If a pack .idx file has a corrupted offset for an object, we
may try to access an offset in the .idx or .pack file that
is larger than the file's size. For the .pack case, we have
use_pack() to protect us, which realizes the access is out
of bounds. But if the corrupted value asks us to look in the
.idx file's secondary 64-bit offset table, we blindly add it
to the mmap'd index data and access arbitrary memory.
We can fix this with a simple bounds-check compared to the
size we found when we opened the .idx file.
Note that there's similar code in index-pack that is
triggered only during "index-pack --verify". To support
both, we pull the bounds-check into a separate function,
which dies when it sees a corrupted file.
It would be nice if we could return an error, so that the
pack code could try to find a good copy of the object
elsewhere. Currently nth_packed_object_offset doesn't have
any way to return an error, but it could probably use "0" as
a sentinel value (since no object can start there). This is
the minimal fix, and we can improve the resilience later on
top.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Rename git_config_set_or_die functions to git_config_set, leading
to the new default behavior of dying whenever a configuration
error occurs.
By now all callers that shall die on error have been transitioned
to the _or_die variants, thus making this patch a simple rename
of the functions.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The desired default behavior for `git_config_set` is to die
whenever an error occurs. Dying is the default for a lot of
internal functions when failures occur and is in this case the
right thing to do for most callers as otherwise we might run into
inconsistent repositories without noticing.
As some code may rely on the actual return values for
`git_config_set` we still require the ability to invoke these
functions without aborting. Rename the existing `git_config_set`
functions to `git_config_set_gently` to keep them available for
those callers.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use the config origin_type to print more detailed error messages that
inform the user about the origin of a config error (file, stdin, blob).
Helped-by: Ramsay Jones <ramsay@ramsayjones.plus.com>
Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This matches the naming used in the index_{fd,mem,...} functions.
Suggested-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When running a pager, we need to run the program git_pager() gave
us, but we need to make sure we spawn it via the shell (i.e. it is
valid to say PAGER='less -S', for example) and give default values
to $LESS and $LV environment variables. Factor out these details
to a separate helper function.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A lot of call-sites for the existing family of `git_config_set`
functions do not check for errors that may occur, e.g. when the
configuration file is locked. In many cases we simply want to die
when such a situation arises.
Introduce wrappers that will cause the program to die in those
cases. These wrappers are temporary only to ease the transition
to let `git_config_set` die by default. They will be removed
later on when `git_config_set` itself has been replaced by
`git_config_set_gently`.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To correctly perform its testing function,
test-dump-untracked-cache should not change the state of the
untracked cache in the index.
As a previous patch makes read_index_from() change the state of
the untracked cache and as test-dump-untracked-cache indirectly
calls this function, we need a mechanism to prevent
read_index_from() from changing the untracked cache state when
it's called from test-dump-untracked-cache.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we know that mtime on directory as given by the environment
is usable for the purpose of untracked cache, we may want the
untracked cache to be always used without any mtime test or
kernel name check being performed.
Also when we know that mtime is not usable for the purpose of
untracked cache, for example because the repo is shared over a
network file system, we may want the untracked-cache to be
automatically removed from the index.
Allow the user to express such preference by setting the
'core.untrackedCache' configuration variable, which can take
'keep', 'false', or 'true' and default to 'keep'.
When read_index_from() is called, it now adds or removes the
untracked cache in the index to respect the value of this
variable. So it does nothing if the value is `keep` or if the
variable is unset; it adds the untracked cache if the value is
`true`; and it removes the cache if the value is `false`.
`git update-index --[no-|force-]untracked-cache` still adds the
untracked cache to, or removes it, from the index, but this
shows a warning if it goes against the value of
core.untrackedCache, because the next time the index is read
the untracked cache will be added or removed if the
configuration is set to do so.
Also `--untracked-cache` used to check that the underlying
operating system and file system change `st_mtime` field of a
directory if files are added or deleted in that directory. But
because those tests take a long time, `--untracked-cache` no
longer performs them. Instead, there is now
`--test-untracked-cache` to perform the tests. This change
makes `--untracked-cache` the same as `--force-untracked-cache`.
This last change is backward incompatible and should be
mentioned in the release notes.
