Commit Graph

270 Commits

Author SHA1 Message Date
Michael Haggerty
f23092f19e cache_ref_iterator_begin(): avoid priming unneeded directories
When iterating over references, reference priming is used to make sure
that loose references are read into the ref-cache before packed
references, to avoid races. It used to be that the prefix passed to
reference iterators almost always ended in `/`, for example
`refs/heads/`. In that case, the priming code would read all loose
references under `find_containing_dir("refs/heads/")`, which is
"refs/heads/". That's just what we want.

But now that `ref-filter` knows how to pass refname prefixes to
`for_each_fullref_in()`, the prefix might come from user input; for
example,

    git for-each-ref refs/heads

Since the argument doesn't include a trailing slash, the reference
iteration code would prime all of the loose references under
`find_containing_dir("refs/heads")`, which is "refs/". Thus we would
unnecessarily read tags, remote-tracking references, etc., when the
user is only interested in branches.

It is a bit awkward to get around this problem. We can't just append a
slash to the argument, because we don't know ab initio whether an
argument like `refs/tags/release` corresponds to a single tag or to a
directory containing tags.

Moreover, until now a `prefix_ref_iterator` was used to make the final
decision about which references fall within the prefix (the
`cache_ref_iterator` only did a rough cut). This is also inefficient,
because the `prefix_ref_iterator` can't know, for example, that while
you are in a subdirectory that is completely within the prefix, you
don't have to do the prefix check.

So:

* Move the responsibility for doing the prefix check directly to
  `cache_ref_iterator`. This means that `cache_ref_iterator_begin()`
  never has to wrap its return value in a `prefix_ref_iterator`.

* Teach `cache_ref_iterator_begin()` (and `prime_ref_dir()`) to be
  stricter about what they iterate over and what directories they
  prime.

* Teach `cache_ref_iterator` to keep track of whether the current
  `cache_ref_iterator_level` is fully within the prefix. If so, skip
  the prefix checks entirely.

The main benefit of these optimizations is for loose references, since
packed references are always read all at once.

Note that after this change, `prefix_ref_iterator` is only ever used
for its trimming feature and not for its "prefix" feature. But I'm not
ripping out the latter yet, because it might be useful for another
patch series that I'm working on.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-24 21:21:21 +09:00
Michael Haggerty
c1da06c6f1 create_ref_entry(): remove check_name option
Only one caller was using it, so move the check to that caller.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-23 14:29:56 +09:00
Michael Haggerty
0a0865b8f1 refs_ref_iterator_begin(): handle GIT_REF_PARANOIA
Instead of handling `GIT_REF_PARANOIA` in
`files_ref_iterator_begin()`, handle it in
`refs_ref_iterator_begin()`, where it will cover all reference stores.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-23 14:29:56 +09:00
Michael Haggerty
89c571da56 read_packed_refs(): report unexpected fopen() failures
The old code ignored any errors encountered when trying to fopen the
"packed-refs" file, treating all such failures as if the file didn't
exist. But it could be that there is some other error opening the
file (e.g., permissions problems), and we don't want to silently
ignore such problems. So report any failures that are not due to
ENOENT.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-23 14:29:56 +09:00
Michael Haggerty
099a912a27 read_packed_refs(): do more of the work of reading packed refs
Teach `read_packed_refs()` to also

* Allocate and initialize the new `packed_ref_cache`
* Open and close the `packed-refs` file
* Update the `validity` field of the new object

This decreases the coupling between `packed_refs_cache` and
`files_ref_store` by a little bit.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-23 14:29:55 +09:00
Michael Haggerty
28ed9830b1 get_packed_ref_cache(): assume "packed-refs" won't change while locked
If we've got the "packed-refs" file locked, then it can't change;
there's no need to keep calling `stat_validity_check()` on it.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-23 14:29:55 +09:00
Michael Haggerty
531cc4a56d should_pack_ref(): new function, extracted from files_pack_refs()
Extract a function for deciding whether a reference should be packed.
It is a self-contained bit of logic, so splitting it out improves
readability.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-23 14:29:55 +09:00
Michael Haggerty
2ced105cb1 ref_update_reject_duplicates(): expose function to whole refs module
It will soon have some other users.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-23 14:29:55 +09:00
Michael Haggerty
30173b8851 ref_transaction_prepare(): new optional step for reference updates
In the future, compound reference stores will sometimes need to modify
references in two different reference stores at the same time, meaning
that a single logical reference transaction might have to be
implemented as two internal sub-transactions. They won't want to call
`ref_transaction_commit()` for the two sub-transactions one after the
other, because that wouldn't be atomic (the first commit could succeed
and the second one fail). Instead, they will want to prepare both
sub-transactions (i.e., obtain any necessary locks and do any
pre-checks), and only if both prepare steps succeed, then commit both
sub-transactions.

Start preparing for that day by adding a new, optional
`ref_transaction_prepare()` step to the reference transaction
sequence, which obtains the locks and does any prechecks, reporting
any errors that occur. Also add a `ref_transaction_abort()` function
that can be used to abort a sub-transaction even if it has already
been prepared.

That is on the side of the public-facing API. On the side of the
`ref_store` VTABLE, get rid of `transaction_commit` and instead add
methods `transaction_prepare`, `transaction_finish`, and
`transaction_abort`. A `ref_transaction_commit()` now basically calls
methods `transaction_prepare` then `transaction_finish`.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-23 14:29:55 +09:00
Michael Haggerty
8d4240d3c8 ref_transaction_commit(): check for valid transaction->state
Move the check that `transaction->state` is valid from
`files_transaction_commit()` to `ref_transaction_commit()`, where
other future reference backends can benefit from it as well.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-23 14:29:55 +09:00
Michael Haggerty
c0ca935764 files_transaction_cleanup(): new helper function
Extract the cleanup functionality from `files_transaction_commit()`
into a new function. It will soon have another caller.

