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Junio C Hamano a737e1f1d2 Merge branch 'mt/parallel-checkout-part-3'
The final part of "parallel checkout".

* mt/parallel-checkout-part-3:
  ci: run test round with parallel-checkout enabled
  parallel-checkout: add tests related to .gitattributes
  t0028: extract encoding helpers to lib-encoding.sh
  parallel-checkout: add tests related to path collisions
  parallel-checkout: add tests for basic operations
  checkout-index: add parallel checkout support
  builtin/checkout.c: complete parallel checkout support
  make_transient_cache_entry(): optionally alloc from mem_pool
2021-05-16 21:05:23 +09:00
Matheus Tavares 9616882780 make_transient_cache_entry(): optionally alloc from mem_pool
Allow make_transient_cache_entry() to optionally receive a mem_pool
struct in which it should allocate the entry. This will be used in the
following patch, to store some transient entries which should persist
until parallel checkout finishes.

Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-05-05 12:25:25 +09:00
Junio C Hamano a1cac26cc6 Merge branch 'mt/parallel-checkout-part-2'
The checkout machinery has been taught to perform the actual
write-out of the files in parallel when able.

* mt/parallel-checkout-part-2:
  parallel-checkout: add design documentation
  parallel-checkout: support progress displaying
  parallel-checkout: add configuration options
  parallel-checkout: make it truly parallel
  unpack-trees: add basic support for parallel checkout
2021-04-30 13:50:26 +09:00
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
Matheus Tavares 1c4d6f46be parallel-checkout: support progress displaying
Original-patch-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-19 11:57:05 -07:00
Matheus Tavares 7531e4b66e parallel-checkout: add configuration options
Make parallel checkout configurable by introducing two new settings:
checkout.workers and checkout.thresholdForParallelism. The first defines
the number of workers (where one means sequential checkout), and the
second defines the minimum number of entries to attempt parallel
checkout.

To decide the default value for checkout.workers, the parallel version
was benchmarked during three operations in the linux repo, with cold
cache: cloning v5.8, checking out v5.8 from v2.6.15 (checkout I) and
checking out v5.8 from v5.7 (checkout II). The four tables below show
the mean run times and standard deviations for 5 runs in: a local file
system on SSD, a local file system on HDD, a Linux NFS server, and
Amazon EFS (all on Linux). Each parallel checkout test was executed with
the number of workers that brings the best overall results in that
environment.

Local SSD:
             Sequential             10 workers            Speedup
Clone        8.805 s ± 0.043 s      3.564 s ± 0.041 s     2.47 ± 0.03
Checkout I   9.678 s ± 0.057 s      4.486 s ± 0.050 s     2.16 ± 0.03
Checkout II  5.034 s ± 0.072 s      3.021 s ± 0.038 s     1.67 ± 0.03

Local HDD:
             Sequential             10 workers             Speedup
Clone        32.288 s ± 0.580 s     30.724 s ± 0.522 s    1.05 ± 0.03
Checkout I   54.172 s ±  7.119 s    54.429 s ± 6.738 s    1.00 ± 0.18
Checkout II  40.465 s ± 2.402 s     38.682 s ± 1.365 s    1.05 ± 0.07

Linux NFS server (v4.1, on EBS, single availability zone):

             Sequential             32 workers            Speedup
Clone        240.368 s ± 6.347 s    57.349 s ± 0.870 s    4.19 ± 0.13
Checkout I   242.862 s ± 2.215 s    58.700 s ± 0.904 s    4.14 ± 0.07
Checkout II  65.751 s ± 1.577 s     23.820 s ± 0.407 s    2.76 ± 0.08

EFS (v4.1, replicated over multiple availability zones):

             Sequential             32 workers            Speedup
Clone        922.321 s ± 2.274 s    210.453 s ± 3.412 s   4.38 ± 0.07
Checkout I   1011.300 s ± 7.346 s   297.828 s ± 0.964 s   3.40 ± 0.03
Checkout II  294.104 s ± 1.836 s    126.017 s ± 1.190 s   2.33 ± 0.03

The above benchmarks show that parallel checkout is most effective on
repositories located on an SSD or over a distributed file system. For
local file systems on spinning disks, and/or older machines, the
parallelism does not always bring a good performance. For this reason,
the default value for checkout.workers is one, a.k.a. sequential
checkout.

