Share the text used to explain configuration variables used by "git
<subcmd>" in "git help <subcmd>" with the text from "git help config".
* ab/dedup-config-and-command-docs:
docs: add CONFIGURATION sections that fuzzy map to built-ins
docs: add CONFIGURATION sections that map to a built-in
log docs: de-duplicate configuration sections
difftool docs: de-duplicate configuration sections
notes docs: de-duplicate and combine configuration sections
apply docs: de-duplicate configuration sections
send-email docs: de-duplicate configuration sections
grep docs: de-duplicate configuration sections
docs: add and use include template for config/* includes
Inspired by 24966cd982 ("doc: fix repeated words", 08-09-2019),
I ran "egrep -R "\<([a-zA-Z]+)\> \<\1\>" ./Documentation/*" to
find current cases of repeated words such as "the the" that were
quite clearly typos.
There were many false positives reported, such as "really really"
or valid uses of "that that" which I left alone.
Signed-off-by: Jacob Stopak <jacob@initialcommit.io>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git format-patch --from=<ident>" can be told to add an in-body
"From:" line even for commits that are authored by the given
<ident> with "--force-in-body-from"option.
* jc/format-patch-force-in-body-from:
format-patch: learn format.forceInBodyFrom configuration variable
format-patch: allow forcing the use of in-body From: header
pretty: separate out the logic to decide the use of in-body from
Include the "config/difftool.txt" file in "git-difftool.txt", and move
the relevant part of git-difftool(1) configuration from
"config/diff.txt" to config/difftool.txt".
Doing this is slightly odd, as we usually discuss configuration in
alphabetical order, but by doing it we're able to include the full set
of configuration used by git-difftool(1) (and only that configuration)
in its own documentation.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Reviewed-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Combine the various "notes" configuration sections spread across
Documentation/config/notes.txt and Documentation/git-notes.txt to live
in the former, and to be included in the latter.
We'll now forward link from "git notes" to the "CONFIGURATION" section
below, rather than to "git-config(1)" when discussing configuration
variables that are (also) discussed in that section.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Reviewed-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
De-duplicate the discussion of "send-email" configuration, such that
the "git-config(1)" manual page becomes the source of truth, and
"git-send-email(1)" includes the relevant part.
Most commands that suffered from such duplication had diverging text
discussing the same variables, but in this case some config was also
only discussed in one or the other.
This is mostly a move-only change, the exception is a minor rewording
of changing wording like "see above" to "see linkgit:git-config[1]",
as well as a clarification about the big section of command-line
option tweaking config being discussed in git-send-email(1)'s main
docs.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Reviewed-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Include the "config/grep.txt" file in "git-grep.txt", instead of
repeating an almost identical description of the "grep" configuration
variables in two places.
There is no loss of information here that isn't shown in the addition
to "grep.txt". This change was made by copying the contents of
"git-grep.txt"'s version over the "grep.txt" version. Aside from the
change "grep.txt" being made here the two were identical.
This documentation started being copy/pasted around in
b22520a37c8 (grep: allow -E and -n to be turned on by default via
configuration, 2011-03-30). After that in e.g. 6453f7b3486 (grep: add
grep.fullName config variable, 2014-03-17) they started drifting
apart, with only grep.fullName being described in the command
documentation.
In 434e6e753fe (config.txt: move grep.* to a separate file,
2018-10-27) we gained the include, but didn't do this next step, let's
do it now.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Reviewed-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The pack bitmap file gained a bitmap-lookup table to speed up
locating the necessary bitmap for a given commit.
* ac/bitmap-lookup-table:
pack-bitmap-write: drop unused pack_idx_entry parameters
bitmap-lookup-table: add performance tests for lookup table
pack-bitmap: prepare to read lookup table extension
pack-bitmap-write: learn pack.writeBitmapLookupTable and add tests
pack-bitmap-write.c: write lookup table extension
bitmap: move `get commit positions` code to `bitmap_writer_finish`
Documentation/technical: describe bitmap lookup table extension
The namespaces used by "log --decorate" from "refs/" hierarchy by
default has been tightened.
