Change the bitfield added in 58300f4743 (sparse-index: add
index.sparse config option, 2021-03-30) and 3964fc2aae (sparse-index:
add guard to ensure full index, 2021-03-30) to just use an "int"
boolean instead.
It might be smart to optimize the space here in the future, but by
consistently using an "int" we can take its address and pass it to
repo_cfg_bool(), and therefore don't need to handle "sparse_index" as
a special-case when reading the "index.sparse" setting.
There's no corresponding config for "command_requires_full_index", but
let's change it too for consistency and to prevent future bugs
creeping in due to one of these being "unsigned".
Using "int" consistently also prevents subtle bugs or undesired
control flow creeping in here. Before the preceding commit the
initialization of "command_requires_full_index" in
prepare_repo_settings() did nothing, i.e. this:
r->settings.command_requires_full_index = 1
Was redundant to the earlier memset() to -1. Likewise for
"sparse_index" added in 58300f4743 (sparse-index: add index.sparse
config option, 2021-03-30) the code and comment added there was
misleading, we weren't initializing it to off, but re-initializing it
from "1" to "0", and then finally checking the config, and perhaps
setting it to "1" again. I.e. we could have applied this patch before
the preceding commit:
+ assert(r->settings.command_requires_full_index == 1);
r->settings.command_requires_full_index = 1;
/*
* Initialize this as off.
*/
+ assert(r->settings.sparse_index == 1);
r->settings.sparse_index = 0;
if (!repo_config_get_bool(r, "index.sparse", &value) && value)
r->settings.sparse_index = 1;
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Simplify the setup code in repo-settings.c in various ways, making the
code shorter, easier to read, and requiring fewer hacks to do the same
thing as it did before:
Since 7211b9e753 (repo-settings: consolidate some config settings,
2019-08-13) we have memset() the whole "settings" structure to -1 in
prepare_repo_settings(), and subsequently relied on the -1 value.
Most of the fields did not need to be initialized to -1, and because
we were doing that we had the enum labels "UNTRACKED_CACHE_UNSET" and
"FETCH_NEGOTIATION_UNSET" purely to reflect the resulting state
created this memset() in prepare_repo_settings(). No other code used
or relied on them, more on that below.
For the rest most of the subsequent "are we -1, then read xyz" can
simply be removed by re-arranging what we read first. E.g. when
setting the "index.version" setting we should have first read
"feature.experimental", so that it (and "feature.manyfiles") can
provide a default for our "index.version".
Instead the code setting it, added when "feature.manyFiles"[1] was
created, was using the UPDATE_DEFAULT_BOOL() macro added in an earlier
commit[2]. That macro is now gone, since it was only needed for this
pattern of reading things in the wrong order.
This also fixes an (admittedly obscure) logic error where we'd
conflate an explicit "-1" value in the config with our own earlier
memset() -1.
We can also remove the UPDATE_DEFAULT_BOOL() wrapper added in
[3]. Using it is redundant to simply using the return value from
repo_config_get_bool(), which is non-zero if the provided key exists
in the config.
Details on edge cases relating to the memset() to -1, continued from
"more on that below" above:
* UNTRACKED_CACHE_KEEP:
In [4] the "unset" and "keep" handling for core.untrackedCache was
consolidated. But it while we understand the "keep" value, we don't
handle it differently than the case of any other unknown value.
So let's retain UNTRACKED_CACHE_KEEP and remove the
UNTRACKED_CACHE_UNSET setting (which was always implicitly
UNTRACKED_CACHE_KEEP before). We don't need to inform any code
after prepare_repo_settings() that the setting was "unset", as far
as anyone else is concerned it's core.untrackedCache=keep. if
"core.untrackedcache" isn't present in the config.
* FETCH_NEGOTIATION_UNSET & FETCH_NEGOTIATION_NONE:
Since these two two enum fields added in [5] don't rely on the
memzero() setting them to "-1" anymore we don't have to provide
them with explicit values.