Use the common cleanup code even on early exit if the transaction is
empty, to reduce code duplication.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-23 14:29:55 +09:00
Michael Haggerty
00d174489e files_ref_store: put the packed files lock directly in this struct
Instead of using a global `lock_file` instance for the main
"packed-refs" file and using a pointer in `files_ref_store` to keep
track of whether it is locked, embed the `lock_file` instance directly
in the `files_ref_store` struct and use the new
`is_lock_file_locked()` function to keep track of whether it is
locked. This keeps related data together and makes the main reference
store less of a special case.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-23 14:29:54 +09:00
Michael Haggerty
55c6bc37c9 files-backend: move lock member to files_ref_store
Move the `lock` member from `packed_ref_cache` to `files_ref_store`,
since at most one cache can have a locked "packed-refs" file
associated with it. Rename it to `packed_refs_lock` to make its
purpose clearer in its new home. More changes are coming here shortly.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-23 14:29:54 +09:00
Michael Haggerty
64da41993a ref_store: take a msg parameter when deleting references
Just because the files backend can't retain reflogs for deleted
references is no reason that they shouldn't be supported by the
virtual method interface. Also, `delete_ref()` and `refs_delete_ref()`
have already gained `msg` parameters. Now let's add them to
`delete_refs()` and `refs_delete_refs()`.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-23 14:29:53 +09:00
Michael Haggerty
43a2dfde76 refs: use size_t indexes when iterating over ref transaction updates
Eliminate any chance of integer overflow on platforms where the two
types have different sizes.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-23 14:29:53 +09:00
Michael Haggerty
b9c8e7f2fb prefix_ref_iterator: don't trim too much
The `trim` parameter can be set independently of `prefix`. So if some
caller were to set `trim` to be greater than `strlen(prefix)`, we
could end up pointing the `refname` field of the iterator past the NUL
of the actual reference name string.

That can't happen currently, because `trim` is always set either to
zero or to `strlen(prefix)`. But even the latter could lead to
confusion, if a refname is exactly equal to the prefix, because then
we would set the outgoing `refname` to the empty string.

And we're about to decouple the `prefix` and `trim` arguments even
more, so let's be cautious here. Report a bug if ever asked to trim a
reference whose name is not longer than `trim`.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-23 14:29:52 +09:00
Michael Haggerty
04aea8d4df files-backend: use die("BUG: ..."), not die("internal error: ...")
The former is by far more common in our codebase.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-23 14:29:52 +09:00
Michael Haggerty
e186057138 ref_iterator_begin_fn(): fix docstring
The iterator returned by this function only includes references whose
names start with the whole prefix, not all of those in
`find_containing_dir(prefix)` as the old docstring claimed. This
docstring was probably copy-pasted from old ref-cache code, which had
the old specification. But now, `cache_ref_iterator_begin()`
(from which the files reference iterator gets its values)
automatically wraps its output using `prefix_ref_iterator_begin()`
when necessary, so it has the stricter behavior.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-23 14:29:52 +09:00
Junio C Hamano
ca7b2ab07d Merge branch 'bc/object-id'
* bc/object-id: (53 commits)
  object: convert parse_object* to take struct object_id
  tree: convert parse_tree_indirect to struct object_id
  sequencer: convert do_recursive_merge to struct object_id
  diff-lib: convert do_diff_cache to struct object_id
  builtin/ls-tree: convert to struct object_id
  merge: convert checkout_fast_forward to struct object_id
  sequencer: convert fast_forward_to to struct object_id
  builtin/ls-files: convert overlay_tree_on_cache to object_id
  builtin/read-tree: convert to struct object_id
  sha1_name: convert internals of peel_onion to object_id
  upload-pack: convert remaining parse_object callers to object_id
  revision: convert remaining parse_object callers to object_id
  revision: rename add_pending_sha1 to add_pending_oid
  http-push: convert process_ls_object and descendants to object_id
  refs/files-backend: convert many internals to struct object_id
  refs: convert struct ref_update to use struct object_id
  ref-filter: convert some static functions to struct object_id
  Convert struct ref_array_item to struct object_id
  Convert the verify_pack callback to struct object_id
  Convert lookup_tag to struct object_id
  ...
2017-05-23 14:29:19 +09:00
Junio C Hamano
b15667bbdc Merge branch 'js/larger-timestamps'
Some platforms have ulong that is smaller than time_t, and our
historical use of ulong for timestamp would mean they cannot
represent some timestamp that the platform allows.  Invent a
separate and dedicated timestamp_t (so that we can distingiuish
timestamps and a vanilla ulongs, which along is already a good
move), and then declare uintmax_t is the type to be used as the
timestamp_t.

* js/larger-timestamps:
  archive-tar: fix a sparse 'constant too large' warning
  use uintmax_t for timestamps
  date.c: abort if the system time cannot handle one of our timestamps
  timestamp_t: a new data type for timestamps
  PRItime: introduce a new "printf format" for timestamps
  parse_timestamp(): specify explicitly where we parse timestamps
  t0006 & t5000: skip "far in the future" test when time_t is too limited
  t0006 & t5000: prepare for 64-bit timestamps
  ref-filter: avoid using `unsigned long` for catch-all data type
2017-05-16 11:51:59 +09:00
Junio C Hamano
4b44b7b1df Merge branch 'nd/worktree-kill-parse-ref'
"git gc" did not interact well with "git worktree"-managed
per-worktree refs.