To decide the default value for checkout.thresholdForParallelism,
another benchmark was executed in the "Local SSD" setup, where parallel
checkout showed to be beneficial. This time, we compared the runtime of
a `git checkout -f`, with and without parallelism, after randomly
removing an increasing number of files from the Linux working tree. The
"sequential fallback" column below corresponds to the executions where
checkout.workers was 10 but checkout.thresholdForParallelism was equal
to the number of to-be-updated files plus one (so that we end up writing
sequentially). Each test case was sampled 15 times, and each sample had
a randomly different set of files removed. Here are the results:

             sequential fallback   10 workers           speedup
10   files    772.3 ms ± 12.6 ms   769.0 ms ± 13.6 ms   1.00 ± 0.02
20   files    780.5 ms ± 15.8 ms   775.2 ms ±  9.2 ms   1.01 ± 0.02
50   files    806.2 ms ± 13.8 ms   767.4 ms ±  8.5 ms   1.05 ± 0.02
100  files    833.7 ms ± 21.4 ms   750.5 ms ± 16.8 ms   1.11 ± 0.04
200  files    897.6 ms ± 30.9 ms   730.5 ms ± 14.7 ms   1.23 ± 0.05
500  files   1035.4 ms ± 48.0 ms   677.1 ms ± 22.3 ms   1.53 ± 0.09
1000 files   1244.6 ms ± 35.6 ms   654.0 ms ± 38.3 ms   1.90 ± 0.12
2000 files   1488.8 ms ± 53.4 ms   658.8 ms ± 23.8 ms   2.26 ± 0.12

From the above numbers, 100 files seems to be a reasonable default value
for the threshold setting.

Note: Up to 1000 files, we observe a drop in the execution time of the
parallel code with an increase in the number of files. This is a rather
odd behavior, but it was observed in multiple repetitions. Above 1000
files, the execution time increases according to the number of files, as
one would expect.

About the test environments: Local SSD tests were executed on an
i7-7700HQ (4 cores with hyper-threading) running Manjaro Linux. Local
HDD tests were executed on an Intel(R) Xeon(R) E3-1230 (also 4 cores
with hyper-threading), HDD Seagate Barracuda 7200.14 SATA 3.1, running
Debian. NFS and EFS tests were executed on an Amazon EC2 c5n.xlarge
instance, with 4 vCPUs. The Linux NFS server was running on a m6g.large
instance with 2 vCPUSs and a 1 TB EBS GP2 volume. Before each timing,
the linux repository was removed (or checked out back to its previous
state), and `sync && sysctl vm.drop_caches=3` was executed.

Co-authored-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-19 11:57:05 -07:00
Matheus Tavares 04155bdad8 unpack-trees: add basic support for parallel checkout
This new interface allows us to enqueue some of the entries being
checked out to later uncompress them, apply in-process filters, and
write out the files in parallel. For now, the parallel checkout
machinery is enabled by default and there is no user configuration, but
run_parallel_checkout() just writes the queued entries in sequence
(without spawning additional workers). The next patch will actually
implement the parallelism and, later, we will make it configurable.

Note that, to avoid potential data races, not all entries are eligible
for parallel checkout. Also, paths that collide on disk (e.g.
case-sensitive paths in case-insensitive file systems), are detected by
the parallel checkout code and skipped, so that they can be safely
sequentially handled later. The collision detection works like the
following:

- If the collision was at basename (e.g. 'a/b' and 'a/B'), the framework
  detects it by looking for EEXIST and EISDIR errors after an
  open(O_CREAT | O_EXCL) failure.

