Currently, we have functions that turn an arbitrary SHA-1 value or an
object ID into hex format, either using a static buffer or with a
user-provided buffer. Add variants of these functions that can handle
an arbitrary hash algorithm, specified by constant. Update the
documentation as well.
While we're at it, remove the "extern" declaration from this family of
functions, since it's not needed and our style now recommends against
it.
We use the variant taking the algorithm structure pointer as the
internal variant, since taking an algorithm pointer is the easiest way
to handle all of the variants in use.
Note that we maintain these functions because there are hashes which
must change based on the hash algorithm in use but are not object IDs
(such as pack checksums).
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
One of the problems with "git checkout" is that it does so many
different things and could confuse people specially when we fail to
handle ambiguation correctly.
One way to help with that is tell the user what sort of operation is
actually carried out. When switching branches, we always print
something unless --quiet, either
- "HEAD is now at ..."
- "Reset branch ..."
- "Already on ..."
- "Switched to and reset ..."
- "Switched to a new branch ..."
- "Switched to branch ..."
Checking out paths however is silent. Print something so that if we
got the user intention wrong, they won't waste too much time to find
that out. For the remaining cases of checkout we now print either
- "Checked out ... paths out of the index"
- "Checked out ... paths out of <abbrev hash>"
Since the purpose of printing this is to help disambiguate. Only do it
when "--" is missing.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The helper function to refresh the cached stat information in the
in-core index has learned to perform the lstat() part of the
operation in parallel on multi-core platforms.
* bp/refresh-index-using-preload:
refresh_index: remove unnecessary calls to preload_index()
speed up refresh_index() by utilizing preload_index()
The submodule support has been updated to read from the blob at
HEAD:.gitmodules when the .gitmodules file is missing from the
working tree.
* ao/submodule-wo-gitmodules-checked-out:
t/helper: add test-submodule-nested-repo-config
submodule: support reading .gitmodules when it's not in the working tree
submodule: add a helper to check if it is safe to write to .gitmodules
t7506: clean up .gitmodules properly before setting up new scenario
submodule: use the 'submodule--helper config' command
submodule--helper: add a new 'config' subcommand
t7411: be nicer to future tests and really clean things up
t7411: merge tests 5 and 6
submodule: factor out a config_set_in_gitmodules_file_gently function
submodule: add a print_config_from_gitmodules() helper
A fourth class of configuration files (in addition to the
traditional "system wide", "per user in the $HOME directory" and
"per repository in the $GIT_DIR/config") has been introduced so
that different worktrees that share the same repository (hence the
same $GIT_DIR/config file) can use different customization.
* nd/per-worktree-config:
worktree: add per-worktree config files
t1300: extract and use test_cmp_config()
Rewrite of the remaining "rebase -i" machinery in C.
* ag/rebase-i-in-c:
rebase -i: move rebase--helper modes to rebase--interactive
rebase -i: remove git-rebase--interactive.sh
rebase--interactive2: rewrite the submodes of interactive rebase in C
rebase -i: implement the main part of interactive rebase as a builtin
rebase -i: rewrite init_basic_state() in C
rebase -i: rewrite write_basic_state() in C
rebase -i: rewrite the rest of init_revisions_and_shortrevisions() in C
rebase -i: implement the logic to initialize $revisions in C
rebase -i: remove unused modes and functions
rebase -i: rewrite complete_action() in C
t3404: todo list with commented-out commands only aborts
sequencer: change the way skip_unnecessary_picks() returns its result
sequencer: refactor append_todo_help() to write its message to a buffer
rebase -i: rewrite checkout_onto() in C
rebase -i: rewrite setup_reflog_action() in C
sequencer: add a new function to silence a command, except if it fails
rebase -i: rewrite the edit-todo functionality in C
editor: add a function to launch the sequence editor
rebase -i: rewrite append_todo_help() in C
sequencer: make three functions and an enum from sequencer.c public
Speed up refresh_index() by utilizing preload_index() to do most of the work
spread across multiple threads. This works because most cache entries will
get marked CE_UPTODATE so that refresh_cache_ent() can bail out early when
called from within refresh_index().
On a Windows repo with ~200K files, this drops refresh times from 6.64
seconds to 2.87 seconds for a savings of 57%.
Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The codepath to support the experimental split-index mode had
remaining "racily clean" issues fixed.
* sg/split-index-racefix:
split-index: BUG() when cache entry refers to non-existing shared entry
split-index: smudge and add racily clean cache entries to split index
split-index: don't compare cached data of entries already marked for split index
split-index: count the number of deleted entries
t1700-split-index: date back files to avoid racy situations
split-index: add tests to demonstrate the racy split index problem
t1700-split-index: document why FSMONITOR is disabled in this test script
A new repo extension is added, worktreeConfig. When it is present:
- Repository config reading by default includes $GIT_DIR/config _and_
$GIT_DIR/config.worktree. "config" file remains shared in multiple
worktree setup.
- The special treatment for core.bare and core.worktree, to stay
effective only in main worktree, is gone. These config settings are
supposed to be in config.worktree.
This extension is most useful in multiple worktree setup because you
now have an option to store per-worktree config (which is either
.git/config.worktree for main worktree, or
.git/worktrees/xx/config.worktree for linked ones).
This extension can be used in single worktree mode, even though it's
pretty much useless (but this can happen after you remove all linked
worktrees and move back to single worktree).
"git config" reads from both "config" and "config.worktree" by default
(i.e. without either --user, --file...) when this extension is
present. Default writes still go to "config", not "config.worktree". A
new option --worktree is added for that (*).
Since a new repo extension is introduced, existing git binaries should
refuse to access to the repo (both from main and linked worktrees). So
they will not misread the config file (i.e. skip the config.worktree
part). They may still accidentally write to the config file anyway if
they use with "git config --file <path>".
This design places a bet on the assumption that the majority of config
variables are shared so it is the default mode. A safer move would be
default writes go to per-worktree file, so that accidental changes are
isolated.
(*) "git config --worktree" points back to "config" file when this
extension is not present and there is only one worktree so that it
works in any both single and multiple worktree setups.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git status" learns to show progress bar when refreshing the index
takes a long time.
* nd/status-refresh-progress:
status: show progress bar if refreshing the index takes too long
Various codepaths in the core-ish part learn to work on an
arbitrary in-core index structure, not necessarily the default
instance "the_index".
* nd/the-index: (23 commits)
revision.c: reduce implicit dependency the_repository
revision.c: remove implicit dependency on the_index
ws.c: remove implicit dependency on the_index
tree-diff.c: remove implicit dependency on the_index
submodule.c: remove implicit dependency on the_index
line-range.c: remove implicit dependency on the_index
userdiff.c: remove implicit dependency on the_index
rerere.c: remove implicit dependency on the_index
sha1-file.c: remove implicit dependency on the_index
patch-ids.c: remove implicit dependency on the_index
merge.c: remove implicit dependency on the_index
merge-blobs.c: remove implicit dependency on the_index
ll-merge.c: remove implicit dependency on the_index
diff-lib.c: remove implicit dependency on the_index
read-cache.c: remove implicit dependency on the_index
diff.c: remove implicit dependency on the_index
grep.c: remove implicit dependency on the_index
diff.c: remove the_index dependency in textconv() functions
blame.c: rename "repo" argument to "r"
combine-diff.c: remove implicit dependency on the_index
...
Ever since the split index feature was introduced [1], refreshing a
split index is prone to a variant of the classic racy git problem.
Consider the following sequence of commands updating the split index
when the shared index contains a racily clean cache entry, i.e. an
entry whose cached stat data matches with the corresponding file in
the worktree and the cached mtime matches that of the index:
echo "cached content" >file
git update-index --split-index --add file
echo "dirty worktree" >file # size stays the same!
# ... wait ...
git update-index --add other-file
Normally, when a non-split index is updated, then do_write_index()
(the function responsible for writing all kinds of indexes, "regular",
split, and shared) recognizes racily clean cache entries, and writes
them with smudged stat data, i.e. with file size set to 0. When
subsequent git commands read the index, they will notice that the
smudged stat data doesn't match with the file in the worktree, and
then go on to check the file's content and notice its dirtiness.
In the above example, however, in the second 'git update-index'
prepare_to_write_split_index() decides which cache entries stored only
in the shared index should be replaced in the new split index. Alas,
this function never looks out for racily clean cache entries, and
since the file's stat data in the worktree hasn't changed since the
shared index was written, it won't be replaced in the new split index.
Consequently, do_write_index() doesn't even get this racily clean
cache entry, and can't smudge its stat data. Subsequent git commands
will then see that the index has more recent mtime than the file and
that the (not smudged) cached stat data still matches with the file in
the worktree, and, ultimately, will erroneously consider the file
clean.
Modify prepare_to_write_split_index() to recognize racily clean cache
entries, and mark them to be added to the split index. Note that
there are two places where it should check raciness: first those cache
entries that are only stored in the shared index, and then those that
have been copied by unpack_trees() from the shared index while it
constructed a new index. This way do_write_index() will get these
racily clean cache entries as well, and will then write them with
smudged stat data to the new split index.
This change makes all tests in 't1701-racy-split-index.sh' pass, so
flip the two 'test_expect_failure' tests to success. Also add the '#'
(as in nr. of trial) to those tests' description that were omitted
when the tests expected failure.
Note that after this change if the index is split when it contains a
racily clean cache entry, then a smudged cache entry will be written
both to the new shared and to the new split indexes. This doesn't
affect regular git commands: as far as they are concerned this is just
an entry in the split index replacing an outdated entry in the shared
index. It did affect a few tests in 't1700-split-index.sh', though,
because they actually check which entries are stored in the split
index; a previous patch in this series has already made the necessary
adjustments in 't1700'. And racily clean cache entries and index
splitting are rare enough to not worry about the resulting duplicated
smudged cache entries, and the additional complexity required to
prevent them is not worth it.
Several tests failed occasionally when the test suite was run with
'GIT_TEST_SPLIT_INDEX=yes'. Here are those that I managed to trace
back to this racy split index problem, starting with those failing
more frequently, with a link to a failing Travis CI build job for
each. The highlighted line [2] shows when the racy file was written,
which is not always in the failing test but in a preceeding setup
test.
t3903-stash.sh:
https://travis-ci.org/git/git/jobs/385542084#L5858
t4024-diff-optimize-common.sh:
https://travis-ci.org/git/git/jobs/386531969#L3174
t4015-diff-whitespace.sh:
https://travis-ci.org/git/git/jobs/360797600#L8215
t2200-add-update.sh:
https://travis-ci.org/git/git/jobs/382543426#L3051
t0090-cache-tree.sh:
https://travis-ci.org/git/git/jobs/416583010#L3679
There might be others, e.g. perhaps 't1000-read-tree-m-3way.sh' and
others using 'lib-read-tree-m-3way.sh', but I couldn't confirm yet.
[1] In the branch leading to the merge commit v2.1.0-rc0~45 (Merge
branch 'nd/split-index', 2014-07-16).
[2] Note that those highlighted lines are in the 'after failure' fold,
and your browser might unhelpfully fold it up before you could
take a good look.
Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce a helper function named is_writing_gitmodules_ok() to verify
that the .gitmodules file is safe to write.
The function name follows the scheme of is_staging_gitmodules_ok().
The two symbolic constants GITMODULES_INDEX and GITMODULES_HEAD are used
to get help from the C preprocessor in preventing typos, especially for
future users.
This is in preparation for a future change which teaches git how to read
.gitmodules from the index or from the current branch if the file is not
available in the working tree.
The rationale behind the check is that writing to .gitmodules requires
the file to be present in the working tree, unless a brand new
.gitmodules is being created (in which case the .gitmodules file would
not exist at all: neither in the working tree nor in the index or in the
current branch).
