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>
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>
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>
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>
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>
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>
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.
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
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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
...
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
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>
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>
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>
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>
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>
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>
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
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
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
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
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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()
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
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
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
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
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>
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>
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>
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>
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>
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>
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>
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>
"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
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>
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>
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>
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>
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>
"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>
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>
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>
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>
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>
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>
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>
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>
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 *
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>
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
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>
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>
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>
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>
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>
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>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
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>
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>
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
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
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
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
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>
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>
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>
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>
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>
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>
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
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
...
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
"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
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>
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>
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
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>
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>
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>
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>
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>
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>
"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
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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"
...
"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
* 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"
...
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>
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>
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
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
"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
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>
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>
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>
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>
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>
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>
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>
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>
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>
Our loop should always process all lines, even if we hit the
beginning of the file. We have a conditional after the loop
ends to double-check that there is nothing left and to
process it. But this should never happen, and is a sign of a
logic bug in the loop. Let's turn it into a BUG assertion.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we read a reflog file in reverse, we read whole chunks
of BUFSIZ bytes, then loop over the buffer, parsing any
lines we find. We find the beginning of each line by looking
for the newline from the previous line. If we don't find
one, we know that we are either at the beginning of
the file, or that we have to read another block.
In the latter case, we stuff away what we have into a
strbuf, read another block, and continue our parse. But we
missed one case here. If we did find a newline, and it is at
the beginning of the block, we must also stuff that newline
into the strbuf, as it belongs to the block we are about to
read.
The minimal fix here would be to add this special case to
the conditional that checks whether we found a newline.
But we can make the flow a little clearer by rearranging a
bit: we first handle lines that we are going to show, and
then at the end of each loop, stuff away any leftovers if
necessary. That lets us fold this special-case in with the
more common "we ended in the middle of a line" case.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu>
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>
The ref_transaction_update function can already be used to create refs by
passing null_sha1 as the old_sha1 parameter. Simplify by replacing
transaction_create with a thin wrapper.
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu>
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>
In the previous patch, git_snpath() is modified to allocate a new
strbuf buffer because vsnpath() needs that. But that makes it
awkward because git_snpath() receives a pre-allocated buffer from
outside and has to copy data back. Rename it to strbuf_git_path()
and make it receive strbuf directly.
Using git_path() in update_refs_for_switch() which used to call
git_snpath() is safe because that function and all of its callers do
not keep any pointer to the round-robin buffer pool allocated by
get_pathname().
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before the previous commit, get_pathname returns an array of PATH_MAX
length. Even if git_path() and similar functions does not use the
whole array, git_path() caller can, in theory.
After the commit, get_pathname() may return a buffer that has just
enough room for the returned string and git_path() caller should never
write beyond that.
Make git_path(), mkpath() and git_path_submodule() return a const
buffer to make sure callers do not write in it at all.
This could have been part of the previous commit, but the "const"
conversion is too much distraction from the core changes in path.c.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Most of the callers have string_lists available already, whereas two
of them had to read data out of a string_list into an array of strings
just to call this function. So change repack_without_refs() to take
the list of refnames to omit as a string_list, and change the callers
accordingly.
Suggested-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
lock_ref_sha1_basic is inconsistent about when it calls
die() and when it returns NULL to signal an error. This is
annoying to any callers that want to recover from a locking
error.
This seems to be mostly historical accident. It was added in
4bd18c4 (Improve abstraction of ref lock/write.,
2006-05-17), which returned an error in all cases except
calling safe_create_leading_directories, in which case it
died. Later, 40aaae8 (Better error message when we are
unable to lock the index file, 2006-08-12) asked
hold_lock_file_for_update to die for us, leaving the
resolve_ref code-path the only one which returned NULL.
We tried to correct that in 5cc3cef (lock_ref_sha1(): do not
sometimes error() and sometimes die()., 2006-09-30),
by converting all of the die() calls into returns. But we
missed the "die" flag passed to the lock code, leaving us
inconsistent. This state persisted until e5c223e
(lock_ref_sha1_basic(): if locking fails with ENOENT, retry,
2014-01-18). Because of its retry scheme, it does not ask
the lock code to die, but instead manually dies with
unable_to_lock_die().