* nd/worktree-kill-parse-ref:
  refs: kill set_worktree_head_symref()
  worktree.c: kill parse_ref() in favor of refs_resolve_ref_unsafe()
  refs: introduce get_worktree_ref_store()
  refs: add REFS_STORE_ALL_CAPS
  refs.c: make submodule ref store hashmap generic
  environment.c: fix potential segfault by get_git_common_dir()
2017-05-16 11:51:51 +09:00
brian m. carlson
c251c83df2 object: convert parse_object* to take struct object_id
Make parse_object, parse_object_or_die, and parse_object_buffer take a
pointer to struct object_id.  Remove the temporary variables inserted
earlier, since they are no longer necessary.  Transform all of the
callers using the following semantic patch:

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

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

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

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

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

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

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-08 15:12:58 +09:00
brian m. carlson
4417df8c49 refs/files-backend: convert many internals to struct object_id
Convert many of the internals of the files backend to use struct
object_id.  Avoid converting public APIs (except one change to
refs/ref-cache.c) to limit the scope of the changes.

Convert one use of get_sha1_hex to parse_oid_hex, and rely on the fact
that a strbuf will be NUL-terminated and that parse_oid_hex will fail on
truncated input to avoid the need to check the length.

This is a requirement to convert parse_object later on.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-08 15:12:58 +09:00
brian m. carlson
984912989d refs: convert struct ref_update to use struct object_id
Convert struct ref_array_item to use struct object_id by changing the
definition and applying the following semantic patch, plus the standard
object_id transforms:

@@
struct ref_update E1;
@@
- E1.new_sha1
+ E1.new_oid.hash

@@
struct ref_update *E1;
@@
- E1->new_sha1
+ E1->new_oid.hash

@@
struct ref_update E1;
@@
- E1.old_sha1
+ E1.old_oid.hash

@@
struct ref_update *E1;
@@
- E1->old_sha1
+ E1->old_oid.hash

This transformation allows us to convert write_ref_to_lockfile, which is
required to convert parse_object.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-08 15:12:58 +09:00
brian m. carlson
4322478a49 reflog_expire: convert to struct object_id
Adjust the callback functions to take struct object_id * instead of
unsigned char *, and modify related static functions accordingly.

Introduce a temporary object_id instance into files_reflog_expire and
copy the SHA-1 value passed in.  This is necessary because the sha1
parameter can come indirectly from get_sha1.  Without the temporary, it
would require much more refactoring to be able to convert this function.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-08 15:12:57 +09:00
Johannes Schindelin
dddbad728c timestamp_t: a new data type for timestamps
Git's source code assumes that unsigned long is at least as precise as
time_t. Which is incorrect, and causes a lot of problems, in particular
where unsigned long is only 32-bit (notably on Windows, even in 64-bit
versions).

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

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

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

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-27 13:07:39 +09:00
Junio C Hamano
77b34eaa07 Merge branch 'mh/separate-ref-cache'
The internals of the refs API around the cached refs has been
streamlined.

* mh/separate-ref-cache:
  do_for_each_entry_in_dir(): delete function
  files_pack_refs(): use reference iteration
  commit_packed_refs(): use reference iteration
  cache_ref_iterator_begin(): make function smarter
  get_loose_ref_cache(): new function
  get_loose_ref_dir(): function renamed from get_loose_refs()
  do_for_each_entry_in_dir(): eliminate `offset` argument
  refs: handle "refs/bisect/" in `loose_fill_ref_dir()`
  ref-cache: use a callback function to fill the cache
  refs: record the ref_store in ref_cache, not ref_dir
  ref-cache: introduce a new type, ref_cache
  refs: split `ref_cache` code into separate files
  ref-cache: rename `remove_entry()` to `remove_entry_from_dir()`
  ref-cache: rename `find_ref()` to `find_ref_entry()`
  ref-cache: rename `add_ref()` to `add_ref_entry()`
  refs_verify_refname_available(): use function in more places
  refs_verify_refname_available(): implement once for all backends
  refs_ref_iterator_begin(): new function
  refs_read_raw_ref(): new function
  get_ref_dir(): don't call read_loose_refs() for "refs/bisect"
2017-04-26 15:39:13 +09:00
Nguyễn Thái Ngọc Duy
d026a25657 refs: kill set_worktree_head_symref()
70999e9cec (branch -m: update all per-worktree HEADs - 2016-03-27)
added this function in order to update HEADs of all relevant
worktrees, when a branch is renamed.

It, as a public ref api, kind of breaks abstraction when it uses
internal functions of files backend. With the introduction of
refs_create_symref(), we can move back pretty close to the code before
70999e9cec, where create_symref() was used for updating HEAD.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-24 21:28:55 -07:00
Nguyễn Thái Ngọc Duy
0d8a814d8a refs: add REFS_STORE_ALL_CAPS
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-24 21:28:55 -07:00
Junio C Hamano
f9096db54b Merge branch 'rs/misc-cppcheck-fixes'
Various small fixes.

* rs/misc-cppcheck-fixes:
  server-info: avoid calling fclose(3) twice in update_info_file()
  files_for_each_reflog_ent_reverse(): close stream and free strbuf on error
  am: close stream on error, but not stdin
2017-04-23 22:07:56 -07:00
Johannes Schindelin
cb71f8bdb5 PRItime: introduce a new "printf format" for timestamps
Currently, Git's source code treats all timestamps as if they were
unsigned longs. Therefore, it is okay to write "%lu" when printing them.

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

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

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-23 20:19:15 -07:00
Johannes Schindelin
1aeb7e756c parse_timestamp(): specify explicitly where we parse timestamps
Currently, Git's source code represents all timestamps as `unsigned
long`. In preparation for using a more appropriate data type, let's
introduce a symbol `parse_timestamp` (currently being defined to
`strtoul`) where appropriate, so that we can later easily switch to,
say, use `strtoull()` instead.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-23 20:19:15 -07:00
René Scharfe
be686f03e0 files_for_each_reflog_ent_reverse(): close stream and free strbuf on error
Exit the loop orderly through the cleanup code, instead of dashing out
with logfp still open and sb leaking.

