11 11:50:19 -07:00
Michael Haggerty
e911104c84 refs: check for D/F conflicts among refs created in a transaction
If two references that D/F conflict (e.g., "refs/foo" and
"refs/foo/bar") are created in a single transaction, the old code
discovered the problem only after the "commit" phase of
ref_transaction_commit() had already begun. This could leave some
references updated and others not, which violates the promise of
atomicity.

Instead, check for such conflicts during the "locking" phase:

* Teach is_refname_available() to take an "extras" parameter that can
  contain extra reference names with which the specified refname must
  not conflict.

* Change lock_ref_sha1_basic() to take an "extras" parameter, which it
  passes through to is_refname_available().

* Change ref_transaction_commit() to pass "affected_refnames" to
  lock_ref_sha1_basic() as its "extras" argument.

This change fixes a test case in t1404.

This code is a bit stricter than it needs to be. We could conceivably
allow reference "refs/foo/bar" to be created in the same transaction
as "refs/foo" is deleted (or vice versa). But that would be
complicated to implement, because it is not possible to lock
"refs/foo/bar" while "refs/foo" exists as a loose reference, but on
the other hand we don't want to delete some references before adding
others (because that could leave a gap during which required objects
are unreachable). There is also a complication that reflog files'
paths can conflict.

Any less-strict implementation would probably require tricks like the
packing of all references before the start of the real transaction, or
the use of temporary intermediate reference names.

So for now let's accept too-strict checks. Some reference update
transactions will be rejected unnecessarily, but they will be rejected
in their entirety rather than leaving the repository in an
intermediate state, as would happen now.

Please note that there is still one kind of D/F conflict that is *not*
handled correctly. If two processes are running at the same time, and
one tries to create "refs/foo" at the same time that the other tries
to create "refs/foo/bar", then they can race with each other. Both
processes can obtain their respective locks ("refs/foo.lock" and
"refs/foo/bar.lock"), proceed to the "commit" phase of
ref_transaction_commit(), and then the slower process will discover
that it cannot rename its lockfile into place (after possibly having
committed changes to other references). There appears to be no way to
fix this race without changing the locking policy, which in turn would
require a change to *all* Git clients.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
2015-05-11 11:50:19 -07:00
Michael Haggerty
07f9c881d6 ref_transaction_commit(): use a string_list for detecting duplicates
Detect duplicates by storing the reference names in a string_list and
sorting that, instead of sorting the ref_updates directly.

* In a moment the string_list will be used for another purpose, too.

* This removes the need for the custom comparison function
  ref_update_compare().

* This means that we can carry out the updates in the order that the
  user specified them instead of reordering them. This might be handy
  someday if, we want to permit multiple updates to a single reference
  as long as they are compatible with each other.

Note: we can't use string_list_remove_duplicates() to check for
duplicates, because we need to know the name of the reference that
appeared multiple times, to be used in the error message.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
2015-05-11 11:50:19 -07:00
Michael Haggerty
61da596992 is_refname_available(): use dirname in first loop
In the first loop (over prefixes of refname), use dirname to keep
track of the current prefix. This is not an improvement in itself, but
in a moment we will start using dirname for a role where a
NUL-terminated string is needed.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
2015-05-11 11:50:18 -07:00
Michael Haggerty
521331cc9f struct nonmatching_ref_data: store a refname instead of a ref_entry
Now that we don't need a ref_entry to pass to
report_refname_conflict(), it is sufficient to store the refname of
the conflicting reference.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
2015-05-11 11:50:18 -07:00
Michael Haggerty
385e8af5a2 report_refname_conflict(): inline function
It wasn't pulling its weight. And we are about to need code similar to
this where no ref_entry is available and with more diverse error
messages. Rather than try to generalize the function, just inline it.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
2015-05-11 11:50:18 -07:00
Michael Haggerty
8bfac19ab4 entry_matches(): inline function
It wasn't pulling its weight. And in a moment we will need similar
tests that take a refname rather than a ref_entry as parameter, which
would have made entry_matches() even less useful.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
2015-05-11 11:50:18 -07:00
Michael Haggerty
6075f3076e is_refname_available(): convert local variable "dirname" to strbuf
This change wouldn't be worth it by itself, but in a moment we will
use the strbuf for more string juggling.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
2015-05-11 11:50:17 -07:00
Michael Haggerty
9ef6eaa287 is_refname_available(): avoid shadowing "dir" variable
The function had a "dir" parameter that was shadowed by a local "dir"
variable within a code block. Use the former in place of the latter.
(This is consistent with "dir"'s use elsewhere in the function.)