1. c6cc4c5afd (repo-settings: create feature.manyFiles setting,
2019-08-13)
2. 31b1de6a09 (commit-graph: turn on commit-graph by default,
2019-08-13)
3. 31b1de6a09 (commit-graph: turn on commit-graph by default,
2019-08-13)
4. ad0fb65999 (repo-settings: parse core.untrackedCache,
2019-08-13)
5. aaf633c2ad (repo-settings: create feature.experimental setting,
2019-08-13)
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Instead of the global ignore_untracked_cache_config variable added in
dae6c322fa (test-dump-untracked-cache: don't modify the untracked
cache, 2016-01-27) we can make use of the new facility to set config
via environment variables added in d8d77153ea (config: allow
specifying config entries via envvar pairs, 2021-01-12).
It's arguably a bit hacky to use setenv() and getenv() to pass
messages between the same program, but since the test helpers are not
the main intended audience of repo-settings.c I think it's better than
hardcoding the test-only special-case in prepare_repo_settings().
This uses the xsetenv() wrapper added in the preceding commit, if we
don't set these in the environment we'll fail in
t7063-status-untracked-cache.sh, but let's fail earlier anyway if that
were to happen.
This breaks any parent process that's potentially using the
GIT_CONFIG_* and GIT_CONFIG_PARAMETERS mechanism to pass one-shot
config setting down to a git subprocess, but in this case we don't
care about the general case of such potential parents. This process
neither spawns other "git" processes, nor is it interested in other
configuration. We might want to pick up other test modes here, but
those will be passed via GIT_TEST_* environment variables.
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When enabled, this config option signals that index writes should
attempt to use sparse-directory entries.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Upcoming changes will introduce modifications to the index format that
allow sparse directories. It will be useful to have a mechanism for
converting those sparse index files into full indexes by walking the
tree at those sparse directories. Name this method ensure_full_index()
as it will guarantee that the index is fully expanded.
This method is not implemented yet, and instead we focus on the
scaffolding to declare it and call it at the appropriate time.
Add a 'command_requires_full_index' member to struct repo_settings. This
will be an indicator that we need the index in full mode to do certain
index operations. This starts as being true for every command, then we
will set it to false as some commands integrate with sparse indexes.
If 'command_requires_full_index' is true, then we will immediately
expand a sparse index to a full one upon reading from disk. This
suffices for now, but we will want to add more callers to
ensure_full_index() later.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git commit-graph write" learned to limit the number of bloom
filters that are computed from scratch with the --max-new-filters
option.
* tb/bloom-improvements:
commit-graph: introduce 'commitGraph.maxNewFilters'
builtin/commit-graph.c: introduce '--max-new-filters=<n>'
commit-graph: rename 'split_commit_graph_opts'
bloom: encode out-of-bounds filters as non-empty
bloom/diff: properly short-circuit on max_changes
bloom: use provided 'struct bloom_filter_settings'
bloom: split 'get_bloom_filter()' in two
commit-graph.c: store maximum changed paths
commit-graph: respect 'commitGraph.readChangedPaths'
t/helper/test-read-graph.c: prepare repo settings
commit-graph: pass a 'struct repository *' in more places
t4216: use an '&&'-chain
commit-graph: introduce 'get_bloom_filter_settings()'
The core.multiPackIndex setting has been around since c4d25228eb
(config: create core.multiPackIndex setting, 2018-07-12), but has been
disabled by default. If a user wishes to use the multi-pack-index
feature, then they must enable this config and run 'git multi-pack-index
write'.
The multi-pack-index feature is relatively stable now, so make the
config option true by default. For users that do not use a
multi-pack-index, the only extra cost will be a file lookup to see if a
multi-pack-index file exists (once per process, per object directory).
Also, this config option will be referenced by an upcoming
"incremental-repack" task in the maintenance builtin, so move the config
option into the repository settings struct. Note that if
GIT_TEST_MULTI_PACK_INDEX=1, then we want to ignore the config option
and treat core.multiPackIndex as enabled.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Git uses the 'core.commitGraph' configuration value to control whether
or not the commit graph is used when parsing commits or performing a
traversal.
