Commit graph

124 commits

Author SHA1 Message Date
Derrick Stolee 9fadb373dd sparse-index: introduce partially-sparse indexes
A future change will present a temporary, in-memory mode where the index
can both contain sparse directory entries but also not be completely
collapsed to the smallest possible sparse directories. This will be
necessary for modifying the sparse-checkout definition while using a
sparse index.

For now, convert the single-bit member 'sparse_index' in 'struct
index_state' to be a an 'enum sparse_index_mode' with three modes:

* INDEX_EXPANDED (0): No sparse directories exist. This is always the
  case for repositories that do not use cone-mode sparse-checkout.

* INDEX_COLLAPSED: Sparse directories may exist. Files outside the
  sparse-checkout cone are reduced to sparse directory entries whenever
  possible.

* INDEX_PARTIALLY_SPARSE: Sparse directories may exist. Some file
  entries outside the sparse-checkout cone may exist. Running
  convert_to_sparse() may further reduce those files to sparse directory
  entries.

The main reason to store this extra information is to allow
convert_to_sparse() to short-circuit when the index is already in
INDEX_EXPANDED mode but to actually do the necessary work when in
INDEX_PARTIALLY_SPARSE mode.

The INDEX_PARTIALLY_SPARSE mode will be used in an upcoming change.

Signed-off-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-05-23 11:08:21 -07:00
Elijah Newren 2d95707a02 sparse-checkout: make --cone the default
Make cone mode the default, and update the documentation accordingly.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-04-21 23:12:38 -07:00
Junio C Hamano d674bf5570 Merge branch 'ep/remove-duplicated-includes'
Code clean-up.

* ep/remove-duplicated-includes:
  attr.h: remove duplicate struct definition
  t/helper/test-run-command.c: delete duplicate include
  builtin/stash.c: delete duplicate include
  builtin/sparse-checkout.c: delete duplicate include
  builtin/gc.c: delete duplicate include
  attr.c: delete duplicate include
2022-03-23 14:09:30 -07:00
Junio C Hamano ccafbbfb4e Merge branch 'ab/plug-random-leaks'
Plug random memory leaks.

* ab/plug-random-leaks:
  repository.c: free the "path cache" in repo_clear()
  range-diff: plug memory leak in read_patches()
  range-diff: plug memory leak in common invocation
  lockfile API users: simplify and don't leak "path"
  commit-graph: stop fill_oids_from_packs() progress on error and free()
  commit-graph: fix memory leak in misused string_list API
  submodule--helper: fix trivial leak in module_add()
  transport: stop needlessly copying bundle header references
  bundle: call strvec_clear() on allocated strvec
  remote-curl.c: free memory in cmd_main()
  urlmatch.c: add and use a *_release() function
  diff.c: free "buf" in diff_words_flush()
  merge-base: free() allocated "struct commit **" list
  index-pack: fix memory leaks
2022-03-13 22:56:18 +00:00
Elia Pinto 07b04ebe86 builtin/sparse-checkout.c: delete duplicate include
cache.h is included more than once.

Signed-off-by: Elia Pinto <gitter.spiros@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-13 22:23:16 +00:00
Junio C Hamano 967176465a Merge branch 'en/sparse-checkout-fixes'
Further polishing of "git sparse-checkout".

* en/sparse-checkout-fixes:
  sparse-checkout: reject arguments in cone-mode that look like patterns
  sparse-checkout: error or warn when given individual files
  sparse-checkout: pay attention to prefix for {set, add}
  sparse-checkout: correctly set non-cone mode when expected
  sparse-checkout: correct reapply's handling of options
2022-03-06 21:25:30 -08:00
Ævar Arnfjörð Bjarmason ef3fe21448 lockfile API users: simplify and don't leak "path"
Fix a memory leak in code added in 6c622f9f0b (commit-graph: write
commit-graph chains, 2019-06-18). We needed to free the "lock_name" if
we encounter errors, and the "graph_name" after we'd run unlink() on
it.

For the case of write_commit_graph_file() refactoring the code to free
the "lock_name" after we were done using the "struct lock_file lk"
would have made the control flow more complex. Luckily we can free the
"lock_file" right after the hold_lock_file_for_update() call, if it
makes use of "path" at all it'll have copied its contents to a "struct
strbuf" of its own.

While I'm at it let's fix code added in fb10ca5b54 (sparse-checkout:
write using lockfile, 2019-11-21) in write_patterns_and_update() to
avoid the same complexity that I thought I needed when I wrote the
initial fix for write_commit_graph_file(). We can free the
"sparse_filename" right after calling hold_lock_file_for_update(), we
don't need to wait until we're exiting the function to do so.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-03-04 13:24:19 -08:00
Junio C Hamano d21d5ddfe6 Merge branch 'ja/i18n-common-messages'
Unify more messages to help l10n.

* ja/i18n-common-messages:
  i18n: fix some misformated placeholders in command synopsis
  i18n: remove from i18n strings that do not hold translatable parts
  i18n: factorize "invalid value" messages
  i18n: factorize more 'incompatible options' messages
2022-02-25 15:47:35 -08:00
Junio C Hamano 6249ce2d1b Merge branch 'ds/sparse-checkout-requires-per-worktree-config'
"git sparse-checkout" wants to work with per-worktree configuration,
but did not work well in a worktree attached to a bare repository.

* ds/sparse-checkout-requires-per-worktree-config:
  config: make git_configset_get_string_tmp() private
  worktree: copy sparse-checkout patterns and config on add
  sparse-checkout: set worktree-config correctly
  config: add repo_config_set_worktree_gently()
  worktree: create init_worktree_config()
  Documentation: add extensions.worktreeConfig details
2022-02-25 15:47:33 -08:00
Elijah Newren 8dd7c4739b sparse-checkout: reject arguments in cone-mode that look like patterns
In sparse-checkout add/set under cone mode, the arguments passed are
supposed to be directories rather than gitignore-style patterns.
However, given the amount of effort spent in the manual discussing
patterns, it is easy for users to assume they need to pass patterns such
as
   /foo/*
or
   !/bar/*/
or perhaps they really do ignore the directory rule and specify a
random gitignore-style pattern like
   *.c

To help catch such mistakes, throw an error if any of the positional
arguments:
  * starts with any of '/!'
  * contains any of '*?[]'

Inform users they can pass --skip-checks if they have a directory that
really does have such special characters in its name.  (We exclude '\'
because of sparse-checkout's special handling of backslashes; see
the MINGW test in t1091.46.)