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
2015-05-11 11:50:17 -07:00
Michael Haggerty
49e818762a is_refname_available(): revamp the comments
Change the comments to a running example of running the function with
refname set to "refs/foo/bar". Add some more explanation of the logic.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
2015-05-11 11:50:17 -07:00
Stefan Beller
1238ac8c5d refs.c: remove lock_fd from struct ref_lock
The 'lock_fd' is the same as 'lk->fd'. No need to store it twice so remove
it.

No functional changes intended.

Signed-off-by: Stefan Beller <sbeller@google.com>
Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-10 21:13:26 -07:00
Jeff King
03afcbee9b read_packed_refs: avoid double-checking sane refs
Prior to d0f810f (refs.c: allow listing and deleting badly
named refs, 2014-09-03), read_packed_refs would barf on any
malformed refnames by virtue of calling create_ref_entry
with the "check" parameter set to 1. That commit loosened
our reading so that we call check_refname_format ourselves
and just set a REF_BAD_NAME flag.

We then call create_ref_entry with the check parameter set
to 0. That function learned to do an extra safety check even
when the check parameter is 0, so that we don't load any
dangerous refnames (like "../../../etc/passwd"). This is
implemented by calling refname_is_safe() in
create_ref_entry().

However, we can observe that refname_is_safe() can only be
true if check_refname_format() also failed. So in the common
case of a sanely named ref, we perform _both_ checks, even
though we know that the latter will never trigger. This has
a noticeable performance impact when the packed-refs file is
large.

Let's drop the refname_is_safe check from create_ref_entry(),
and make it the responsibility of the caller.  Of the three
callers that pass a check parameter of "0", two will have
just called check_refname_format(), and can check the
refname-safety only when it fails. The third case,
pack_if_possible_fn, is copying from an existing ref entry,
which must have previously passed our safety check.

With this patch, running "git rev-parse refs/heads/does-not-exist"
on a repo with a large (1.6GB) packed-refs file went from:

  real    0m6.768s
  user    0m6.340s
  sys     0m0.432s

to:

  real    0m5.703s
  user    0m5.276s
  sys     0m0.432s

for a wall-clock speedup of 15%.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-04-16 08:15:05 -07:00
Junio C Hamano
05e816e37f Merge branch 'jk/prune-with-corrupt-refs'
"git prune" used to largely ignore broken refs when deciding which
objects are still being used, which could spread an existing small
damage and make it a larger one.

* jk/prune-with-corrupt-refs:
  refs.c: drop curate_packed_refs
  repack: turn on "ref paranoia" when doing a destructive repack
  prune: turn on ref_paranoia flag
  refs: introduce a "ref paranoia" flag
  t5312: test object deletion code paths in a corrupted repository
2015-03-25 12:54:26 -07:00
Jeff King
ea56c4e02f refs.c: drop curate_packed_refs
When we delete a ref, we have to rewrite the entire
packed-refs file. We take this opportunity to "curate" the
packed-refs file and drop any entries that are crufty or
broken.

Dropping broken entries (e.g., with bogus names, or ones
that point to missing objects) is actively a bad idea, as it
means that we lose any notion that the data was there in the
first place. Aside from the general hackiness that we might
lose any information about ref "foo" while deleting an
unrelated ref "bar", this may seriously hamper any attempts
by the user at recovering from the corruption in "foo".

They will lose the sha1 and name of "foo"; the exact pointer
may still be useful even if they recover missing objects
from a different copy of the repository. But worse, once the
ref is gone, there is no trace of the corruption. A
follow-up "git prune" may delete objects, even though it
would otherwise bail when seeing corruption.

We could just drop the "broken" bits from
curate_packed_refs, and continue to drop the "crufty" bits:
refs whose loose counterpart exists in the filesystem. This
is not wrong to do, and it does have the advantage that we
may write out a slightly smaller packed-refs file. But it
has two disadvantages:

  1. It is a potential source of races or mistakes with
     respect to these refs that are otherwise unrelated to
     the operation. To my knowledge, there aren't any active
     problems in this area, but it seems like an unnecessary
     risk.