Found with Cppcheck.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Reviewed-by: Jeff King <peff@peff.net>
Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-17 17:37:10 -07:00
Michael Haggerty
f890db83ee do_for_each_entry_in_dir(): delete function
Its only remaining caller was itself.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-16 21:32:46 -07:00
Michael Haggerty
50c2d8555b files_pack_refs(): use reference iteration
Use reference iteration rather than `do_for_each_entry_in_dir()` in
the definition of `files_pack_refs()`. This makes the code shorter and
easier to follow, because the logic can be inline rather than spread
between the main function and a callback function, and it removes the
need to use `pack_refs_cb_data` to preserve intermediate state.

This removes the last callers of `entry_resolves_to_object()` and
`get_loose_ref_dir()`, so delete those functions.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-16 21:32:46 -07:00
Michael Haggerty
1710fbafb6 commit_packed_refs(): use reference iteration
Use reference iteration rather than do_for_each_entry_in_dir() in the
definition of commit_packed_refs().

Note that an internal consistency check that was previously done in
`write_packed_entry_fn()` is not there anymore. This is actually an
improvement:

The old error message was emitted when there is an entry in the
packed-ref cache that is not `REF_KNOWS_PEELED`, and when we attempted
to peel the reference, the result was `PEEL_INVALID`,
`PEEL_IS_SYMREF`, or `PEEL_BROKEN`. Since a packed ref cannot be a
symref, `PEEL_IS_SYMREF` and `PEEL_BROKEN` can be ruled out. So we're
left with `PEEL_INVALID`.

An entry without `REF_KNOWS_PEELED` can get into the packed-refs cache
in the following two ways:

* The reference was read from a `packed-refs` file that didn't have
  the `fully-peeled` attribute. In that case, we *don't want* to emit
  an error, because the broken value is presumably a stale value of
  the reference that is now masked by a loose version of the same
  reference (which we just don't happen to be packing this time). This
  is a perfectly legitimate situation and doesn't indicate that the
  repository is corrupt. The old code incorrectly emits an error
  message in this case. (It was probably never reported as a bug
  because this scenario is rare.)

* The reference was a loose reference that was just added to the
  packed ref cache by `files_packed_refs()` via
  `pack_if_possible_fn()` in preparation for being packed. The latter
  function refuses to pack a reference for which
  `entry_resolves_to_object()` returns false, and otherwise calls
  `peel_entry()` itself and checks the return value. So an entry added
  this way should always have `REF_KNOWS_PEELED` and shouldn't trigger
  the error message in either the old code or the new.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-16 21:32:46 -07:00
Michael Haggerty
059ae35a48 cache_ref_iterator_begin(): make function smarter
Change `cache_ref_iterator_begin()` to take two new arguments:

* `prefix` -- to iterate only over references with the specified
  prefix.

* `prime_dir` -- to "prime" (i.e., pre-load) the cache before starting
  the iteration.

The new functionality makes it possible for
`files_ref_iterator_begin()` to be made more ignorant of the internals
of `ref_cache`, and `find_containing_dir()` and `prime_ref_dir()` to
be made private.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-16 21:32:46 -07:00
Michael Haggerty
a714b19ca8 get_loose_ref_cache(): new function
Extract a new function, `get_loose_ref_cache()`, from
get_loose_ref_dir(). The function returns the `ref_cache` for the
loose refs of a `files_ref_store`.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-16 21:32:46 -07:00
Michael Haggerty
86f423584b get_loose_ref_dir(): function renamed from get_loose_refs()
The new name is more analogous to `get_packed_ref_dir()`.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-16 21:32:46 -07:00
Michael Haggerty
5c7bba77b2 do_for_each_entry_in_dir(): eliminate offset argument
It was never used.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-16 21:32:46 -07:00
Michael Haggerty
e3bf2989ca refs: handle "refs/bisect/" in loose_fill_ref_dir()
That "refs/bisect/" has to be handled specially when filling the
ref_cache for loose references is a peculiarity of the files backend,
and the ref-cache code shouldn't need to know about it. So move this
code to the callback function, `loose_fill_ref_dir()`.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-16 21:32:46 -07:00
Michael Haggerty
df30875987 ref-cache: use a callback function to fill the cache
It is a leveling violation for `ref_cache` to know about
`files_ref_store` or that it should call `read_loose_refs()` to lazily
fill cache directories. So instead, have its constructor take as an
argument a callback function that it should use for lazy-filling, and
change `files_ref_store` to supply a pointer to function
`read_loose_refs` (renamed to `loose_fill_ref_dir`) when creating the
ref cache for its loose refs.

This means that we can generify the type of the back-pointer in
`struct ref_cache` from `files_ref_store` to `ref_store`.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-16 21:32:46 -07:00
Michael Haggerty
e00d1a4ff7 refs: record the ref_store in ref_cache, not ref_dir
Instead of keeping a pointer to the `ref_store` in every `ref_dir`
entry, store it once in `struct ref_cache`, and change `struct
ref_dir` to include a pointer to its containing `ref_cache` instead.
This makes it easier to add to the information that is accessible from
a `ref_dir` without increasing the size of every `ref_dir` instance.

Note that previously, every `ref_dir` pointed at the containing
`files_ref_store` regardless of whether it was a part of the loose or
packed reference cache. Now we have to be sure to initialize the
instances to point at the correct containing `ref_cache`. So change
`create_dir_entry()` to take a `ref_cache` parameter, and change its
callers to pass the correct `ref_cache` depending on the purpose of
the new `dir_entry`.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-16 21:32:46 -07:00
Michael Haggerty
7c22bc8a18 ref-cache: introduce a new type, ref_cache
For now, it just wraps a `ref_entry *` that points at the root of the
tree. Soon it will hold more information.

Add two new functions, `create_ref_cache()` and `free_ref_cache()`.
Make `free_ref_entry()` private.

Change files-backend to use this type to hold its caches.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-16 21:32:46 -07:00
Michael Haggerty
958f964691 refs: split ref_cache code into separate files
The `ref_cache` code is currently too tightly coupled to
`files-backend`, making the code harder to understand and making it
awkward for new code to use `ref_cache` (as we indeed have planned).
Start loosening that coupling by splitting `ref_cache` into a separate
module.