Reviewed-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-20 00:01:15 -08:00
Elijah Newren 4ce504360b sparse-checkout: error or warn when given individual files
The set and add subcommands accept multiple positional arguments.
The meaning of these arguments differs slightly in the two modes:

Cone mode only accepts directories.  If given a file, it would
previously treat it as a directory, causing not just the file itself to
be included but all sibling files as well -- likely against users'
expectations.  Throw an error if the specified path is a file in the
index.  Provide a --skip-checks argument to allow users to override
(e.g. for the case when the given path IS a directory on another
branch).

Non-cone mode accepts general gitignore patterns.  There are many
reasons to avoid this mode, but one possible reason to use it instead of
cone mode: to be able to select individual files within a directory.
However, if a file is passed to set/add in non-cone mode, you won't be
selecting a single file, you'll be selecting a file with the same name
in any directory.  Thus users will likely want to prefix any paths they
specify with a leading '/' character; warn users if the patterns they
specify exactly name a file because it means they are likely missing
such a leading slash.

Reviewed-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-20 00:01:15 -08:00
Elijah Newren bb8b5e9a90 sparse-checkout: pay attention to prefix for {set, add}
In cone mode, non-option arguments to set & add are clearly paths, and
as such, we should pay attention to prefix.

In non-cone mode, it is not clear that folks intend to provide paths
since the inputs are gitignore-style patterns.  Paying attention to
prefix would prevent folks from doing things like
   git sparse-checkout add /.gitattributes
   git sparse-checkout add '/toplevel-dir/*'
In fact, the former will result in
   fatal: '/.gitattributes' is outside repository...
while the later will result in
   fatal: Invalid path '/toplevel-dir': No such file or directory
despite the fact that both are valid gitignore-style patterns that would
select real files if added to the sparse-checkout file.  This might lead
people to just use the path without the leading slash, potentially
resulting in them grabbing files with the same name throughout the
directory hierarchy contrary to their expectations.  See also [1] and
[2].  Adding prefix seems to just be fraught with error; so for now
simply throw an error in non-cone mode when sparse-checkout set/add are
run from a subdirectory.

[1] https://lore.kernel.org/git/e1934710-e228-adc4-d37c-f706883bd27c@gmail.com/
[2] https://lore.kernel.org/git/CABPp-BHXZ-XLxY0a3wCATfdq=6-EjW62RzbxKAoFPeXfJswD2w@mail.gmail.com/

Helped-by: Junio Hamano <gitster@pobox.com>
Reviewed-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-20 00:01:15 -08:00
Elijah Newren d526b4dbe1 sparse-checkout: correctly set non-cone mode when expected
commit f2e3a218e8 ("sparse-checkout: enable `set` to initialize
sparse-checkout mode", 2021-12-14) made the `set` command able to
initialize sparse-checkout mode, but it also had to function when
sparse-checkout mode was already setup and the user just wanted to
change the sparsity paths.  So, if the user passed --cone or --no-cone,
then we should override the current setting, but if they didn't pass
either, we should use whatever the current cone mode setting is.

Unfortunately, there was a small error in the logic in that it would not
set the in-memory cone mode value (core_sparse_checkout_one) when
--no-cone was specified, but since it did set the config setting on
disk, any subsequent git invocation would correctly get non-cone mode.
As such, the error did not previously matter.  However, a subsequent
commit will add some logic that depends on core_sparse_checkout_cone
being set to the correct mode, so make sure it is set consistently with
the config values we will be writing to disk.

Reviewed-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-20 00:01:15 -08:00
Elijah Newren f748012e01 sparse-checkout: correct reapply's handling of options
Commit 4e256731d6 ("sparse-checkout: enable reapply to take
--[no-]{cone,sparse-index}", 2021-12-14) made it so that reapply could
take additional options but added no tests.  Tests would have shown that
the feature doesn't work because the initial values are set AFTER
parsing the command line options instead of before.  Add a test and set
the initial value at the appropriate time.

Reviewed-by: Derrick Stolee <derrickstolee@github.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-20 00:01:15 -08:00
Junio C Hamano 9210a00d65 Merge branch 'en/sparse-checkout-leakfix'
Leakfix.

* en/sparse-checkout-leakfix:
  sparse-checkout: fix a couple minor memory leaks
2022-02-11 16:56:01 -08:00
Junio C Hamano bb754fe0b8 Merge branch 'jt/sparse-checkout-leading-dir-fix'
"git sparse-checkout init" failed to write into $GIT_DIR/info
directory when the repository was created without one, which has
been corrected to auto-create it.

* jt/sparse-checkout-leading-dir-fix:
  sparse-checkout: create leading directory
2022-02-09 14:21:00 -08:00
Derrick Stolee 7316dc5f6f sparse-checkout: set worktree-config correctly
`git sparse-checkout set/init` enables worktree-specific
configuration[*] by setting extensions.worktreeConfig=true, but neglects
to perform the additional necessary bookkeeping of relocating
`core.bare=true` and `core.worktree` from $GIT_COMMON_DIR/config to
$GIT_COMMON_DIR/config.worktree, as documented in git-worktree.txt. As a
result of this oversight, these settings, which are nonsensical for
secondary worktrees, can cause Git commands to incorrectly consider a
worktree bare (in the case of `core.bare`) or operate on the wrong
worktree (in the case of `core.worktree`). Fix this problem by taking
advantage of the recently-added init_worktree_config() which enables
`extensions.worktreeConfig` and takes care of necessary bookkeeping.

While at it, for backward-compatibility reasons, also stop upgrading the
repository format to "1" since doing so is (unintentionally) not
required to take advantage of `extensions.worktreeConfig`, as explained
by 11664196ac ("Revert "check_repository_format_gently(): refuse
extensions for old repositories"", 2020-07-15).

[*] The main reason to use worktree-specific config for the
sparse-checkout builtin was to avoid enabling sparse-checkout patterns
in one and causing a loss of files in another. If a worktree does not
have a sparse-checkout patterns file, then the sparse-checkout logic
will not kick in on that worktree.