  2. We have to spend time looking up the matching loose
     refs for every item in the packed-refs file. If you
     have a large number of packed refs that do not change,
     that outweighs the benefit from writing out a smaller
     packed-refs file (it doesn't get smaller, and you do a
     bunch of directory traversal to find that out).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-20 12:41:41 -07:00
Jeff King
49672f26d9 refs: introduce a "ref paranoia" flag
Most operations that iterate over refs are happy to ignore
broken cruft. However, some operations should be performed
with knowledge of these broken refs, because it is better
for the operation to choke on a missing object than it is to
silently pretend that the ref did not exist (e.g., if we are
computing the set of reachable tips in order to prune
objects).

These processes could just call for_each_rawref, except that
ref iteration is often hidden behind other interfaces. For
instance, for a destructive "repack -ad", we would have to
inform "pack-objects" that we are destructive, and then it
would in turn have to tell the revision code that our
"--all" should include broken refs.

It's much simpler to just set a global for "dangerous"
operations that includes broken refs in all iterations.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-20 12:40:49 -07:00
Junio C Hamano
82b7e65199 Merge branch 'mh/expire-updateref-fixes'
Various issues around "reflog expire", e.g. using --updateref when
expiring a reflog for a symbolic reference, have been corrected
and/or made saner.

* mh/expire-updateref-fixes:
  reflog_expire(): never update a reference to null_sha1
  reflog_expire(): ignore --updateref for symbolic references
  reflog: improve and update documentation
  struct ref_lock: delete the force_write member
  lock_ref_sha1_basic(): do not set force_write for missing references
  write_ref_sha1(): move write elision test to callers
  write_ref_sha1(): remove check for lock == NULL
2015-03-10 13:52:40 -07:00
Michael Haggerty
423c688b85 reflog_expire(): never update a reference to null_sha1
Currently, if --updateref is specified and the very last reflog entry
is expired or deleted, the reference's value is set to 0{40}. This is
an invalid state of the repository, and breaks, for example, "git
fsck" and "git for-each-ref".

The only place we use --updateref in our own code is when dropping
stash entries. In that code, the very next step is to check if the
reflog has been made empty, and if so, delete the "refs/stash"
reference entirely. Thus that code path ultimately leaves the
repository in a valid state.

But we don't want to the repository in an invalid state even
temporarily, and we don't want to leave an invalid state if other
callers of "git reflog expire|delete --updateref" don't think to do
the extra cleanup step.

So, if "git reflog expire|delete" leaves no more entries in the
reflog, just leave the reference unchanged.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-05 12:35:37 -08:00
Michael Haggerty
5e6f003ca8 reflog_expire(): ignore --updateref for symbolic references
If we are expiring reflog entries for a symbolic reference, then how
should --updateref be handled if the newest reflog entry is expired?

Option 1: Update the referred-to reference. (This is what the current
code does.) This doesn't make sense, because the referred-to reference
has its own reflog, which hasn't been rewritten.

Option 2: Update the symbolic reference itself (as in, REF_NODEREF).
This would convert the symbolic reference into a non-symbolic
reference (e.g., detaching HEAD), which is surely not what a user
would expect.

Option 3: Error out. This is plausible, but it would make the
following usage impossible:

    git reflog expire ... --updateref --all

Option 4: Ignore --updateref for symbolic references.

We choose to implement option 4.

Note: another problem in this code will be fixed in a moment.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-05 12:35:37 -08:00
Stefan Beller
5a6f47077b struct ref_lock: delete the force_write member
Instead, compute the value when it is needed.

Signed-off-by: Stefan Beller <sbeller@google.com>
Edited-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-05 12:35:36 -08:00
Michael Haggerty
074336e5ed lock_ref_sha1_basic(): do not set force_write for missing references
If a reference is missing, its SHA-1 will be null_sha1, which can't
possibly match a new value that ref_transaction_commit() is trying to
update it to. So there is no need to set force_write in this scenario.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-05 12:35:36 -08:00
Michael Haggerty
706d5f816f write_ref_sha1(): move write elision test to callers
write_ref_sha1() previously skipped the write if the reference already
had the desired value, unless lock->force_write was set. Instead,
perform that test at the callers.