* ds/decorate-filter-tweak:
fetch: use ref_namespaces during prefetch
maintenance: stop writing log.excludeDecoration
log: create log.initialDecorationSet=all
log: add --clear-decorations option
log: add default decoration filter
log-tree: use ref_namespaces instead of if/else-if
refs: use ref_namespaces for replace refs base
refs: add array of ref namespaces
t4207: test coloring of grafted decorations
t4207: modernize test
refs: allow "HEAD" as decoration filter
As the need to use the "--force-in-body-from" option primarily is
tied to which mailing list the mails go to (and get their From:
address mangled), it is likely that a user who needs to use this
option once to interact with their upstream project needs to use it
for all patches they send out.
Add a configuration variable, suitable for setting in the local
configuration file per repository, for this.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Teach Git to provide a way for users to enable/disable bitmap lookup
table extension by providing a config option named 'writeBitmapLookupTable'.
Default is false.
Also add test to verify writting of lookup table.
Mentored-by: Taylor Blau <me@ttaylorr.com>
Co-Mentored-by: Kaartic Sivaraam <kaartic.sivaraam@gmail.com>
Co-Authored-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Abhradeep Chakraborty <chakrabortyabhradeep79@gmail.com>
Reviewed-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Expose a lot of "tech docs" via "git help" interface.
* ab/tech-docs-to-help:
docs: move http-protocol docs to man section 5
docs: move cruft pack docs to gitformat-pack
docs: move pack format docs to man section 5
docs: move signature docs to man section 5
docs: move index format docs to man section 5
docs: move protocol-related docs to man section 5
docs: move commit-graph format docs to man section 5
git docs: add a category for file formats, protocols and interfaces
git docs: add a category for user-facing file, repo and command UX
git help doc: use "<doc>" instead of "<guide>"
help.c: remove common category behavior from drop_prefix() behavior
help.c: refactor drop_prefix() to use a "switch" statement"
The previous change introduced the --clear-decorations option for users
who do not want their decorations limited to a narrow set of ref
namespaces.
Add a config option that is equivalent to specifying --clear-decorations
by default.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Continue the move of existing Documentation/technical/* protocol and
file-format documentation into our main documentation space by moving
the various documentation pertaining to the *.pack format and related
files, and updating things that refer to it to link to the new
location.
By moving these we can properly link from the newly created
gitformat-commit-graph to a gitformat-chunk-format page.
Integrating "Documentation/technical/bitmap-format.txt" and
"Documentation/technical/cruft-packs.txt" might logically be part of
this change, but as those cover parts of the wider "pack
format" (including associated files) that's documented outside of
"Documentation/technical/pack-format.txt" let's leave those for now,
subsequent commit(s) will address those.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Continue the move of existing Documentation/technical/* protocol and
file-format documentation into our main documentation space. By moving
the things that discuss the protocol we can properly link from
e.g. lsrefs.unborn and protocol.version documentation to a manpage we
build by default.
So far we have been using the "gitformat-" prefix for the
documentation we've been moving over from Documentation/technical/*,
but for protocol documentation let's use "gitprotocol-*".
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git rebase -i" learns to update branches whose tip appear in the
rebased range with "--update-refs" option.
source: <pull.1247.v5.git.1658255624.gitgitgadget@gmail.com>
* ds/rebase-update-ref:
sequencer: notify user of --update-refs activity
sequencer: ignore HEAD ref under --update-refs
rebase: add rebase.updateRefs config option
sequencer: rewrite update-refs as user edits todo list
rebase: update refs from 'update-ref' commands
rebase: add --update-refs option
sequencer: add update-ref command
sequencer: define array with enum values
rebase-interactive: update 'merge' description
branch: consider refs under 'update-refs'
t2407: test branches currently using apply backend
t2407: test bisect and rebase as black-boxes
Add missing documentation for "include" and "includeIf" features in
"git config" file format, which incidentally teaches the command
line completion to include them in its offerings.
* mb/config-document-include:
config.txt: document include, includeIf
The previous change added the --update-refs command-line option. For
users who always want this mode, create the rebase.updateRefs config
option which behaves the same way as rebase.autoSquash does with the
--autosquash option.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The sparse checkout feature can be used in "cone mode" or "non-cone
mode". In this one instance in the documentation, we refer to the latter
as "non cone mode" with whitespace rather than a hyphen. Align this with
the rest of our documentation.