Expose the functionality also via a "submodule-helper config
--check-writeable" command, as git scripts may want to perform the check
before modifying submodules configuration.
Signed-off-by: Antonio Ospite <ao2@ao2.it>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This function calls do_diff_cache() which eventually needs to set this
"istate" to unpack_options->src_index [1]. This is an unfortunate fact
that unpack_trees() _will_ update [2] src_index so we can't really pass a
const index_state there. Just remove 'const'.
[1] Right now diff_cache() in diff-lib.c assigns the_index to
src_index. But the plan is to get rid of the_index, so it should
be 'istate' from here that gets assigned to src_index.
[2] Some transient bits in the source index are touched. Optional
extensions can also be removed. But other than that the source
tree should still be valid.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
spatch transformation to replace boolean uses of !hashcmp() to
newly introduced oideq() is added, and applied, to regain
performance lost due to support of multiple hash algorithms.
* jk/cocci:
show_dirstat: simplify same-content check
read-cache: use oideq() in ce_compare functions
convert hashmap comparison functions to oideq()
convert "hashcmp() != 0" to "!hasheq()"
convert "oidcmp() != 0" to "!oideq()"
convert "hashcmp() == 0" to hasheq()
convert "oidcmp() == 0" to oideq()
introduce hasheq() and oideq()
coccinelle: use <...> for function exclusion
Running "git clone" against a project that contain two files with
pathnames that differ only in cases on a case insensitive
filesystem would result in one of the files lost because the
underlying filesystem is incapable of holding both at the same
time. An attempt is made to detect such a case and warn.
* nd/clone-case-smashing-warning:
clone: report duplicate entries on case-insensitive filesystems
Refreshing the index is usually very fast, but it can still take a
long time sometimes. Cold cache is one. Or copying a repo to a new
place (*). It's good to show something to let the user know "git
status" is not hanging, it's just busy doing something.
(*) In this case, all stat info in the index becomes invalid and git
falls back to rehashing all file content to see if there's any
difference between updating stat info in the index. This is quite
expensive. Even with a repo as small as git.git, it takes 3
seconds.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is the partner patch to the previous one, but covering
the "hash" variants instead of "oid". Note that our
coccinelle rule is slightly more complex to avoid triggering
the call in hasheq().
I didn't bother to add a new rule to convert:
- hasheq(E1->hash, E2->hash)
+ oideq(E1, E2)
Since these are new functions, there won't be any such
existing callers. And since most of the code is already
using oideq, we're not likely to introduce new ones.
We might still see "!hashcmp(E1->hash, E2->hash)" from topics
in flight. But because our new rule comes after the existing
ones, that should first get converted to "!oidcmp(E1, E2)"
and then to "oideq(E1, E2)".
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Using the more restrictive oideq() should, in the long run,
give the compiler more opportunities to optimize these
callsites. For now, this conversion should be a complete
noop with respect to the generated code.
The result is also perhaps a little more readable, as it
avoids the "zero is equal" idiom. Since it's so prevalent in
C, I think seasoned programmers tend not to even notice it
anymore, but it can sometimes make for awkward double
negations (e.g., we can drop a few !!oidcmp() instances
here).
This patch was generated almost entirely by the included
coccinelle patch. This mechanical conversion should be
completely safe, because we check explicitly for cases where
oidcmp() is compared to 0, which is what oideq() is doing
under the hood. Note that we don't have to catch "!oidcmp()"
separately; coccinelle's standard isomorphisms make sure the
two are treated equivalently.
I say "almost" because I did hand-edit the coccinelle output
to fix up a few style violations (it mostly keeps the
original formatting, but sometimes unwraps long lines).
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The main comparison functions we provide for comparing
object ids are hashcmp() and oidcmp(). These are more
flexible than a strict equality check, since they also
express ordering. That makes them useful for sorting and
binary searching. However, it also makes them potentially
slower than a strict equality check. Consider this C code,
which is traditionally what our hashcmp has looked like:
#include <string.h>
int hashcmp(const unsigned char *a, const unsigned char *b)
{
return memcmp(a, b, 20);
}
Compiling with "gcc -O2 -S -fverbose-asm", the generated
assembly shows that we actually call memcmp(). But if we
change this to a strict equality check:
return !memcmp(a, b, 20);
we get a faster inline version:
movq (%rdi), %rax # MEM[(void *)a_4(D)], MEM[(void *)a_4(D)]
movq 8(%rdi), %rdx # MEM[(void *)a_4(D)], tmp101
xorq (%rsi), %rax # MEM[(void *)b_5(D)], tmp94
xorq 8(%rsi), %rdx # MEM[(void *)b_5(D)], tmp93
orq %rax, %rdx # tmp94, tmp93
jne .L2 #,
movl 16(%rsi), %eax # MEM[(void *)b_5(D)], tmp104
cmpl %eax, 16(%rdi) # tmp104, MEM[(void *)a_4(D)]
je .L5 #,
Obviously our hashcmp() doesn't include the "!". But because
it's an inline function, optimizing compilers are able to
see "!hashcmp(a,b)" in calling code and take advantage of
this case. So there has been no value thus far in
introducing a more restricted interface for doing strict
equality checks.
But as Git learns about more values for the_hash_algo, our
hashcmp() will grow more complicated and may even delegate
at runtime to functions optimized specifically for that hash
size. That breaks the inline connection we have, and the
compiler will have to assume that the caller really cares
about the sign and magnitude of the memcmp() result, even
though the vast majority don't.
We can solve that by introducing a hasheq() function (and
matching oideq() wrapper), which callers can use to make it
clear that they only care about equality. For now, the
implementation will literally be "!hashcmp()", but it frees
us up later to introduce code optimized specifically for the
equality check.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Prior to 509f6f62a4 (cache: update object ID functions for
the_hash_algo, 2018-07-16), hashcmp() called memcmp() with a
constant size of 20 bytes. Some compilers were able to turn
that into a few quad-word comparisons, which is faster than
actually calling memcmp().
In 509f6f62a4, we started using the_hash_algo->rawsz
instead. Even though this will always be 20, the compiler
doesn't know that while inlining hashcmp() and ends up just
generating a call to memcmp().
Eventually we'll have to deal with multiple hash sizes, but
for the upcoming v2.19, we can restore some of the original
performance by asserting on the size. That gives the
compiler enough information to know that the memcmp will
always be called with a length of 20, and it performs the
same optimization.
Here are numbers for p0001.2 run against linux.git on a few
versions. This is using -O2 with gcc 8.2.0.
Test v2.18.0 v2.19.0-rc0 HEAD
------------------------------------------------------------------------------
0001.2: 34.24(33.81+0.43) 34.83(34.42+0.40) +1.7% 33.90(33.47+0.42) -1.0%
You can see that v2.19 is a little slower than v2.18. This
commit ended up slightly faster than v2.18, but there's a
fair bit of run-to-run noise (the generated code in the two
cases is basically the same). This patch does seem to be
consistently 1-2% faster than v2.19.
I tried changing hashcpy(), which was also touched by
509f6f62a4, in the same way, but couldn't measure any
speedup. Which makes sense, at least for this workload. A
traversal of the whole commit graph requires looking up
every entry of every tree via lookup_object(). That's many
multiples of the numbers of objects in the repository (most
of the lookups just return "yes, we already saw that
object").
[jn: verified using "make object.s" that the memcmp call goes away.]
Reported-by: Derrick Stolee <stolee@gmail.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>
Code hygiene improvement for the header files.
* en/incl-forward-decl:
Remove forward declaration of an enum
compat/precompose_utf8.h: use more common include guard style
urlmatch.h: fix include guard
Move definition of enum branch_track from cache.h to branch.h
alloc: make allocate_alloc_state and clear_alloc_state more consistent
Add missing includes and forward declarations
The API to iterate over all objects learned to optionally list
objects in the order they appear in packfiles, which helps locality
of access if the caller accesses these objects while as objects are
enumerated.
* jk/for-each-object-iteration:
for_each_*_object: move declarations to object-store.h
cat-file: use a single strbuf for all output
cat-file: split batch "buf" into two variables
cat-file: use oidset check-and-insert
cat-file: support "unordered" output for --batch-all-objects
cat-file: rename batch_{loose,packed}_object callbacks
t1006: test cat-file --batch-all-objects with duplicates
for_each_packed_object: support iterating in pack-order
for_each_*_object: give more comprehensive docstrings
for_each_*_object: take flag arguments as enum
for_each_*_object: store flag definitions in a single location
Paths that only differ in case work fine in a case-sensitive
filesystems, but if those repos are cloned in a case-insensitive one,
you'll get problems. The first thing to notice is "git status" will
never be clean with no indication what exactly is "dirty".
This patch helps the situation a bit by pointing out the problem at
clone time. Even though this patch talks about case sensitivity, the
patch makes no assumption about folding rules by the filesystem. It
simply observes that if an entry has been already checked out at clone
time when we're about to write a new path, some folding rules are
behind this.
In the case that we can't rely on filesystem (via inode number) to do
this check, fall back to fspathcmp() which is not perfect but should
not give false positives.
This patch is tested with vim-colorschemes and Sublime-Gitignore
repositories on a JFS partition with case insensitive support on
Linux.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a script (in contrib/) to help users of VSCode work better with
our codebase.
* js/vscode:
vscode: let cSpell work on commit messages, too
vscode: add a dictionary for cSpell
vscode: use 8-space tabs, no trailing ws, etc for Git's source code
vscode: wrap commit messages at column 72 by default
vscode: only overwrite C/C++ settings
mingw: define WIN32 explicitly
cache.h: extract enum declaration from inside a struct declaration
vscode: hard-code a couple defines
contrib: add a script to initialize VS Code configuration
A new configuration variable core.usereplacerefs has been added,
primarily to help server installations that want to ignore the
replace mechanism altogether.
* jk/core-use-replace-refs:
add core.usereplacerefs config option
check_replace_refs: rename to read_replace_refs
check_replace_refs: fix outdated comment
'branch_track' feels more closely related to branching, and it is
needed later in branch.h; rather than #include'ing cache.h in branch.h
for this small enum, just move the enum and the external declaration
for git_branch_track to branch.h.
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The for_each_loose_object() and for_each_packed_object()
functions are meant to be part of a unified interface: they
use the same set of for_each_object_flags, and it's not
inconceivable that we might one day add a single
for_each_object() wrapper around them.
Let's put them together in a single file, so we can avoid
awkwardness like saying "the flags for this function are
over in cache.h". Moving the loose functions to packfile.h
is silly. Moving the packed functions to cache.h works, but
makes the "cache.h is a kitchen sink" problem worse. The
best place is the recently-created object-store.h, since
these are quite obviously related to object storage.
The for_each_*_in_objdir() functions do not use the same
flags, but they are logically part of the same interface as
for_each_loose_object(), and share callback signatures. So
we'll move those, as well, as they also make sense in
object-store.h.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We currently iterate over objects within a pack in .idx
order, which uses the object hashes. That means that it
is effectively random with respect to the location of the
object within the pack. If you're going to access the actual
object data, there are two reasons to move linearly through
the pack itself:
1. It improves the locality of access in the packfile. In
the cold-cache case, this may mean fewer disk seeks, or
better usage of disk cache.
2. We store related deltas together in the packfile. Which
means that the delta base cache can operate much more
efficiently if we visit all of those related deltas in
sequence, as the earlier items are likely to still be
in the cache. Whereas if we visit the objects in
random order, our cache entries are much more likely to
have been evicted by unrelated deltas in the meantime.
So in general, if you're going to access the object contents
pack order is generally going to end up more efficient.
But if you're simply generating a list of object names, or
if you're going to end up sorting the result anyway, you're
better off just using the .idx order, as finding the pack
order means generating the in-memory pack-revindex.