Two of the callers (in rename_ref()) unconditionally set force_write
just before calling write_ref_sha1(), so they don't need the extra
check at all. Nor do they need to set force_write anymore.

The last caller, in ref_transaction_commit(), still needs the test.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-05 12:35:36 -08:00
Michael Haggerty
8280bbebd1 write_ref_sha1(): remove check for lock == NULL
None of the callers pass NULL to this function, and there doesn't seem
to be any usefulness to allowing them to do so.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-05 12:35:36 -08:00
Junio C Hamano
faf723a631 Merge branch 'jk/blame-commit-label' into maint
"git blame HEAD -- missing" failed to correctly say "HEAD" when it
tried to say "No such path 'missing' in HEAD".

* jk/blame-commit-label:
  blame.c: fix garbled error message
  use xstrdup_or_null to replace ternary conditionals
  builtin/commit.c: use xstrdup_or_null instead of envdup
  builtin/apply.c: use xstrdup_or_null instead of null_strdup
  git-compat-util: add xstrdup_or_null helper
2015-02-24 22:09:54 -08:00
Michael Haggerty
4b7b520b9f update_ref(): improve documentation
Add a docstring for update_ref(), emphasizing its similarity to
ref_transaction_update(). Rename its parameters to match those of
ref_transaction_update().

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-02-17 11:25:03 -08:00
Michael Haggerty
1618033401 ref_transaction_verify(): new function to check a reference's value
If NULL is passed to ref_transaction_update()'s new_sha1 parameter,
then just verify old_sha1 (under lock) without trying to change the
new value of the reference.

Use this functionality to add a new function ref_transaction_verify(),
which checks the current value of the reference under lock but doesn't
change it.

Use ref_transaction_verify() in the implementation of "git update-ref
--stdin"'s "verify" command to avoid the awkward need to "update" the
reference to its existing value.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-02-17 11:24:59 -08:00
Michael Haggerty
60294596ba ref_transaction_delete(): check that old_sha1 is not null_sha1
It makes no sense to delete a reference that is already known not to
exist.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-02-17 11:24:55 -08:00
Michael Haggerty
f04c5b5522 ref_transaction_create(): check that new_sha1 is valid
Creating a reference requires a new_sha1 that is not NULL and not
null_sha1.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-02-17 11:24:48 -08:00
Michael Haggerty
fb5a6bb61c ref_transaction_delete(): remove "have_old" parameter
Instead, verify the reference's old value if and only if old_sha1 is
non-NULL.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-02-17 11:23:48 -08:00
Michael Haggerty
1d147bdff0 ref_transaction_update(): remove "have_old" parameter
Instead, verify the reference's old value if and only if old_sha1 is
non-NULL.

ref_transaction_delete() will get the same treatment in a moment.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-02-17 11:22:50 -08:00
Michael Haggerty
8df4e51138 struct ref_update: move "have_old" into "flags"
Instead of having a separate have_old field, record this boolean value
as a bit in the "flags" field.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-02-17 11:22:42 -08:00
Michael Haggerty
fec14ec38c refs.c: change some "flags" to "unsigned int"
Change the following functions' "flags" arguments from "int" to
"unsigned int":

 * ref_transaction_update()
 * ref_transaction_create()
 * ref_transaction_delete()
 * update_ref()
 * delete_ref()
 * lock_ref_sha1_basic()

Also change the "flags" member in "struct ref_update" to unsigned.

Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-02-17 11:22:29 -08:00
Michael Haggerty
31e79f0a54 refs: remove the gap in the REF_* constant values
There is no reason to "reserve" a gap between the public and private
flags values.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-02-12 11:42:53 -08:00
Michael Haggerty
581d4e0cdb refs: move REF_DELETING to refs.c
It is only used internally now. Document it a little bit better, too.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-02-12 11:42:53 -08:00
Junio C Hamano
4d5c4e498a Merge branch 'mh/reflog-expire'
Restructure "reflog expire" to fit the reflogs better with the
recently updated ref API.

Looked reasonable (except that some shortlog entries stood out like
a sore thumb).