A few words later in the same paragraph, there's mention of "a more
flexible patterns". Drop that leading "a" to fix the grammar.
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Acked-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Git config's tab completion does not yet know about the "include"
and "includeIf" sections, nor the related "path" variable.
Add a description for these two sections in
'Documentation/config/includeif.txt', which points to git-config's
documentation, specifically the "Includes" and "Conditional Includes"
subsections.
As a side effect, tab completion can successfully complete the
'include', 'includeIf', and 'include.add' expressions.
This effect is tested by two new ad-hoc tests.
Variable completion only works for "include" for now.
Credit for the ideas behind this patch goes to
Ævar Arnfjörð Bjarmason.
Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Manuel Boni <ziosombrero@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There is a known social engineering attack that takes advantage of the
fact that a working tree can include an entire bare repository,
including a config file. A user could run a Git command inside the bare
repository thinking that the config file of the 'outer' repository would
be used, but in reality, the bare repository's config file (which is
attacker-controlled) is used, which may result in arbitrary code
execution. See [1] for a fuller description and deeper discussion.
A simple mitigation is to forbid bare repositories unless specified via
`--git-dir` or `GIT_DIR`. In environments that don't use bare
repositories, this would be minimally disruptive.
Create a config variable, `safe.bareRepository`, that tells Git whether
or not to die() when working with a bare repository. This config is an
enum of:
- "all": allow all bare repositories (this is the default)
- "explicit": only allow bare repositories specified via --git-dir
or GIT_DIR.
If we want to protect users from such attacks by default, neither value
will suffice - "all" provides no protection, but "explicit" is
impractical for bare repository users. A more usable default would be to
allow only non-embedded bare repositories ([2] contains one such
proposal), but detecting if a repository is embedded is potentially
non-trivial, so this work is not implemented in this series.
[1]: https://lore.kernel.org/git/kl6lsfqpygsj.fsf@chooglen-macbookpro.roam.corp.google.com
[2]: https://lore.kernel.org/git/5b969c5e-e802-c447-ad25-6acc0b784582@github.com
Signed-off-by: Glen Choo <chooglen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Use git_protected_config() to read `safe.directory` instead of
read_very_early_config(), making it 'protected configuration only'.
As a result, `safe.directory` now respects "-c", so update the tests and
docs accordingly. It used to ignore "-c" due to how it was implemented,
not because of security or correctness concerns [1].
[1] https://lore.kernel.org/git/xmqqlevabcsu.fsf@gitster.g/
Signed-off-by: Glen Choo <chooglen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
For security reasons, there are config variables that are only trusted
when they are specified in certain configuration scopes, which are
sometimes referred to on-list as 'protected configuration' [1]. A future
commit will introduce another such variable, so let's define our terms
so that we can have consistent documentation and implementation.
In our documentation, define 'protected configuration' as the system,
global and command config scopes. As a shorthand, I will refer to
variables that are only respected in protected configuration as
'protected configuration only', but this term is not used in the
documentation.
This definition of protected configuration is based on whether or not
Git can reasonably protect the user by ignoring the configuration scope:
- System, global and command line config are considered protected
because an attacker who has control over any of those can do plenty of
harm without Git, so we gain very little by ignoring those scopes.
- On the other hand, local (and similarly, worktree) config are not
considered protected because it is relatively easy for an attacker to
control local config, e.g.:
- On some shared user environments, a non-admin attacker can create a
repository high up the directory hierarchy (e.g. C:\.git on
Windows), and a user may accidentally use it when their PS1
automatically invokes "git" commands.
`safe.directory` prevents attacks of this form by making sure that
the user intended to use the shared repository. It obviously
shouldn't be read from the repository, because that would end up
trusting the repository that Git was supposed to reject.
- "git upload-pack" is expected to run in repositories that may not be
controlled by the user. We cannot ignore all config in that
repository (because "git upload-pack" would fail), but we can limit
the risks by ignoring `uploadpack.packObjectsHook`.