- If the collision was at dirname (e.g. 'a/b' and 'A'), it is detected
  at the has_dirs_only_path() check, which is done for the leading path
  of each item in the parallel checkout queue.

Both verifications rely on the fact that, before enqueueing an entry for
parallel checkout, checkout_entry() makes sure that there is no file at
the entry's path and that its leading components are all real
directories. So, any later change in these conditions indicates that
there was a collision (either between two parallel-eligible entries or
between an eligible and an ineligible one).

After all parallel-eligible entries have been processed, the collided
(and thus, skipped) entries are sequentially fed to checkout_entry()
again. This is similar to the way the current code deals with
collisions, overwriting the previously checked out entries with the
subsequent ones. The only difference is that, since we no longer create
the files in the same order that they appear on index, we are not able
to determine which of the colliding entries will survive on disk (for
the classic code, it is always the last entry).

Co-authored-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Co-authored-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-19 11:57:05 -07:00
Junio C Hamano c47679d040 Merge branch 'mt/parallel-checkout-part-1'
Preparatory API changes for parallel checkout.

* mt/parallel-checkout-part-1:
  entry: add checkout_entry_ca() taking preloaded conv_attrs
  entry: move conv_attrs lookup up to checkout_entry()
  entry: extract update_ce_after_write() from write_entry()
  entry: make fstat_output() and read_blob_entry() public
  entry: extract a header file for entry.c functions
  convert: add classification for conv_attrs struct
  convert: add get_stream_filter_ca() variant
  convert: add [async_]convert_to_working_tree_ca() variants
  convert: make convert_attrs() and convert structs public
2021-04-02 14:43:14 -07:00
Junio C Hamano 9210c68d2a Merge branch 'mt/checkout-remove-nofollow'
When "git checkout" removes a path that does not exist in the
commit it is checking out, it wasn't careful enough not to follow
symbolic links, which has been corrected.

* mt/checkout-remove-nofollow:
  checkout: don't follow symlinks when removing entries
  symlinks: update comment on threaded_check_leading_path()
2021-03-30 14:35:36 -07:00
Derrick Stolee 13e1331247 unpack-trees: allow sparse directories
The index_pos_by_traverse_info() currently throws a BUG() when a
directory entry exists exactly in the index. We need to consider that it
is possible to have a directory in a sparse index as long as that entry
is itself marked with the skip-worktree bit.

The 'pos' variable is assigned a negative value if an exact match is not
found. Since a directory name can be an exact match, it is no longer an
error to have a nonnegative 'pos' value.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-30 12:57:47 -07:00
Derrick Stolee 6863df3550 unpack-trees: ensure full index
The next change will translate full indexes into sparse indexes at write
time. The existing logic provides a way for every sparse index to be
expanded to a full index at read time. However, there are cases where an
index is written and then continues to be used in-memory to perform
further updates.

unpack_trees() is frequently called after such a write. In particular,
commands like 'git reset' do this double-update of the index.

Ensure that we have a full index when entering unpack_trees(), but only
when command_requires_full_index is true. This is always true at the
moment, but we will later relax that after unpack_trees() is updated to
handle sparse directory entries.

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
Matheus Tavares d052cc0382 entry: extract a header file for entry.c functions
The declarations of entry.c's public functions and structures currently
reside in cache.h. Although not many, they contribute to the size of
cache.h and, when changed, cause the unnecessary recompilation of
modules that don't really use these functions. So let's move them to a
new entry.h header. While at it let's also move a comment related to
checkout_entry() from entry.c to entry.h as it's more useful to describe
the function there.

Original-patch-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-23 10:34:05 -07:00
Junio C Hamano f5c73f69fd Merge branch 'dl/stash-show-untracked'
"git stash show" learned to optionally show untracked part of the
stash.

* dl/stash-show-untracked:
  stash show: learn stash.showIncludeUntracked
  stash show: teach --include-untracked and --only-untracked
2021-03-22 14:00:24 -07:00
Junio C Hamano 1dd4e74522 Merge branch 'js/fsmonitor-unpack-fix'
The data structure used by fsmonitor interface was not properly
duplicated during an in-core merge, leading to use-after-free etc.

