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
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>
There were several instances of 32 sprinkled throughout this file, all
of which were used for allocating a buffer to store the header of an
object. Introduce a constant, MAX_HEADER_LEN, for this purpose.
Note that this constant is slightly larger than required; the longest
possible header is 28 (7 for "commit", 1 for a space, 20 for a 63-bit
length in decimal, and 1 for the NUL). However, the overallocation
should not cause any problems, so leave it as it is.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
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 the remaining caller of sha1_object_info_extended to use struct
object_id. Introduce temporaries, which will be removed later, since
there is a dependency loop between sha1_object_info_extended and
lookup_replace_object_extended. This allows us to convert the code in a
piecemeal fashion instead of all at once.
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 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 the index_bulk_checkin function, and the static functions it
calls, to use pointers to struct object_id.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Support for the OBJECT_INFO_QUICK flag in sha1_object_info_extended()
was added in commit dfdd4afcf9 ("sha1_file: teach
sha1_object_info_extended more flags", 2017-06-26) in order to support
commit e83e71c5e1 ("sha1_file: refactor has_sha1_file_with_flags",
2017-06-26), but it was inadvertently removed in commit 8b4c0103a9
("sha1_file: support lazily fetching missing objects", 2017-12-08).
Restore this functionality.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
getenv() is supposed to work on the main repository only. This delayed
getenv() code in sha1_file.c makes it more difficult to convert
sha1_file.c to a generic object store that could be used by both
submodule and main repositories.
Move the getenv() back in setup_git_env() where other env vars are
also fetched.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.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>
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>
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
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
Switch various uses of explicit calls to SHA-1 into references to
the_hash_algo for better abstraction. Convert some calls to use struct
object_id.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In various parts of our code, we want to allocate a structure
representing the internal state of a hash algorithm. The original
implementation of the hash algorithm abstraction assumed we would do
that using heap allocations, and added a context size element to struct
git_hash_algo. However, most of the existing code uses stack
allocations and conversion would needlessly complicate various parts of
the code. Add a union for the purpose of allocating hash contexts on
the stack and a typedef for ease of use. Use this union for defining
the init, update, and final functions to avoid casts. Remove the ctxsz
element for struct git_hash_algo, which is no longer very useful.
This does mean that stack allocations will grow slightly as additional
hash functions are added, but this should not be a significant problem,
since we don't allocate many hash contexts. The improved usability and
benefits from avoiding dynamic allocation outweigh this small downside.
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 static write_loose_object
function to struct object_id.
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>
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 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>
As sha1_file_name() could be performance sensitive, let's
make it faster by using strbuf_addstr() and strbuf_addc()
instead of strbuf_addf().
Helped-by: Derrick Stolee <stolee@gmail.com>
Helped-by: Jeff Hostetler <git@jeffhostetler.com>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
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>
When calling convert_to_git(), the checksafe parameter defined what
should happen if the EOL conversion (CRLF --> LF --> CRLF) does not
roundtrip cleanly. In addition, it also defined if line endings should
be renormalized (CRLF --> LF) or kept as they are.
checksafe was an safe_crlf enum with these values:
SAFE_CRLF_FALSE: do nothing in case of EOL roundtrip errors
SAFE_CRLF_FAIL: die in case of EOL roundtrip errors
SAFE_CRLF_WARN: print a warning in case of EOL roundtrip errors
SAFE_CRLF_RENORMALIZE: change CRLF to LF
SAFE_CRLF_KEEP_CRLF: keep all line endings as they are
In some cases the integer value 0 was passed as checksafe parameter
instead of the correct enum value SAFE_CRLF_FALSE. That was no problem
because SAFE_CRLF_FALSE is defined as 0.
FALSE/FAIL/WARN are different from RENORMALIZE and KEEP_CRLF. Therefore,
an enum is not ideal. Let's use a integer bit pattern instead and rename
the parameter to conv_flags to make it more generically usable. This
allows us to extend the bit pattern in a subsequent commit.
Reported-By: Randall S. Becker <rsbecker@nexbridge.com>
Helped-By: Lars Schneider <larsxschneider@gmail.com>
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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
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>
Internaly we use 0{40} as a placeholder object name to signal the
codepath that there is no such object (e.g. the fast-forward check
while "git fetch" stores a new remote-tracking ref says "we know
there is no 'old' thing pointed at by the ref, as we are creating
it anew" by passing 0{40} for the 'old' side), and expect that a
codepath to locate an in-core object to return NULL as a sign that
the object does not exist. A look-up for an object that does not
exist however is quite costly with a repository with large number
of packfiles. This access pattern has been optimized.