Only `uploadpack.packObjectsHook` is 'protected configuration only'. The
following variables are intentionally excluded:
- `safe.directory` should be 'protected configuration only', but it does
not technically fit the definition because it is not respected in the
"command" scope. A future commit will fix this.
- `trace2.*` happens to read the same scopes as `safe.directory` because
they share an implementation. However, this is not for security
reasons; it is because we want to start tracing so early that
repository-level config and "-c" are not available [2].
This requirement is unique to `trace2.*`, so it does not makes sense
for protected configuration to be subject to the same constraints.
[1] For example,
https://lore.kernel.org/git/6af83767-576b-75c4-c778-0284344a8fe7@github.com/
[2] https://lore.kernel.org/git/a0c89d0d-669e-bf56-25d2-cbb09b012e70@jeffhostetler.com/
Signed-off-by: Glen Choo <chooglen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Allow large objects read from a packstream to be streamed into a
loose object file straight, without having to keep it in-core as a
whole.
* hx/unpack-streaming:
unpack-objects: use stream_loose_object() to unpack large objects
core doc: modernize core.bigFileThreshold documentation
object-file.c: add "stream_loose_object()" to handle large object
object-file.c: factor out deflate part of write_loose_object()
object-file.c: refactor write_loose_object() to several steps
unpack-objects: low memory footprint for get_data() in dry_run mode
"git push" sometimes perform poorly when reachability bitmaps are
used, even in a repository where other operations are helped by
bitmaps. The push.useBitmaps configuration variable is introduced
to allow disabling use of reachability bitmaps only for "git push".
* zk/push-use-bitmaps:
send-pack.c: add config push.useBitmaps
43966ab315 (revert: optionally refer to commit in the "reference"
format, 2022-05-26) added the documentation file config/revert.txt.
Actually include it in config.txt.
Make is used with a bare infinitive after the object; remove the "to".
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit 7281c196b1 (transfer doc: move fetch.credentialsInUrl to
"transfer" config namespace, 2022-06-15) propagates a typo from
6dcbdc0d66 (remote: create fetch.credentialsInUrl config, 2022-06-06),
where "other" is misspelled as "oher". Fix the typo accordingly.
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
* maint-2.34:
Git 2.34.4
Git 2.33.4
Git 2.32.3
Git 2.31.4
Git 2.30.5
setup: tighten ownership checks post CVE-2022-24765
git-compat-util: allow root to access both SUDO_UID and root owned
t0034: add negative tests and allow git init to mostly work under sudo
git-compat-util: avoid failing dir ownership checks if running privileged
t: regression git needs safe.directory when using sudo
* maint-2.33:
Git 2.33.4
Git 2.32.3
Git 2.31.4
Git 2.30.5
setup: tighten ownership checks post CVE-2022-24765
git-compat-util: allow root to access both SUDO_UID and root owned
t0034: add negative tests and allow git init to mostly work under sudo
git-compat-util: avoid failing dir ownership checks if running privileged
t: regression git needs safe.directory when using sudo
* maint-2.32:
Git 2.32.3
Git 2.31.4
Git 2.30.5
setup: tighten ownership checks post CVE-2022-24765
git-compat-util: allow root to access both SUDO_UID and root owned
t0034: add negative tests and allow git init to mostly work under sudo
git-compat-util: avoid failing dir ownership checks if running privileged
t: regression git needs safe.directory when using sudo
* maint-2.31:
Git 2.31.4
Git 2.30.5
setup: tighten ownership checks post CVE-2022-24765
git-compat-util: allow root to access both SUDO_UID and root owned
t0034: add negative tests and allow git init to mostly work under sudo
git-compat-util: avoid failing dir ownership checks if running privileged
t: regression git needs safe.directory when using sudo
* maint-2.30:
Git 2.30.5
setup: tighten ownership checks post CVE-2022-24765
git-compat-util: allow root to access both SUDO_UID and root owned
t0034: add negative tests and allow git init to mostly work under sudo
git-compat-util: avoid failing dir ownership checks if running privileged
t: regression git needs safe.directory when using sudo
"sudo git foo" used to consider a repository owned by the original
user a safe one to access; it now also considers a repository owned
by root a safe one, too (after all, if an attacker can craft a
malicious repository owned by root, the box is 0wned already).