* mh/reflog-expire: (24 commits)
  refs.c: let fprintf handle the formatting
  refs.c: don't expose the internal struct ref_lock in the header file
  lock_any_ref_for_update(): inline function
  refs.c: remove unlock_ref/close_ref/commit_ref from the refs api
  reflog_expire(): new function in the reference API
  expire_reflog(): treat the policy callback data as opaque
  Move newlog and last_kept_sha1 to "struct expire_reflog_cb"
  expire_reflog(): move rewrite to flags argument
  expire_reflog(): move verbose to flags argument
  expire_reflog(): pass flags through to expire_reflog_ent()
  struct expire_reflog_cb: a new callback data type
  Rename expire_reflog_cb to expire_reflog_policy_cb
  expire_reflog(): move updateref to flags argument
  expire_reflog(): move dry_run to flags argument
  expire_reflog(): add a "flags" argument
  expire_reflog(): extract two policy-related functions
  Extract function should_expire_reflog_ent()
  expire_reflog(): use a lock_file for rewriting the reflog file
  expire_reflog(): return early if the reference has no reflog
  expire_reflog(): rename "ref" parameter to "refname"
  ...
2015-02-11 13:43:38 -08:00
Junio C Hamano
092c4be7f5 Merge branch 'jk/blame-commit-label'
"git blame HEAD -- missing" failed to correctly say "HEAD" when it
tried to say "No such path 'missing' in HEAD".

* jk/blame-commit-label:
  blame.c: fix garbled error message
  use xstrdup_or_null to replace ternary conditionals
  builtin/commit.c: use xstrdup_or_null instead of envdup
  builtin/apply.c: use xstrdup_or_null instead of null_strdup
  git-compat-util: add xstrdup_or_null helper
2015-02-11 13:39:50 -08:00
Junio C Hamano
61c9475221 Merge branch 'mh/reflog-expire' into mh/ref-trans-value-check
* mh/reflog-expire: (24 commits)
  refs.c: let fprintf handle the formatting
  refs.c: don't expose the internal struct ref_lock in the header file
  lock_any_ref_for_update(): inline function
  refs.c: remove unlock_ref/close_ref/commit_ref from the refs api
  reflog_expire(): new function in the reference API
  expire_reflog(): treat the policy callback data as opaque
  Move newlog and last_kept_sha1 to "struct expire_reflog_cb"
  expire_reflog(): move rewrite to flags argument
  expire_reflog(): move verbose to flags argument
  expire_reflog(): pass flags through to expire_reflog_ent()
  struct expire_reflog_cb: a new callback data type
  Rename expire_reflog_cb to expire_reflog_policy_cb
  expire_reflog(): move updateref to flags argument
  expire_reflog(): move dry_run to flags argument
  expire_reflog(): add a "flags" argument
  expire_reflog(): extract two policy-related functions
  Extract function should_expire_reflog_ent()
  expire_reflog(): use a lock_file for rewriting the reflog file
  expire_reflog(): return early if the reference has no reflog
  expire_reflog(): rename "ref" parameter to "refname"
  ...
2015-02-09 14:37:01 -08:00
Jeff King
8c53f0719b use xstrdup_or_null to replace ternary conditionals
This replaces "x ? xstrdup(x) : NULL" with xstrdup_or_null(x).
The change is fairly mechanical, with the exception of
resolve_refdup, which can eliminate a temporary variable.

There are still a few hits grepping for "?.*xstrdup", but
these are of slightly different forms and cannot be
converted (e.g., "x ? xstrdup(x->foo) : NULL").

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-01-13 10:05:48 -08:00
René Scharfe
33adc83ddb refs: plug strbuf leak in lock_ref_sha1_basic()
Don't just reset, but release the resource held by the local
variable that is about to go out of scope.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-12-29 13:14:16 -08:00
Junio C Hamano
aa9066fccd Merge branch 'jk/read-packed-refs-without-path-max'
Git did not correctly read an overlong refname from a packed refs
file.

* jk/read-packed-refs-without-path-max:
  read_packed_refs: use skip_prefix instead of static array
  read_packed_refs: pass strbuf to parse_ref_line
  read_packed_refs: use a strbuf for reading lines
2014-12-22 12:28:04 -08:00
Junio C Hamano
6f3abb7a87 Merge branch 'jk/for-each-reflog-ent-reverse'
The code that reads the reflog from the newer to the older entries
did not handle an entry that crosses a boundary of block it uses to
read them correctly.