According to the numbers in 8b8dfd5132 (pack-revindex:
radix-sort the revindex, 2013-07-11), that takes about 200ms
for linux.git, and 20ms for git.git (those numbers are a few
years old but are still a good ballpark).
That makes it a good optimization for some cases (we can
save tens of seconds in git.git by having good locality of
delta access, for a 20ms cost), but a bad one for others
(e.g., right now "cat-file --batch-all-objects
--batch-check="%(objectname)" is 170ms in git.git, so adding
20ms to that is noticeable).
Hence this patch makes it an optional flag. You can't
actually do any interesting timings yet, as it's not plumbed
through to any user-facing tools like cat-file. That will
come in a later patch.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We already mention the local/alternate behavior of these
functions, but we can help clarify a few other behaviors:
- there's no need to mention LOCAL_ONLY specifically, since
we already reference the flags by type (and as we add
more flags, we don't want to have to mention each)
- clarify that reachability doesn't matter here; this is
all accessible objects
- what ordering/uniqueness guarantees we give
- how pack-specific flags are handled for the loose case
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It's not wrong to pass our flags in an "unsigned", as we
know it will be at least as large as the enum. However,
using the enum in the declaration makes it more obvious
where to find the list of flags.
While we're here, let's also drop the "extern" noise-words
from the declarations, per our modern coding style.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
These flags were split between cache.h and packfile.h,
because some of the flags apply only to packs. However, they
share a single numeric namespace, since both are respected
for the packed variant. Let's make sure they're defined
together so that nobody accidentally adds a new flag in one
location that duplicates the other.
While we're here, let's also put them in an enum (which
helps debugger visibility) and use "(1<<n)" rather than
counting powers of 2 manually.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As part of the rewrite of interactive rebase, the sequencer will need to
open the sequence editor to allow the user to edit the todo list.
Instead of duplicating the existing launch_editor() function, this
refactors it to a new function, launch_specified_editor(), which takes
the editor as a parameter, in addition to the path, the buffer and the
environment variables. launch_sequence_editor() is then added to launch
the sequence editor.
Signed-off-by: Alban Gruin <alban.gruin@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The recursive merge strategy did not properly ensure there was no
change between HEAD and the index before performing its operation,
which has been corrected.
* en/dirty-merge-fixes:
merge: fix misleading pre-merge check documentation
merge-recursive: enforce rule that index matches head before merging
t6044: add more testcases with staged changes before a merge is invoked
merge-recursive: fix assumption that head tree being merged is HEAD
merge-recursive: make sure when we say we abort that we actually abort
t6044: add a testcase for index matching head, when head doesn't match HEAD
t6044: verify that merges expected to abort actually abort
index_has_changes(): avoid assuming operating on the_index
read-cache.c: move index_has_changes() from merge.c
For a large tree, the index needs to hold many cache entries
allocated on heap. These cache entries are now allocated out of a
dedicated memory pool to amortize malloc(3) overhead.
* jm/cache-entry-from-mem-pool:
block alloc: add validations around cache_entry lifecyle
block alloc: allocate cache entries from mem_pool
mem-pool: fill out functionality
mem-pool: add life cycle management functions
mem-pool: only search head block for available space
block alloc: add lifecycle APIs for cache_entry structs
read-cache: teach make_cache_entry to take object_id
read-cache: teach refresh_cache_entry to take istate
Conversion from uchar[40] to struct object_id continues.
* bc/object-id:
pretty: switch hard-coded constants to the_hash_algo
sha1-file: convert constants to uses of the_hash_algo
log-tree: switch GIT_SHA1_HEXSZ to the_hash_algo->hexsz
diff: switch GIT_SHA1_HEXSZ to use the_hash_algo
builtin/merge-recursive: make hash independent
builtin/merge: switch to use the_hash_algo
builtin/fmt-merge-msg: make hash independent
builtin/update-index: simplify parsing of cacheinfo
builtin/update-index: convert to using the_hash_algo
refs/files-backend: use the_hash_algo for writing refs
sha1-name: use the_hash_algo when parsing object names
strbuf: allocate space with GIT_MAX_HEXSZ
commit: express tree entry constants in terms of the_hash_algo
hex: switch to using the_hash_algo
tree-walk: replace hard-coded constants with the_hash_algo
cache: update object ID functions for the_hash_algo
While it is technically possible, it is confusing. Not only the user,
but also VS Code's intellisense.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This was added as a NEEDSWORK in c3c36d7de2 (replace-object:
check_replace_refs is safe in multi repo environment, 2018-04-11),
waiting for a calmer period. Since doing so now doesn't conflict
with anything in 'pu', it seems as good a time as any.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit afc711b8e1 (rename read_replace_refs to
check_replace_refs, 2014-02-18) added a comment mentioning
that check_replace_refs is set in two ways:
- from user intent via --no-replace-objects, etc
- after seeing there are no replace refs to respect
Since c3c36d7de2 (replace-object: check_replace_refs is safe
in multi repo environment, 2018-04-11) the second is no
longer true. Let's drop that part of the comment.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The conversion to pass "the_repository" and then "a_repository"
throughout the object access API continues.
* sb/object-store-grafts:
commit: allow lookup_commit_graft to handle arbitrary repositories
commit: allow prepare_commit_graft to handle arbitrary repositories
shallow: migrate shallow information into the object parser
path.c: migrate global git_path_* to take a repository argument
cache: convert get_graft_file to handle arbitrary repositories
commit: convert read_graft_file to handle arbitrary repositories
commit: convert register_commit_graft to handle arbitrary repositories
commit: convert commit_graft_pos() to handle arbitrary repositories
shallow: add repository argument to is_repository_shallow
shallow: add repository argument to check_shallow_file_for_update
shallow: add repository argument to register_shallow
shallow: add repository argument to set_alternate_shallow_file
commit: add repository argument to lookup_commit_graft
commit: add repository argument to prepare_commit_graft
commit: add repository argument to read_graft_file
commit: add repository argument to register_commit_graft
commit: add repository argument to commit_graft_pos
object: move grafts to object parser
object-store: move object access functions to object-store.h
Add a struct repository argument to the functions in commit-graph.h that
read the commit graph. (This commit does not affect functions that write
commit graphs.)
Because the commit graph functions can now read the commit graph of any
repository, the global variable core_commit_graph has been removed.
Instead, the config option core.commitGraph is now read on the first
time in a repository that a commit is attempted to be parsed using its
commit graph.
This commit includes a test that exercises the functionality on an
arbitrary repository that is not the_repository.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Most of our code has been converted to use struct object_id for object
IDs. However, there are some places that still have not, and there are
a variety of places that compare equivalently sized hashes that are not
object IDs. All of these hashes are artifacts of the internal hash
algorithm in use, and when we switch to NewHash for object storage, all
of these uses will also switch.
Update the hashcpy, hashclr, and hashcmp functions to use the_hash_algo,
since they are used in a variety of places to copy and manipulate
buffers that need to move data into or out of struct object_id. This
has the effect of making the corresponding oid* functions use
the_hash_algo as well.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
`git merge-recursive` does a three-way merge between user-specified trees
base, head, and remote. Since the user is allowed to specify head, we can
not necesarily assume that head == HEAD.
Modify index_has_changes() to take an extra argument specifying the tree
to compare against. If NULL, it will compare to HEAD. We then use this
from merge-recursive to make sure we compare to the user-specified head.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Modify index_has_changes() to take a struct istate* instead of just
operating on the_index. This is only a partial conversion, though,
because we call do_diff_cache() which implicitly assumes work is to be
done on the_index. Ongoing work is being done elsewhere to do the
remainder of the conversion, and thus is not duplicated here. Instead,
a simple check is put in place until that work is complete.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add an option (controlled by an environment variable) perform extra
validations on mem_pool allocated cache entries. When set:
1) Invalidate cache_entry memory when discarding cache_entry.
2) When discarding index_state struct, verify that all cache_entries
were allocated from expected mem_pool.
3) When discarding mem_pools, invalidate mem_pool memory.
This should provide extra checks that mem_pools and their allocated
cache_entries are being used as expected.
Signed-off-by: Jameson Miller <jamill@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When reading large indexes from disk, a portion of the time is
dominated in malloc() calls. This can be mitigated by allocating a
large block of memory and manage it ourselves via memory pools.
This change moves the cache entry allocation to be on top of memory
pools.
Design:
The index_state struct will gain a notion of an associated memory_pool
from which cache_entries will be allocated from. When reading in the
index from disk, we have information on the number of entries and
their size, which can guide us in deciding how large our initial
memory allocation should be. When an index is discarded, the
associated memory_pool will be discarded as well - so the lifetime of
a cache_entry is tied to the lifetime of the index_state that it was
allocated for.
In the case of a Split Index, the following rules are followed. 1st,
some terminology is defined:
Terminology:
- 'the_index': represents the logical view of the index
- 'split_index': represents the "base" cache entries. Read from the
split index file.
'the_index' can reference a single split_index, as well as
cache_entries from the split_index. `the_index` will be discarded
before the `split_index` is. This means that when we are allocating
cache_entries in the presence of a split index, we need to allocate
the entries from the `split_index`'s memory pool. This allows us to
follow the pattern that `the_index` can reference cache_entries from
the `split_index`, and that the cache_entries will not be freed while
they are still being referenced.
Managing transient cache_entry structs:
Cache entries are usually allocated for an index, but this is not always
the case. Cache entries are sometimes allocated because this is the
type that the existing checkout_entry function works with. Because of
this, the existing code needs to handle cache entries associated with an
index / memory pool, and those that only exist transiently. Several
strategies were contemplated around how to handle this:
Chosen approach:
An extra field was added to the cache_entry type to track whether the
cache_entry was allocated from a memory pool or not. This is currently
an int field, as there are no more available bits in the existing
ce_flags bit field. If / when more bits are needed, this new field can
be turned into a proper bit field.
Alternatives:
1) Do not include any information about how the cache_entry was
allocated. Calling code would be responsible for tracking whether the
cache_entry needed to be freed or not.
Pro: No extra memory overhead to track this state
Con: Extra complexity in callers to handle this correctly.
The extra complexity and burden to not regress this behavior in the
future was more than we wanted.
2) cache_entry would gain knowledge about which mem_pool allocated it
Pro: Could (potentially) do extra logic to know when a mem_pool no
longer had references to any cache_entry
Con: cache_entry would grow heavier by a pointer, instead of int
We didn't see a tangible benefit to this approach
3) Do not add any extra information to a cache_entry, but when freeing a
cache entry, check if the memory exists in a region managed by existing
mem_pools.
Pro: No extra memory overhead to track state
Con: Extra computation is performed when freeing cache entries
We decided tracking and iterating over known memory pool regions was
less desirable than adding an extra field to track this stae.
Signed-off-by: Jameson Miller <jamill@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It has been observed that the time spent loading an index with a large
number of entries is partly dominated by malloc() calls. This change
is in preparation for using memory pools to reduce the number of
malloc() calls made to allocate cahce entries when loading an index.
Add an API to allocate and discard cache entries, abstracting the
details of managing the memory backing the cache entries. This commit
does actually change how memory is managed - this will be done in a
later commit in the series.
This change makes the distinction between cache entries that are
associated with an index and cache entries that are not associated with
an index. A main use of cache entries is with an index, and we can
optimize the memory management around this. We still have other cases
where a cache entry is not persisted with an index, and so we need to
handle the "transient" use case as well.
To keep the congnitive overhead of managing the cache entries, there
will only be a single discard function. This means there must be enough
information kept with the cache entry so that we know how to discard
them.
A summary of the main functions in the API is:
make_cache_entry: create cache entry for use in an index. Uses specified
parameters to populate cache_entry fields.
make_empty_cache_entry: Create an empty cache entry for use in an index.