* js/fsmonitor-unpack-fix:
  fsmonitor: do not forget to release the token in `discard_index()`
  fsmonitor: fix memory corruption in some corner cases
2021-03-19 15:25:37 -07:00
Matheus Tavares fab78a0c3d checkout: don't follow symlinks when removing entries
At 1d718a5108 ("do not overwrite untracked symlinks", 2011-02-20),
symlink.c:check_leading_path() started returning different codes for
FL_ENOENT and FL_SYMLINK. But one of its callers, unlink_entry(), was
not adjusted for this change, so it started to follow symlinks on the
leading path of to-be-removed entries. Fix that and add a regression
test.

Note that since 1d718a5108 check_leading_path() no longer differentiates
the case where it found a symlink in the path's leading components from
the cases where it found a regular file or failed to lstat() the
component. So, a side effect of this current patch is that
unlink_entry() now returns early in all of these three cases. And
because we no longer try to unlink such paths, we also don't get the
warning from remove_or_warn().

For the regular file and symlink cases, it's questionable whether the
warning was useful in the first place: unlink_entry() removes tracked
paths that should no longer be present in the state we are checking out
to. If the path had its leading dir replaced by another file, it means
that the basename already doesn't exist, so there is no need for a
warning. Sure, we are leaving a regular file or symlink behind at the
path's dirname, but this file is either untracked now (so again, no
need to warn), or it will be replaced by a tracked file during the next
phase of this checkout operation.

As for failing to lstat() one of the leading components, the basename
might still exist only we cannot unlink it (e.g. due to the lack of the
required permissions). Since the user expect it to be removed
(especially with checkout's --no-overlay option), add back the warning
in this more relevant case.

Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-18 12:58:10 -07:00
Johannes Schindelin 3dfd30598b fsmonitor: fix memory corruption in some corner cases
In 56c6910028 (fsmonitor: change last update timestamp on the
index_state to opaque token, 2020-01-07), we forgot to adjust the part
of `unpack_trees()` that copies the FSMonitor "last-update" information
that we copy from the source index to the result index since 679f2f9fdd
(unpack-trees: skip stat on fsmonitor-valid files, 2019-11-20).

Since the "last-update" information is no longer a 64-bit number, but a
free-form string that has been allocated, we need to duplicate it rather
than just copying it.

This is important because there _are_ cases when `unpack_trees()` will
perform a oneway merge that implicitly calls `refresh_fsmonitor()`
(which will allocate that "last-update" token). This happens _after_
that token was copied into the result index. However, we _then_ call
`check_updates()` on that index, which will _also_ call
`refresh_fsmonitor()`, accessing the "last-update" string, which by now
would be released already.

In the instance that lead to this patch, this caused a segmentation
fault during a lengthy, complicated rebase involving the todo command
`reset` that (crucially) had to updated many files. Unfortunately, it
seems very hard to trigger that crash, therefore this patch is not
accompanied by a regression test.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-17 12:19:26 -07:00
Junio C Hamano 56a57652ef Sync with Git 2.30.2 for CVE-2021-21300
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-08 16:09:07 -08:00
Denton Liu d3c7bf73bd stash show: teach --include-untracked and --only-untracked
Stash entries can be made with untracked files via
`git stash push --include-untracked`. However, because the untracked
files are stored in the third parent of the stash entry and not the
stash entry itself, running `git stash show` does not include the
untracked files as part of the diff.

With --include-untracked, untracked paths, which are recorded in the
third-parent if it exists, are shown in addition to the paths that have
modifications between the stash base and the working tree in the stash.

It is possible to manually craft a malformed stash entry where duplicate
untracked files in the stash entry will mask tracked files. We detect
and error out in that case via a custom unpack_trees() callback:
stash_worktree_untracked_merge().