We can make this consistent with the other return paths by
converting this to use unable_to_lock_message(), and
returning NULL. This is safe to do because all callers
already needed to check the return value of the function,
since it could fail (and return NULL) for other reasons.
[jk: Added excessive history explanation]
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Corner-case bugfixes for "git fetch" around reflog handling.
* jk/fetch-reflog-df-conflict:
ignore stale directories when checking reflog existence
fetch: load all default config at startup
When we update a ref, we have two rules for whether or not
we actually update the reflog:
1. If the reflog already exists, we will always append to
it.
2. If log_all_ref_updates is set, we will create a new
reflog file if necessary.
We do the existence check by trying to open the reflog file,
either with or without O_CREAT (depending on log_all_ref_updates).
If it fails, then we check errno to see what happened.
If we were not using O_CREAT and we got ENOENT, the file
doesn't exist, and we return success (there isn't a reflog
already, and we were not told to make a new one).
If we get EISDIR, then there is likely a stale directory
that needs to be removed (e.g., there used to be "foo/bar",
it was deleted, and the directory "foo" was left. Now we
want to create the ref "foo"). If O_CREAT is set, then we
catch this case, try to remove the directory, and retry our
open. So far so good.
But if we get EISDIR and O_CREAT is not set, then we treat
this as any other error, which is not right. Like ENOENT,
EISDIR is an indication that we do not have a reflog, and we
should silently return success (we were not told to create
it). Instead, the current code reports this as an error, and
we fail to update the ref at all.
Note that this is relatively unlikely to happen, as you
would have to have had reflogs turned on, and then later
turned them off (it could also happen due to a bug in fetch,
but that was fixed in the previous commit). However, it's
quite easy to fix: we just need to treat EISDIR like ENOENT
for the non-O_CREAT case, and silently return (note that
this early return means we can also simplify the O_CREAT
case).
Our new tests cover both cases (O_CREAT and non-O_CREAT).
The first one already worked, of course.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When removal of a loose or packed ref fails, bail out instead of
trying to finish the transaction. This way, a single error message
can be printed (instead of multiple messages being concatenated by
mistake) and the operator can try to solve the underlying problem
before there is a chance to muck things up even more.
In particular, when git fails to remove a ref, git goes on to try to
delete the reflog. Exiting early lets us keep the reflog.
When git succeeds in deleting a ref A and fails to remove a ref B, it
goes on to try to delete both reflogs. It would be better to just
remove the reflog for A, but that would be a more invasive change.
Failing early means we keep both reflogs, which puts the operator in a
good position to understand the problem and recover.
A long term goal is to avoid these problems altogether and roll back
the transaction on failure. That kind of transactionality will have
to wait for a later series (the plan for which is to make all
destructive work happen in a single update of the packed-refs file).
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Reviewed-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some functions that take a strbuf argument to append an error treat
!err as an indication that the message should be suppressed (e.g.,
ref_update_reject_duplicates). Others write the message to stderr on
!err (e.g., repack_without_refs). Others crash (e.g.,
ref_transaction_update).
Some of these behaviors are for historical reasons and others were
accidents. Luckily no callers pass err == NULL any more. Simplify
by consistently requiring the strbuf argument.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Reviewed-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We currently do not handle badly named refs well:
$ cp .git/refs/heads/master .git/refs/heads/master.....@\*@\\.
$ git branch
fatal: Reference has invalid format: 'refs/heads/master.....@*@\.'
$ git branch -D master.....@\*@\\.
error: branch 'master.....@*@\.' not found.
Users cannot recover from a badly named ref without manually finding
and deleting the loose ref file or appropriate line in packed-refs.
Making that easier will make it easier to tweak the ref naming rules
in the future, for example to forbid shell metacharacters like '`'
and '"', without putting people in a state that is hard to get out of.
So allow "branch --list" to show these refs and allow "branch -d/-D"
and "update-ref -d" to delete them. Other commands (for example to
rename refs) will continue to not handle these refs but can be changed
in later patches.