* cb/path-owner-check-with-sudo-plus:
git-compat-util: allow root to access both SUDO_UID and root owned
Reachability bitmaps are designed to speed up the "counting objects"
phase of generating a pack during a clone or fetch. They are not
optimized for Git clients sending a small topic branch via "git push".
In some cases (see [1]), using reachability bitmaps during "git push"
can cause significant performance regressions.
Add a new "push.useBitmaps" configuration variable to allow users to
tell "git push" not to use bitmaps. We already have "pack.bitmaps"
that controls the use of bitmaps, but a separate configuration variable
allows the reachability bitmaps to still be used in other areas,
such as "git upload-pack", while disabling it only for "git push".
[1]: https://lore.kernel.org/git/87zhoz8b9o.fsf@evledraar.gmail.com/
Signed-off-by: Kyle Zhao <kylezhao@tencent.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Previous changes introduced a regression which will prevent root for
accessing repositories owned by thyself if using sudo because SUDO_UID
takes precedence.
Loosen that restriction by allowing root to access repositories owned
by both uid by default and without having to add a safe.directory
exception.
A previous workaround that was documented in the tests is no longer
needed so it has been removed together with its specially crafted
prerequisite.
Helped-by: Johanness Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Carlo Marcelo Arenas Belón <carenas@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Some config variables are combinations of multiple words, and we
typically write them in camelCase forms in manpage and translatable
strings. It's not easy to find mismatches for these camelCase config
variables during code reviews, but occasionally they are identified
during localization translations.
To check for mismatched config variables, I introduced a new feature
in the helper program for localization[^1]. The following mismatched
config variables have been identified by running the helper program,
such as "git-po-helper check-pot".
Lowercase in manpage should use camelCase:
* Documentation/config/http.txt: http.pinnedpubkey
Lowercase in translable strings should use camelCase:
* builtin/fast-import.c: pack.indexversion
* builtin/gc.c: gc.logexpiry
* builtin/index-pack.c: pack.indexversion
* builtin/pack-objects.c: pack.indexversion
* builtin/repack.c: pack.writebitmaps
* commit.c: i18n.commitencoding
* gpg-interface.c: user.signingkey
* http.c: http.postbuffer
* submodule-config.c: submodule.fetchjobs
Mismatched camelCases, choose the former:
* Documentation/config/transfer.txt: transfer.credentialsInUrl
remote.c: transfer.credentialsInURL
[^1]: https://github.com/git-l10n/git-po-helper
Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Rename fetch.credentialsInUrl to transfer.credentialsInUrl as the
single configuration variable should work both in pushing and
fetching.
* ab/credentials-in-url-more:
transfer doc: move fetch.credentialsInUrl to "transfer" config namespace
fetch doc: note "pushurl" caveat about "credentialsInUrl", elaborate
"git revert" learns "--reference" option to use more human-readable
reference to the commit it reverts in the message template it
prepares for the user.
* jc/revert-show-parent-info:
revert: --reference should apply only to 'revert', not 'cherry-pick'
revert: optionally refer to commit in the "reference" format
Rename the "fetch.credentialsInUrl" configuration variable introduced
in 6dcbdc0d661 (remote: create fetch.credentialsInUrl config,
2022-06-06) to "transfer".
There are existing exceptions, but generally speaking the
"<namespace>.<var>" configuration should only apply to command
described in the "namespace" (and its sub-commands, so e.g. "clone.*"
or "fetch.*" might also configure "git-remote-https").
But in the case of "fetch.credentialsInUrl" we've got a configuration
variable that configures the behavior of all of "clone", "push" and
"fetch", someone adjusting "fetch.*" configuration won't expect to
have the behavior of "git push" altered, especially as we have the
pre-existing "{transfer,fetch,receive}.fsckObjects", which configures
different parts of the transfer dialog.
So let's move this configuration variable to the "transfer" namespace
before it's exposed in a release. We could add all of
"{transfer,fetch,pull}.credentialsInUrl" at some other time, but once
we have "fetch" configure "pull" such an arrangement would would be a
confusing mess, as we'd at least need to have "fetch" configure
"push" (but not the other way around), or change existing behavior.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Acked-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Amend the documentation and release notes entry for the
"fetch.credentialsInUrl" feature added in 6dcbdc0d661 (remote: create
fetch.credentialsInUrl config, 2022-06-06), it currently doesn't
detect passwords in `remote.<name>.pushurl` configuration. We
shouldn't lull users into a false sense of security, so we need to
mention that prominently.