This commit moves code, adds declarations, and changes the visibility
of some functions, but doesn't change any code.

The modules are still too tightly coupled, but the situation will be
improved in subsequent commits.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-16 21:32:45 -07:00
Michael Haggerty
9fc3b06311 ref-cache: rename remove_entry() to remove_entry_from_dir()
This function's visibility is about to be increased, so give it a more
distinctive name.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-16 21:32:45 -07:00
Michael Haggerty
bc1c696e89 ref-cache: rename find_ref() to find_ref_entry()
This function's visibility is about to be increased, so give it a more
distinctive name.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-16 21:32:45 -07:00
Michael Haggerty
a3ade2baba ref-cache: rename add_ref() to add_ref_entry()
This function's visibility is about to be increased, so give it a more
distinctive name.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-16 21:32:45 -07:00
Michael Haggerty
524a9fdb51 refs_verify_refname_available(): use function in more places
Change `lock_raw_ref()` and `lock_ref_sha1_basic()` to use
`refs_verify_refname_available()` instead of
`verify_refname_available_dir()`. This means that those callsites now
check for conflicts with all references rather than just packed refs,
but the performance cost shouldn't be significant (and will be
regained later).

These were the last callers of `verify_refname_available_dir()`, so
also delete that (very complicated) function.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-16 21:32:45 -07:00
Michael Haggerty
b05855b5bc refs_verify_refname_available(): implement once for all backends
It turns out that we can now implement
`refs_verify_refname_available()` based on the other virtual
functions, so there is no need for it to be defined at the backend
level. Instead, define it once in `refs.c` and remove the
`files_backend` definition.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-16 21:32:45 -07:00
Michael Haggerty
e121b9cb5f refs_ref_iterator_begin(): new function
Extract a new function from `do_for_each_ref()`. It will be useful
elsewhere.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-14 03:54:31 -07:00
Michael Haggerty
470be51862 refs_read_raw_ref(): new function
Extract a new function from `refs_resolve_ref_unsafe()`. It will be
useful elsewhere.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-14 03:54:31 -07:00
Michael Haggerty
68fb02e40d get_ref_dir(): don't call read_loose_refs() for "refs/bisect"
Since references under "refs/bisect/" are per-worktree, they have to
be sought in the worktree rather than in the main repository. But
since loose references are found by traversing directories, the
reference iterator won't even get the idea to look for a
"refs/bisect/" directory in the worktree if there is not a directory
with that name in the main repository. Thus `get_ref_dir()` manually
inserts a dir_entry for "refs/bisect/" whenever it reads the entry for
"refs/".

The current code then immediately calls `read_loose_refs()` on that
directory. But since the dir_entry is created with its `incomplete`
flag set, any traversal that gets to this point will read the
directory automatically. So there is no need to call
`read_loose_refs()` explicitly; the lazy mechanism suffices.

And in fact, the attempt to `read_loose_refs()` was broken anyway.
That function needs its `dirname` argument to have a trailing `/`
character, but the invocation here was passing it "refs/bisect"
without a trailing slash. So `read_loose_refs()` would read
`$GIT_DIR/refs/bisect" correctly, but if it found an entry "foo" in
that directory, it would try to read "$GIT_DIR/refs/bisectfoo".
Normally it wouldn't find anything at that path, but the failure was
canceled out because `get_ref_dir()` *also* forgot to reset the
`REF_INCOMPLETE` bit on the dir_entry. So the read was attempted again
when it was accessed, via the lazy mechanism, and this time the read
was done correctly.

This code has been broken since it was first introduced.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-14 03:54:31 -07:00
Nguyễn Thái Ngọc Duy
2f40e95472 files-backend: avoid ref api targeting main ref store
A small step towards making files-backend work as a non-main ref store
using the newly added store-aware API.

For the record, `join` and `nm` on refs.o and files-backend.o tell me
that files-backend no longer uses functions that default to
get_main_ref_store().

I'm not yet comfortable at the idea of removing
files_assert_main_repository() (or converting REF_STORE_MAIN to
REF_STORE_WRITE). More staring and testing is required before that can
happen. Well, except peel_ref(). I'm pretty sure that function is safe.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-14 03:53:25 -07:00
Nguyễn Thái Ngọc Duy
c0fe4e8ba3 refs: new transaction related ref-store api
The transaction struct now takes a ref store at creation and will
operate on that ref store alone.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-14 03:53:25 -07:00
Nguyễn Thái Ngọc Duy
7d2df051d0 refs: add new ref-store api
This is not meant to cover all existing API. It adds enough to test ref
stores with the new test program test-ref-store, coming soon and to be
used by files-backend.c.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-14 03:53:25 -07:00
Nguyễn Thái Ngọc Duy
18d0002d6d refs: rename get_ref_store() to get_submodule_ref_store() and make it public
This function is intended to replace *_submodule() refs API. It provides
a ref store for a specific submodule, which can be operated on by a new
set of refs API.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-14 03:53:25 -07:00
Nguyễn Thái Ngọc Duy
9e7ec634a1 files-backend: replace submodule_allowed check in files_downcast()
files-backend.c is unlearning submodules. Instead of having a specific
check for submodules to see what operation is allowed, files backend
now takes a set of flags at init. Each operation will check if the
required flags is present before performing.

For now we have four flags: read, write and odb access. Main ref store
has all flags, obviously, while submodule stores are read-only and have
access to odb (*).

The "main" flag stays because many functions in the backend calls
frontend ones without a ref store, so these functions always target the
main ref store. Ideally the flag should be gone after ref-store-aware
api is in place and used by backends.