Details:
In resolving functions, refuse to resolve refs that don't pass the
git-check-ref-format(1) check unless the new RESOLVE_REF_ALLOW_BAD_NAME
flag is passed. Even with RESOLVE_REF_ALLOW_BAD_NAME, refuse to
resolve refs that escape the refs/ directory and do not match the
pattern [A-Z_]* (think "HEAD" and "MERGE_HEAD").
In locking functions, refuse to act on badly named refs unless they
are being deleted and either are in the refs/ directory or match [A-Z_]*.
Just like other invalid refs, flag resolved, badly named refs with the
REF_ISBROKEN flag, treat them as resolving to null_sha1, and skip them
in all iteration functions except for for_each_rawref.
Flag badly named refs (but not symrefs pointing to badly named refs)
with a REF_BAD_NAME flag to make it easier for future callers to
notice and handle them specially. For example, in a later patch
for-each-ref will use this flag to detect refs whose names can confuse
callers parsing for-each-ref output.
In the transaction API, refuse to create or update badly named refs,
but allow deleting them (unless they try to escape refs/ and don't match
[A-Z_]*).
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since v1.7.9-rc1~10^2 (write_head_info(): handle "extra refs" locally,
2012-01-06), this trick to keep track of ".have" refs that are only
valid on the wire and not on the filesystem is not needed any more.
Simplify by removing support for the REFNAME_DOT_COMPONENT flag.
This means we'll be slightly stricter with invalid refs found in a
packed-refs file or during clone. read_loose_refs() already checks
for and skips refnames with .components so it is not affected.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Reviewed-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If a repository gets in a broken state with too much symref nesting,
it cannot be repaired with "git branch -d":
$ git symbolic-ref refs/heads/nonsense refs/heads/nonsense
$ git branch -d nonsense
error: branch 'nonsense' not found.
Worse, "git update-ref --no-deref -d" doesn't work for such repairs
either:
$ git update-ref -d refs/heads/nonsense
error: unable to resolve reference refs/heads/nonsense: Too many levels of symbolic links
Fix both by teaching resolve_ref_unsafe a new RESOLVE_REF_NO_RECURSE
flag and passing it when appropriate.
Callers can still read the value of a symref (for example to print a
message about it) with that flag set --- resolve_ref_unsafe will
resolve one level of symrefs and stop there.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Reviewed-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
resolve_ref_unsafe takes a boolean argument for reading (a nonexistent ref
resolves successfully for writing but not for reading). Change this to be
a flags field instead, and pass the new constant RESOLVE_REF_READING when
we want this behaviour.
While at it, swap two of the arguments in the function to put output
arguments at the end. As a nice side effect, this ensures that we can
catch callers that were unaware of the new API so they can be audited.
Give the wrapper functions resolve_refdup and read_ref_full the same
treatment for consistency.
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
No external users call write_ref_sha1 any more so let's declare it static.
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In _commit, ENOTDIR can happen in the call to lock_ref_sha1_basic, either
when we lstat the new refname or if the name checking function reports that
the same type of conflict happened. In both cases, it means that we can not
create the new ref due to a name conflict.
Start defining specific return codes for _commit. TRANSACTION_NAME_CONFLICT
refers to a failure to create a ref due to a name conflict with another ref.
TRANSACTION_GENERIC_ERROR is for all other errors.
When "git fetch" is creating refs, name conflicts differ from other errors in
that they are likely to be resolved by running "git remote prune <remote>".
"git fetch" currently inspects errno to decide whether to give that advice.
Once it switches to the transaction API, it can check for
TRANSACTION_NAME_CONFLICT instead.
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change is_refname_available to take a list of strings to exclude when
checking for conflicts instead of just one single name. We can already
exclude a single name for the sake of renames. This generalizes that support.
ref_transaction_commit already tracks a set of refs that are being deleted
in an array. This array is then used to exclude refs from being written to
the packed-refs file. At some stage we will want to change this array to a
struct string_list and then we can pass it to is_refname_available via the
call to lock_ref_sha1_basic. That will allow us to perform transactions
that perform multiple renames as long as there are no conflicts within the
starting or ending state.
For example, that would allow a single transaction that contains two
renames that are both individually conflicting:
m -> n/n
n -> m/m
No functional change intended yet.
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Skip using the lock_any_ref_for_update wrapper and call lock_ref_sha1_basic
directly from the commit function.