Also, teach stash the --only-untracked option which only shows the
untracked files of a stash entry. This is similar to `git show stash^3`
but it is nice to provide a convenient abstraction for it so that users
do not have to think about the underlying implementation.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-05 14:31:26 -08:00
Johannes Schindelin d7bdabe52f Sync with 2.28.1
* maint-2.28:
  Git 2.28.1
  Git 2.27.1
  Git 2.26.3
  Git 2.25.5
  Git 2.24.4
  Git 2.23.4
  Git 2.22.5
  Git 2.21.4
  Git 2.20.5
  Git 2.19.6
  Git 2.18.5
  Git 2.17.6
  unpack_trees(): start with a fresh lstat cache
  run-command: invalidate lstat cache after a command finished
  checkout: fix bug that makes checkout follow symlinks in leading path
2021-02-12 15:50:14 +01:00
Johannes Schindelin 2d1142a3e8 Sync with 2.26.3
* maint-2.26:
  Git 2.26.3
  Git 2.25.5
  Git 2.24.4
  Git 2.23.4
  Git 2.22.5
  Git 2.21.4
  Git 2.20.5
  Git 2.19.6
  Git 2.18.5
  Git 2.17.6
  unpack_trees(): start with a fresh lstat cache
  run-command: invalidate lstat cache after a command finished
  checkout: fix bug that makes checkout follow symlinks in leading path
2021-02-12 15:50:04 +01:00
Johannes Schindelin 8f80393c14 Sync with 2.25.5
* maint-2.25:
  Git 2.25.5
  Git 2.24.4
  Git 2.23.4
  Git 2.22.5
  Git 2.21.4
  Git 2.20.5
  Git 2.19.6
  Git 2.18.5
  Git 2.17.6
  unpack_trees(): start with a fresh lstat cache
  run-command: invalidate lstat cache after a command finished
  checkout: fix bug that makes checkout follow symlinks in leading path
2021-02-12 15:49:59 +01:00
Johannes Schindelin 97d1dcb1ef Sync with 2.24.4
* maint-2.24:
  Git 2.24.4
  Git 2.23.4
  Git 2.22.5
  Git 2.21.4
  Git 2.20.5
  Git 2.19.6
  Git 2.18.5
  Git 2.17.6
  unpack_trees(): start with a fresh lstat cache
  run-command: invalidate lstat cache after a command finished
  checkout: fix bug that makes checkout follow symlinks in leading path
2021-02-12 15:49:55 +01:00
Johannes Schindelin 92ac04b8ee Sync with 2.23.4
* maint-2.23:
  Git 2.23.4
  Git 2.22.5
  Git 2.21.4
  Git 2.20.5
  Git 2.19.6
  Git 2.18.5
  Git 2.17.6
  unpack_trees(): start with a fresh lstat cache
  run-command: invalidate lstat cache after a command finished
  checkout: fix bug that makes checkout follow symlinks in leading path
2021-02-12 15:49:50 +01:00
Johannes Schindelin 4bd06fd490 Sync with 2.22.5
* maint-2.22:
  Git 2.22.5
  Git 2.21.4
  Git 2.20.5
  Git 2.19.6
  Git 2.18.5
  Git 2.17.6
  unpack_trees(): start with a fresh lstat cache
  run-command: invalidate lstat cache after a command finished
  checkout: fix bug that makes checkout follow symlinks in leading path
2021-02-12 15:49:45 +01:00
Johannes Schindelin bcf08f33d8 Sync with 2.21.4
* maint-2.21:
  Git 2.21.4
  Git 2.20.5
  Git 2.19.6
  Git 2.18.5
  Git 2.17.6
  unpack_trees(): start with a fresh lstat cache
  run-command: invalidate lstat cache after a command finished
  checkout: fix bug that makes checkout follow symlinks in leading path
2021-02-12 15:49:41 +01:00
Johannes Schindelin b1726b1a38 Sync with 2.20.5
* maint-2.20:
  Git 2.20.5
  Git 2.19.6
  Git 2.18.5
  Git 2.17.6
  unpack_trees(): start with a fresh lstat cache
  run-command: invalidate lstat cache after a command finished
  checkout: fix bug that makes checkout follow symlinks in leading path
2021-02-12 15:49:35 +01:00
Johannes Schindelin 804963848e Sync with 2.19.6
* maint-2.19:
  Git 2.19.6
  Git 2.18.5
  Git 2.17.6
  unpack_trees(): start with a fresh lstat cache
  run-command: invalidate lstat cache after a command finished
  checkout: fix bug that makes checkout follow symlinks in leading path
2021-02-12 15:49:17 +01:00
Johannes Schindelin fb049fd85b Sync with 2.18.5
* maint-2.18:
  Git 2.18.5
  Git 2.17.6
  unpack_trees(): start with a fresh lstat cache
  run-command: invalidate lstat cache after a command finished
  checkout: fix bug that makes checkout follow symlinks in leading path
2021-02-12 15:47:47 +01:00
Johannes Schindelin 9b77cec89b Sync with 2.17.6
* maint-2.17:
  Git 2.17.6
  unpack_trees(): start with a fresh lstat cache
  run-command: invalidate lstat cache after a command finished
  checkout: fix bug that makes checkout follow symlinks in leading path
2021-02-12 15:47:42 +01:00
Matheus Tavares 22539ec3b5 unpack_trees(): start with a fresh lstat cache
We really want to avoid relying on stale information.

