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@dscho dscho commented Nov 23, 2018

This is a relatively painless successor to #71. The main changes:

  • I also modified the serialized status file format to talk about committable instead of commitable.
  • I dropped 914c991 (pack-objects: ignore ambiguous object warnings, 2018-11-06) which made it into v2.20.0-rc1 as a4544b3.

Ben Peart and others added 30 commits November 23, 2018 20:36
This is just a bug fix to git so that the pager won't close stdin/out
before other atexit functions run. The easy way to repro the bug is to
turn on GIT_TRACE_PERFORMANCE and run a command that runs the pager. Then
notice you don't get your performance data at the end. With this fix, you
do actually get the performance trace data.

Signed-off-by: Ben Peart <Ben.Peart@microsoft.com>
While using the reset --stdin feature on windows path added may have a
\r at the end of the path that wasn't getting removed so didn't match
the path in the index and wasn't reset.

Signed-off-by: Kevin Willford <kewillf@microsoft.com>
Signed-off-by: Saeed Noursalehi <sanoursa@microsoft.com>
Signed-off-by: Johannes Schindelin <johasc@microsoft.com>
This header file will accumulate GVFS-specific definitions.

Signed-off-by: Kevin Willford <kewillf@microsoft.com>
This does not do anything yet. The next patches will add various values
for that config setting that correspond to the various features
offered/required by GVFS.

Signed-off-by: Kevin Willford <kewillf@microsoft.com>
This takes a substantial amount of time, and if the user is reasonably
sure that the files' integrity is not compromised, that time can be saved.

Git no longer verifies the SHA-1 by default, anyway.

Signed-off-by: Kevin Willford <kewillf@microsoft.com>
Signed-off-by: Kevin Willford <kewillf@microsoft.com>
Prevent the sparse checkout to delete files that were marked with
skip-worktree bit and are not in the sparse-checkout file.

This is because everything with the skip-worktree bit turned on is being
virtualized and will be removed with the change of HEAD.

There was only one failing test when running with these changes that was
checking to make sure the worktree narrows on checkout which was
expected since we would no longer be narrowing the worktree.

Signed-off-by: Kevin Willford <kewillf@microsoft.com>
While performing a fetch with a virtual file system we know that there
will be missing objects and we don't want to download them just because
of the reachability of the commits.  We also don't want to download a
pack file with commits, trees, and blobs since these will be downloaded
on demand.

This flag will skip the first connectivity check and by returning zero
will skip the upload pack. It will also skip the second connectivity
check but continue to update the branches to the latest commit ids.

Signed-off-by: Kevin Willford <kewillf@microsoft.com>
Ensure all filters and EOL conversions are blocked when running under
GVFS so that our projected file sizes will match the actual file size
when it is hydrated on the local machine.

Signed-off-by: Ben Peart <Ben.Peart@microsoft.com>
The two existing members of the run_hook*() family, run_hook_ve() and
run_hook_le(), are good for callers that know the precise number of
parameters already. Let's introduce a new sibling that takes an argv
array for callers that want to pass a variable number of parameters.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
The idea is to allow blob objects to be missing from the local repository,
and to load them lazily on demand.

After discussing this idea on the mailing list, we will rename the feature
to "lazy clone" and work more on this.

Signed-off-by: Ben Peart <Ben.Peart@microsoft.com>
Hydrate missing loose objects in check_and_freshen() when running
virtualized. Add test cases to verify read-object hook works when
running virtualized.

This hook is called in check_and_freshen() rather than
check_and_freshen_local() to make the hook work also with alternates.

Helped-by: Kevin Willford <kewillf@microsoft.com>
Signed-off-by: Ben Peart <Ben.Peart@microsoft.com>
…ng objects

This commit converts the existing read_object hook proc model for
downloading missing blobs to use a background process that is started
the first time git encounters a missing blob and stays running until git
exits.  Git and the read-object process communicate via stdin/stdout and
a versioned, capability negotiated interface as documented in
Documentation/technical/read-object-protocol.txt.  The advantage of this
over the previous hook proc is that it saves the overhead of spawning a
new hook process for every missing blob.