Now that commit-graphs can also contain a section for changed-path Bloom
filters, administrators that already have commit-graphs may find it
convenient to use those graphs without relying on their changed-path
Bloom filters. This can happen, for example, during a staged roll-out,
or in the event of an incident.
Introduce 'commitGraph.readChangedPaths' to control whether or not Bloom
filters are read. Note that this configuration is independent from both:
- 'core.commitGraph', to allow flexibility in using all parts of a
commit-graph _except_ for its Bloom filters.
- The '--changed-paths' option for 'git commit-graph write', to allow
reading and writing Bloom filters to be controlled independently.
When the variable is set, pretend as if no Bloom data was specified at
all. This avoids adding additional special-casing outside of the
commit-graph internals.
Suggested-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a noop fetch negotiator. This is introduced to allow partial clones
to skip the unneeded negotiation step when fetching missing objects
using a "git fetch" subprocess. (The implementation of spawning a "git
fetch" subprocess will be done in a subsequent patch.) But this can also
be useful for end users, e.g. as a blunt fix for object corruption.
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The fetch.writeCommitGraph feature makes fetches write out a commit
graph file for the newly downloaded pack on fetch. This improves the
performance of various commands that would perform a revision walk and
eventually ought to be the default for everyone. To prepare for that
future, it's enabled by default for users that set
feature.experimental=true to experience such future defaults.
Alas, for --unshallow fetches from a shallow clone it runs into a
snag: by the time Git has fetched the new objects and is writing a
commit graph, it has performed a revision walk and r->parsed_objects
contains information about the shallow boundary from *before* the
fetch. The commit graph writing code is careful to avoid writing a
commit graph file in shallow repositories, but the new state is not
shallow, and the result is that from that point on, commands like "git
log" make use of a newly written commit graph file representing a
fictional history with the old shallow boundary.
We could fix this by making the commit graph writing code more careful
to avoid writing a commit graph that could have used any grafts or
shallow state, but it is possible that there are other pieces of
mutated state that fetch's commit graph writing code may be relying
on. So disable it in the feature.experimental configuration.
Google developers have been running in this configuration (by setting
fetch.writeCommitGraph=false in the system config) to work around this
bug since it was discovered in April. Once the fix lands, we'll
enable fetch.writeCommitGraph=true again to give it some early testing
before rolling out to a wider audience.
In other words:
- this patch only affects behavior with feature.experimental=true
- it makes feature.experimental match the configuration Google has
been using for the last few months, meaning it would leave users in
a better tested state than without it
- this should improve testing for other features guarded by
feature.experimental, by making feature.experimental safer to use
Reported-by: Jay Conrod <jayconrod@google.com>
Helped-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The pack.useSparse config option was introduced by 3d036eb0
(pack-objects: create pack.useSparse setting, 2019-01-19) and was
first available in v2.21.0. When enabled, the pack-objects process
during 'git push' will use a sparse tree walk when deciding which
trees and blobs to send to the remote. The algorithm was introduced
by d5d2e93 (revision: implement sparse algorithm, 2019-01-16) and
has been in production use by VFS for Git since around that time.
The features.experimental config option also enabled pack.useSparse,
so hopefully that has also increased exposure.
It is worth noting that pack.useSparse has a possibility of
sending more objects across a push, but requires a special
arrangement of exact _copies_ across directories. There is a test
in t5322-pack-objects-sparse.sh that demonstrates this possibility.
This test uses the --sparse option to "git pack-objects" but we
can make it implied by the config value to demonstrate that the
default value has changed.
While updating that test, I noticed that the documentation did not
include an option for --no-sparse, which is now more important than
it was before.
Since the downside is unlikely but the upside is significant, set
the default value of pack.useSparse to true. Remove it from the
set of options implied by features.experimental.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The codepath that reads the index.version configuration was broken
with a recent update, which has been corrected.