Signed-off-by: Matheus Tavares <matheus.bernardino@usp.br>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
2021-02-12 15:47:02 +01:00
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
Derrick Stolee fb0882648e cache-tree: clean up cache_tree_update()
Make the method safer by allocating a cache_tree member for the given
index_state if it is not already present. This is preferrable to a
BUG() statement or returning with an error because future callers will
want to populate an empty cache-tree using this method.

Callers can also remove their conditional allocations of cache_tree.

Also drop local variables that can be found directly from the 'istate'
parameter.

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
Derrick Stolee c338898a47 unpack-trees: add trace2 regions
The unpack_trees() method is quite complicated and its performance can
change dramatically depending on how it is used. We already have some
performance tracing regions, but they have not been updated to the
trace2 API. Do so now.

We already have trace2 regions in unpack_trees.c:clear_ce_flags(), which
uses a linear scan through the index without recursing into trees.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-04 15:23:08 -08:00
Jeff King c972bf4cf5 strvec: convert remaining callers away from argv_array name
We eventually want to drop the argv_array name and just use strvec
consistently. There's no particular reason we have to do it all at once,
or care about interactions between converted and unconverted bits.
Because of our preprocessor compat layer, the names are interchangeable
to the compiler (so even a definition and declaration using different
names is OK).

This patch converts all of the remaining files, as the resulting diff is
reasonably sized.

The conversion was done purely mechanically with:

  git ls-files '*.c' '*.h' |
  xargs perl -i -pe '
    s/ARGV_ARRAY/STRVEC/g;
    s/argv_array/strvec/g;
  '

We'll deal with any indentation/style fallouts separately.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-28 15:02:18 -07:00
Jeff King dbbcd44fb4 strvec: rename files from argv-array to strvec
This requires updating #include lines across the code-base, but that's
all fairly mechanical, and was done with:

  git ls-files '*.c' '*.h' |
  xargs perl -i -pe 's/argv-array.h/strvec.h/'

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-28 15:02:17 -07:00
Junio C Hamano fde4622c08 Merge branch 'en/sparse-checkout'
Consistency fix to a topic already in 'master'.

* en/sparse-checkout:
  unpack-trees: also allow get_progress() to work on a different index
2020-05-20 08:33:29 -07:00
Elijah Newren 6c34239de6 unpack-trees: also allow get_progress() to work on a different index
commit b0a5a12a60 ("unpack-trees: allow check_updates() to work on a
different index", 2020-03-27) allowed check_updates() to work on a
different index, but it called get_progress() which was hardcoded to
work on o->result much like check_updates() had been.  Update it to also
accept an index parameter and have check_updates() pass that parameter
along so that both are working on the same index.