Returns cache entry with empty fields.
make_transient_cache_entry: create cache entry that is not used in an
index. Uses specified parameters to populate
cache_entry fields.
make_empty_transient_cache_entry: create cache entry that is not used in
an index. Returns cache entry with
empty fields.
discard_cache_entry: A single function that knows how to discard a cache
entry regardless of how it was allocated.
Signed-off-by: Jameson Miller <jamill@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Refactor refresh_cache_entry() to work on a specific index, instead of
implicitly using the_index. This is in preparation for making the
make_cache_entry function apply to a specific index.
Signed-off-by: Jameson Miller <jamill@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The conversion to pass "the_repository" and then "a_repository"
throughout the object access API continues.
* sb/object-store-alloc:
alloc: allow arbitrary repositories for alloc functions
object: allow create_object to handle arbitrary repositories
object: allow grow_object_hash to handle arbitrary repositories
alloc: add repository argument to alloc_commit_index
alloc: add repository argument to alloc_report
alloc: add repository argument to alloc_object_node
alloc: add repository argument to alloc_tag_node
alloc: add repository argument to alloc_commit_node
alloc: add repository argument to alloc_tree_node
alloc: add repository argument to alloc_blob_node
object: add repository argument to grow_object_hash
object: add repository argument to create_object
repository: introduce parsed objects field
The list of commands with their various attributes were spread
across a few places in the build procedure, but it now is getting a
bit more consolidated to allow more automation.
* nd/command-list:
completion: allow to customize the completable command list
completion: add and use --list-cmds=alias
completion: add and use --list-cmds=nohelpers
Move declaration for alias.c to alias.h
completion: reduce completable command list
completion: let git provide the completable command list
command-list.txt: documentation and guide line
help: use command-list.txt for the source of guides
help: add "-a --verbose" to list all commands with synopsis
git: support --list-cmds=list-<category>
completion: implement and use --list-cmds=main,others
git --list-cmds: collect command list in a string_list
git.c: convert --list-* to --list-cmds=*
Remove common-cmds.h
help: use command-list.h for common command list
generate-cmds.sh: export all commands to command-list.h
generate-cmds.sh: factor out synopsis extract code
Conversion from uchar[20] to struct object_id continues.
* bc/object-id: (42 commits)
merge-one-file: compute empty blob object ID
add--interactive: compute the empty tree value
Update shell scripts to compute empty tree object ID
sha1_file: only expose empty object constants through git_hash_algo
dir: use the_hash_algo for empty blob object ID
sequencer: use the_hash_algo for empty tree object ID
cache-tree: use is_empty_tree_oid
sha1_file: convert cached object code to struct object_id
builtin/reset: convert use of EMPTY_TREE_SHA1_BIN
builtin/receive-pack: convert one use of EMPTY_TREE_SHA1_HEX
wt-status: convert two uses of EMPTY_TREE_SHA1_HEX
submodule: convert several uses of EMPTY_TREE_SHA1_HEX
sequencer: convert one use of EMPTY_TREE_SHA1_HEX
merge: convert empty tree constant to the_hash_algo
builtin/merge: switch tree functions to use object_id
builtin/am: convert uses of EMPTY_TREE_SHA1_BIN to the_hash_algo
sha1-file: add functions for hex empty tree and blob OIDs
builtin/receive-pack: avoid hard-coded constants for push certs
diff: specify abbreviation size in terms of the_hash_algo
upload-pack: replace use of several hard-coded constants
...
"git pack-objects" needs to allocate tons of "struct object_entry"
while doing its work, and shrinking its size helps the performance
quite a bit.
* nd/pack-objects-pack-struct:
ci: exercise the whole test suite with uncommon code in pack-objects
pack-objects: reorder members to shrink struct object_entry
pack-objects: shrink delta_size field in struct object_entry
pack-objects: shrink size field in struct object_entry
pack-objects: clarify the use of object_entry::size
pack-objects: don't check size when the object is bad
pack-objects: shrink z_delta_size field in struct object_entry
pack-objects: refer to delta objects by index instead of pointer
pack-objects: move in_pack out of struct object_entry
pack-objects: move in_pack_pos out of struct object_entry
pack-objects: use bitfield for object_entry::depth
pack-objects: use bitfield for object_entry::dfs_state
pack-objects: turn type and in_pack_type to bitfields
pack-objects: a bit of document about struct object_entry
read-cache.c: make $GIT_TEST_SPLIT_INDEX boolean
The codepath around object-info API has been taught to take the
repository object (which in turn tells the API which object store
the objects are to be located).
* sb/oid-object-info:
cache.h: allow oid_object_info to handle arbitrary repositories
packfile: add repository argument to cache_or_unpack_entry
packfile: add repository argument to unpack_entry
packfile: add repository argument to read_object
packfile: add repository argument to packed_object_info
packfile: add repository argument to packed_to_object_type
packfile: add repository argument to retry_bad_packed_offset
cache.h: add repository argument to oid_object_info
cache.h: add repository argument to oid_object_info_extended
* maint-2.16:
Git 2.16.4
Git 2.15.2
Git 2.14.4
Git 2.13.7
verify_path: disallow symlinks in .gitmodules
update-index: stat updated files earlier
verify_dotfile: mention case-insensitivity in comment
verify_path: drop clever fallthrough
skip_prefix: add case-insensitive variant
is_{hfs,ntfs}_dotgitmodules: add tests
is_ntfs_dotgit: match other .git files
is_hfs_dotgit: match other .git files
is_ntfs_dotgit: use a size_t for traversing string
submodule-config: verify submodule names as paths
* maint-2.15:
Git 2.15.2
Git 2.14.4
Git 2.13.7
verify_path: disallow symlinks in .gitmodules
update-index: stat updated files earlier
verify_dotfile: mention case-insensitivity in comment
verify_path: drop clever fallthrough
skip_prefix: add case-insensitive variant
is_{hfs,ntfs}_dotgitmodules: add tests
is_ntfs_dotgit: match other .git files
is_hfs_dotgit: match other .git files
is_ntfs_dotgit: use a size_t for traversing string
submodule-config: verify submodule names as paths
* maint-2.14:
Git 2.14.4
Git 2.13.7
verify_path: disallow symlinks in .gitmodules
update-index: stat updated files earlier
verify_dotfile: mention case-insensitivity in comment
verify_path: drop clever fallthrough
skip_prefix: add case-insensitive variant
is_{hfs,ntfs}_dotgitmodules: add tests
is_ntfs_dotgit: match other .git files
is_hfs_dotgit: match other .git files
is_ntfs_dotgit: use a size_t for traversing string
submodule-config: verify submodule names as paths
* maint-2.13:
Git 2.13.7
verify_path: disallow symlinks in .gitmodules
update-index: stat updated files earlier
verify_dotfile: mention case-insensitivity in comment
verify_path: drop clever fallthrough
skip_prefix: add case-insensitive variant
is_{hfs,ntfs}_dotgitmodules: add tests
is_ntfs_dotgit: match other .git files
is_hfs_dotgit: match other .git files
is_ntfs_dotgit: use a size_t for traversing string
submodule-config: verify submodule names as paths
There are a few reasons it's not a good idea to make
.gitmodules a symlink, including:
1. It won't be portable to systems without symlinks.
2. It may behave inconsistently, since Git may look at
this file in the index or a tree without bothering to
resolve any symbolic links. We don't do this _yet_, but
the config infrastructure is there and it's planned for
the future.
With some clever code, we could make (2) work. And some
people may not care about (1) if they only work on one
platform. But there are a few security reasons to simply
disallow it:
a. A symlinked .gitmodules file may circumvent any fsck
checks of the content.
b. Git may read and write from the on-disk file without
sanity checking the symlink target. So for example, if
you link ".gitmodules" to "../oops" and run "git
submodule add", we'll write to the file "oops" outside
the repository.
Again, both of those are problems that _could_ be solved
with sufficient code, but given the complications in (1) and
(2), we're better off just outlawing it explicitly.
Note the slightly tricky call to verify_path() in
update-index's update_one(). There we may not have a mode if
we're not updating from the filesystem (e.g., we might just
be removing the file). Passing "0" as the mode there works
fine; since it's not a symlink, we'll just skip the extra
checks.
Signed-off-by: Jeff King <peff@peff.net>
When we started to catch NTFS short names that clash with .git, we only
looked for GIT~1. This is sufficient because we only ever clone into an
empty directory, so .git is guaranteed to be the first subdirectory or
file in that directory.
However, even with a fresh clone, .gitmodules is *not* necessarily the
first file to be written that would want the NTFS short name GITMOD~1: a
malicious repository can add .gitmodul0000 and friends, which sorts
before `.gitmodules` and is therefore checked out *first*. For that
reason, we have to test not only for ~1 short names, but for others,
too.
It's hard to just adapt the existing checks in is_ntfs_dotgit(): since
Windows 2000 (i.e., in all Windows versions still supported by Git),
NTFS short names are only generated in the <prefix>~<number> form up to
number 4. After that, a *different* prefix is used, calculated from the
long file name using an undocumented, but stable algorithm.
For example, the short name of .gitmodules would be GITMOD~1, but if it
is taken, and all of ~2, ~3 and ~4 are taken, too, the short name
GI7EBA~1 will be used. From there, collisions are handled by
incrementing the number, shortening the prefix as needed (until ~9999999
is reached, in which case NTFS will not allow the file to be created).
We'd also want to handle .gitignore and .gitattributes, which suffer
from a similar problem, using the fall-back short names GI250A~1 and
GI7D29~1, respectively.
To accommodate for that, we could reimplement the hashing algorithm, but
it is just safer and simpler to provide the known prefixes. This
algorithm has been reverse-engineered and described at
https://usn.pw/blog/gen/2015/06/09/filenames/, which is defunct but
still available via https://web.archive.org/.
These can be recomputed by running the following Perl script:
-- snip --
use warnings;
use strict;
sub compute_short_name_hash ($) {
my $checksum = 0;
foreach (split('', $_[0])) {
$checksum = ($checksum * 0x25 + ord($_)) & 0xffff;
}
$checksum = ($checksum * 314159269) & 0xffffffff;
$checksum = 1 + (~$checksum & 0x7fffffff) if ($checksum & 0x80000000);
$checksum -= (($checksum * 1152921497) >> 60) * 1000000007;
return scalar reverse sprintf("%x", $checksum & 0xffff);
}
print compute_short_name_hash($ARGV[0]);
-- snap --
E.g., running that with the argument ".gitignore" will
result in "250a" (which then becomes "gi250a" in the code).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jeff King <peff@peff.net>
This conversion was done without the #define trick used in the earlier
series refactoring to have better repository access, because this function
is easy to review, as all lines are converted and it has only one caller.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This should make these functions easier to find and cache.h less
overwhelming to read.
In particular, this moves:
- read_object_file
- oid_object_info
- write_object_file
As a result, most of the codebase needs to #include object-store.h.
In this patch the #include is only added to files that would fail to
compile otherwise. It would be better to #include wherever
identifiers from the header are used. That can happen later
when we have better tooling for it.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We have to convert all of the alloc functions at once, because alloc_report
uses a funky macro for reporting. It is better for the sake of mechanical
conversion to convert multiple functions at once rather than changing the
structure of the reporting function.
We record all memory allocation in alloc.c, and free them in
clear_alloc_state, which is called for all repositories except
the_repository.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The current document mentions OBJ_* constants without their actual
values. A git developer would know these are from cache.h but that's
not very friendly to a person who wants to read this file to implement
a pack file parser.
Similarly, the deltified representation is not documented at all (the
"document" is basically patch-delta.c). Translate that C code to
English with a bit more about what ofs-delta and ref-delta mean.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is a small mechanical change; it doesn't change the
implementation to handle repositories other than the_repository yet.