This also elaborates and clarifies the "exposes the password in
multiple ways" part of the documentation. As noted in [1] a user
unfamiliar with git's implementation won't know what to make of that
scary claim, e.g. git hypothetically have novel git-specific ways of
exposing configured credentials.
The reality is that this configuration is intended as an aid for users
who can't fully trust their OS's or system's security model, so lets
say that's what this is intended for, and mention the most common ways
passwords stored in configuration might inadvertently get exposed.
1. https://lore.kernel.org/git/220524.86ilpuvcqh.gmgdl@evledraar.gmail.com/
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Acked-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The "fetch.credentialsInUrl" configuration variable controls what
happens when a URL with embedded login credential is used.
* ds/credentials-in-url:
remote: create fetch.credentialsInUrl config
Make use of the stream_loose_object() function introduced in the
preceding commit to unpack large objects. Before this we'd need to
malloc() the size of the blob before unpacking it, which could cause
OOM with very large blobs.
We could use the new streaming interface to unpack all blobs, but
doing so would be much slower, as demonstrated e.g. with this
benchmark using git-hyperfine[0]:
rm -rf /tmp/scalar.git &&
git clone --bare https://github.com/Microsoft/scalar.git /tmp/scalar.git &&
mv /tmp/scalar.git/objects/pack/*.pack /tmp/scalar.git/my.pack &&
git hyperfine \
-r 2 --warmup 1 \
-L rev origin/master,HEAD -L v "10,512,1k,1m" \
-s 'make' \
-p 'git init --bare dest.git' \
-c 'rm -rf dest.git' \
'./git -C dest.git -c core.bigFileThreshold={v} unpack-objects </tmp/scalar.git/my.pack'
Here we'll perform worse with lower core.bigFileThreshold settings
with this change in terms of speed, but we're getting lower memory use
in return:
Summary
'./git -C dest.git -c core.bigFileThreshold=10 unpack-objects </tmp/scalar.git/my.pack' in 'origin/master' ran
1.01 ± 0.01 times faster than './git -C dest.git -c core.bigFileThreshold=1k unpack-objects </tmp/scalar.git/my.pack' in 'origin/master'
1.01 ± 0.01 times faster than './git -C dest.git -c core.bigFileThreshold=1m unpack-objects </tmp/scalar.git/my.pack' in 'origin/master'
1.01 ± 0.02 times faster than './git -C dest.git -c core.bigFileThreshold=1m unpack-objects </tmp/scalar.git/my.pack' in 'HEAD'
1.02 ± 0.00 times faster than './git -C dest.git -c core.bigFileThreshold=512 unpack-objects </tmp/scalar.git/my.pack' in 'origin/master'
1.09 ± 0.01 times faster than './git -C dest.git -c core.bigFileThreshold=1k unpack-objects </tmp/scalar.git/my.pack' in 'HEAD'
1.10 ± 0.00 times faster than './git -C dest.git -c core.bigFileThreshold=512 unpack-objects </tmp/scalar.git/my.pack' in 'HEAD'
1.11 ± 0.00 times faster than './git -C dest.git -c core.bigFileThreshold=10 unpack-objects </tmp/scalar.git/my.pack' in 'HEAD'
A better benchmark to demonstrate the benefits of that this one, which
creates an artificial repo with a 1, 25, 50, 75 and 100MB blob:
rm -rf /tmp/repo &&
git init /tmp/repo &&
(
cd /tmp/repo &&
for i in 1 25 50 75 100
do
dd if=/dev/urandom of=blob.$i count=$(($i*1024)) bs=1024
done &&
git add blob.* &&
git commit -mblobs &&
git gc &&
PACK=$(echo .git/objects/pack/pack-*.pack) &&
cp "$PACK" my.pack
) &&
git hyperfine \
--show-output \
-L rev origin/master,HEAD -L v "512,50m,100m" \
-s 'make' \
-p 'git init --bare dest.git' \
-c 'rm -rf dest.git' \
'/usr/bin/time -v ./git -C dest.git -c core.bigFileThreshold={v} unpack-objects </tmp/repo/my.pack 2>&1 | grep Maximum'
Using this test we'll always use >100MB of memory on
origin/master (around ~105MB), but max out at e.g. ~55MB if we set
core.bigFileThreshold=50m.