Noticed-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-05-15 07:59:27 -07:00
Junio C Hamano ce1adb1157 Merge branch 'ds/sparse-updates-oob-access-fix'
The code to skip unmerged paths in the index when sparse checkout
is in use would have made out-of-bound access of the in-core index
when the last path was unmerged, which has been corrected.

* ds/sparse-updates-oob-access-fix:
  unpack-trees: avoid array out-of-bounds error
2020-05-13 12:19:20 -07:00
Junio C Hamano e9acbd6836 Merge branch 'ds/sparse-allow-empty-working-tree'
The sparse-checkout patterns have been forbidden from excluding all
paths, leaving an empty working tree, for a long time.  This
limitation has been lifted.

* ds/sparse-allow-empty-working-tree:
  sparse-checkout: stop blocking empty workdirs
2020-05-08 14:25:06 -07:00
Derrick Stolee 0eeb3be4c4 unpack-trees: avoid array out-of-bounds error
The loop in warn_conflicted_path() that checks for the count of
entries with the same path uses "i+count" for the array
entry. However, the loop only verifies that the value of count is
below the array size. Fix this by adding i to the condition.

I hit this condition during a test of the in-tree sparse-checkout
feature, so it is exercised by the end of the series.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
[jc: readability fix]
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-05-08 11:01:27 -07:00
Derrick Stolee ace224ac5f sparse-checkout: stop blocking empty workdirs
Remove the error condition when updating the sparse-checkout leaves
an empty working directory.

This behavior was added in 9e1afb167 (sparse checkout: inhibit empty
worktree, 2009-08-20). The comment was added in a7bc906f2 (Add
explanation why we do not allow to sparse checkout to empty working
tree, 2011-09-22) in response to a "dubious" comment in 84563a624
(unpack-trees.c: cosmetic fix, 2010-12-22).

With the recent "cone mode" and "git sparse-checkout init [--cone]"
command, it is common to set a reasonable sparse-checkout pattern
set of

	/*
	!/*/

which matches only files at root. If the repository has no such files,
then their "git sparse-checkout init" command will fail.

Now that we expect this to be a common pattern, we should not have the
commands fail on an empty working directory. If it is a confusing
result, then the user can recover with "git sparse-checkout disable"
or "git sparse-checkout set". This is especially simple when using cone
mode.

Reported-by: Lars Schneider <larsxschneider@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-05-04 12:57:15 -07:00
Junio C Hamano 48eee46d6a Merge branch 'en/sparse-checkout'
"sparse-checkout" UI improvements.

* en/sparse-checkout:
  sparse-checkout: provide a new reapply subcommand
  unpack-trees: failure to set SKIP_WORKTREE bits always just a warning
  unpack-trees: provide warnings on sparse updates for unmerged paths too
  unpack-trees: make sparse path messages sound like warnings
  unpack-trees: split display_error_msgs() into two
  unpack-trees: rename ERROR_* fields meant for warnings to WARNING_*
  unpack-trees: move ERROR_WOULD_LOSE_SUBMODULE earlier
  sparse-checkout: use improved unpack_trees porcelain messages
  sparse-checkout: use new update_sparsity() function
  unpack-trees: add a new update_sparsity() function
  unpack-trees: pull sparse-checkout pattern reading into a new function
  unpack-trees: do not mark a dirty path with SKIP_WORKTREE
  unpack-trees: allow check_updates() to work on a different index
  t1091: make some tests a little more defensive against failures
  unpack-trees: simplify pattern_list freeing
  unpack-trees: simplify verify_absent_sparse()
  unpack-trees: remove unused error type
  unpack-trees: fix minor typo in comment
2020-04-29 16:15:30 -07:00
Junio C Hamano 8f5dc5a4af Merge branch 'jt/avoid-prefetch-when-able-in-diff'
"git diff" in a partial clone learned to avoid lazy loading blob
objects in more casese when they are not needed.