Use a macro to catch callers passing a repository other than
the_repository at compile time.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is a small mechanical change; it doesn't change the
implementation to handle repositories other than the_repository yet.
Use a macro to catch callers passing a repository other than
the_repository at compile time.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is a small mechanical change; it doesn't change the
implementation to handle repositories other than the_repository yet.
Use a macro to catch callers passing a repository other than
the_repository at compile time.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is a small mechanical change; it doesn't change the
implementation to handle repositories other than the_repository yet.
Use a macro to catch callers passing a repository other than
the_repository at compile time.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is a small mechanical change; it doesn't change the
implementation to handle repositories other than the_repository yet.
Use a macro to catch callers passing a repository other than
the_repository at compile time.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is a small mechanical change; it doesn't change the
implementation to handle repositories other than the_repository yet.
Use a macro to catch callers passing a repository other than
the_repository at compile time.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is a small mechanical change; it doesn't change the
implementation to handle repositories other than the_repository yet.
Use a macro to catch callers passing a repository other than
the_repository at compile time.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The effort to pass the repository in-core structure throughout the
API continues. This round deals with the code that implements the
refs/replace/ mechanism.
* sb/object-store-replace:
replace-object: allow lookup_replace_object to handle arbitrary repositories
replace-object: allow do_lookup_replace_object to handle arbitrary repositories
replace-object: allow prepare_replace_object to handle arbitrary repositories
refs: allow for_each_replace_ref to handle arbitrary repositories
refs: store the main ref store inside the repository struct
replace-object: add repository argument to lookup_replace_object
replace-object: add repository argument to do_lookup_replace_object
replace-object: add repository argument to prepare_replace_object
refs: add repository argument to for_each_replace_ref
refs: add repository argument to get_main_ref_store
replace-object: check_replace_refs is safe in multi repo environment
replace-object: eliminate replace objects prepared flag
object-store: move lookup_replace_object to replace-object.h
replace-object: move replace_map to object store
replace_object: use oidmap
Precompute and store information necessary for ancestry traversal
in a separate file to optimize graph walking.
* ds/commit-graph:
commit-graph: implement "--append" option
commit-graph: build graph from starting commits
commit-graph: read only from specific pack-indexes
commit: integrate commit graph with commit parsing
commit-graph: close under reachability
commit-graph: add core.commitGraph setting
commit-graph: implement git commit-graph read
commit-graph: implement git-commit-graph write
commit-graph: implement write_commit_graph()
commit-graph: create git-commit-graph builtin
graph: add commit graph design document
commit-graph: add format document
csum-file: refactor finalize_hashfile() method
csum-file: rename hashclose() to finalize_hashfile()
A build-time option has been added to allow Git to be told to refer
to its associated files relative to the main binary, in the same
way that has been possible on Windows for quite some time, for
Linux, BSDs and Darwin.
* dj/runtime-prefix:
Makefile: quote $INSTLIBDIR when passing it to sed
Makefile: remove unused @@PERLLIBDIR@@ substitution variable
mingw/msvc: use the new-style RUNTIME_PREFIX helper
exec_cmd: provide a new-style RUNTIME_PREFIX helper for Windows
exec_cmd: RUNTIME_PREFIX on some POSIX systems
Makefile: add Perl runtime prefix support
Makefile: generate Perl header from template file
There really isn't any case in which we want to expose the constants for
empty trees and blobs outside of using the hash algorithm abstraction.
Make these constants static and stop exposing the defines in cache.h.
Remove the constants which are no longer in use.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Oftentimes, we'll want to refer to an empty tree or empty blob by its
hex name without having to call oid_to_hex or explicitly refer to
the_hash_algo. Add helper functions that format these values into
static buffers and return them for easy use.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Adjust struct index_state to use struct object_id instead of unsigned
char [20].
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert the various functions for freshening objects and
has_loose_object_nonlocal to use struct object_id.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The sha1 member in struct pack_entry is unused except for one instance
in which we store a value in it. Since nobody ever reads this value,
don't bother to compute it and remove the member from struct pack_entry.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The tree member of struct object_context is unused except in one place
where we write to it. Since there are no users of this member, remove
it.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In various places throughout the codebase, we need to read data into a
struct object_id from a pack or other unsigned char buffer. Add an
inline function that does this based on the current hash algorithm in
use, and use it in several places.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This involves also adapting oid_object_info_extended and a some
internal functions that are used to implement these. It all has to
happen in one patch, because of a single recursive chain of calls visits
all these functions.
oid_object_info_extended is also used in partial clones, which allow
fetching missing objects. As this series will not add the repository
struct to the transport code and fetch_object(), add a TODO note and
omit fetching if a user tries to use a partial clone in a repository
other than the_repository.
Among the functions modified to handle arbitrary repositories,
unpack_entry() is one of them. Note that it still references the globals
"delta_base_cache" and "delta_base_cached", but those are safe to be
referenced (the former is indexed partly by "struct packed_git *", which
is repo-specific, and the latter is only used to limit the size of the
former as an optimization).
Helped-by: Brandon Williams <bmwill@google.com>
Helped-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Stefan Beller <sbeller@google.com>
Reviewed-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a repository argument to allow the callers of oid_object_info
to be more specific about which repository to handle. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.
As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.
Signed-off-by: Stefan Beller <sbeller@google.com>
Reviewed-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a repository argument to allow oid_object_info_extended callers
to be more specific about which repository to act on. This is a small
mechanical change; it doesn't change the implementation to handle
repositories other than the_repository yet.
Signed-off-by: Stefan Beller <sbeller@google.com>
Reviewed-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some codepaths, including the refs API, get and keep relative
paths, that go out of sync when the process does chdir(2). The
chdir-notify API is introduced to let these codepaths adjust these
cached paths to the new current directory.
* jk/relative-directory-fix:
refs: use chdir_notify to update cached relative paths
set_work_tree: use chdir_notify
add chdir-notify API
trace.c: export trace_setup_key
set_git_dir: die when setenv() fails
An extra field type_valid is added to carry the equivalent of OBJ_BAD
in the original "type" field. in_pack_type always contains a valid
type so we only need 3 bits for it.
A note about accepting OBJ_NONE as "valid" type. The function
read_object_list_from_stdin() can pass this value [1] and it
eventually calls create_object_entry() where current code skip setting
"type" field if the incoming type is zero. This does not have any bad
side effects because "type" field should be memset()'d anyway.
But since we also need to set type_valid now, skipping oe_set_type()
leaves type_valid zero/false, which will make oe_type() return
OBJ_BAD, not OBJ_NONE anymore. Apparently we do care about OBJ_NONE in
prepare_pack(). This switch from OBJ_NONE to OBJ_BAD may trigger
fatal: unable to get type of object ...
Accepting OBJ_NONE [2] does sound wrong, but this is how it is has
been for a very long time and I haven't time to dig in further.
[1] See 5c49c11686 (pack-objects: better check_object() performances -
2007-04-16)
[2] 21666f1aae (convert object type handling from a string to a number
- 2007-02-26)
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
lookup_replace_object is a low-level function that most users of the
object store do not need to use directly.
Move it to replace-object.h to avoid a dependency loop in an upcoming
change to its inline definition that will make use of repository.h.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Enable Git to resolve its own binary location using a variety of
OS-specific and generic methods, including:
- procfs via "/proc/self/exe" (Linux)
- _NSGetExecutablePath (Darwin)
- KERN_PROC_PATHNAME sysctl on BSDs.
- argv0, if absolute (all, including Windows).
This is used to enable RUNTIME_PREFIX support for non-Windows systems,
notably Linux and Darwin. When configured with RUNTIME_PREFIX, Git will
do a best-effort resolution of its executable path and automatically use
this as its "exec_path" for relative helper and data lookups, unless
explicitly overridden.
Small incidental formatting cleanup of "exec_cmd.c".
Signed-off-by: Dan Jacques <dnj@google.com>
Thanks-to: Robbie Iannucci <iannucci@google.com>
Thanks-to: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Refactoring the internal global data structure to make it possible
to open multiple repositories, work with and then close them.
Rerolled by Duy on top of a separate preliminary clean-up topic.
The resulting structure of the topics looked very sensible.
* sb/object-store: (27 commits)
sha1_file: allow sha1_loose_object_info to handle arbitrary repositories
sha1_file: allow map_sha1_file to handle arbitrary repositories
sha1_file: allow map_sha1_file_1 to handle arbitrary repositories
sha1_file: allow open_sha1_file to handle arbitrary repositories
sha1_file: allow stat_sha1_file to handle arbitrary repositories
sha1_file: allow sha1_file_name to handle arbitrary repositories
sha1_file: add repository argument to sha1_loose_object_info
sha1_file: add repository argument to map_sha1_file
sha1_file: add repository argument to map_sha1_file_1
sha1_file: add repository argument to open_sha1_file
sha1_file: add repository argument to stat_sha1_file
sha1_file: add repository argument to sha1_file_name
sha1_file: allow prepare_alt_odb to handle arbitrary repositories
sha1_file: allow link_alt_odb_entries to handle arbitrary repositories
sha1_file: add repository argument to prepare_alt_odb
sha1_file: add repository argument to link_alt_odb_entries
sha1_file: add repository argument to read_info_alternates
sha1_file: add repository argument to link_alt_odb_entry
sha1_file: add raw_object_store argument to alt_odb_usable
pack: move approximate object count to object store
...
The commit graph feature is controlled by the new core.commitGraph config
setting. This defaults to 0, so the feature is opt-in.
The intention of core.commitGraph is that a user can always stop checking
for or parsing commit graph files if core.commitGraph=0.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Code clean-up for the "repository" abstraction.
* nd/remove-ignore-env-field:
repository.h: add comment and clarify repo_set_gitdir
repository: delete ignore_env member
sha1_file.c: move delayed getenv(altdb) back to setup_git_env()
repository.c: delete dead functions
repository.c: move env-related setup code back to environment.c
repository: initialize the_repository in main()
Conversion from uchar[20] to struct object_id continues.
* bc/object-id: (36 commits)
convert: convert to struct object_id
sha1_file: introduce a constant for max header length
Convert lookup_replace_object to struct object_id
sha1_file: convert read_sha1_file to struct object_id
sha1_file: convert read_object_with_reference to object_id
tree-walk: convert tree entry functions to object_id
streaming: convert istream internals to struct object_id
tree-walk: convert get_tree_entry_follow_symlinks internals to object_id
builtin/notes: convert static functions to object_id
builtin/fmt-merge-msg: convert remaining code to object_id
sha1_file: convert sha1_object_info* to object_id
Convert remaining callers of sha1_object_info_extended to object_id
packfile: convert unpack_entry to struct object_id
sha1_file: convert retry_bad_packed_offset to struct object_id
sha1_file: convert assert_sha1_type to object_id
builtin/mktree: convert to struct object_id
streaming: convert open_istream to use struct object_id
sha1_file: convert check_sha1_signature to struct object_id
sha1_file: convert read_loose_object to use struct object_id
builtin/index-pack: convert struct ref_delta_entry to object_id
...
A "git fetch" from a repository with insane number of refs into a
repository that is already up-to-date still wasted too many cycles
making many lstat(2) calls to see if these objects at the tips
exist as loose objects locally. These lstat(2) calls are optimized
away by enumerating all loose objects beforehand.
It is unknown if the new strategy negatively affects existing use
cases, fetching into a repository with many loose objects from a
repository with small number of refs.
* ti/fetch-everything-local-optim:
fetch-pack.c: use oidset to check existence of loose object
The set_git_dir() function returns an error if setenv()
fails, but there are zero callers who pay attention to this
return value. If this ever were to happen, it could cause
confusing results, as sub-processes would see a potentially
stale GIT_DIR (e.g., if it is relative and we chdir()-ed to
the root of the working tree).