The relevant "Maximum resident set size" lines were manually added
below the relevant benchmark:
'/usr/bin/time -v ./git -C dest.git -c core.bigFileThreshold=50m unpack-objects </tmp/repo/my.pack 2>&1 | grep Maximum' in 'origin/master' ran
Maximum resident set size (kbytes): 107080
1.02 ± 0.78 times faster than '/usr/bin/time -v ./git -C dest.git -c core.bigFileThreshold=512 unpack-objects </tmp/repo/my.pack 2>&1 | grep Maximum' in 'origin/master'
Maximum resident set size (kbytes): 106968
1.09 ± 0.79 times faster than '/usr/bin/time -v ./git -C dest.git -c core.bigFileThreshold=100m unpack-objects </tmp/repo/my.pack 2>&1 | grep Maximum' in 'origin/master'
Maximum resident set size (kbytes): 107032
1.42 ± 1.07 times faster than '/usr/bin/time -v ./git -C dest.git -c core.bigFileThreshold=100m unpack-objects </tmp/repo/my.pack 2>&1 | grep Maximum' in 'HEAD'
Maximum resident set size (kbytes): 107072
1.83 ± 1.02 times faster than '/usr/bin/time -v ./git -C dest.git -c core.bigFileThreshold=50m unpack-objects </tmp/repo/my.pack 2>&1 | grep Maximum' in 'HEAD'
Maximum resident set size (kbytes): 55704
2.16 ± 1.19 times faster than '/usr/bin/time -v ./git -C dest.git -c core.bigFileThreshold=512 unpack-objects </tmp/repo/my.pack 2>&1 | grep Maximum' in 'HEAD'
Maximum resident set size (kbytes): 4564
This shows that if you have enough memory this new streaming method is
slower the lower you set the streaming threshold, but the benefit is
more bounded memory use.
An earlier version of this patch introduced a new
"core.bigFileStreamingThreshold" instead of re-using the existing
"core.bigFileThreshold" variable[1]. As noted in a detailed overview
of its users in [2] using it has several different meanings.
Still, we consider it good enough to simply re-use it. While it's
possible that someone might want to e.g. consider objects "small" for
the purposes of diffing but "big" for the purposes of writing them
such use-cases are probably too obscure to worry about. We can always
split up "core.bigFileThreshold" in the future if there's a need for
that.
0. https://github.com/avar/git-hyperfine/
1. https://lore.kernel.org/git/20211210103435.83656-1-chiyutianyi@gmail.com/
2. https://lore.kernel.org/git/20220120112114.47618-5-chiyutianyi@gmail.com/
Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Helped-by: Derrick Stolee <stolee@gmail.com>
Helped-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
Signed-off-by: Han Xin <chiyutianyi@gmail.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The core.bigFileThreshold documentation has been largely unchanged
since 5eef828bc03 (fast-import: Stream very large blobs directly to
pack, 2010-02-01).
But since then this setting has been expanded to affect a lot more
than that description indicated. Most notably in how "git diff" treats
them, see 6bf3b813486 (diff --stat: mark any file larger than
core.bigfilethreshold binary, 2014-08-16).
In addition to that, numerous commands and APIs make use of a
streaming mode for files above this threshold.
So let's attempt to summarize 12 years of changes in behavior, which
can be seen with:
git log --oneline -Gbig_file_thre 5eef828bc03.. -- '*.c'
To do that turn this into a bullet-point list. The summary Han Xin
produced in [1] helped a lot, but is a bit too detailed for
documentation aimed at users. Let's instead summarize how
user-observable behavior differs, and generally describe how we tend
to stream these files in various commands.
1. https://lore.kernel.org/git/20220120112114.47618-5-chiyutianyi@gmail.com/
Helped-by: Han Xin <chiyutianyi@gmail.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
