Introduce an optional configuration to allow the trailing hash that
protects the index file from bit flipping.
* ds/omit-trailing-hash-in-index:
features: feature.manyFiles implies fast index writes
test-lib-functions: add helper for trailing hash
read-cache: add index.skipHash config option
hashfile: allow skipping the hash function
The recent addition of the index.skipHash config option allows index
writes to speed up by skipping the hash computation for the trailing
checksum. This is particularly critical for repositories with many files
at HEAD, so add this config option to two cases where users in that
scenario may opt-in to such behavior:
1. The feature.manyFiles config option enables some options that are
helpful for repositories with many files at HEAD.
2. 'scalar register' and 'scalar reconfigure' set config options that
optimize for large repositories.
In both of these cases, set index.skipHash=true to gain this
speedup. Add tests that demonstrate the proper way that
index.skipHash=true can override feature.manyFiles=true.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The previous change allowed skipping the hashing portion of the
hashwrite API, using it instead as a buffered write API. Disabling the
hashwrite can be particularly helpful when the write operation is in a
critical path.
One such critical path is the writing of the index. This operation is so
critical that the sparse index was created specifically to reduce the
size of the index to make these writes (and reads) faster.
This trade-off between file stability at rest and write-time performance
is not easy to balance. The index is an interesting case for a couple
reasons:
1. Writes block users. Writing the index takes place in many user-
blocking foreground operations. The speed improvement directly
impacts their use. Other file formats are typically written in the
background (commit-graph, multi-pack-index) or are super-critical to
correctness (pack-files).
2. Index files are short lived. It is rare that a user leaves an index
for a long time with many staged changes. Outside of staged changes,
the index can be completely destroyed and rewritten with minimal
impact to the user.
Following a similar approach to one used in the microsoft/git fork [1],
add a new config option (index.skipHash) that allows disabling this
hashing during the index write. The cost is that we can no longer
validate the contents for corruption-at-rest using the trailing hash.
[1] 21fed2d914
We load this config from the repository config given by istate->repo,
with a fallback to the_repository if it is not set.
While older Git versions will not recognize the null hash as a special
case, the file format itself is still being met in terms of its
structure. Using this null hash will still allow Git operations to
function across older versions.
The one exception is 'git fsck' which checks the hash of the index file.
This used to be a check on every index read, but was split out to just
the index in a33fc72fe9 (read-cache: force_verify_index_checksum,
2017-04-14) and released first in Git 2.13.0. Document the versions that
relaxed these restrictions, with the optimistic expectation that this
change will be included in Git 2.40.0.
Here, we disable this check if the trailing hash is all zeroes. We add a
warning to the config option that this may cause undesirable behavior
with older Git versions.
As a quick comparison, I tested 'git update-index --force-write' with
and without index.skipHash=true on a copy of the Linux kernel
repository.
Benchmark 1: with hash
Time (mean ± σ): 46.3 ms ± 13.8 ms [User: 34.3 ms, System: 11.9 ms]
Range (min … max): 34.3 ms … 79.1 ms 82 runs
Benchmark 2: without hash
Time (mean ± σ): 26.0 ms ± 7.9 ms [User: 11.8 ms, System: 14.2 ms]
Range (min … max): 16.3 ms … 42.0 ms 69 runs
Summary
'without hash' ran
1.78 ± 0.76 times faster than 'with hash'
These performance benefits are substantial enough to allow users the
ability to opt-in to this feature, even with the potential confusion
with older 'git fsck' versions.
Test this new config option, both at a command-line level and within a
submodule. The confirmation is currently limited to confirm that 'git
fsck' does not complain about the index. Future updates will make this
test more robust.
It is critical that this test is placed before the test_index_version
tests, since those tests obliterate the .git/config file and hence lose
the setting from GIT_TEST_DEFAULT_HASH, if set.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git format-patch" learned to honor format.mboxrd even when sending
patches to the standard output stream,
* ew/format-patch-mboxrd:
format-patch: support format.mboxrd with --stdout
Bundle URIs part 4.