The model for the background process was refactored from the recent git
LFS work.  I refactored that code into a shared module (sub-process.c/h)
and then updated convert.c to consume the new library.  I then used the
same sub-process module when implementing the read-object background
process.

Signed-off-by: Ben Peart <Ben.Peart@microsoft.com>
If we are going to write an object there is no use in calling
the read object hook to get an object from a potentially remote
source.  We would rather just write out the object and avoid the
potential round trip for an object that doesn't exist.

This change adds a flag to the check_and_freshen() and
freshen_loose_object() functions' signatures so that the hook
is bypassed when the functions are called before writing loose
objects. The check for a local object is still performed so we
don't overwrite something that has already been written to one
of the objects directories.

Based on a patch by Kevin Willford.

Signed-off-by: Johannes Schindelin <johasc@microsoft.com>
This adds hard-coded call to GVFS.hooks.exe before and after each Git
command runs.

To make sure that this is only called on repositories cloned with GVFS, we
test for the tell-tale .gvfs.

Signed-off-by: Ben Peart <Ben.Peart@microsoft.com>
The use case here is to allow usage statistics to be gathered by
running hooks before and after every hook, and to make that
configurable via hooks.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
GVFS Git introduced pre-command and post-command hooks, to gather usage
statistics and to be able to adjust the worktree if necessary.

As run_hooks() implicitly calls setup_git_directory(), and that
function does surprising things to the global state (sometimes even
changing the current working directory), it cannot be used here.

This commit introduces the pre-command/post-command hooks, based on
the previous patches that culminate in support for running hooks early,
i.e. before setup_git_directory() was called.

Signed-off-by: Ben Peart <Ben.Peart@microsoft.com>
Suggested by Ben Peart.

Signed-off-by: Johannes Schindelin <johasc@microsoft.com>
Signed-off-by: Alejandro Pauly <alpauly@microsoft.com>
When using the sparse-checkout feature, the file might not be on disk
because the skip-worktree bit is on.

Signed-off-by: Kevin Willford <kewillf@microsoft.com>
When using the sparse-checkout feature git should not write to the working
directory for files with the skip-worktree bit on.  With the skip-worktree
bit on the file may or may not be in the working directory and if it is
not we don't want or need to create it by calling checkout_entry.

There are two callers of checkout_target.  Both of which check that the
file does not exist before calling checkout_target.  load_current which
make a call to lstat right before calling checkout_target and
check_preimage which will only run checkout_taret it stat_ret is less than
zero.  It sets stat_ret to zero and only if !stat->cached will it lstat
the file and set stat_ret to something other than zero.

This patch checks if skip-worktree bit is on in checkout_target and just
returns so that the entry doesn't not end up in the working directory.
This is so that apply will not create a file in the working directory,
then update the index but not keep the working directory up to date with
the changes that happened in the index.

Signed-off-by: Kevin Willford <kewillf@microsoft.com>
We need to respect that config setting even if we already know that we
have a repository, but have not yet read the config.

The regression test was written by Alejandro Pauly.

Signed-off-by: Johannes Schindelin <johasc@microsoft.com>
When using the sparse checkout feature the git reset command will add
entries to the index that will have the skip-worktree bit off but will
leave the working directory empty.  File data is lost because the index
version of the files has been changed but there is nothing that is in
the working directory.  This will cause the next status call to show
either deleted for files modified or deleting or nothing for files
added.  The added files should be shown as untracked and modified files
should be shown as modified.

To fix this when the reset is running if there is not a file in the
working directory and if it will be missing with the new index entry or
was not missing in the previous version, we create the previous index
version of the file in the working directory so that status will report
correctly and the files will be availble for the user to deal with.