Helped-by: Duy Nguyen <pclouds@gmail.com>
Helped-by: Torsten Bögershausen <tboegi@web.de>
Helped-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
read-cache: Duy'sfixup
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We have always had is_git_directory(), for looking at a
specific directory to see if it contains a git repo. In
0179ca7 (clean: improve performance when removing lots of
directories, 2015-06-15), we added is_git_repository() which
checks for a non-bare repository by looking at its ".git"
entry.
However, the fix in 0179ca7 needs to be applied other
places, too. Let's make this new helper globally available.
We need to give it a better name, though, to avoid confusion
with is_git_directory(). This patch does that, documents
both functions with a comment to reduce confusion, and
removes the clean-specific references in the comments.
Based-on-a-patch-by: Andreas Krey <a.krey@gmx.de>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We sometimes use 32-bit unsigned integers as bit-fields.
It's fine to access the MSB, because it's unsigned. However,
doing so as "1 << 31" is wrong, because the constant "1" is
a signed int, and we shift into the sign bit, causing
undefined behavior.
We can fix this by using "1U" as the constant.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A pack_revindex struct has two elements: the revindex
entries themselves, and a pointer to the packed_git. We need
both to do lookups, because only the latter knows things
like the number of objects in the pack.
Now that packed_git contains the pack_revindex struct it's
just as easy to pass around the packed_git itself, and we do
not need the extra back-pointer.
We can instead just store the entries directly in the pack.
All functions which took a pack_revindex now just take a
packed_git. We still lazy-load in find_pack_revindex, so
most callers are unaffected.
The exception is the bitmap code, which computes the
revindex and caches the pointer when we load the bitmaps. We
can continue to load, drop the extra cache pointer, and just
access bitmap_git.pack.revindex directly.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The main entry point to the pack-revindex code is
find_pack_revindex(). This calls revindex_for_pack(), which
lazily computes and caches the revindex for the pack.
We store the cache in a very simple hash table. It's created
by init_pack_revindex(), which inserts an entry for every
packfile we know about, and we never grow or shrink the
hash. If we ever need the revindex for a pack that isn't in
the hash, we die() with an internal error.
This can lead to a race, because we may load more packs
after having called init_pack_revindex(). For example,
imagine we have one process which needs to look at the
revindex for a variety of objects (e.g., cat-file's
"%(objectsize:disk)" format). Simultaneously, git-gc is
running, which is doing a `git repack -ad`. We might hit a
sequence like:
1. We need the revidx for some packed object. We call
find_pack_revindex() and end up in init_pack_revindex()
to create the hash table for all packs we know about.
2. We look up another object and can't find it, because
the repack has removed the pack it's in. We re-scan the
pack directory and find a new pack containing the
object. It gets added to our packed_git list.
3. We call find_pack_revindex() for the new object, which
hits revindex_for_pack() for our new pack. It can't
find the packed_git in the revindex hash, and dies.
You could also replace the `repack` above with a push or
fetch to create a new pack, though these are less likely
(you would have to somehow learn about the new objects to
look them up).
Prior to 1a6d8b9 (do not discard revindex when re-preparing
packfiles, 2014-01-15), this was safe, as we threw away the
revindex whenever we re-scanned the pack directory (and thus
re-created the revindex hash on the fly). However, we don't
want to simply revert that commit, as it was solving a
different race.
So we have a few options:
- We can fix the race in 1a6d8b9 differently, by having
the bitmap code look in the revindex hash instead of
caching the pointer. But this would introduce a lot of
extra hash lookups for common bitmap operations.
- We could teach the revindex to dynamically add new packs
to the hash table. This would perform the same, but
would mean adding extra code to the revindex hash (which
currently cannot be resized at all).
- We can get rid of the hash table entirely. There is
exactly one revindex per pack, so we can just store it
in the packed_git struct. Since it's initialized lazily,
it does not add to the startup cost.
This is the best of both worlds: less code and fewer
hash table lookups. The original code likely avoided
this in the name of encapsulation. But the packed_git
and reverse_index code are fairly intimate already, so
it's not much of a loss.
This patch implements the final option. It's a minimal
conversion that retains the pack_revindex struct. No callers
need to change, and we can do further cleanup in a follow-on
patch.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
null_oid is the struct object_id equivalent to null_sha1.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add has_object_file, which is a wrapper around has_sha1_file, but for
struct object_id.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Jeff King <peff@peff.net>
Soon we will want to create initdb functions for ref backends, and
code from initdb that calls this function needs to move into the files
backend. So this function needs to be public.