* ds/bundle-uri-4:
clone: unbundle the advertised bundles
bundle-uri: download bundles from an advertised list
bundle-uri: allow relative URLs in bundle lists
strbuf: introduce strbuf_strip_file_from_path()
bundle-uri: serve bundle.* keys from config
bundle-uri client: add helper for testing server
transport: rename got_remote_heads
bundle-uri client: add boolean transfer.bundleURI setting
clone: request the 'bundle-uri' command when available
t: create test harness for 'bundle-uri' command
protocol v2: add server-side "bundle-uri" skeleton
mboxrd is a more robust output format when used with --stdout
and needs more exposure. Introducing this config knob lets
users choose the more robust format for all their --stdout
uses.
Relying on --pretty=mboxrd and including all of pretty-formats.txt
in the `git format-patch' documentation would likely be
confusing to users. Furthermore, this setting is useful across
multiple invocations. So introduce `format.mboxrd' as a boolean
configuration knob that changes the default --pretty=email format
to --pretty=mboxrd when (and only when) --stdout is in use.
Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The yet-to-be introduced client support for bundle-uri will always
fall back on a full clone, but we'd still like to be able to ignore a
server's bundle-uri advertisement entirely.
The new transfer.bundleURI config option defaults to 'false', but a user
can set it to 'true' to enable checking for bundle URIs from the origin
Git server using protocol v2.
Co-authored-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Git learned pushing submodules without pushing the superproject by
the user specifying --recurse-submodules=only through 6c656c3fe4
("submodules: add RECURSE_SUBMODULES_ONLY value", 2016-12-20) and
225e8bf778 ("push: add option to push only submodules", 2016-12-20).
For users who use this feature regularly, it is desirable to have an
equivalent configuration.
It turns out that such a configuration (push.recurseSubmodules=only) is
already supported, even though it is neither documented nor mentioned
in the commit messages, due to the way the --recurse-submodules=only
feature was implemented (a function used to parse --recurse-submodules
was updated to support "only", but that same function is used to parse
push.recurseSubmodules too). What is left is to document it and test it,
which is what this commit does.
There is a possible point of confusion when recursing into a submodule
that itself has the push.recurseSubmodules=only configuration, because
if a repository has only its submodules pushed and not itself, its
superproject can never be pushed. Therefore, treat such configurations
as being "on-demand", and print a warning message.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
The glossary entries for "commit-graph file" and "reachability
bitmap" have been added.
* po/glossary-around-traversal:
glossary: add reachability bitmap description
glossary: add "commit graph" description
doc: use 'object database' not ODB or abbreviation
doc: use "commit-graph" hyphenation consistently
Enable gc.cruftpacks by default for those who opt into
feature.experimental setting.
* es/mark-gc-cruft-as-experimental:
config: let feature.experimental imply gc.cruftPacks=true
gc: add tests for --cruft and friends
Define the logical elements of a "bundle list", data structure to
store them in-core, format to transfer them, and code to parse
them.
* ds/bundle-uri-3:
bundle-uri: suppress stderr from remote-https
bundle-uri: quiet failed unbundlings
bundle: add flags to verify_bundle()
bundle-uri: fetch a list of bundles
bundle: properly clear all revision flags
bundle-uri: limit recursion depth for bundle lists
bundle-uri: parse bundle list in config format
bundle-uri: unit test "key=value" parsing
bundle-uri: create "key=value" line parsing
bundle-uri: create base key-value pair parsing
bundle-uri: create bundle_list struct and helpers
bundle-uri: use plain string in find_temp_filename()
Note, historical release notes have not been updated.
Signed-off-by: Philip Oakley <philipoakley@iee.email>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
We are interested in exploring whether gc.cruftPacks=true should become
the default value.
To determine whether it is safe to do so, let's encourage more users to
try it out.
Users who have set feature.experimental=true have already volunteered to
try new and possibly-breaking config changes, so let's try this new
default with that set of users.
Signed-off-by: Emily Shaffer <emilyshaffer@google.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The documentation lacks mention of specific <msg-id> that are supported.