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move the check for check_refname_format from lock_any_ref_for_update to
lock_ref_sha1_basic. At some later stage we will get rid of
lock_any_ref_for_update completely. This has no visible impact to callers
except for the inability to lock badly named refs, which is not possible
today already for other reasons.(*)
Keep lock_any_ref_for_update as a no-op wrapper. It is the public facing
version of this interface and keeping it as a separate function will make
it easier to experiment with the internal lock_ref_sha1_basic signature.
(*) For example, if lock_ref_sha1_basic checks the refname format and
refuses to lock badly named refs, it will not be possible to delete
such refs because the first step of deletion is to lock the ref. We
currently already fail in that case because these refs are not recognized
to exist:
$ cp .git/refs/heads/master .git/refs/heads/echo...\*\*
$ git branch -D .git/refs/heads/echo...\*\*
error: branch '.git/refs/heads/echo...**' not found.
This has been broken for a while. Later patches in the series will start
repairing the handling of badly named refs.
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We call read_ref_full with a pointer to flags from rename_ref but since
we never actually use the returned flags we can just pass NULL here instead.
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change the ref transaction API so that we pass the reflog message to the
create/delete/update functions instead of to ref_transaction_commit.
This allows different reflog messages for each ref update in a multi-ref
transaction.
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add an err argument to delete_ref_loose so that we can pass a descriptive
error string back to the caller. Pass the err argument from transaction
commit to this function so that transaction users will have a nice error
string if the transaction failed due to delete_ref_loose.
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
lock_ref_sha1_basic is used to lock refs that sit directly in the .git
dir such as HEAD and MERGE_HEAD in addition to the more ordinary refs
under "refs/". Remove the note claiming otherwise.
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Simplify the function warn_if_unremovable slightly. Additionally, change
behaviour slightly. If we failed to remove the object because the object
does not exist, we can still return success back to the caller since none of
the callers depend on "fail if the file did not exist".
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move the interface declaration for the functions in lockfile.c from
cache.h to a new file, lockfile.h. Add #includes where necessary (and
remove some redundant includes of cache.h by files that already
include builtin.h).
Move the documentation of the lock_file state diagram from lockfile.c
to the new header file.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a function to return the path of the file that is locked by a
lock_file object. This reduces the knowledge that callers have to have
about the lock_file layout.
Suggested-by: Ronnie Sahlberg <sahlberg@google.com>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This makes it harder to misread the name as LOCK_NODE_REF.
Suggested-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
For now, we still make sure to allocate at least PATH_MAX characters
for the strbuf because resolve_symlink() doesn't know how to expand
the space for its return value. (That will be fixed in a moment.)
Another alternative would be to just use a strbuf as scratch space in
lock_file() but then store a pointer to the naked string in struct
lock_file. But lock_file objects are often reused. By reusing the
same strbuf, we can avoid having to reallocate the string most times
when a lock_file object is reused.
Helped-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It's bad manners. Especially since there could be a signal during the
call to unlink_or_warn(), in which case the signal handler will see
the wrong filename and delete the reference file, leaving the lockfile
behind.
So make our own copy to work with.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are a few places that use these values, so define constants for
them.
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This function is used for other things besides the index, so rename it
accordingly.
Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Reviewed-by: Ronnie Sahlberg <sahlberg@google.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"rev-parse --verify --quiet $name" is meant to quietly exit with a
non-zero status when $name is not a valid object name, but still
gave error messages in some cases.
* da/rev-parse-verify-quiet:
stash: prefer --quiet over shell redirection of the standard error stream
refs: make rev-parse --quiet actually quiet
t1503: use test_must_be_empty
Documentation: a note about stdout for git rev-parse --verify --quiet
Optimize the check to see if a ref $F can be created by making sure
no existing ref has $F/ as its prefix, which especially matters in
a repository with a large number of existing refs.
* jk/faster-name-conflicts:
refs: speed up is_refname_available
Optimize the code path to write out the packed-refs file, which
especially matters in a repository with a large number of refs.
* jk/write-packed-refs-via-stdio:
refs: write packed_refs file using stdio
When a reflog is deleted, e.g. when "git stash" clears its stashes,
"git rev-parse --verify --quiet" dies:
fatal: Log for refs/stash is empty.