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>
Using the previous commit's inredirection mechanism for SHA1,
support a chunked implementation of SHA1_Update() that limits the
amount of data in the chunk passed to SHA1_Update().
This is enabled by using the Makefile variable SHA1_MAX_BLOCK_SIZE
to specify chunk size. When using Apple's CommonCrypto library this
is set to 1GiB (the implementation cannot handle more 4GiB).
Signed-off-by: Atousa Pahlevan Duprat <apahlevan@ieee.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The git source uses git_SHA1_Update() and friends to call into the
code that computes the hashes. Traditionally, we used to map these
directly to underlying implementation of the SHA-1 hash (e.g.
SHA1_Update() from OpenSSL or blk_SHA1_Update() from block-sha1/).
This arrangement however makes it hard to tweak behaviour of the
underlying implementation without fully replacing. If we want to
introduce a tweaked_SHA1_Update() wrapper to implement the "Update"
in a slightly different way, for example, the implementation of the
wrapper still would want to call into the underlying implementation,
but tweaked_SHA1_Update() cannot call git_SHA1_Update() to get to
the underlying implementation (often but not always SHA1_Update()).
Add another level of indirection that maps platform_SHA1_Update()
and friends to their underlying implementations, and by default make
git_SHA1_Update() and friends map to platform_SHA1_* functions.
Doing it this way will later allow us to map git_SHA1_Update() to
tweaked_SHA1_Update(), and the latter can use platform_SHA1_Update()
in its implementation.
Signed-off-by: Atousa Pahlevan Duprat <apahlevan@ieee.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Stop reusing cache_entry in dir_entry; doing so causes a
use-after-free bug.
During merges, we free entries that we no longer need in the
destination index. But those entries might have also been stored in
the dir_entry cache, and when a later call to add_to_index found them,
they would be used after being freed.
To prevent this, change dir_entry to store a copy of the name instead
of a pointer to a cache_entry. This entails some refactoring of code
that expects the cache_entry.
Keith McGuigan <kmcguigan@twitter.com> diagnosed this bug and wrote
the initial patch, but this version does not use any of Keith's code.
Helped-by: Keith McGuigan <kmcguigan@twitter.com>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
On Windows, files that are in use cannot be removed or renamed. That
means that we have to release pack files when we are about to, say,
repack them. Let's introduce a convenient function to close all the
pack files and their idx files.
While at it, we consolidate the close windows/close fd/close index
stanza in `free_pack_by_name()` into the `close_pack()` function that
is used by the new `close_all_packs()` function to avoid repeated code.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We have the path "foo.idx", and we create a buffer big
enough to hold "foo.pack" and "foo.keep", and then strcpy
straight into it. This isn't a bug (we have enough space),
but it's very hard to tell from the strcpy that this is so.
Let's instead use strip_suffix to take off the ".idx",
record the size of our allocation, and use xsnprintf to make
sure we don't violate our assumptions.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The sha1_to_hex and find_unique_abbrev functions always
write into reusable static buffers. There are a few problems
with this:
- future calls overwrite our result. This is especially
annoying with find_unique_abbrev, which does not have a
ring of buffers, so you cannot even printf() a result
that has two abbreviated sha1s.
- if you want to put the result into another buffer, we
often strcpy, which looks suspicious when auditing for
overflows.
This patch introduces sha1_to_hex_r and find_unique_abbrev_r,
which write into a user-provided buffer. Of course this is
just punting on the overflow-auditing, as the buffer
obviously needs to be GIT_SHA1_HEXSZ + 1 bytes. But it is
much easier to audit, since that is a well-known size.
We retain the non-reentrant forms, which just become thin
wrappers around the reentrant ones. This patch also adds a
strbuf variant of find_unique_abbrev, which will be handy in
later patches.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If you have a function that uses git_path a lot, but would
prefer to avoid the static buffers, it's useful to keep a
single scratch buffer locally and reuse it for each call.
You used to be able to do this with git_snpath:
char buf[PATH_MAX];
foo(git_snpath(buf, sizeof(buf), "foo"));
bar(git_snpath(buf, sizeof(buf), "bar"));
but since 1a83c24, git_snpath has been replaced with
strbuf_git_path. This is good, because it removes the
arbitrary PATH_MAX limit. But using strbuf_git_path is more
awkward for two reasons:
1. It adds to the buffer, rather than replacing it. This
is consistent with other strbuf functions, but makes
reuse of a single buffer more tedious.