(*) Submodule code needs for_each_ref. Try take REF_STORE_ODB flag
out. At least t3404 would fail. The "have access to odb" in submodule is
a bit hacky since we don't know from he whether add_submodule_odb() has
been called.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-04-14 03:53:18 -07:00
Nguyễn Thái Ngọc Duy
5d0bc90e5d refs: move submodule code out of files-backend.c
files-backend is now initialized with a $GIT_DIR. Converting a submodule
path to where real submodule gitdir is located is done in get_ref_store().

This gives a slight performance improvement for submodules since we
don't convert submodule path to gitdir at every backend call like
before. We pay that once at ref-store creation.

More cleanup in files_downcast() and files_assert_main_repository()
follows shortly. It's separate to keep noises from this patch.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-27 10:23:40 -07:00
Nguyễn Thái Ngọc Duy
077be78d7f refs.c: make get_main_ref_store() public and use it
get_ref_store() will soon be renamed to get_submodule_ref_store().
Together with future get_worktree_ref_store(), the three functions
provide an appropriate ref store for different operation modes. New APIs
will be added to operate directly on ref stores.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-27 10:23:39 -07:00
Nguyễn Thái Ngọc Duy
f57f37e2e1 files-backend: remove the use of git_path()
Given $GIT_DIR and $GIT_COMMON_DIR, files-backend is now in charge of
deciding what goes where (*). The end goal is to pass $GIT_DIR only. A
refs "view" of a linked worktree is a logical ref store that combines
two files backends together.

(*) Not entirely true since strbuf_git_path_submodule() still does path
translation underneath. But that's for another patch.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-27 10:23:39 -07:00
Nguyễn Thái Ngọc Duy
19e02f4f46 files-backend: add and use files_ref_path()
Keep repo-related path handling in one place. This will make it easier
to add submodule/multiworktree support later.

This automatically adds the "if submodule then use the submodule version
of git_path" to other call sites too. But it does not mean those
operations are submodule-ready. Not yet.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-27 10:23:39 -07:00
Nguyễn Thái Ngọc Duy
802de3da07 files-backend: add and use files_reflog_path()
Keep repo-related path handling in one place. This will make it easier
to add submodule/multiworktree support later.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-27 10:23:39 -07:00
Nguyễn Thái Ngọc Duy
a5c1efd693 files-backend: move "logs/" out of TMP_RENAMED_LOG
This makes reflog path building consistent, always in the form of

    strbuf_git_path(sb, "logs/%s", refname);

It reduces the mental workload a bit in the next patch when that
function call is converted.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-27 10:23:39 -07:00
Nguyễn Thái Ngọc Duy
e9dcc3054f files-backend: convert git_path() to strbuf_git_path()
git_path() and friends are going to be killed in files-backend.c in near
future. And because there's a risk with overwriting buffer in
git_path(), let's convert them all to strbuf_git_path(). We'll have
easier time killing/converting strbuf_git_path() then because we won't
have to worry about memory management again.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-27 10:23:39 -07:00
Nguyễn Thái Ngọc Duy
0a3f07d6c0 files-backend: make sure files_rename_ref() always reach the end
This is a no-op patch. It prepares the function so that we can release
resources (to be added later in this function) before we return.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-27 10:23:39 -07:00
Nguyễn Thái Ngọc Duy
33dfb9f3f2 files-backend: add and use files_packed_refs_path()
Keep repo-related path handling in one place. This will make it easier
to add submodule/multiworktree support later.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-27 10:23:39 -07:00
Nguyễn Thái Ngọc Duy
1eab194bf0 files-backend: delete dead code in files_init_db()
safe_create_dir() can do adjust_shared_perm() internally, and init-db
has always created 'refs' in shared mode since the beginning,
af6e277c5e (git-init-db: initialize shared repositories with --shared -
2005-12-22). So this code looks like extra adjust_shared_perm calls are
unnecessary.

And they are. But let's see why there are here in the first place.

This code was added in 6fb5acfd8f (refs: add methods to init refs db -
2016-09-04). From the diff alone this looks like a faithful refactored
code from init-db.c. But there is a subtle difference:

Between the safe_create_dir() block and adjust_shared_perm() block in
the old init-db.c, we may copy/recreate directories from the repo
template. So it makes sense that adjust_shared_perm() is re-executed
then to fix potential permission screwups.

After 6fb5acfd8f, refs dirs are created after template is copied. Nobody
will change directory permission again. So the extra adjust_shared_perm()
is redudant. Delete them.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-27 10:23:39 -07:00
Nguyễn Thái Ngọc Duy
4f43731268 files-backend.c: delete dead code in files_ref_iterator_begin()
It's not in the diff context, but files_downcast() is called before this
check. If "refs" is NULL, we would have segfaulted before reaching the
check here. And we should never see NULL refs in backend code (frontend
should have caught it).

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-27 10:23:39 -07:00
Nguyễn Thái Ngọc Duy
11f8457fb9 files-backend: make files_log_ref_write() static
Created in 5f3c3a4e6f (files_log_ref_write: new function - 2015-11-10)
but probably never used outside refs-internal.c

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-27 10:23:39 -07:00
Junio C Hamano
e1fae93019 Merge branch 'bc/object-id'
"uchar [40]" to "struct object_id" conversion continues.

* bc/object-id:
  wt-status: convert to struct object_id
  builtin/merge-base: convert to struct object_id
  Convert object iteration callbacks to struct object_id
  sha1_file: introduce an nth_packed_object_oid function
  refs: simplify parsing of reflog entries
  refs: convert each_reflog_ent_fn to struct object_id
  reflog-walk: convert struct reflog_info to struct object_id
  builtin/replace: convert to struct object_id
  Convert remaining callers of resolve_refdup to object_id
  builtin/merge: convert to struct object_id
  builtin/clone: convert to struct object_id
  builtin/branch: convert to struct object_id
  builtin/grep: convert to struct object_id
  builtin/fmt-merge-message: convert to struct object_id
  builtin/fast-export: convert to struct object_id
  builtin/describe: convert to struct object_id
  builtin/diff-tree: convert to struct object_id
  builtin/commit: convert to struct object_id
  hex: introduce parse_oid_hex
2017-03-17 13:50:25 -07:00
Junio C Hamano
c13c783c9d Merge branch 'km/delete-ref-reflog-message'
"git update-ref -d" and other operations to delete references did
not leave any entry in HEAD's reflog when the reference being
deleted was the current branch.  This is not a problem in practice
because you do not want to delete the branch you are currently on,
but caused renaming of the current branch to something else not to
be logged in a useful way.