The reason is that the get_sha1() code path does not allow us
to suppress this message.
Pass the flags bitfield through get_sha1_with_context() so that
read_ref_at() can suppress the message.
Use get_sha1_with_context1() instead of get_sha1() in rev-parse
so that the --quiet flag is honored.
Signed-off-by: David Aguilar <davvid@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Our filesystem ref storage does not allow D/F conflicts; so
if "refs/heads/a/b" exists, we do not allow "refs/heads/a"
to exist (and vice versa). This falls out naturally for
loose refs, where the filesystem enforces the condition. But
for packed-refs, we have to make the check ourselves.
We do so by iterating over the entire packed-refs namespace
and checking whether each name creates a conflict. If you
have a very large number of refs, this is quite inefficient,
as you end up doing a large number of comparisons with
uninteresting bits of the ref tree (e.g., we know that all
of "refs/tags" is uninteresting in the example above, yet we
check each entry in it).
Instead, let's take advantage of the fact that we have the
packed refs stored as a trie of ref_entry structs. We can
find each component of the proposed refname as we walk
through the trie, checking for D/F conflicts as we go. For a
refname of depth N (i.e., 4 in the above example), we only
have to visit N nodes. And at each visit, we can binary
search the M names at that level, for a total complexity of
O(N lg M). ("M" is different at each level, of course, but
we can take the worst-case "M" as a bound).
In a pathological case of fetching 30,000 fresh refs into a
repository with 8.5 million refs, this dropped the time to
run "git fetch" from tens of minutes to ~30s.
This may also help smaller cases in which we check against
loose refs (which we do when renaming a ref), as we may
avoid a disk access for unrelated loose directories.
Note that the tests we add appear at first glance to be
redundant with what is already in t3210. However, the early
tests are not robust; they are run with reflogs turned on,
meaning that we are not actually testing
is_refname_available at all! The operations will still fail
because the reflogs will hit D/F conflicts in the
filesystem. To get a true test, we must turn off reflogs
(but we don't want to do so for the entire script, because
the point of turning them on was to cover some other cases).
Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
After "pack-refs --prune" packed refs at the top-level, it failed
to prune them.
* jk/prune-top-level-refs-after-packing:
pack-refs: prune top-level refs like "refs/foo"
The second batch of the transactional ref update series.
* rs/ref-transaction-1: (22 commits)
update-ref --stdin: pass transaction around explicitly
update-ref --stdin: narrow scope of err strbuf
refs.c: make delete_ref use a transaction
refs.c: make prune_ref use a transaction to delete the ref
refs.c: remove lock_ref_sha1
refs.c: remove the update_ref_write function
refs.c: remove the update_ref_lock function
refs.c: make lock_ref_sha1 static
walker.c: use ref transaction for ref updates
fast-import.c: use a ref transaction when dumping tags
receive-pack.c: use a reference transaction for updating the refs
refs.c: change update_ref to use a transaction
branch.c: use ref transaction for all ref updates
fast-import.c: change update_branch to use ref transactions
sequencer.c: use ref transactions for all ref updates
commit.c: use ref transactions for updates
replace.c: use the ref transaction functions for updates
tag.c: use ref transactions when doing updates
refs.c: add transaction.status and track OPEN/CLOSED
refs.c: make ref_transaction_begin take an err argument
...
We write each line of a new packed-refs file individually
using a write() syscall (and sometimes 2, if the ref is
peeled). Since each line is only about 50-100 bytes long,
this creates a lot of system call overhead.
We can instead open a stdio handle around our descriptor and
use fprintf to write to it. The extra buffering is not a
problem for us, because nobody will read our new packed-refs
file until we call commit_lock_file (by which point we have
flushed everything).
On a pathological repository with 8.5 million refs, this
dropped the time to run `git pack-refs` from 20s to 6s.
Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Change delete_ref to use a ref transaction for the deletion. At the same time
since we no longer have any callers of repack_without_ref we can now delete
this function.
Change delete_ref to return 0 on success and 1 on failure instead of the
previous 0 on success either 1 or -1 on failure.
Signed-off-by: Ronnie Sahlberg <sahlberg@google.com>
Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