2. It doesn't return the buffer, so you can't format
as part of a function's arguments.
The new git_path_buf solves both of these, so you can use it
like:
struct strbuf buf = STRBUF_INIT;
foo(git_path_buf(&buf, "foo"));
bar(git_path_buf(&buf, "bar"));
strbuf_release(&buf);
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When submodule is a linked worktree, "git diff --submodule" and other
calls which directly access the submodule's object database do not correctly
calculate its path. Fix it by changing the git_pathdup_submodule() behavior,
to use either common or per-worktree directory.
Do it similarly as for parent repository, but ignore the GIT_COMMON_DIR
environment variable, because it would mean common directory for the parent
repository and does not make sense for submodule.
Also add test for functionality which uses this call.
Signed-off-by: Max Kirillov <max@max630.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Most of our "--date" modes are about the format of the date:
which items we show and in what order. But "--date=local" is
a bit of an oddball. It means "show the date in the normal
format, but using the local timezone". The timezone we use
is orthogonal to the actual format, and there is no reason
we could not have "localized iso8601", etc.
This patch adds a "local" boolean field to "struct
date_mode", and drops the DATE_LOCAL element from the
date_mode_type enum (it's now just DATE_NORMAL plus
local=1). The new feature is accessible to users by adding
"-local" to any date mode (e.g., "iso-local"), and we retain
"local" as an alias for "default-local" for backwards
compatibility.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: John Keeping <john@keeping.me.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
All callers except three passed 1 for the "fatal" parameter to ask
this function to die upon error, but to a casual reader of the code,
it was not all obvious what that 1 meant. Instead, split the
function into two based on a common write_file_v() that takes the
flag, introduce write_file_gently() as a new way to attempt creating
a file without dying on error, and make three callers to call it.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When we are running the git command "foo", we may have to
look up the config keys "pager.foo" and "alias.foo". These
config schemes are mis-designed, as the command names can be
anything, but the config syntax has some restrictions. For
example:
$ git foo_bar
error: invalid key: pager.foo_bar
error: invalid key: alias.foo_bar
git: 'foo_bar' is not a git command. See 'git --help'.
You cannot name an alias with an underscore. And if you have
an external command with one, you cannot configure its
pager.
In the long run, we may develop a different config scheme
for these features. But in the near term (and because we'll
need to support the existing scheme indefinitely), we should
at least squelch the error messages shown above.
These errors come from git_config_parse_key. Ideally we
would pass a "quiet" flag to the config machinery, but there
are many layers between the pager code and the key parsing.
Passing a flag through all of those would be an invasive
change.
Instead, let's provide a config function to report on
whether a key is syntactically valid, and have the pager and
alias code skip lookup for bogus keys. We can build this
easily around the existing git_config_parse_key, with two
minor modifications:
1. We now handle a NULL store_key, to validate but not
write out the normalized key.
2. We accept a "quiet" flag to avoid writing to stderr.
This doesn't need to be a full-blown public "flags"
field, because we can make the existing implementation
a static helper function, keeping the mess contained
inside config.c.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This helper function does not complain about the config variable
but just silently reports failure to the caller. It is useful for
callers that need to parse any string that could be boolean or other
string (e.g. tristate yes/no/auto).
Signed-off-by: Dave Borowitz <dborowitz@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The hook to report "garbage" files in $GIT_OBJECT_DIRECTORY/pack/
could be generic but is too specific to count-object's needs.
Move the part to produce human-readable messages to count-objects,
and refine the interface to callback with the "bits" with values
defined in the cache.h header file, so that other callers (e.g.
prune) can later use the same mechanism to enumerate different
kinds of garbage files and do something intelligent about them,
other than reporting in textual messages.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
One of the most common uses of git_path() is to pass a
constant, like git_path("MERGE_MSG"). This has two
drawbacks:
1. The return value is a static buffer, and the lifetime
is dependent on other calls to git_path, etc.
2. There's no compile-time checking of the pathname. This
is OK for a one-off (after all, we have to spell it
correctly at least once), but many of these constant
strings appear throughout the code.
This patch introduces a series of functions to "memoize"
these strings, which are essentially globals for the
lifetime of the program. We compute the value once, take
ownership of the buffer, and return the cached value for
subsequent calls. cache.h provides a helper macro for
defining these functions as one-liners, and defines a few
common ones for global use.