* jk/for-each-reflog-ent-reverse:
  for_each_reflog_ent_reverse: turn leftover check into assertion
  for_each_reflog_ent_reverse: fix newlines on block boundaries
2014-12-22 12:27:32 -08:00
Junio C Hamano
a7ddaa8eac Merge branch 'mh/simplify-repack-without-refs'
"git remote update --prune" to drop many refs has been optimized.

* mh/simplify-repack-without-refs:
  sort_string_list(): rename to string_list_sort()
  prune_remote(): iterate using for_each_string_list_item()
  prune_remote(): rename local variable
  repack_without_refs(): make the refnames argument a string_list
  prune_remote(): sort delete_refs_list references en masse
  prune_remote(): initialize both delete_refs lists in a single loop
  prune_remote(): exit early if there are no stale references
2014-12-22 12:26:50 -08:00
Stefan Beller
c653e0343d refs.c: let fprintf handle the formatting
Instead of calculating whether to put a plus or minus sign, offload
the responsibilty to the fprintf function.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-12-22 10:13:16 -08:00
Stefan Beller
3581d79335 refs.c: don't expose the internal struct ref_lock in the header file
Now the struct ref_lock is used completely internally, so let's
remove it from the header file.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-12-22 10:13:15 -08:00
Michael Haggerty
31e07f76a9 lock_any_ref_for_update(): inline function
Inline the function at its one remaining caller (which is within
refs.c) and remove it.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-12-22 10:13:15 -08:00
Ronnie Sahlberg
0b1e654801 refs.c: remove unlock_ref/close_ref/commit_ref from the refs api
unlock|close|commit_ref can be made static since there are no more external
callers.

Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-12-22 10:13:15 -08:00
Michael Haggerty
fa5b1830b0 reflog_expire(): new function in the reference API
Move expire_reflog() into refs.c and rename it to reflog_expire().
Turn the three policy functions into function pointers that are passed
into reflog_expire(). Add function prototypes and documentation to
refs.h.

[jc: squashed in $gmane/261582, drop "extern" in function definition]

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Stefan Beller <sbeller@google.com>
Tweaked-by: Ramsay Jones
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-12-22 10:11:40 -08:00
Ronnie Sahlberg
2c6207abbd refs.c: add a function to append a reflog entry to a fd
Break out the code to create the string and writing it to the file
descriptor from log_ref_write and add it into a dedicated function
log_ref_write_fd. It is a nice unit of work.

For now this is only used from log_ref_write, but in the future it
might have other callers.

Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-12-12 11:42:00 -08:00
Jeff King
ea417833ea read_packed_refs: use skip_prefix instead of static array
We want to recognize the packed-refs header and skip to the
"traits" part of the line. We currently do it by feeding
sizeof() a static const array to strncmp. However, it's a
bit simpler to just skip_prefix, which expresses the
intention more directly, and without remembering to account
for the NUL-terminator in each sizeof() call.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-12-10 09:40:33 -08:00
Jeff King
6a49870a72 read_packed_refs: pass strbuf to parse_ref_line
Now that we have a strbuf in read_packed_refs, we can pass
it straight to the line parser, which saves us an extra
strlen.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-12-10 09:28:54 -08:00
Jeff King
10c497aa0c read_packed_refs: use a strbuf for reading lines
Current code uses a fixed PATH_MAX-sized buffer for reading
packed-refs lines. This is a reasonable guess, in the sense
that git generally cannot work with refs larger than
PATH_MAX.  However, there are a few cases where it is not
great:

  1. Some systems may have a low value of PATH_MAX, but can
     actually handle larger paths in practice. Fixing this
     code path probably isn't enough to make them work
     completely with long refs, but it is a step in the
     right direction.

  2. We use fgets, which will happily give us half a line on
     the first read, and then the rest of the line on the
     second. This is probably OK in practice, because our
     refline parser is careful enough to look for the
     trailing newline on the first line. The second line may
     look like a peeled line to us, but since "^" is illegal
     in refnames, it is not likely to come up.

     Still, it does not hurt to be more careful.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-12-10 09:27:24 -08:00