We _could_ try to fix each caller, but there's really
nothing useful to do after this failure except die. Let's
just lump setenv() failure into the same category as malloc
failure: things that should never happen and cause us to
abort catastrophically.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a repository argument to allow map_sha1_file callers to be more
specific about which repository to handle. This is a small mechanical
change; it doesn't change the implementation to handle repositories
other than the_repository yet.
As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.
While at it, move the declaration to object-store.h, where it should
be easier to find.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a repository argument to allow sha1_file_name callers to be more
specific about which repository to handle. This is a small mechanical
change; it doesn't change the implementation to handle repositories
other than the_repository yet.
As with the previous commits, use a macro to catch callers passing a
repository other than the_repository at compile time.
While at it, move the declaration to object-store.h, where it should
be easier to find.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a process with multiple repositories open, packfile accessors
should be associated to a single repository and not shared globally.
Move packed_git and packed_git_mru into the_repository and adjust
callers to reflect this.
[nd: while at there, wrap access to these two fields in get_packed_git()
and get_packed_git_mru(). This allows us to lazily initialize these
fields without caller doing that explicitly]
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Migrate the struct alternate_object_database and all its related
functions to the object store as these functions are easier found in
that header. The migration is just a verbatim copy, no need to
include the object store header at any C file, because cache.h includes
repository.h which in turn includes the object-store.h
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The split-index mode had a few corner case bugs fixed.
* tg/split-index-fixes:
travis: run tests with GIT_TEST_SPLIT_INDEX
split-index: don't write cache tree with null oid entries
read-cache: fix reading the shared index for other repos
Internal API clean-up to allow write_locked_index() optionally skip
writing the in-core index when it is not modified.
* ma/skip-writing-unchanged-index:
write_locked_index(): add flag to avoid writing unchanged index
When fetching from a repository with large number of refs, because to
check existence of each refs in local repository to packed and loose
objects, 'git fetch' ends up doing a lot of lstat(2) to non-existing
loose form, which makes it slow.
Instead of making as many lstat(2) calls as the refs the remote side
advertised to see if these objects exist in the loose form, first
enumerate all the existing loose objects in hashmap beforehand and use
it to check existence of them if the number of refs is larger than the
number of loose objects.
With this patch, the number of lstat(2) calls in `git fetch` is reduced
from 411412 to 13794 for chromium repository, it has more than 480000
remote refs.
I took time stat of `git fetch` when fetch-pack happens for chromium
repository 3 times on linux with SSD.
* with this patch
8.105s
8.309s
7.640s
avg: 8.018s
* master
12.287s
11.175s
12.227s
avg: 11.896s
On my MacBook Air which has slower lstat(2).
* with this patch
14.501s
* master
1m16.027s
`git fetch` on slow disk will be improved largely.
Signed-off-by: Takuto Ikuta <tikuta@chromium.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert both the argument and the return value to be pointers to struct
object_id. Update the callers and their internals to deal with the new
type. Remove several temporaries which are no longer needed.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert read_sha1_file to take a pointer to struct object_id and rename
it read_object_file. Do the same for read_sha1_file_extended.
Convert one use in grep.c to use the new function without any other code
change, since the pointer being passed is a void pointer that is already
initialized with a pointer to struct object_id. Update the declaration
and definitions of the modified functions, and apply the following
semantic patch to convert the remaining callers:
@@
expression E1, E2, E3;
@@
- read_sha1_file(E1.hash, E2, E3)
+ read_object_file(&E1, E2, E3)
@@
expression E1, E2, E3;
@@
- read_sha1_file(E1->hash, E2, E3)
+ read_object_file(E1, E2, E3)
@@
expression E1, E2, E3, E4;
@@
- read_sha1_file_extended(E1.hash, E2, E3, E4)
+ read_object_file_extended(&E1, E2, E3, E4)
@@
expression E1, E2, E3, E4;
@@
- read_sha1_file_extended(E1->hash, E2, E3, E4)
+ read_object_file_extended(E1, E2, E3, E4)
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert read_object_with_reference to take pointers to struct object_id.
Update the internals of the function accordingly.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert sha1_object_info and sha1_object_info_extended to take pointers
to struct object_id and rename them to use "oid" instead of "sha1" in
their names. Update the declaration and definition and apply the
following semantic patch, plus the standard object_id transforms:
@@
expression E1, E2;
@@
- sha1_object_info(E1.hash, E2)
+ oid_object_info(&E1, E2)
@@
expression E1, E2;
@@
- sha1_object_info(E1->hash, E2)
+ oid_object_info(E1, E2)
@@
expression E1, E2, E3;
@@
- sha1_object_info_extended(E1.hash, E2, E3)
+ oid_object_info_extended(&E1, E2, E3)
@@
expression E1, E2, E3;
@@
- sha1_object_info_extended(E1->hash, E2, E3)
+ oid_object_info_extended(E1, E2, E3)
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert this function to take a pointer to struct object_id and rename
it to assert_oid_type.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert this function to take a pointer to struct object_id and rename
it check_object_signature. Introduce temporaries to convert the return
values of lookup_replace_object and lookup_replace_object_extended into
struct object_id.
The temporaries are needed because in order to convert
lookup_replace_object, open_istream needs to be converted, and
open_istream needs check_sha1_signature to be converted, causing a loop
of dependencies. The temporaries will be removed in a future patch.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert find_unique_abbrev and find_unique_abbrev_r to each take a
pointer to struct object_id.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It does not make sense that generic repository code contains handling
of environment variables, which are specific for the main repository
only. Refactor repo_set_gitdir() function to take $GIT_DIR and
optionally _all_ other customizable paths. These optional paths can be
NULL and will be calculated according to the default directory layout.
Note that some dead functions are left behind to reduce diff
noise. They will be deleted in the next patch.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We have several callers like
if (active_cache_changed && write_locked_index(...))
handle_error();
rollback_lock_file(...);
where the final rollback is needed because "!active_cache_changed"
shortcuts the if-expression. There are also a few variants of this,
including some if-else constructs that make it more clear when the
explicit rollback is really needed.
Teach `write_locked_index()` to take a new flag SKIP_IF_UNCHANGED and
simplify the callers. Leave the most complicated of the callers (in
builtin/update-index.c) unchanged. Rewriting it to use this new flag
would end up duplicating logic.
We could have made the new flag behave the other way round
("FORCE_WRITE"), but that could break existing users behind their backs.
Let's take the more conservative approach. We can still migrate existing
callers to use our new flag. Later we might even be able to flip the
default, possibly without entirely ignoring the risk to in-flight or
out-of-tree topics.
Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Rename C++ keyword in order to bring the codebase closer to being able
to be compiled with a C++ compiler.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
More abstraction of hash function from the codepath.
* bc/hash-algo:
hash: update obsolete reference to SHA1_HEADER
bulk-checkin: abstract SHA-1 usage
csum-file: abstract uses of SHA-1
csum-file: rename sha1file to hashfile
read-cache: abstract away uses of SHA-1
pack-write: switch various SHA-1 values to abstract forms
pack-check: convert various uses of SHA-1 to abstract forms
fast-import: switch various uses of SHA-1 to the_hash_algo
sha1_file: switch uses of SHA-1 to the_hash_algo
builtin/unpack-objects: switch uses of SHA-1 to the_hash_algo
builtin/index-pack: improve hash function abstraction
hash: create union for hash context allocation
hash: move SHA-1 macros to hash.h
Rename C++ keyword in order to bring the codebase closer to being able
to be compiled with a C++ compiler.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The split-index mode had a few corner case bugs fixed.
* tg/split-index-fixes:
travis: run tests with GIT_TEST_SPLIT_INDEX
split-index: don't write cache tree with null oid entries
read-cache: fix reading the shared index for other repos
Retire mru API as it does not give enough abstraction over
underlying list API to be worth it.
* gs/retire-mru:
mru: Replace mru.[ch] with list.h implementation
The machinery to clone & fetch, which in turn involves packing and
unpacking objects, have been told how to omit certain objects using
the filtering mechanism introduced by the jh/object-filtering
topic, and also mark the resulting pack as a promisor pack to
tolerate missing objects, taking advantage of the mechanism
introduced by the jh/fsck-promisors topic.
* jh/partial-clone:
t5616: test bulk prefetch after partial fetch
fetch: inherit filter-spec from partial clone
t5616: end-to-end tests for partial clone
fetch-pack: restore save_commit_buffer after use
unpack-trees: batch fetching of missing blobs
clone: partial clone
partial-clone: define partial clone settings in config
fetch: support filters
fetch: refactor calculation of remote list
fetch-pack: test support excluding large blobs
fetch-pack: add --no-filter
fetch-pack, index-pack, transport: partial clone
upload-pack: add object filtering for partial clone
In preparation for implementing narrow/partial clone, the machinery
for checking object connectivity used by gc and fsck has been
taught that a missing object is OK when it is referenced by a
packfile specially marked as coming from trusted repository that
promises to make them available on-demand and lazily.
* jh/fsck-promisors:
gc: do not repack promisor packfiles
rev-list: support termination at promisor objects
sha1_file: support lazily fetching missing objects
introduce fetch-object: fetch one promisor object
index-pack: refactor writing of .keep files
fsck: support promisor objects as CLI argument
fsck: support referenced promisor objects
fsck: support refs pointing to promisor objects
fsck: introduce partialclone extension
extension.partialclone: introduce partial clone extension
Most of the other code dealing with SHA-1 and other hashes is located in
hash.h, which is in turn loaded by cache.h. Move the SHA-1 macros to
hash.h as well, so we can use them in additional hash-related items in
the future.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This function was already converted to use struct object_id earlier.
Signed-off-by: Patryk Obara <patryk.obara@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert the definition and declaration of force_object_loose to
struct object_id and adjust usage of this function.
Signed-off-by: Patryk Obara <patryk.obara@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert the definition and declaration of write_sha1_file to
struct object_id and adjust usage of this function.
This commit also converts static function write_sha1_file_prepare, as it
is closely related.
Rename these functions to write_object_file and
write_object_file_prepare respectively.
Replace sha1_to_hex, hashcpy and hashclr with their oid equivalents
wherever possible.
Signed-off-by: Patryk Obara <patryk.obara@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As long as GIT_SHA1_RAWSZ is equal to GIT_MAX_RAWSZ there's no problem,
but when new hashing algorithm will be in place this memset will clear
only 20-byte prefix of hash buffer.
Alternatively, hashclr implementation could be adjusted, but this
function is almost removed from codebase already. Separate
implementation of oidclr prevents potential buffer overrun in case
someone incorrectly used hashclr on object_id in future.
Signed-off-by: Patryk Obara <patryk.obara@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert the declaration and definition of hash_sha1_file to use
struct object_id and adjust all function calls.
Rename this function to hash_object_file.
Signed-off-by: Patryk Obara <patryk.obara@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert the declaration of struct sha1_stat. Adjust all usages of this
struct and replace hash{clr,cmp,cpy} with oid{clr,cmp,cpy} wherever
possible. Rename it to struct oid_stat.
Rename static function load_sha1_stat to load_oid_stat.
Remove macro EMPTY_BLOB_SHA1_BIN, as it's no longer used.
Signed-off-by: Patryk Obara <patryk.obara@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Convert the declaration and definition of pretend_sha1_file to use
struct object_id and adjust all usages of this function. Rename it to
pretend_object_file.
Signed-off-by: Patryk Obara <patryk.obara@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Replace the custom calls to mru.[ch] with calls to list.h. This patch is
the final step in removing the mru API completely and inlining the logic.
This patch leads to significant code reduction and the mru API hence, is
not a useful abstraction anymore.