* jt/avoid-prefetch-when-able-in-diff:
  diff: restrict when prefetching occurs
  diff: refactor object read
  diff: make diff_populate_filespec_options struct
  promisor-remote: accept 0 as oid_nr in function
2020-04-28 15:50:04 -07:00
Jonathan Tan db7ed7418b promisor-remote: accept 0 as oid_nr in function
There are 3 callers to promisor_remote_get_direct() that first check if
the number of objects to be fetched is equal to 0. Fold that check into
promisor_remote_get_direct(), and in doing so, be explicit as to what
promisor_remote_get_direct() does if oid_nr is 0 (it returns 0, success,
immediately).

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-04-02 12:42:32 -07:00
Elijah Newren 681c637b4a unpack-trees: failure to set SKIP_WORKTREE bits always just a warning
Setting and clearing of the SKIP_WORKTREE bit is not only done when
users run 'sparse-checkout'; other commands such as 'checkout' also run
through unpack_trees() which has logic for handling this special bit.
As such, we need to consider how they handle special cases.  A couple
comparison points should help explain the rationale for changing how
unpack_trees() handles these bits:

    Ignoring sparse checkouts for a moment, if you are switching
    branches and have dirty changes, it is only considered an error that
    will prevent the branch switching from being successful if the dirty
    file happens to be one of the paths with different contents.

    SKIP_WORKTREE has always been considered advisory; for example, if
    rebase or merge need or even want to materialize a path as part of
    their work, they have always been allowed to do so regardless of the
    SKIP_WORKTREE setting.  This has been used for unmerged paths, but
    it was often used for paths it wasn't needed just because it made
    the code simpler.  It was a best-effort consideration, and when it
    materialized paths contrary to the SKIP_WORKTREE setting, it was
    never required to even print a warning message.

In the past if you trying to run e.g. 'git checkout' and:
  1) you had a path that was materialized and had some dirty changes
  2) the path was listed in $GITDIR/info/sparse-checkout
  3) this path did not different between the current and target branches
then despite the comparison points above, the inability to set
SKIP_WORKTREE was treated as a *hard* error that would abort the
checkout operation.  This is completely inconsistent with how
SKIP_WORKTREE is handled elsewhere, and rather annoying for users as
leaving the paths materialized in the working copy (with a simple
warning) should present no problem at all.

Downgrade any errors from inability to toggle the SKIP_WORKTREE bit to a
warning and allow the operations to continue.

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 ebb568b9e2 unpack-trees: provide warnings on sparse updates for unmerged paths too
When sparse-checkout runs to update the list of sparsity patterns, it
gives warnings if it can't remove paths from the working tree because
those files have dirty changes.  Add a similar warning for unmerged
paths as well.

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 22ab0b37d8 unpack-trees: make sparse path messages sound like warnings
The messages for problems with sparse paths are phrased as errors that
cause the operation to abort, even though we are not making the
operation abort.  Reword the messages to make sense in their new
context.

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 6271d77cb1 unpack-trees: split display_error_msgs() into two
display_error_msgs() is never called to show messages of both ERROR_*
and WARNING_* types at the same time; it is instead called multiple
times, separately for each type.  Since we want to display these types
differently, make two slightly different versions of this function.

A subsequent commit will further modify unpack_trees() and how it calls
the new display_warning_msgs().

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 1ac83f42da unpack-trees: rename ERROR_* fields meant for warnings to WARNING_*
We want to treat issues with setting the SKIP_WORKTREE bit as a warning
rather than an error; rename the enum values to reflect this intent as
a simple step towards that goal.

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 cd002c1561 unpack-trees: move ERROR_WOULD_LOSE_SUBMODULE earlier
A minor change, but we want to convert the sparse messages to warnings
and this allows us to group warnings and errors.

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