Using a macro is a little bit gross, but it does nicely
document the purpose of the functions. If we need to touch
them all later (e.g., because we learned how to change the
git_dir variable at runtime, and need to invalidate all of
the stored values), it will be much easier to have the
complete list.
Note that the shared-global functions have separate, manual
declarations. We could do something clever with the macros
(e.g., expand it to a declaration in some places, and a
declaration _and_ a definition in path.c). But there aren't
that many, and it's probably better to stay away from
too-magical macros.
Likewise, if we abandon the C preprocessor in favor of
generating these with a script, we could get much fancier.
E.g., normalizing "FOO/BAR-BAZ" into "git_path_foo_bar_baz".
But the small amount of saved typing is probably not worth
the resulting confusion to readers who want to grep for the
function's definition.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are no callers of the slightly-dangerous static-buffer
git_path_submodule left. Let's drop it.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The git_path function has "git_pathdup" and
"strbuf_git_path" variants, but git_submodule_path only
comes in the dangerous, static-buffer variant. That makes
refactoring callers to use the safer functions hard (since
they don't exist).
Since we're already using a strbuf behind the scenes, it's
easy to expose all three of these interfaces with thin
wrappers.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The comment above these functions actually describes
sha1_file_name, and comes from the very first revision of
git. Commit 723c31f (Add "git_path()" and "head_ref()"
helper functions., 2005-07-05) added git_path, pushing the
comment away from the function it describes; later commits
added more functions in this block.
Let's fix the comment to describe these related functions in
more detail. Let's also make sure to point out their safer
alternatives (and move those alternatives below, which makes
more sense when reading the file).
Note that we do not need to move the existing comment to
sha1_file_name. Commit d40d535 (sha1_file.c: document a
bunch of functions defined in the file, 2014-02-21) already
added a much more descriptive comment to it.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since 5a688fe4 ("core.sharedrepository = 0mode" should set, not
loosen, 2009-03-25), we kept reminding ourselves:
NEEDSWORK: this should be renamed to finalize_temp_file() as
"moving" is only a part of what it does, when no patch between
master to pu changes the call sites of this function.
without doing anything about it. Let's do so.
The purpose of this function was not to move but to finalize. The
detail of the primarily implementation of finalizing was to link the
temporary file to its final name and then to unlink, which wasn't
even "moving". The alternative implementation did "move" by calling
rename(2), which is a fun tangent.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This feeds the format directly to strftime. Besides being a
little more flexible, the main advantage is that your system
strftime may know more about your locale's preferred format
(e.g., how to spell the days of the week).
Signed-off-by: Jeff King <peff@peff.net>
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>
If this extension is used in a repository, then no
operations should run which may drop objects from the object
storage. This can be useful if you are sharing that storage
with other repositories whose refs you cannot see.
For instance, if you do:
$ git clone -s parent child
$ git -C parent config extensions.preciousObjects true
$ git -C parent config core.repositoryformatversion 1
you now have additional safety when running git in the
parent repository. Prunes and repacks will bail with an
error, and `git gc` will skip those operations (it will
continue to pack refs and do other non-object operations).
Older versions of git, when run in the repository, will
fail on every operation.
Note that we do not set the preciousObjects extension by
default when doing a "clone -s", as doing so breaks
backwards compatibility. It is a decision the user should
make explicitly.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Normally we try to avoid bumps of the whole-repository
core.repositoryformatversion field. However, it is
unavoidable if we want to safely change certain aspects of
git in a backwards-incompatible way (e.g., modifying the set
of ref tips that we must traverse to generate a list of
unreachable, safe-to-prune objects).
If we were to bump the repository version for every such
change, then any implementation understanding version `X`
would also have to understand `X-1`, `X-2`, and so forth,
even though the incompatibilities may be in orthogonal parts
of the system, and there is otherwise no reason we cannot
implement one without the other (or more importantly, that
the user cannot choose to use one feature without the other,
weighing the tradeoff in compatibility only for that
particular feature).
This patch documents the existing repositoryformatversion
strategy and introduces a new format, "1", which lets a
repository specify that it must run with an arbitrary set of
extensions. This can be used, for example:
- to inform git that the objects should not be pruned based
only on the reachability of the ref tips (e.g, because it
has "clone --shared" children)
- that the refs are stored in a format besides the usual
"refs" and "packed-refs" directories
Because we bump to format "1", and because format "1"
requires that a running git knows about any extensions
mentioned, we know that older versions of the code will not
do something dangerous when confronted with these new
formats.