Signed-off-by: Gargi Sharma <gs051095@gmail.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In a96d3cc3f6 ("cache-tree: reject entries with null sha1", 2017-04-21)
we made sure that broken cache entries do not get propagated to new
trees. Part of that was making sure not to re-use an existing cache
tree that includes a null oid.
It did so by dropping the cache tree in 'do_write_index()' if one of
the entries contains a null oid. In split index mode however, there
are two invocations to 'do_write_index()', one for the shared index
and one for the split index. The cache tree is only written once, to
the split index.
As we only loop through the elements that are effectively being
written by the current invocation, that may not include the entry with
a null oid in the split index (when it is already written to the
shared index), where we write the cache tree. Therefore in split
index mode we may still end up writing the cache tree, even though
there is an entry with a null oid in the index.
Fix this by checking for null oids in prepare_to_write_split_index,
where we loop the entries of the shared index as well as the entries for
the split index.
This fixes t7009 with GIT_TEST_SPLIT_INDEX. Also add a new test that's
more specifically showing the problem.
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
read_index_from() takes a path argument for the location of the index
file. For reading the shared index in split index mode however it just
ignores that path argument, and reads it from the gitdir of the current
repository.
This works as long as an index in the_repository is read. Once that
changes, such as when we read the index of a submodule, or of a
different working tree than the current one, the gitdir of
the_repository will no longer contain the appropriate shared index,
and git will fail to read it.
For example t3007-ls-files-recurse-submodules.sh was broken with
GIT_TEST_SPLIT_INDEX set in 188dce131f ("ls-files: use repository
object", 2017-06-22), and t7814-grep-recurse-submodules.sh was also
broken in a similar manner, probably by introducing struct repository
there, although I didn't track down the exact commit for that.
be489d02d2 ("revision.c: --indexed-objects add objects from all
worktrees", 2017-08-23) breaks with split index mode in a similar
manner, not erroring out when it can't read the index, but instead
carrying on with pruning, without taking the index of the worktree into
account.
Fix this by passing an additional gitdir parameter to read_index_from,
to indicate where it should look for and read the shared index from.
read_cache_from() defaults to using the gitdir of the_repository. As it
is mostly a convenience macro, having to pass get_git_dir() for every
call seems overkill, and if necessary users can have more control by
using read_index_from().
Helped-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Using a static buffer in sha1_file_name() is error prone
and the performance improvements it gives are not needed
in many of the callers.
So let's get rid of this static buffer and, if necessary
or helpful, let's use one in the caller.
Suggested-by: Jeff Hostetler <git@jeffhostetler.com>
Helped-by: Kevin Daudt <me@ikke.info>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* ew/empty-merge-with-dirty-index-maint:
merge-recursive: avoid incorporating uncommitted changes in a merge
move index_has_changes() from builtin/am.c to merge.c for reuse
t6044: recursive can silently incorporate dirty changes in a merge
index_has_changes() is a function we want to reuse outside of just am,
making it also available for merge-recursive and merge-ort.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Git shows a message to tell the user that it is waiting for the
user to finish editing when spawning an editor, in case the editor
opens to a hidden window or somewhere obscure and the user gets
lost.
* ls/editor-waiting-message:
launch_editor(): indicate that Git waits for user input
refactor "dumb" terminal determination
Ancient part of codebase still shows dots after an abbreviated
object name just to show that it is not a full object name, but
these ellipses are confusing to people who newly discovered Git
who are used to seeing abbreviated object names and find them
confusing with the range syntax.
* ar/unconfuse-three-dots:
t2020: test variations that matter
t4013: test new output from diff --abbrev --raw
diff: diff_aligned_abbrev: remove ellipsis after abbreviated SHA-1 value
t4013: prepare for upcoming "diff --raw --abbrev" output format change
checkout: describe_detached_head: remove ellipsis after committish
print_sha1_ellipsis: introduce helper
Documentation: user-manual: limit usage of ellipsis
Documentation: revisions: fix typo: "three dot" ---> "three-dot" (in line with "two-dot").
An infrastructure to define what hash function is used in Git is
introduced, and an effort to plumb that throughout various
codepaths has been started.
* bc/hash-algo:
repository: fix a sparse 'using integer as NULL pointer' warning
Switch empty tree and blob lookups to use hash abstraction
Integrate hash algorithm support with repo setup
Add structure representing hash algorithm
setup: expose enumerated repo info
Create get and set routines for "partial clone" config settings.
These will be used in a future commit by clone and fetch to
remember the promisor remote and the default filter-spec.
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach sha1_file to fetch objects from the remote configured in
extensions.partialclone whenever an object is requested but missing.
The fetching of objects can be suppressed through a global variable.
This is used by fsck and index-pack.
However, by default, such fetching is not suppressed. This is meant as a
temporary measure to ensure that all Git commands work in such a
situation. Future patches will update some commands to either tolerate
missing objects (without fetching them) or be more efficient in fetching
them.
In order to determine the code changes in sha1_file.c necessary, I
investigated the following:
(1) functions in sha1_file.c that take in a hash, without the user
regarding how the object is stored (loose or packed)
(2) functions in packfile.c (because I need to check callers that know
about the loose/packed distinction and operate on both differently,
and ensure that they can handle the concept of objects that are
neither loose nor packed)
(1) is handled by the modification to sha1_object_info_extended().
For (2), I looked at for_each_packed_object and others. For
for_each_packed_object, the callers either already work or are fixed in
this patch:
- reachable - only to find recent objects
- builtin/fsck - already knows about missing objects
- builtin/cat-file - warning message added in this commit
Callers of the other functions do not need to be changed:
- parse_pack_index
- http - indirectly from http_get_info_packs
- find_pack_entry_one
- this searches a single pack that is provided as an argument; the
caller already knows (through other means) that the sought object
is in a specific pack
- find_sha1_pack
- fast-import - appears to be an optimization to not store a file if
it is already in a pack
- http-walker - to search through a struct alt_base
- http-push - to search through remote packs
- has_sha1_pack
- builtin/fsck - already knows about promisor objects
- builtin/count-objects - informational purposes only (check if loose
object is also packed)
- builtin/prune-packed - check if object to be pruned is packed (if
not, don't prune it)
- revision - used to exclude packed objects if requested by user
- diff - just for optimization
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
A new mechanism to upgrade the wire protocol in place is proposed
and demonstrated that it works with the older versions of Git
without harming them.
* bw/protocol-v1:
Documentation: document Extra Parameters
ssh: introduce a 'simple' ssh variant
i5700: add interop test for protocol transition
http: tell server that the client understands v1
connect: tell server that the client understands v1
connect: teach client to recognize v1 server response
upload-pack, receive-pack: introduce protocol version 1
daemon: recognize hidden request arguments
protocol: introduce protocol extension mechanisms
pkt-line: add packet_write function
connect: in ref advertisement, shallows are last
Currently, Git does not support repos with very large numbers of objects
or repos that wish to minimize manipulation of certain blobs (for
example, because they are very large) very well, even if the user
operates mostly on part of the repo, because Git is designed on the
assumption that every referenced object is available somewhere in the
repo storage. In such an arrangement, the full set of objects is usually
available in remote storage, ready to be lazily downloaded.
Teach fsck about the new state of affairs. In this commit, teach fsck
that missing promisor objects referenced from the reflog are not an
error case; in future commits, fsck will be taught about other cases.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce new repository extension option:
`extensions.partialclone`
See the update to Documentation/technical/repository-version.txt
in this patch for more information.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Move the code to detect "dumb" terminals into a single location. This
avoids duplicating the terminal detection code yet again in a subsequent
commit.
Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Introduce a helper print_sha1_ellipsis() that pays attention to the
GIT_PRINT_SHA1_ELLIPSIS environment variable, and prepare the tests to
unconditionally set it for the test pieces that will be broken once the code
stops showing the extra dots by default.
The removal of these dots is merely a plan at this step and has not happened
yet but soon will.
Document GIT_PRINT_SHA1_ELLIPSIS.
Signed-off-by: Ann T Ropea <bedhanger@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git add --renormalize ." is a new and safer way to record the fact
that you are correcting the end-of-line convention and other
"convert_to_git()" glitches in the in-repository data.
* tb/add-renormalize:
add: introduce "--renormalize"
Various fixes to bp/fsmonitor topic.
* av/fsmonitor:
fsmonitor: simplify determining the git worktree under Windows
fsmonitor: store fsmonitor bitmap before splitting index
fsmonitor: read from getcwd(), not the PWD environment variable
fsmonitor: delay updating state until after split index is merged
fsmonitor: document GIT_TRACE_FSMONITOR
fsmonitor: don't bother pretty-printing JSON from watchman
fsmonitor: set the PWD to the top of the working tree
We learned to talk to watchman to speed up "git status" and other
operations that need to see which paths have been modified.
* bp/fsmonitor:
fsmonitor: preserve utf8 filenames in fsmonitor-watchman log
fsmonitor: read entirety of watchman output
fsmonitor: MINGW support for watchman integration
fsmonitor: add a performance test
fsmonitor: add a sample integration script for Watchman
fsmonitor: add test cases for fsmonitor extension
split-index: disable the fsmonitor extension when running the split index test
fsmonitor: add a test tool to dump the index extension
update-index: add fsmonitor support to update-index
ls-files: Add support in ls-files to display the fsmonitor valid bit
fsmonitor: add documentation for the fsmonitor extension.
fsmonitor: teach git to optionally utilize a file system monitor to speed up detecting new or changed files.
update-index: add a new --force-write-index option
preload-index: add override to enable testing preload-index
bswap: add 64 bit endianness helper get_be64
Make it safer to normalize the line endings in a repository.
Files that had been commited with CRLF will be commited with LF.
The old way to normalize a repo was like this:
# Make sure that there are not untracked files
$ echo "* text=auto" >.gitattributes
$ git read-tree --empty
$ git add .
$ git commit -m "Introduce end-of-line normalization"
The user must make sure that there are no untracked files,
otherwise they would have been added and tracked from now on.
The new "add --renormalize" does not add untracked files:
$ echo "* text=auto" >.gitattributes
$ git add --renormalize .
$ git commit -m "Introduce end-of-line normalization"
Note that "git add --renormalize <pathspec>" is the short form for
"git add -u --renormalize <pathspec>".
While at it, document that the same renormalization may be needed,
whenever a clean filter is added or changed.
Helped-By: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Drop (perhaps overly cautious) sanity check before using the index
read from the filesystem at runtime.
* bp/read-index-from-skip-verification:
read_index_from(): speed index loading by skipping verification of the entry order
Switch the uses of empty_tree_oid and empty_blob_oid to use the
current_hash abstraction that represents the current hash algorithm in
use.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In future versions of Git, we plan to support an additional hash
algorithm. Integrate the enumeration of hash algorithms with repository
setup, and store a pointer to the enumerated data in struct repository.
Of course, we currently only support SHA-1, so hard-code this value in
read_repository_format. In the future, we'll enumerate this value from
the configuration.
Add a constant, the_hash_algo, which points to the hash_algo structure
pointer in the repository global. Note that this is the hash which is
used to serialize data to disk, not the hash which is used to display
items to the user. The transition plan anticipates that these may be
different. We can add an additional element in the future (say,
ui_hash_algo) to provide for this case.
Include repository.h in cache.h since we now need to have access to
these struct and variable definitions.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There is code in post_read_index_from() to catch out of order
entries when reading an index file. This order verification is ~13%
of the cost of every call to read_index_from().
Update check_ce_order() so that it skips this verification unless
the "verify_ce_order" global variable is set.
Teach fsck to force this verification.
The effect can be seen using t/perf/p0002-read-cache.sh:
Test HEAD HEAD~1
--------------------------------------------------------------------------------------
0002.1: read_cache/discard_cache 1000 times 0.41(0.04+0.04) 0.50(0.00+0.10) +22.0%
Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
An earlier update made it possible to use an on-stack in-core
lockfile structure (as opposed to having to deliberately leak an
on-heap one). Many codepaths have been updated to take advantage
of this new facility.