* km/delete-ref-reflog-message:
  branch: record creation of renamed branch in HEAD's log
  rename_ref: replace empty message in HEAD's log
  update-ref: pass reflog message to delete_ref()
  delete_ref: accept a reflog message argument
2017-02-27 13:57:18 -08:00
Junio C Hamano
466be3e1de Merge branch 'mh/submodule-hash'
Code and design clean-up for the refs API.

* mh/submodule-hash:
  read_loose_refs(): read refs using resolve_ref_recursively()
  files_ref_store::submodule: use NULL for the main repository
  base_ref_store_init(): remove submodule argument
  refs: push the submodule attribute down
  refs: store submodule ref stores in a hashmap
  register_ref_store(): new function
  refs: remove some unnecessary handling of submodule == ""
  refs: make some ref_store lookup functions private
  refs: reorder some function definitions
2017-02-27 13:57:15 -08:00
Junio C Hamano
3ad8b5bf26 Merge branch 'mh/ref-remove-empty-directory'
Deletion of a branch "foo/bar" could remove .git/refs/heads/foo
once there no longer is any other branch whose name begins with
"foo/", but we didn't do so so far.  Now we do.

* mh/ref-remove-empty-directory: (23 commits)
  files_transaction_commit(): clean up empty directories
  try_remove_empty_parents(): teach to remove parents of reflogs, too
  try_remove_empty_parents(): don't trash argument contents
  try_remove_empty_parents(): rename parameter "name" -> "refname"
  delete_ref_loose(): inline function
  delete_ref_loose(): derive loose reference path from lock
  log_ref_write_1(): inline function
  log_ref_setup(): manage the name of the reflog file internally
  log_ref_write_1(): don't depend on logfile argument
  log_ref_setup(): pass the open file descriptor back to the caller
  log_ref_setup(): improve robustness against races
  log_ref_setup(): separate code for create vs non-create
  log_ref_write(): inline function
  rename_tmp_log(): improve error reporting
  rename_tmp_log(): use raceproof_create_file()
  lock_ref_sha1_basic(): use raceproof_create_file()
  lock_ref_sha1_basic(): inline constant
  raceproof_create_file(): new function
  safe_create_leading_directories(): set errno on SCLD_EXISTS
  safe_create_leading_directories_const(): preserve errno
  ...
2017-02-27 13:57:12 -08:00
brian m. carlson
43bc3b6cee refs: simplify parsing of reflog entries
The current code for reflog entries uses a lot of hard-coded constants,
making it hard to read and modify.  Use parse_oid_hex and two temporary
variables to simplify the code and reduce the use of magic constants.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-02-22 10:12:15 -08:00
brian m. carlson
9461d27240 refs: convert each_reflog_ent_fn to struct object_id
Make each_reflog_ent_fn take two struct object_id pointers instead of
two pointers to unsigned char.  Convert the various callbacks to use
struct object_id as well.  Also, rename fsck_handle_reflog_sha1 to
fsck_handle_reflog_oid.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-02-22 10:12:15 -08:00
Kyle Meyer
39ee4c6c2f branch: record creation of renamed branch in HEAD's log
Renaming the current branch adds an event to the current branch's log
and to HEAD's log.  However, the logged entries differ.  The entry in
the branch's log represents the entire renaming operation (the old and
new hash are identical), whereas the entry in HEAD's log represents
the deletion only (the new sha1 is null).

Extend replace_each_worktree_head_symref(), whose only caller is
branch_rename(), to take a reflog message argument.  This allows the
creation of the new ref to be recorded in HEAD's log.  As a result,
the renaming event is represented by two entries (a deletion and a
creation entry) in HEAD's log.

It's a bit unfortunate that the branch's log and HEAD's log now
represent the renaming event in different ways.  Given that the
renaming operation is not atomic, the two-entry form is a more
accurate representation of the operation and is more useful for
debugging purposes if a failure occurs between the deletion and
creation events.  It would make sense to move the branch's log to the
two-entry form, but this would involve changes to how the rename is
carried out and to how the update flags and reflogs are processed for
deletions, so it may not be worth the effort.

Based-on-patch-by: Jeff King <peff@peff.net>
Signed-off-by: Kyle Meyer <kyle@kyleam.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-02-20 22:04:47 -08:00
Kyle Meyer
893dbf5ba1 rename_ref: replace empty message in HEAD's log
When the current branch is renamed, the deletion of the old ref is
recorded in HEAD's log with an empty message.  Now that delete_ref()
accepts a reflog message, provide a more descriptive message by
passing along the log message that is given to rename_ref().

The next step will be to extend HEAD's log to also include the second
part of the rename, the creation of the new branch.

Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Kyle Meyer <kyle@kyleam.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-02-20 22:04:47 -08:00
Kyle Meyer
755b49ae96 delete_ref: accept a reflog message argument
When the current branch is renamed with 'git branch -m/-M' or deleted
with 'git update-ref -m<msg> -d', the event is recorded in HEAD's log
with an empty message.  In preparation for adding a more meaningful
message to HEAD's log in these cases, update delete_ref() to take a
message argument and pass it along to ref_transaction_delete().
Modify all callers to pass NULL for the new message argument; no
change in behavior is intended.