For example, if the user chooses to use database storage for
refs, they may set the "extensions.refbackend" config to
"db". Older versions of git will not understand format "1"
and bail. Versions of git which understand "1" but do not
know about "refbackend", or which know about "refbackend"
but not about the "db" backend, will refuse to run. This is
annoying, of course, but much better than the alternative of
claiming that there are no refs in the repository, or
writing to a location that other implementations will not
read.
Note that we are only defining the rules for format 1 here.
We do not ever write format 1 ourselves; it is a tool that
is meant to be used by users and future extensions to
provide safety with older implementations.
Signed-off-by: Jeff King <peff@peff.net>
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>
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>
read_gitfile_gently will allocate a buffer to fit the entire file that
should be read. Add a sanity check of the file size before opening to
avoid allocating a potentially huge amount of memory if we come across
a large file that someone happened to name ".git". The limit is set to
a sufficiently unreasonable size that should never be exceeded by a
genuine .git file.
Signed-off-by: Erik Elfström <erik.elfstrom@gmail.com>
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>
read_gitfile will die on most error cases. This makes it unsuitable
for speculative calls. Extract the core logic and provide a gentle
version that returns NULL on failure.
The first usecase of the new gentle version will be to probe for
submodules during git clean.
Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Erik Elfström <erik.elfstrom@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since 45e8a74 (has_sha1_file: re-check pack directory before
giving up, 2013-08-30), we spend extra effort for
has_sha1_file to give the right answer when somebody else is
repacking. Usually this effort does not matter, because
after finding that the object does not exist, the next step
is usually to die().
However, some code paths make a large number of
has_sha1_file checks which are _not_ expected to return 1.
The collision test in index-pack.c is such a case. On a
local system, this can cause a performance slowdown of
around 5%. But on a system with high-latency system calls
(like NFS), it can be much worse.
This patch introduces a "quick" flag to has_sha1_file which
callers can use when they would prefer high performance at
the cost of false negatives during repacks. There may be
other code paths that can use this, but the index-pack one
is the most obviously critical, so we'll start with
switching that one.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We want to use the new function elsewhere in a moment.
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Reviewed-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Wire up get_sha1_with_context to call get_tree_entry_follow_symlinks
when GET_SHA1_FOLLOW_SYMLINKS is passed in flags. G_S_FOLLOW_SYMLINKS
is incompatible with G_S_ONLY_TO_DIE because the diagnosis
that ONLY_TO_DIE triggers does not at present consider symlinks, and
it would be a significant amount of additional code to allow it to
do so.
Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When copy_fd() function encounters errors, it emits error messages
itself, which makes it impossible for callers to take responsibility
for reporting errors, especially when they want to ignore certain
errors.
Move the error reporting to its callers in preparation.
- copy_file() and copy_file_with_time() by indirection get their
own calls to error().
- hold_lock_file_for_append(), when told to die on error, used to
exit(128) relying on the error message from copy_fd(), but now it
does its own die() instead. Note that the callers that do not
pass LOCK_DIE_ON_ERROR need to be adjusted for this change, but
fortunately there is none ;-)
- filter_buffer_or_fd() has its own error() already, in addition to
the message from copy_fd(), so this will change the output but
arguably in a better way.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Update sha1_loose_object_info() to optionally allow it to read
from a loose object file of unknown/bogus type; as the function
usually returns the type of the object it read in the form of enum
for known types, add an optional "typename" field to receive the
name of the type in textual form and a flag to indicate the reading
of a loose object file of unknown/bogus type.
Add parse_sha1_header_extended() which acts as a wrapper around
parse_sha1_header() allowing more information to be obtained.
Add unpack_sha1_header_to_strbuf() to unpack sha1 headers of
unknown/corrupt objects which have a unknown sha1 header size to
a strbuf structure. This was written by Junio C Hamano but tested
by me.
Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Helped-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Hepled-by: Jeff King <peff@peff.net>
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
home_config_paths() combines distinct functionality already implemented
by expand_user_path() and xdg_config_home(), and it also hard-codes the
path ~/.gitconfig, which makes it unsuitable to use for other home
config file paths. Since its use will just add unnecessary complexity to
the code, remove it.
Signed-off-by: Paul Tan <pyokagan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Jeff King