While git-help --config will display a list of these options, often
developers' first instinct is to consult the git docs to find valid
config values.
Add a list of fsck error messages, and link to it from the git-fsck
documentation.
Signed-off-by: John Cai <johncai86@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
By default, use of fsmonitor on a repository on networked
filesystem is disabled. Add knobs to make it workable on macOS.
* ed/fsmonitor-on-networked-macos:
fsmonitor: fix leak of warning message
fsmonitor: add documentation for allowRemote and socketDir options
fsmonitor: check for compatability before communicating with fsmonitor
fsmonitor: deal with synthetic firmlinks on macOS
fsmonitor: avoid socket location check if using hook
fsmonitor: relocate socket file if .git directory is remote
fsmonitor: refactor filesystem checks to common interface
There will be two primary ways to advertise a bundle list: as a list of
packet lines in Git's protocol v2 and as a config file served from a
bundle URI. Both of these fundamentally use a list of key-value pairs.
We will use the same set of key-value pairs across these formats.
Create a new bundle_list_update() method that is currently unusued, but
will be used in the next change. It inspects each key to see if it is
understood and then applies it to the given bundle_list. Here are the
keys that we teach Git to understand:
* bundle.version: This value should be an integer. Git currently
understands only version 1 and will ignore the list if the version is
any other value. This version can be increased in the future if we
need to add new keys that Git should not ignore. We can add new
"heuristic" keys without incrementing the version.
* bundle.mode: This value should be one of "all" or "any". If this
mode is not understood, then Git will ignore the list. This mode
indicates whether Git needs all of the bundle list items to make a
complete view of the content or if any single item is sufficient.
The rest of the keys use a bundle identifier "<id>" as part of the key
name. Keys using the same "<id>" describe a single bundle list item.
* bundle.<id>.uri: This stores the URI of the bundle item. This
currently is expected to be an absolute URI, but will be relaxed to be
a relative URI in the future.
While parsing, return an error if a URI key is repeated, since we can
make that restriction with bundle lists.
Make the git_parse_int() method global so we can parse the integer
version value carefully.
Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add documentation for 'fsmonitor.allowRemote' and 'fsmonitor.socketDir'.
Call-out experimental nature of 'fsmonitor.allowRemote' and limited
filesystem support for 'fsmonitor.socketDir'.
Signed-off-by: Eric DeCosta <edecosta@mathworks.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
An earlier patch discussed and fixed a scenario where Git could be used
as a vector to exfiltrate sensitive data through a Docker container when
a potential victim clones a suspicious repository with local submodules
that contain symlinks.
That security hole has since been plugged, but a similar one still
exists. Instead of convincing a would-be victim to clone an embedded
submodule via the "file" protocol, an attacker could convince an
individual to clone a repository that has a submodule pointing to a
valid path on the victim's filesystem.
For example, if an individual (with username "foo") has their home
directory ("/home/foo") stored as a Git repository, then an attacker
could exfiltrate data by convincing a victim to clone a malicious
repository containing a submodule pointing at "/home/foo/.git" with
`--recurse-submodules`. Doing so would expose any sensitive contents in
stored in "/home/foo" tracked in Git.
For systems (such as Docker) that consider everything outside of the
immediate top-level working directory containing a Dockerfile as
inaccessible to the container (with the exception of volume mounts, and
so on), this is a violation of trust by exposing unexpected contents in
the working copy.
To mitigate the likelihood of this kind of attack, adjust the "file://"
protocol's default policy to be "user" to prevent commands that execute
without user input (including recursive submodule initialization) from
taking place by default.
Suggested-by: Jeff King <peff@peff.net>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
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
b22520a37c (grep: allow -E and -n to be turned on by default via
configuration, 2011-03-30). After that in e.g. 6453f7b348 (grep: add
grep.fullName config variable, 2014-03-17) they started drifting
apart, with only grep.fullName being described in the command
documentation.
In 434e6e753f (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"
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.
source: <pull.1285.v2.git.1658002423864.gitgitgadget@gmail.com>
* mb/config-document-include:
config.txt: document include, includeIf
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>