Note that this is relevant for HEAD's log but not for the deleted
ref's log, which is currently deleted along with the ref.  Even if it
were not, an entry for the deletion wouldn't be present in the deleted
ref's log.  files_transaction_commit() writes to the log if
REF_NEEDS_COMMIT or REF_LOG_ONLY are set, but lock_ref_for_update()
doesn't set REF_NEEDS_COMMIT for the deleted ref because REF_DELETING
is set.  In contrast, the update for HEAD has REF_LOG_ONLY set by
split_head_update(), resulting in the deletion being logged.

Signed-off-by: Kyle Meyer <kyle@kyleam.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-02-20 22:04:47 -08:00
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
9c7d772b6b files_ref_store::submodule: use NULL for the main repository
The old practice of storing the empty string in this member for the main
repository was a holdover from before 00eebe3 (refs: create a base class
"ref_store" for files_ref_store, 2016-09-04), when the submodule was
stored in a flex array at the end of `struct files_ref_store`. Storing
NULL for this case is more idiomatic and a tiny bit less 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>
2017-02-10 11:13:26 -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
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
Junio C Hamano
fafca0f72a Merge branch 'cw/log-updates-for-all-refs-really'
The "core.logAllRefUpdates" that used to be boolean has been
enhanced to take 'always' as well, to record ref updates to refs
other than the ones that are expected to be updated (i.e. branches,
remote-tracking branches and notes).

* cw/log-updates-for-all-refs-really:
  doc: add note about ignoring '--no-create-reflog'
  update-ref: add test cases for bare repository
  refs: add option core.logAllRefUpdates = always
  config: add markup to core.logAllRefUpdates doc
2017-02-03 11:25:19 -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
René Scharfe
8694769f3c use oidcpy() for copying hashes between instances of struct object_id
Patch generated by Coccinelle and contrib/coccinelle/object_id.cocci.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-01-30 14:23:42 -08:00
Michael Haggerty
446397774a files_transaction_commit(): clean up empty directories
When deleting/pruning references, remove any directories that are made
empty by the deletion of loose references or of reflogs. Otherwise such
empty directories can survive forever and accumulate over time. (Even
'pack-refs', which is smart enough to remove the parent directories of
loose references that it prunes, leaves directories that were already
empty.)

And now that files_transaction_commit() takes care of deleting the
parent directories of loose references that it prunes, we don't have to
do that in prune_ref() anymore.

This change would be unwise if the *creation* of these directories could
race with our deletion of them. But the earlier changes in this patch
series made the creation paths robust against races, so now it is safe
to tidy them up more aggressively.

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>
2017-01-07 19:30:09 -08:00
Michael Haggerty
a8f0db2d99 try_remove_empty_parents(): teach to remove parents of reflogs, too
Add a new "flags" parameter that tells the function whether to remove
empty parent directories of the loose reference file, of the reflog
file, or both. The new functionality is not yet used.

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>
2017-01-07 19:30:09 -08:00
Michael Haggerty
8bdaecb402 try_remove_empty_parents(): don't trash argument contents
It's bad manners and surprising and therefore error-prone.

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>
2017-01-07 19:30:09 -08:00
Michael Haggerty
730e034286 try_remove_empty_parents(): rename parameter "name" -> "refname"
This is the standard nomenclature.

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>
2017-01-07 19:30:09 -08:00
Michael Haggerty
ce0af24de0 delete_ref_loose(): inline function
It was hardly doing anything anymore, and had only one caller.

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>
2017-01-07 19:30:09 -08:00
Michael Haggerty
0e81d016f1 delete_ref_loose(): derive loose reference path from lock
It is simpler to derive the path to the file that must be deleted from
"lock->ref_name" than from the lock_file object.

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>
2017-01-07 19:30:09 -08:00
Michael Haggerty
fc31955294 log_ref_write_1(): inline function
Now files_log_ref_write() doesn't do anything beyond call
log_ref_write_1(), so inline the latter into the former.

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>
2017-01-07 19:30:09 -08:00
Michael Haggerty
4533e5343b log_ref_setup(): manage the name of the reflog file internally
Instead of writing the name of the reflog file into a strbuf that is
supplied by the caller but not needed there, write it into a local
temporary buffer and remove the strbuf parameter entirely.

And while we're adjusting the function signature, reorder the arguments
to move the input parameters before the output parameters.

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>
2017-01-07 19:30:09 -08:00
Michael Haggerty
87b21e05ed log_ref_write_1(): don't depend on logfile argument
It's unnecessary to pass a strbuf holding the reflog path up and down
the call stack now that it is hardly needed by the callers. Remove the
places where log_ref_write_1() uses it, in preparation for making it
internal to log_ref_setup().

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>
2017-01-07 19:30:09 -08:00
Michael Haggerty
e404f459fd log_ref_setup(): pass the open file descriptor back to the caller
This function will most often be called by log_ref_write_1(), which
wants to append to the reflog file. In that case, it is silly to close
the file only for the caller to reopen it immediately. So, in the case
that the file was opened, pass the open file descriptor back to the
caller.

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>
2017-01-07 19:30:09 -08:00
Michael Haggerty
1fb0c80985 log_ref_setup(): improve robustness against races
Change log_ref_setup() to use raceproof_create_file() to create the new
logfile. This makes it more robust against a race against another
process that might be trying to clean up empty directories while we are
trying to create a new logfile.

This also means that it will only call create_leading_directories() if
open() fails, which should be a net win. Even in the cases where we are
willing to create a new logfile, it will usually be the case that the
logfile already exists, or if not then that the directory containing the
logfile already exists. In such cases, we will save some work that was
previously done unconditionally.

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>
2017-01-07 19:30:09 -08:00
Michael Haggerty
854bda6b4f log_ref_setup(): separate code for create vs non-create
The behavior of this function (especially how it handles errors) is
quite different depending on whether we are willing to create the reflog
vs. whether we are only trying to open an existing reflog. So separate
the code paths.

This also simplifies the next steps.

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>
2017-01-07 19:30:09 -08:00