Reported-by: Sean Allred <allred.sean@gmail.com>
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-08 09:49:20 -08:00
Jean-Noël Avila 959d670d1a i18n: remove from i18n strings that do not hold translatable parts
Signed-off-by: Jean-Noël Avila <jn.avila@free.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-02-04 13:58:28 -08:00
Elijah Newren 0f03f04c5c sparse-checkout: fix a couple minor memory leaks
These were introduced in commit 55dfcf9591 ("sparse-checkout: clear
tracked sparse dirs", 2021-09-08) and missed in my review at the time.
Plug the leaks.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-28 13:09:55 -08:00
Jonathan Tan 7f44842ac1 sparse-checkout: create leading directory
When creating the sparse-checkout file, Git does not create the leading
directory, "$GIT_DIR/info", if it does not exist. This causes problems
if the repository does not have that directory. Therefore, ensure that
the leading directory is created.

This is the only "open" in builtin/sparse-checkout.c that does not have
a leading directory check. (The other one in write_patterns_and_update()
does.)

Note that the test needs to explicitly specify a template when running
"git init" because the default template used in the tests has the
"info/" directory included.

Helped-by: Jose Lopes <jabolopes@google.com>
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2022-01-21 12:37:36 -08:00
Junio C Hamano 09481fec21 Merge branch 'ds/sparse-checkout-malformed-pattern-fix'
Certain sparse-checkout patterns that are valid in non-cone mode
led to segfault in cone mode, which has been corrected.

* ds/sparse-checkout-malformed-pattern-fix:
  sparse-checkout: refuse to add to bad patterns
  sparse-checkout: fix OOM error with mixed patterns
  sparse-checkout: fix segfault on malformed patterns
2022-01-10 11:52:49 -08:00
Derrick Stolee a3eca58445 sparse-checkout: refuse to add to bad patterns
When in cone mode sparse-checkout, it is unclear how 'git
sparse-checkout add <dir1> ...' should behave if the existing
sparse-checkout file does not match the cone mode patterns. Change the
behavior to fail with an error message about the existing patterns.

Also, all cone mode patterns start with a '/' character, so add that
restriction. This is necessary for our example test 'cone mode: warn on
bad pattern', but also requires modifying the example sparse-checkout
file we use to test the warnings related to recognizing cone mode
patterns.

This error checking would cause a failure further down the test script
because of a test that adds non-cone mode patterns without cleaning them
up. Perform that cleanup as part of the test now.

Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-30 14:39:57 -08:00
Derrick Stolee 391c3a1020 sparse-checkout: fix OOM error with mixed patterns
Add a test to t1091-sparse-checkout-builtin.sh that would result in an
infinite loop and out-of-memory error before this change. The issue
relies on having non-cone-mode patterns while trying to modify the
patterns in cone-mode.

The fix is simple, allowing us to break from the loop when the input
path does not contain a slash, as the "dir" pattern we added does not.

This is only a fix to the critical out-of-memory error. A better
response to such a strange state will follow in a later change.

Reported-by: Calbabreaker <calbabreaker@gmail.com>
Helped-by: Taylor Blau <me@ttaylorr.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-30 14:39:57 -08:00
Elijah Newren dfac9b609f sparse-checkout: remove stray trailing space
Reported-by: Jiang Xin <worldhello.net@gmail.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-23 11:55:54 -08:00
Elijah Newren 4e256731d6 sparse-checkout: enable reapply to take --[no-]{cone,sparse-index}
Folks may want to switch to or from cone mode, or to or from a
sparse-index without changing their sparsity paths.  Allow them to do so
using the reapply command.

Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Victoria Dye <vdye@github.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-15 11:48:22 -08:00
Elijah Newren f2e3a218e8 sparse-checkout: enable set to initialize sparse-checkout mode
The previously suggested workflow:
  git sparse-checkout init ...
  git sparse-checkout set ...

Suffered from three problems:
  1) It would delete nearly all files in the first step, then
     restore them in the second.  That was poor performance and
     forced unnecessary rebuilds.
  2) The two-step process resulted in two progress bars, which
     was suboptimal from a UI point of view for wrappers that
     invoked both of these commands but only exposed a single
     command to their end users.
  3) With cone mode, the first step would delete nearly all
     ignored files everywhere, because everything was considered
     to be outside of the specified sparsity paths.  (The user was
     not allowed to specify any sparsity paths in the `init` step.)

Avoid these problems by teaching `set` to understand the extra
parameters that `init` takes and performing any necessary initialization
if not already in a sparse checkout.

Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Victoria Dye <vdye@github.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-15 11:48:22 -08:00
Elijah Newren be61fd1181 sparse-checkout: split out code for tweaking settings config
`init` has some code for handling updates to either cone mode or
the sparse-index setting.  We would like to be able to reuse this
elsewhere, namely in `set` and `reapply`.  Split this function out,
and make it slightly more general so it can handle being called from
the new callers.

Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Victoria Dye <vdye@github.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-15 11:48:22 -08:00
Elijah Newren f85751a147 sparse-checkout: disallow --no-stdin as an argument to set
We intentionally added --stdin as an option to `sparse-checkout set`,
but didn't intend for --no-stdin to be permitted as well.

Reported-by: Victoria Dye <vdye@github.com>
Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Victoria Dye <vdye@github.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-15 11:48:21 -08:00
Elijah Newren 45c5e47048 sparse-checkout: add sanity-checks on initial sparsity state
Most sparse-checkout subcommands (list, add, reapply) only make sense
when already in a sparse state.  Add a quick check that will error out
early if this is not the case.

Also document with a comment why we do not exit early in `disable` even
when core.sparseCheckout starts as false.

Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Victoria Dye <vdye@github.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-15 11:48:21 -08:00
Elijah Newren 0b624e039c sparse-checkout: break apart functions for sparse_checkout_(set|add)
sparse_checkout_set() was reused by sparse_checkout_add() with the only
difference being a single parameter being passed to that function.
However, we would like sparse_checkout_set() to do the same work that
sparse_checkout_init() does if sparse checkouts are not already enabled.
To facilitate this transition, give each mode their own copy of the
function.  This does not introduce any behavioral changes; that will
come in a subsequent patch.

Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Victoria Dye <vdye@github.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-15 11:48:21 -08:00
Elijah Newren 1530ff3553 sparse-checkout: pass use_stdin as a parameter instead of as a global
add_patterns_from_input() has relied on a global variable,
set_opts.use_stdin, which has been used by both the `set` and `add`
subcommands of sparse-checkout.  Once we introduce an
add_opts.use_stdin, the hardcoding of set_opts.use_stdin will be
incorrect.  Pass the value as function parameter instead to allow us to
make subsequent changes.

Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Victoria Dye <vdye@github.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-15 11:48:21 -08:00
Derrick Stolee 55dfcf9591 sparse-checkout: clear tracked sparse dirs
When changing the scope of a sparse-checkout using cone mode, we might
have some tracked directories go out of scope. The current logic removes
the tracked files from within those directories, but leaves the ignored
files within those directories. This is a bit unexpected to users who
have given input to Git saying they don't need those directories
anymore.

This is something that is new to the cone mode pattern type: the user
has explicitly said "I want these directories and _not_ those
directories." The typical sparse-checkout patterns more generally apply
to "I want files with with these patterns" so it is natural to leave
ignored files as they are. This focus on directories in cone mode
provides us an opportunity to change the behavior.

Leaving these ignored files in the sparse directories makes it
impossible to gain performance benefits in the sparse index. When we
track into these directories, we need to know if the files are ignored
or not, which might depend on the _tracked_ .gitignore file(s) within
the sparse directory. This depends on the indexed version of the file,
so the sparse directory must be expanded.

We must take special care to look for untracked, non-ignored files in
these directories before deleting them. We do not want to delete any
meaningful work that the users were doing in those directories and
perhaps forgot to add and commit before switching sparse-checkout
definitions. Since those untracked files might be code files that
generated ignored build output, also do not delete any ignored files
from these directories in that case. The users can recover their state
by resetting their sparse-checkout definition to include that directory
and continue. Alternatively, they can see the warning that is presented
and delete the directory themselves to regain the performance they
expect.

By deleting the sparse directories when changing scope (or running 'git
sparse-checkout reapply') we regain these performance benefits as if the
repository was in a clean state.

Since these ignored files are frequently build output or helper files
from IDEs, the users should not need the files now that the tracked
files are removed. If the tracked files reappear, then they will have
newer timestamps than the build artifacts, so the artifacts will need to
be regenerated anyway.

Use the sparse-index as a data structure in order to find the sparse
directories that can be safely deleted. Re-expand the index to a full
one if it was full before.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-07 22:41:10 -07:00
René Scharfe 7431842325 use fspathhash() everywhere
cf2dc1c238 (speed up alt_odb_usable() with many alternates, 2021-07-07)
introduced the function fspathhash() for calculating path hashes while
respecting the configuration option core.ignorecase.  Call it instead of
open-coding it; the resulting code is shorter and less repetitive.

Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-07-30 12:14:27 -07:00
Junio C Hamano 8e97852919 Merge branch 'ds/sparse-index-protections'
Builds on top of the sparse-index infrastructure to mark operations
that are not ready to mark with the sparse index, causing them to
fall back on fully-populated index that they always have worked with.

* ds/sparse-index-protections: (47 commits)
  name-hash: use expand_to_path()
  sparse-index: expand_to_path()
  name-hash: don't add directories to name_hash
  revision: ensure full index
  resolve-undo: ensure full index
  read-cache: ensure full index
  pathspec: ensure full index
  merge-recursive: ensure full index
  entry: ensure full index
  dir: ensure full index
  update-index: ensure full index
  stash: ensure full index
  rm: ensure full index
  merge-index: ensure full index
  ls-files: ensure full index
  grep: ensure full index
  fsck: ensure full index
  difftool: ensure full index
  commit: ensure full index
  checkout: ensure full index
  ...
2021-04-30 13:50:26 +09:00
Derrick Stolee dcc5fd5fd2 sparse-checkout: disable sparse-index
We use 'git sparse-checkout init --cone --sparse-index' to toggle the
sparse-index feature. It makes sense to also disable it when running
'git sparse-checkout disable'. This is particularly important because it
removes the extensions.sparseIndex config option, allowing other tools
to use this Git repository again.

This does mean that 'git sparse-checkout init' will not re-enable the
sparse-index feature, even if it was previously enabled.

While testing this feature, I noticed that the sparse-index was not
being written on the first run, but by a second. This was caught by the
call to 'test-tool read-cache --table'. This requires adjusting some
assignments to core_apply_sparse_checkout and pl.use_cone_patterns in
the sparse_checkout_init() logic.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-30 12:57:48 -07:00
Derrick Stolee 122ba1f7b5 sparse-checkout: toggle sparse index from builtin
The sparse index extension is used to signal that index writes should be
in sparse mode. This was only updated using GIT_TEST_SPARSE_INDEX=1.

Add a '--[no-]sparse-index' option to 'git sparse-checkout init' that
specifies if the sparse index should be used. It also updates the index
to use the correct format, either way. Add a warning in the
documentation that the use of a repository extension might reduce
compatibility with third-party tools. 'git sparse-checkout init' already
sets extension.worktreeConfig, which places most sparse-checkout users
outside of the scope of most third-party tools.

Update t1092-sparse-checkout-compatibility.sh to use this CLI instead of
GIT_TEST_SPARSE_INDEX=1.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-30 12:57:48 -07:00
Derrick Stolee 836e25c51b sparse-checkout: hold pattern list in index
As we modify the sparse-checkout definition, we perform index operations
on a pattern_list that only exists in-memory. This allows easy backing
out in case the index update fails.

However, if the index write itself cares about the sparse-checkout
pattern set, we need access to that in-memory copy. Place a pointer to
a 'struct pattern_list' in the index so we can access this on-demand.
This will be used in the next change which uses the sparse-checkout
definition to filter out directories that are outside the sparse cone.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-30 12:57:46 -07:00
Jeff King 1679d60bfc exclude: add flags parameter to add_patterns()
There are a number of callers of add_patterns() and its sibling
functions. Let's give them a "flags" parameter for adding new options
without having to touch each caller. We'll use this in a future patch to
add O_NOFOLLOW support. But for now each caller just passes 0.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-02-16 09:41:33 -08:00
Derrick Stolee dd23022acb sparse-checkout: load sparse-checkout patterns
A future feature will want to load the sparse-checkout patterns into a
pattern_list, but the current mechanism to do so is a bit complicated.
This is made difficult due to needing to find the sparse-checkout file
in different ways throughout the codebase.

The logic implemented in the new get_sparse_checkout_patterns() was
duplicated in populate_from_existing_patterns() in unpack-trees.c. Use
the new method instead, keeping the logic around handling the struct
unpack_trees_options.

The callers to get_sparse_checkout_filename() in
builtin/sparse-checkout.c manipulate the sparse-checkout file directly,
so it is not appropriate to replace logic in that file with
get_sparse_checkout_patterns().