* ma/lockfile-fixes:
read_cache: roll back lock in `update_index_if_able()`
read-cache: leave lock in right state in `write_locked_index()`
read-cache: drop explicit `CLOSE_LOCK`-flag
cache.h: document `write_locked_index()`
apply: remove `newfd` from `struct apply_state`
apply: move lockfile into `apply_state`
cache-tree: simplify locking logic
checkout-index: simplify locking logic
tempfile: fix documentation on `delete_tempfile()`
lockfile: fix documentation on `close_lock_file_gently()`
treewide: prefer lockfiles on the stack
sha1_file: do not leak `lock_file`
If the fsmonitor extension is used in conjunction with the split index
extension, the set of entries in the index when it is first loaded is
only a subset of the real index. This leads to only the non-"base"
index being marked as CE_FSMONITOR_VALID.
Delay the expansion of the ewah bitmap until after tweak_split_index
has been called to merge in the base index as well.
The new fsmonitor_dirty is kept from being leaked by dint of being
cleaned up in post_read_index_from, which is guaranteed to be called
after do_read_index in read_index_from.
Signed-off-by: Alex Vandiver <alexmv@dropbox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Make the function for converting pairs of hexadecimal digits to binary
available to other call sites.
Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Tell a server that protocol v1 can be used by sending the http header
'Git-Protocol' with 'version=1' indicating this.
Also teach the apache http server to pass through the 'Git-Protocol'
header as an environment variable 'GIT_PROTOCOL'.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Create protocol.{c,h} and provide functions which future servers and
clients can use to determine which protocol to use or is being used.
Also introduce the 'GIT_PROTOCOL' environment variable which will be
used to communicate a colon separated list of keys with optional values
to a server. Unknown keys and values must be tolerated. This mechanism
is used to communicate which version of the wire protocol a client would
like to use with a server.
Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
`update_index_if_able()` used to always commit the lock or roll it back.
Commit 03b866477 (read-cache: new API write_locked_index instead of
write_index/write_cache, 2014-06-13) stopped rolling it back in case a
write was not even attempted. This change in behavior is not motivated
in the commit message and appears to be accidental: the `else`-path was
removed, although that changed the behavior in case the `if` shortcuts.
Reintroduce the rollback and document this behavior. While at it, move
the documentation on this function from the function definition to the
function declaration in cache.h.
If `write_locked_index(..., COMMIT_LOCK)` fails, it will roll back the
lock for us (see the previous commit).
Noticed-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If the original version of `write_locked_index()` returned with an
error, it didn't roll back the lockfile unless the error occured at the
very end, during closing/committing. See commit 03b866477 (read-cache:
new API write_locked_index instead of write_index/write_cache,
2014-06-13).
In commit 9f41c7a6b (read-cache: close index.lock in do_write_index,
2017-04-26), we learned to close the lock slightly earlier in the
callstack. That was mostly a side-effect of lockfiles being implemented
using temporary files, but didn't cause any real harm.
Recently, commit 076aa2cbd (tempfile: auto-allocate tempfiles on heap,
2017-09-05) introduced a subtle bug. If the temporary file is deleted
(i.e., the lockfile is rolled back), the tempfile-pointer in the `struct
lock_file` will be left dangling. Thus, an attempt to reuse the
lockfile, or even just to roll it back, will induce undefined behavior
-- most likely a crash.
Besides not crashing, we clearly want to make things consistent. The
guarantees which the lockfile-machinery itself provides is A) if we ask
to commit and it fails, roll back, and B) if we ask to close and it
fails, do _not_ roll back. Let's do the same for consistency.
Do not delete the temporary file in `do_write_index()`. One of its
callers, `write_locked_index()` will thereby avoid rolling back the
lock. The other caller, `write_shared_index()`, will delete its
temporary file anyway. Both of these callers will avoid undefined
behavior (crashing).
Teach `write_locked_index(..., COMMIT_LOCK)` to roll back the lock
before returning. If we have already succeeded and committed, it will be
a noop. Simplify the existing callers where we now have a superfluous
call to `rollback_lockfile()`. That should keep future readers from
wondering why the callers are inconsistent.
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
`write_locked_index()` takes two flags: `COMMIT_LOCK` and `CLOSE_LOCK`.
At most one is allowed. But it is also possible to use no flag, i.e.,
`0`. But when `write_locked_index()` calls `do_write_index()`, the
temporary file, a.k.a. the lockfile, will be closed. So passing `0` is
effectively the same as `CLOSE_LOCK`, which seems like a bug.
We might feel tempted to restructure the code in order to close the file
later, or conditionally. It also feels a bit unfortunate that we simply
"happen" to close the lock by way of an implementation detail of
lockfiles. But note that we need to close the temporary file before
`stat`-ing it, at least on Windows. See 9f41c7a6b (read-cache: close
index.lock in do_write_index, 2017-04-26).
Drop `CLOSE_LOCK` and make it explicit that `write_locked_index()`
always closes the lock. Whether it is also committed is governed by the
remaining flag, `COMMIT_LOCK`.
This means we neither have nor suggest that we have a mode to write the
index and leave the file open. Whatever extra contents we might
eventually want to write, we should probably write it from within
`write_locked_index()` itself anyway.
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The next patches will tweak the behavior of this function. Document it
in order to establish a basis for those patches.
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some commands (most notably "git status") makes an opportunistic
update when performing a read-only operation to help optimize later
operations in the same repository. The new "--no-optional-locks"
option can be passed to Git to disable them.
* jk/no-optional-locks:
git: add --no-optional-locks option
When the index is read from disk, the fsmonitor index extension is used
to flag the last known potentially dirty index entries. The registered
core.fsmonitor command is called with the time the index was last
updated and returns the list of files changed since that time. This list
is used to flag any additional dirty cache entries and untracked cache
directories.
We can then use this valid state to speed up preload_index(),
ie_match_stat(), and refresh_cache_ent() as they do not need to lstat()
files to detect potential changes for those entries marked
CE_FSMONITOR_VALID.
In addition, if the untracked cache is turned on valid_cached_dir() can
skip checking directories for new or changed files as fsmonitor will
invalidate the cache only for those directories that have been
identified as having potential changes.
To keep the CE_FSMONITOR_VALID state accurate during git operations;
when git updates a cache entry to match the current state on disk,
it will now set the CE_FSMONITOR_VALID bit.
Inversely, anytime git changes a cache entry, the CE_FSMONITOR_VALID bit
is cleared and the corresponding untracked cache directory is marked
invalid.
Signed-off-by: Ben Peart <benpeart@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some tools like IDEs or fancy editors may periodically run
commands like "git status" in the background to keep track
of the state of the repository. Some of these commands may
refresh the index and write out the result in an
opportunistic way: if they can get the index lock, then they
update the on-disk index with any updates they find. And if
not, then their in-core refresh is lost and just has to be
recomputed by the next caller.
But taking the index lock may conflict with other operations
in the repository. Especially ones that the user is doing
themselves, which _aren't_ opportunistic. In other words,
"git status" knows how to back off when somebody else is
holding the lock, but other commands don't know that status
would be happy to drop the lock if somebody else wanted it.
There are a couple possible solutions:
1. Have some kind of "pseudo-lock" that allows other
commands to tell status that they want the lock.
This is likely to be complicated and error-prone to
implement (and maybe even impossible with just
dotlocks to work from, as it requires some
inter-process communication).
2. Avoid background runs of commands like "git status"
that want to do opportunistic updates, preferring
instead plumbing like diff-files, etc.
This is awkward for a couple of reasons. One is that
"status --porcelain" reports a lot more about the
repository state than is available from individual
plumbing commands. And two is that we actually _do_
want to see the refreshed index. We just don't want to
take a lock or write out the result. Whereas commands
like diff-files expect us to refresh the index
separately and write it to disk so that they can depend
on the result. But that write is exactly what we're
trying to avoid.
3. Ask "status" not to lock or write the index.
This is easy to implement. The big downside is that any
work done in refreshing the index for such a call is
lost when the process exits. So a background process
may end up re-hashing a changed file multiple times
until the user runs a command that does an index
refresh themselves.
This patch implements the option 3. The idea (and the test)
is largely stolen from a Git for Windows patch by Johannes
Schindelin, 67e5ce7f63 (status: offer *not* to lock the
index and update it, 2016-08-12). The twist here is that
instead of making this an option to "git status", it becomes
a "git" option and matching environment variable.
The reason there is two-fold:
1. An environment variable is carried through to
sub-processes. And whether an invocation is a
background process or not should apply to the whole
process tree. So you could do "git --no-optional-locks
foo", and if "foo" is a script or alias that calls
"status", you'll still get the effect.
2. There may be other programs that want the same
treatment.
I've punted here on finding more callers to convert,
since "status" is the obvious one to call as a repeated
background job. But "git diff"'s opportunistic refresh
of the index may be a good candidate.
The test is taken from 67e5ce7f63, and it's worth repeating
Johannes's explanation:
Note that the regression test added in this commit does
not *really* verify that no index.lock file was written;
that test is not possible in a portable way. Instead, we
verify that .git/index is rewritten *only* when `git
status` is run without `--no-optional-locks`.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The MRU cache that keeps track of recently used packs is represented
using two global variables:
struct mru packed_git_mru_storage;
struct mru *packed_git_mru = &packed_git_mru_storage;
Callers never assign to the packed_git_mru pointer, though, so we can
simplify by eliminating it and using &packed_git_mru_storage (renamed
to &packed_git_mru) directly. This variable is only used by the
packfile subsystem, making this a relatively uninvasive change (and
any new unadapted callers would trigger a compile error).
Noticed while moving these globals to the object_store struct.
Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git diff" has been taught to optionally paint new lines that are
the same as deleted lines elsewhere differently from genuinely new
lines.
* sb/diff-color-move: (25 commits)
diff: document the new --color-moved setting
diff.c: add dimming to moved line detection
diff.c: color moved lines differently, plain mode
diff.c: color moved lines differently
diff.c: buffer all output if asked to
diff.c: emit_diff_symbol learns about DIFF_SYMBOL_SUMMARY
diff.c: emit_diff_symbol learns about DIFF_SYMBOL_STAT_SEP
diff.c: convert word diffing to use emit_diff_symbol
diff.c: convert show_stats to use emit_diff_symbol
diff.c: convert emit_binary_diff_body to use emit_diff_symbol
submodule.c: migrate diff output to use emit_diff_symbol
diff.c: emit_diff_symbol learns DIFF_SYMBOL_REWRITE_DIFF
diff.c: emit_diff_symbol learns about DIFF_SYMBOL_BINARY_FILES
diff.c: emit_diff_symbol learns DIFF_SYMBOL_HEADER
diff.c: emit_diff_symbol learns DIFF_SYMBOL_FILEPAIR_{PLUS, MINUS}
diff.c: emit_diff_symbol learns DIFF_SYMBOL_CONTEXT_INCOMPLETE
diff.c: emit_diff_symbol learns DIFF_SYMBOL_WORDS[_PORCELAIN]
diff.c: migrate emit_line_checked to use emit_diff_symbol
diff.c: emit_diff_symbol learns DIFF_SYMBOL_NO_LF_EOF
diff.c: emit_diff_symbol learns DIFF_SYMBOL_CONTEXT_FRAGINFO
...
Both sha1_file.c and packfile.c now need read_object(), so a copy of
read_object() was created in packfile.c.
This patch makes both mark_bad_packed_object() and has_packed_and_bad()
global. Unlike most of the other patches in this series, these 2
functions need to remain global.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The function open_packed_git() needs to be temporarily made global. Its
scope will be restored to static in a subsequent commit.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