* jk/fewer-pack-rescan:
sha1_file: fast-path null sha1 as a missing object
everything_local: use "quick" object existence check
p5551: add a script to test fetch pack-dir rescans
t/perf/lib-pack: use fast-import checkpoint to create packs
p5550: factor out nonsense-pack creation
Replace use of strbuf_addf() with strbuf_add() when enumerating
loose objects in for_each_file_in_obj_subdir(). Since we already
check the length and hex-values of the string before consuming
the path, we can prevent extra computation by using the lower-
level method.
One consumer of for_each_file_in_obj_subdir() is the abbreviation
code. OID abbreviations use a cached list of loose objects (per
object subdirectory) to make repeated queries fast, but there is
significant cache load time when there are many loose objects.
Most repositories do not have many loose objects before repacking,
but in the GVFS case the repos can grow to have millions of loose
objects. Profiling 'git log' performance in GitForWindows on a
GVFS-enabled repo with ~2.5 million loose objects revealed 12% of
the CPU time was spent in strbuf_addf().
Add a new performance test to p4211-line-log.sh that is more
sensitive to this cache-loading. By limiting to 1000 commits, we
more closely resemble user wait time when reading history into a
pager.
For a copy of the Linux repo with two ~512 MB packfiles and ~572K
loose objects, running 'git log --oneline --parents --raw -1000'
had the following performance:
HEAD~1 HEAD
----------------------------------------
7.70(7.15+0.54) 7.44(7.09+0.29) -3.4%
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Jeff King <peff@peff.net>
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"
In theory nobody should ever ask the low-level object code
for a null sha1. It's used as a sentinel for "no such
object" in lots of places, so leaking through to this level
is a sign that the higher-level code is not being careful
about its error-checking. In practice, though, quite a few
code paths seem to rely on the null sha1 lookup failing as a
way to quietly propagate non-existence (e.g., by feeding it
to lookup_commit_reference_gently(), which then returns
NULL).
When this happens, we do two inefficient things:
1. We actually search for the null sha1 in packs and in
the loose object directory.
2. When we fail to find it, we re-scan the pack directory
in case a simultaneous repack happened to move it from
loose to packed. This can be very expensive if you have
a large number of packs.
Only the second one actually causes noticeable performance
problems, so we could treat them independently. But for the
sake of simplicity (both of code and of reasoning about it),
it makes sense to just declare that the null sha1 cannot be
a real on-disk object, and looking it up will always return
"no such object".
There's no real loss of functionality to do so Its use as a
sentinel value means that anybody who is unlucky enough to
hit the 2^-160th chance of generating an object with that
sha1 is already going to find the object largely unusable.
In an ideal world, we'd simply fix all of the callers to
notice the null sha1 and avoid passing it to us. But a
simple experiment to catch this with a BUG() shows that
there are a large number of code paths that do so.
So in the meantime, let's fix the performance problem by
taking a fast exit from the object lookup when we see a null
sha1. p5551 shows off the improvement (when a fetched ref is
new, the "old" sha1 is 0{40}, which ends up being passed for
fast-forward checks, the status table abbreviations, etc):
Test HEAD^ HEAD
--------------------------------------------------------
5551.4: fetch 5.51(5.03+0.48) 0.17(0.10+0.06) -96.9%
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We used to add an empty alternate object database to the system
that does not help anything; it has been corrected.
* jk/info-alternates-fix:
link_alt_odb_entries: make empty input a noop
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>
We used to add an empty alternate object database to the system
that does not help anything; it has been corrected.
* jk/info-alternates-fix:
link_alt_odb_entries: make empty input a noop
If an empty string is passed to link_alt_odb_entries(), our
loop finds no entries and we link nothing. But we still do
some preparatory work to normalize the object directory
path, even though we'll never look at the result. This
triggers in basically every git process, since we feed the
usually-empty ALTERNATE_DB_ENVIRONMENT to the function.
Let's detect early that there's nothing to do and return.
While we're at it, let's treat NULL the same as an empty
string as a favor to our callers. That saves
prepare_alt_odb() from having to cover this case.
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