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-23 17:14:07 -08:00
Jeff King 75d3bee157 sparse-checkout: fill in some options boilerplate
The sparse-checkout passes along argv and argc to its sub-command helper
functions. Many of these sub-commands do not yet take any command-line
options, and ignore those parameters.

Let's instead add empty option lists and make sure we call
parse_options(). That will give a useful error message for something
like:

  git sparse-checkout list --nonsense

which currently just silently ignores the unknown option.

As a bonus, it also silences some -Wunused-parameter warnings.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-30 12:53:48 -07:00
Junio C Hamano 1033b98291 Merge branch 'xl/upgrade-repo-format'
Allow runtime upgrade of the repository format version, which needs
to be done carefully.

There is a rather unpleasant backward compatibility worry with the
last step of this series, but it is the right thing to do in the
longer term.

* xl/upgrade-repo-format:
  check_repository_format_gently(): refuse extensions for old repositories
  sparse-checkout: upgrade repository to version 1 when enabling extension
  fetch: allow adding a filter after initial clone
  repository: add a helper function to perform repository format upgrade
2020-06-29 14:17:24 -07:00
Xin Li 98564d8059 sparse-checkout: upgrade repository to version 1 when enabling extension
The 'extensions' configuration variable gets special meaning in the new
repository version, so when enabling the extension we should upgrade the
repository to version 1.

Signed-off-by: Xin Li <delphij@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-06-05 10:13:30 -07:00
Elijah Newren b5bfc08a97 sparse-checkout: avoid staging deletions of all files
sparse-checkout's purpose is to update the working tree to have it
reflect a subset of the tracked files.  As such, it shouldn't be
switching branches, making commits, downloading or uploading data, or
staging or unstaging changes.  Other than updating the worktree, the
only thing sparse-checkout should touch is the SKIP_WORKTREE bit of the
index.  In particular, this sets up a nice invariant: running
sparse-checkout will never change the status of any file in `git status`
(reflecting the fact that we only set the SKIP_WORKTREE bit if the file
is safe to delete, i.e. if the file is unmodified).

Traditionally, we did a _really_ bad job with this goal.  The
predecessor to sparse-checkout involved manual editing of
.git/info/sparse-checkout and running `git read-tree -mu HEAD`.  That
command would stage and unstage changes and overwrite dirty changes in
the working tree.

The initial implementation of the sparse-checkout command was no better;
it simply invoked `git read-tree -mu HEAD` as a subprocess and had the
same caveats, though this issue came up repeatedly in review comments
and workarounds for the problems were put in place before the feature
was merged[1, 2, 3, 4, 5, 6; especially see 4 & 6].

[1] https://lore.kernel.org/git/CABPp-BFT9A5n=_bx5LsjCvbogqwSjiwgr5amcjgbU1iAk4KLJg@mail.gmail.com/
[2] https://lore.kernel.org/git/CABPp-BEmwSwg4tgJg6nVG8a3Hpn_g-=ZjApZF4EiJO+qVgu4uw@mail.gmail.com/
[3] https://lore.kernel.org/git/CABPp-BFV7TA0qwZCQpHCqx9N+JifyRyuBQ-pZ_oGfe-NOgyh7A@mail.gmail.com/
[4] https://lore.kernel.org/git/CABPp-BHYCCD+Vx5fq35jH82eHc1-P53Lz_aGNpHJNcx9kg2K-A@mail.gmail.com/
[5] https://lore.kernel.org/git/CABPp-BF+JWYZfDqp2Tn4AEKVp4b0YMA=Mbz4Nz62D-gGgiduYQ@mail.gmail.com/
[6] https://lore.kernel.org/git/20191121163706.GV23183@szeder.dev/

However, these workarounds, in addition to disabling the feature in a
number of important cases, also missed one special case.  I'll get back
to it later.

In the 2.27.0 cycle, the disabling of the feature was lifted by finally
replacing the internal equivalent of `git read-tree -mu HEAD` with
something that did what we wanted: the new update_sparsity() function in
unpack-trees.c that only ever updates SKIP_WORKTREE bits in the index
and updates the working tree to match.  This new function handles all
the cases that were problematic for the old implementation, except that
it breaks the same special case that avoided the workarounds of the old
implementation, but broke it in a different way.

So...that brings us to the special case: a git clone performed with
--no-checkout.  As per the meaning of the flag, --no-checkout does not
check out any branch, with the implication that you aren't on one and
need to switch to one after the clone.  Implementationally, HEAD is
still set (so in some sense you are partially on a branch), but
  * the index is "unborn" (non-existent)
  * there are no files in the working tree (other than .git/)
  * the next time git switch (or git checkout) is run it will run
    unpack_trees with `initial_checkout` flag set to true.
It is not until you run, e.g. `git switch <somebranch>` that the index
will be written and files in the working tree populated.

With this special --no-checkout case, the traditional `read-tree -mu
HEAD` behavior would have done the equivalent of acting like checkout --
switch to the default branch (HEAD), write out an index that matches
HEAD, and update the working tree to match.  This special case slipped
through the avoid-making-changes checks in the original sparse-checkout
command and thus continued there.

After update_sparsity() was introduced and used (see commit f56f31af03
("sparse-checkout: use new update_sparsity() function", 2020-03-27)),
the behavior for the --no-checkout case changed:  Due to git's
auto-vivification of an empty in-memory index (see do_read_index() and
note that `must_exist` is false), and due to sparse-checkout's
update_working_directory() code to always write out the index after it
was done, we got a new bug.  That made it so that sparse-checkout would
switch the repository from a clone with an "unborn" index (i.e. still
needing an initial_checkout), to one that had a recorded index with no
entries.  Thus, instead of all the files appearing deleted in `git
status` being known to git as a special artifact of not yet being on a
branch, our recording of an empty index made it suddenly look to git as
though it was definitely on a branch with ALL files staged for deletion!
A subsequent checkout or switch then had to contend with the fact that
it wasn't on an initial_checkout but had a bunch of staged deletions.

Make sure that sparse-checkout changes nothing in the index other than
the SKIP_WORKTREE bit; in particular, when the index is unborn we do not
have any branch checked out so there is no sparsification or
de-sparsification work to do.  Simply return from
update_working_directory() early.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-06-05 08:05:50 -07:00
Elijah Newren 5644ca28cd sparse-checkout: provide a new reapply subcommand
If commands like merge or rebase materialize files as part of their work,
or a previous sparse-checkout command failed to update individual files
due to dirty changes, users may want a command to simply 'reapply' the
sparsity rules.  Provide one.

Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-27 11:33:31 -07:00
Elijah Newren 4ee5d50fc3 sparse-checkout: use improved unpack_trees porcelain messages
setup_unpack_trees_porcelain() provides much improved error/warning
messages; instead of a message that assumes that there is only one path
with a given problem despite being used by code that intentionally is
grouping and showing errors together, it uses a message designed to be
used with groups of paths.  For example, this transforms

    error: Entry '	folder1/a
	folder2/a
    ' not uptodate. Cannot update sparse checkout.

into

    error: Cannot update sparse checkout: the following entries are not up to date:
	folder1/a
	folder2/a

In the past the suboptimal messages were never actually triggered
because we would error out if the working directory wasn't clean before
we even called unpack_trees().  The previous commit changed that,
though, so let's use the better error messages.

Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-27 11:33:30 -07:00
Elijah Newren f56f31af03 sparse-checkout: use new update_sparsity() function
Remove the equivalent of 'git read-tree -mu HEAD' in the sparse-checkout
codepaths for setting the SKIP_WORKTREE bits and instead use the new
update_sparsity() function.

Note that when an issue is hit, the error message splits 'error' and
'Cannot update sparse checkout' on separate lines.  For now, we use two
greps to find both pieces of the error message but subsequent commits
will clean up the messages reported to the user.

Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-27 11:33:30 -07:00
Elijah Newren fa0bde45cd unpack-trees: simplify pattern_list freeing
commit e091228e17 ("sparse-checkout: update working directory
in-process", 2019-11-21) allowed passing a pre-defined set of patterns
to unpack_trees().  However, if o->pl was NULL, it would still read the
existing patterns and use those.  If those patterns were read into a
data structure that was allocated, naturally they needed to be free'd.
However, despite the same function being responsible for knowing about
both the allocation and the free'ing, the logic for tracking whether to
free the pattern_list was hoisted to an outer function with an
additional flag in unpack_trees_options.  Put the logic back in the
relevant function and discard the now unnecessary flag.

Reviewed-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-03-27 11:33:29 -07:00
Junio C Hamano f4d7dfce4d Merge branch 'ds/sparse-add'
"git sparse-checkout" learned a new "add" subcommand.

* ds/sparse-add:
  sparse-checkout: allow one-character directories in cone mode
  sparse-checkout: work with Windows paths
  sparse-checkout: create 'add' subcommand
  sparse-checkout: extract pattern update from 'set' subcommand
  sparse-checkout: extract add_patterns_from_input()
2020-03-05 10:43:02 -08:00
Junio C Hamano 9f3f38769d Merge branch 'rs/strbuf-insertstr'
Code clean-up.

* rs/strbuf-insertstr:
  mailinfo: don't insert header prefix for handle_content_type()
  strbuf: add and use strbuf_insertstr()
2020-02-17 13:22:17 -08:00
Derrick Stolee ef07659926 sparse-checkout: work with Windows paths
When using Windows, a user may run 'git sparse-checkout set A\B\C'
to add the Unix-style path A/B/C to their sparse-checkout patterns.
Normalizing the input path converts the backslashes to slashes before we
add the string 'A/B/C' to the recursive hashset.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-11 09:06:47 -08:00
Derrick Stolee 2631dc879d sparse-checkout: create 'add' subcommand
When using the sparse-checkout feature, a user may want to incrementally
grow their sparse-checkout pattern set. Allow adding patterns using a
new 'add' subcommand. This is not much different from the 'set'
subcommand, because we still want to allow the '--stdin' option and
interpret inputs as directories when in cone mode and patterns
otherwise.

When in cone mode, we are growing the cone. This may actually reduce the
set of patterns when adding directory A when A/B is already a directory
in the cone. Test the different cases: siblings, parents, ancestors.

When not in cone mode, we can only assume the patterns should be
appended to the sparse-checkout file.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-11 09:06:46 -08:00
Derrick Stolee 4bf0c06c71 sparse-checkout: extract pattern update from 'set' subcommand
In anticipation of adding "add" and "remove" subcommands to the
sparse-checkout builtin, extract a modify_pattern_list() method from the
sparse_checkout_set() method. This command will read input from the
command-line or stdin to construct a set of patterns, then modify the
existing sparse-checkout patterns after a successful update of the
working directory.

Currently, the only way to modify the patterns is to replace all of the
patterns. This will be extended in a later update.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-11 08:47:13 -08:00
Derrick Stolee 6fb705abcb sparse-checkout: extract add_patterns_from_input()
In anticipation of extending the sparse-checkout builtin with "add"
and "remove" subcommands, extract the code that fills a pattern list
based on the input values. The input changes depending on the
presence of "--stdin" or the value of core.sparseCheckoutCone.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-11 08:47:11 -08:00
René Scharfe a91cc7fad0 strbuf: add and use strbuf_insertstr()
Add a function for inserting a C string into a strbuf.  Use it
throughout the source to get rid of magic string length constants and
explicit strlen() calls.

Like strbuf_addstr(), implement it as an inline function to avoid the
implicit strlen() calls to cause runtime overhead.

Helped-by: Taylor Blau <me@ttaylorr.com>
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-02-10 09:04:45 -08:00
Derrick Stolee e53ffe2704 sparse-checkout: escape all glob characters on write
The sparse-checkout patterns allow special globs according to
fnmatch(3). When writing cone-mode patterns for paths containing
these characters, they must be escaped.

Use is_glob_special() to check which characters must be escaped
this way, and add a path to the tests that contains all glob
characters at once. Note that ']' is not special, since the
initial bracket '[' is escaped.

Reported-by: Jeff King <peff@peff.net>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-31 13:05:29 -08:00
Derrick Stolee e55682ea26 sparse-checkout: use C-style quotes in 'list' subcommand
When in cone mode, the 'git sparse-checkout list' subcommand lists
the directories included in the sparse cone. When these directories
contain odd characters, such as a backslash, then we need to use
C-style quotes similar to 'git ls-tree'.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-31 13:05:29 -08:00
Derrick Stolee bd64de42de sparse-checkout: unquote C-style strings over --stdin
If a user somehow creates a directory with an asterisk (*) or backslash
(\), then the "git sparse-checkout set" command will struggle to provide
the correct pattern in the sparse-checkout file. When not in cone mode,
the provided pattern is written directly into the sparse-checkout file.
However, in cone mode we expect a list of paths to directories and then
we convert those into patterns.