* ds/feature-macros:
repo-settings: read an int for index.version
Several config options were combined into a repo_settings struct in
ds/feature-macros, including a move of the "index.version" config
setting in 7211b9e (repo-settings: consolidate some config settings,
2019-08-13).
Unfortunately, that file looked like a lot of boilerplate and what is
clearly a factor of copy-paste overload, the config setting is parsed
with repo_config_ge_bool() instead of repo_config_get_int(). This means
that a setting "index.version=4" would not register correctly and would
revert to the default version of 3.
I caught this while incorporating v2.24.0-rc0 into the VFS for Git
codebase, where we really care that the index is in version 4.
This was not caught by the codebase because the version checks placed
in t1600-index.sh did not test the "basic" scenario enough. Here, we
modify the test to include these normal settings to not be overridden by
features.manyFiles or GIT_INDEX_VERSION. While the "default" version is
3, this is demoted to version 2 in do_write_index() when not necessary.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The commit-graph feature is now on by default, and is being
written during 'git gc' by default. Typically, Git only writes
a commit-graph when a 'git gc --auto' command passes the gc.auto
setting to actualy do work. This means that a commit-graph will
typically fall behind the commits that are being used every day.
To stay updated with the latest commits, add a step to 'git
fetch' to write a commit-graph after fetching new objects. The
fetch.writeCommitGraph config setting enables writing a split
commit-graph, so on average the cost of writing this file is
very small. Occasionally, the commit-graph chain will collapse
to a single level, and this could be slow for very large repos.
For additional use, adjust the default to be true when
feature.experimental is enabled.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The 'feature.experimental' setting includes config options that are
not committed to become defaults, but could use additional testing.
Update the following config settings to take new defaults, and to
use the repo_settings struct if not already using them:
* 'pack.useSparse=true'
* 'fetch.negotiationAlgorithm=skipping'
In the case of fetch.negotiationAlgorithm, the existing logic
would load the config option only when about to use the setting,
so had a die() statement on an unknown string value. This is
removed as now the config is parsed under prepare_repo_settings().
In general, this die() is probably misplaced and not valuable.
A test was removed that checked this die() statement executed.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The feature.manyFiles setting is suitable for repos with many
files in the working directory. By setting index.version=4 and
core.untrackedCache=true, commands such as 'git status' should
improve.
While adding this setting, modify the index version precedence
tests to check how this setting overrides the default for
index.version is unset.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The core.untrackedCache config setting is slightly complicated,
so clarify its use and centralize its parsing into the repo
settings.
The default value is "keep" (returned as -1), which persists the
untracked cache if it exists.
If the value is set as "false" (returned as 0), then remove the
untracked cache if it exists.
If the value is set as "true" (returned as 1), then write the
untracked cache and persist it.
Instead of relying on magic values of -1, 0, and 1, split these
options into an enum. This allows the use of "-1" as a
default value. After parsing the config options, if the value is
unset we can initialize it to UNTRACKED_CACHE_KEEP.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The commit-graph feature has seen a lot of activity in the past
year or so since it was introduced. The feature is a critical
performance enhancement for medium- to large-sized repos, and
does not significantly hurt small repos.
Change the defaults for core.commitGraph and gc.writeCommitGraph
to true so users benefit from this feature by default.
There are several places in the test suite where the environment
variable GIT_TEST_COMMIT_GRAPH is disabled to avoid reading a
commit-graph, if it exists. The config option overrides the
environment, so swap these. Some GIT_TEST_COMMIT_GRAPH assignments
remain, and those are to avoid writing a commit-graph when a new
commit is created.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are a few important config settings that are not loaded
during git_default_config. These are instead loaded on-demand.
Centralize these config options to a single scan, and store
all of the values in a repo_settings struct. The values for
each setting are initialized as negative to indicate "unset".
This centralization will be particularly important in a later
change to introduce "meta" config settings that change the
defaults for these config settings.
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Ævar Arnfjörð Bjarmason
Derrick Stolee
Junio C Hamano
Taylor Blau
Jonathan Tan
Jonathan Nieder