Even more specifically, the goal is to always allow the following from
the root of a repo:

  git ls-tree --name-only -d HEAD | git sparse-checkout set --stdin

The ls-tree command provides directory names with an unescaped asterisk.
It also quotes the directories that contain an escaped backslash. We
must remove these quotes, then keep the escaped backslashes.

Use unquote_c_style() when parsing lines from stdin. Command-line
arguments will be parsed as-is, assuming the user can do the correct
level of escaping from their environment to match the exact directory
names.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-31 13:05:29 -08:00
Derrick Stolee d585f0e799 sparse-checkout: write escaped patterns in cone mode
If a user somehow creates a directory with an asterisk (*) or backslash
(\), then the "git sparse-checkout set" command will struggle to provide
the correct pattern in the sparse-checkout file. When not in cone mode,
the provided pattern is written directly into the sparse-checkout file.
However, in cone mode we expect a list of paths to directories and then
we convert those into patterns.

However, there is some care needed for the timing of these escapes. The
in-memory pattern list is used to update the working directory before
writing the patterns to disk. Thus, we need the command to have the
unescaped names in the hashsets for the cone comparisons, then escape
the patterns later.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-31 13:05:29 -08:00
Derrick Stolee 3c754067a1 sparse-checkout: create leading directories
The 'git init' command creates the ".git/info" directory and fills it
with some default files. However, 'git worktree add' does not create
the info directory for that worktree. This causes a problem when running
"git sparse-checkout init" inside a worktree. While care was taken to
allow the sparse-checkout config to be specific to a worktree, this
initialization was untested.

Safely create the leading directories for the sparse-checkout file. This
is the safest thing to do even without worktrees, as a user could delete
their ".git/info" directory and expect Git to recover safely.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-01-24 13:26:54 -08:00
Derrick Stolee de11951b03 sparse-checkout: list directories in cone mode
When core.sparseCheckoutCone is enabled, the 'git sparse-checkout set'
command takes a list of directories as input, then creates an ordered
list of sparse-checkout patterns such that those directories are
recursively included and all sibling entries along the parent directories
are also included. Listing the patterns is less user-friendly than the
directories themselves.

In cone mode, and as long as the patterns match the expected cone-mode
pattern types, change the output of 'git sparse-checkout list' to only
show the directories that created the patterns.

With this change, the following piped commands would not change the
working directory:

	git sparse-checkout list | git sparse-checkout set --stdin

The only time this would not work is if core.sparseCheckoutCone is
true, but the sparse-checkout file contains patterns that do not
match the expected pattern types for cone mode.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-30 09:07:18 -08:00
Derrick Stolee 190a65f9db sparse-checkout: respect core.ignoreCase in cone mode
When a user uses the sparse-checkout feature in cone mode, they
add patterns using "git sparse-checkout set <dir1> <dir2> ..."
or by using "--stdin" to provide the directories line-by-line over
stdin. This behaviour naturally looks a lot like the way a user
would type "git add <dir1> <dir2> ..."

If core.ignoreCase is enabled, then "git add" will match the input
using a case-insensitive match. Do the same for the sparse-checkout
feature.

Perform case-insensitive checks while updating the skip-worktree
bits during unpack_trees(). This is done by changing the hash
algorithm and hashmap comparison methods to optionally use case-
insensitive methods.

When this is enabled, there is a small performance cost in the
hashing algorithm. To tease out the worst possible case, the
following was run on a repo with a deep directory structure:

	git ls-tree -d -r --name-only HEAD |
		git sparse-checkout set --stdin

The 'set' command was timed with core.ignoreCase disabled or
enabled. For the repo with a deep history, the numbers were

	core.ignoreCase=false: 62s
	core.ignoreCase=true:  74s (+19.3%)

For reproducibility, the equivalent test on the Linux kernel
repository had these numbers:

	core.ignoreCase=false: 3.1s
	core.ignoreCase=true:  3.6s (+16%)

Now, this is not an entirely fair comparison, as most users
will define their sparse cone using more shallow directories,
and the performance improvement from eb42feca97 ("unpack-trees:
hash less in cone mode" 2019-11-21) can remove most of the
hash cost. For a more realistic test, drop the "-r" from the
ls-tree command to store only the first-level directories.
In that case, the Linux kernel repository takes 0.2-0.25s in
each case, and the deep repository takes one second, plus or
minus 0.05s, in each case.

Thus, we _can_ demonstrate a cost to this change, but it is
unlikely to matter to any reasonable sparse-checkout cone.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-13 12:01:02 -08:00
Derrick Stolee cff4e9138d sparse-checkout: check for dirty status
The index-merge performed by 'git sparse-checkout' will erase any staged
changes, which can lead to data loss. Prevent these attempts by requiring
a clean 'git status' output.

Helped-by: Szeder Gábor <szeder.dev@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-22 16:11:45 +09:00
Derrick Stolee 416adc8711 sparse-checkout: update working directory in-process for 'init'
The 'git sparse-checkout init' subcommand previously wrote directly
to the sparse-checkout file and then updated the working directory.
This may fail if there are modified files not included in the initial
pattern set. However, that left a populated sparse-checkout file.

Use the in-process working directory update to guarantee that the
init subcommand only changes the sparse-checkout file if the working
directory update succeeds.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-22 16:11:45 +09:00
Derrick Stolee fb10ca5b54 sparse-checkout: write using lockfile
If two 'git sparse-checkout set' subcommands are launched at the
same time, the behavior can be unexpected as they compete to write
the sparse-checkout file and update the working directory.

Take a lockfile around the writes to the sparse-checkout file. In
addition, acquire this lock around the working directory update
to avoid two commands updating the working directory in different
ways.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-22 16:11:45 +09:00
Derrick Stolee 99dfa6f970 sparse-checkout: use in-process update for disable subcommand
The 'git sparse-checkout disable' subcommand returns a user to a
full working directory. The old process for doing this required
updating the sparse-checkout file with the "/*" pattern and then
updating the working directory with core.sparseCheckout enabled.
Finally, the sparse-checkout file could be removed and the config
setting disabled.

However, it is valuable to keep a user's sparse-checkout file
intact so they can re-enable the sparse-checkout they previously
used with 'git sparse-checkout init'. This is now possible with
the in-process mechanism for updating the working directory.

Reported-by: Szeder Gábor <szeder.dev@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-22 16:11:45 +09:00
Derrick Stolee e091228e17 sparse-checkout: update working directory in-process
The sparse-checkout builtin used 'git read-tree -mu HEAD' to update the
skip-worktree bits in the index and to update the working directory.
This extra process is overly complex, and prone to failure. It also
requires that we write our changes to the sparse-checkout file before
trying to update the index.

Remove this extra process call by creating a direct call to
unpack_trees() in the same way 'git read-tree -mu HEAD' does. In
addition, provide an in-memory list of patterns so we can avoid
reading from the sparse-checkout file. This allows us to test a
proposed change to the file before writing to it.

An earlier version of this patch included a bug when the 'set' command
failed due to the "Sparse checkout leaves no entry on working directory"
error. It would not rollback the index.lock file, so the replay of the
old sparse-checkout specification would fail. A test in t1091 now
covers that scenario.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-22 16:11:44 +09:00
Derrick Stolee e9de487aa3 sparse-checkout: sanitize for nested folders
If a user provides folders A/ and A/B/ for inclusion in a cone-mode
sparse-checkout file, the parsing logic will notice that A/ appears
both as a "parent" type pattern and as a "recursive" type pattern.
This is unexpected and hence will complain via a warning and revert
to the old logic for checking sparse-checkout patterns.

Prevent this from happening accidentally by sanitizing the folders
for this type of inclusion in the 'git sparse-checkout' builtin.
This happens in two ways:

1. Do not include any parent patterns that also appear as recursive
   patterns.

2. Do not include any recursive patterns deeper than other recursive
   patterns.

In order to minimize duplicate code for scanning parents, create
hashmap_contains_parent() method. It takes a strbuf buffer to
avoid reallocating a buffer when calling in a tight loop.

Helped-by: Eric Wong <e@80x24.org>
Helped-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-22 16:11:44 +09:00
Derrick Stolee af09ce24a9 sparse-checkout: init and set in cone mode
To make the cone pattern set easy to use, update the behavior of
'git sparse-checkout (init|set)'.

Add '--cone' flag to 'git sparse-checkout init' to set the config
option 'core.sparseCheckoutCone=true'.

When running 'git sparse-checkout set' in cone mode, a user only
needs to supply a list of recursive folder matches. Git will
automatically add the necessary parent matches for the leading
directories.

When testing 'git sparse-checkout set' in cone mode, check the
error stream to ensure we do not see any errors. Specifically,
we want to avoid the warning that the patterns do not match
the cone-mode patterns.

Helped-by: Eric Wong <e@80x24.org>
Helped-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-22 16:11:44 +09:00
Derrick Stolee 72918c1ad9 sparse-checkout: create 'disable' subcommand
The instructions for disabling a sparse-checkout to a full
working directory are complicated and non-intuitive. Add a
subcommand, 'git sparse-checkout disable', to perform those
steps for the user.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-22 16:11:44 +09:00
Derrick Stolee 7bffca95ea sparse-checkout: add '--stdin' option to set subcommand
The 'git sparse-checkout set' subcommand takes a list of patterns
and places them in the sparse-checkout file. Then, it updates the
working directory to match those patterns. For a large list of
patterns, the command-line call can get very cumbersome.

Add a '--stdin' option to instead read patterns over standard in.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-22 16:11:44 +09:00
Derrick Stolee f6039a9423 sparse-checkout: 'set' subcommand
The 'git sparse-checkout set' subcommand takes a list of patterns
as arguments and writes them to the sparse-checkout file. Then, it
updates the working directory using 'git read-tree -mu HEAD'.

The 'set' subcommand will replace the entire contents of the
sparse-checkout file. The write_patterns_and_update() method is
extracted from cmd_sparse_checkout() to make it easier to implement
'add' and/or 'remove' subcommands in the future.

If the core.sparseCheckout config setting is disabled, then enable
the config setting in the worktree config. If we set the config
this way and the sparse-checkout fails, then re-disable the config
setting.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-22 16:11:43 +09:00
Derrick Stolee d89f09c828 clone: add --sparse mode
When someone wants to clone a large repository, but plans to work
using a sparse-checkout file, they either need to do a full
checkout first and then reduce the patterns they included, or
clone with --no-checkout, set up their patterns, and then run
a checkout manually. This requires knowing a lot about the repo
shape and how sparse-checkout works.

Add a new '--sparse' option to 'git clone' that initializes the
sparse-checkout file to include the following patterns:

	/*
	!/*/

These patterns include every file in the root directory, but
no directories. This allows a repo to include files like a
README or a bootstrapping script to grow enlistments from that
point.

During the 'git sparse-checkout init' call, we must first look
to see if HEAD is valid, since 'git clone' does not have a valid
HEAD at the point where it initializes the sparse-checkout. The
following checkout within the clone command will create the HEAD
ref and update the working directory correctly.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-22 16:11:43 +09:00
Derrick Stolee bab3c35908 sparse-checkout: create 'init' subcommand
Getting started with a sparse-checkout file can be daunting. Help
users start their sparse enlistment using 'git sparse-checkout init'.
This will set 'core.sparseCheckout=true' in their config, write
an initial set of patterns to the sparse-checkout file, and update
their working directory.

Make sure to use the `extensions.worktreeConfig` setting and write
the sparse checkout config to the worktree-specific config file.
This avoids confusing interactions with other worktrees.

The use of running another process for 'git read-tree' is sub-
optimal. This will be removed in a later change.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-22 16:11:43 +09:00
Derrick Stolee 94c0956b60 sparse-checkout: create builtin with 'list' subcommand
The sparse-checkout feature is mostly hidden to users, as its
only documentation is supplementary information in the docs for
'git read-tree'. In addition, users need to know how to edit the
.git/info/sparse-checkout file with the right patterns, then run
the appropriate 'git read-tree -mu HEAD' command. Keeping the
working directory in sync with the sparse-checkout file requires
care.

Begin an effort to make the sparse-checkout feature a porcelain
feature by creating a new 'git sparse-checkout' builtin. This
builtin will be the preferred mechanism for manipulating the
sparse-checkout file and syncing the working directory.

The documentation provided is adapted from the "git read-tree"
documentation with a few edits for clarity in the new context.
Extra sections are added to hint toward a future change to
a more restricted pattern set.

Helped-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-11-22 16:11:43 +09:00