Signed-off-by: Kevin Willford <kewillf@microsoft.com>
Signed-off-by: Kevin Willford <kewillf@microsoft.com>
jeffhostetler and others added 25 commits November 26, 2018 19:27
The "ahead_behind_flags" field of "struct wt_status" does not
need to be stored in the serialization cache file, since it is
a display property.  Update the code comments in both serialize
and deserialize to reflect that.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Changes to the global or repo-local excludes files can change the
results returned by "git status" for untracked files.  Therefore,
it is important that the exclude-file values used during serialization
are still current at the time of deserialization.

Teach "git status --serialize" to report metadata on the user's global
exclude file (which defaults to "$XDG_HOME/git/ignore") and for the
repo-local excludes file (which is in ".git/info/excludes").  Serialize
will record the pathnames and mtimes for these files in the serialization
header (next to the mtime data for the .git/index file).

Teach "git status --deserialize" to validate this new metadata.  If either
exclude file has changed since the serialization-cache-file was written,
then deserialize will reject the cache file and force a full/normal status
run.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Teach `git status --deserialize` to either wait indefintely
or immediately fail if the status serialization cache file
is stale.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
serialize-status: serialize global and repo-local exclude file metadata
…x has been redirected

Fixes #13

Some git commands spawn helpers and redirect the index to a different
location.  These include "difftool -d" and the sequencer
(i.e. `git rebase -i`, `git cherry-pick` and `git revert`) and others.
In those instances we don't want to update their temporary index with
our virtualization data.

Helped-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Ben Peart <Ben.Peart@microsoft.com>
The virtual file system code incorrectly treated symlinks as directories
instead of regular files.  This meant symlinks were not included even if
they are listed in the list of files returned by the core.virtualFilesystem
hook proc.  Fixes #25

Signed-off-by: Ben Peart <Ben.Peart@microsoft.com>
virtualfilesystem: don't run the virtual file system hook if the index has been redirected
Add check to see if a directory is included in the virtualfilesystem
before checking the directory hashmap.  This allows a directory entry
like foo/ to find all untracked files in subdirectories.
virtualfilesystem: fix bug with symlinks being ignored
Create a new unified tracing facility for git.  The eventual intent is to
replace the current trace_printf* and trace_performance* routines with a
unified set of git_trace2* routines.

In addition to the usual printf-style API, trace2 provides higer-level
event verbs with fixed-fields allowing structured data to be written.
This makes post-processing and analysis easier for external tools.

Trace2 defines 3 output targets.  These are set using the environment
variables "GIT_TR2", "GIT_TR2_PERF", and "GIT_TR2_EVENT".  These may be
set to "1" or to an absolute pathname (just like the current GIT_TRACE).

* GIT_TR2 is intended to be a replacement for GIT_TRACE and logs command
  summary data.

* GIT_TR2_PERF is intended as a replacement for GIT_TRACE_PERFORMANCE.
  It extends the output with columns for the command process, thread,
  repo, absolute and relative elapsed times.  It reports events for
  child process start/stop, thread start/stop, and per-thread function
  nesting.

* GIT_TR2_EVENT is a new structured format. It writes event data as a
  series of JSON records.

Calls to trace2 functions log to any of the 3 output targets enabled
without the need to call different trace_printf* or trace_performance*
routines.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Add trace2_region_enter() and trace2_region_leave() calls around the
various phases of a status scan.  This gives elapsed time for each
phase in the GIT_TR2_PERF and GIT_TR2_EVENT trace target.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Classify editor, pager, and sub-process child processes.

The former two can be used to identify interactive commands,
for example.  A later effort could classify other types of
commands, such as "gc", "hook", and etc.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Add trace2 events when reading and writing the index.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Add trace2 region and data events describing attempts to deserialize
status data using a status cache.

A category:status, label:deserialize region is pushed around the
deserialize code.

Deserialization results when reading from a file are:
    category:status, path   = <path>
    category:status, polled = <number_of_attempts>
    category:status, result = "ok" | "reject"

When reading from STDIN are:
    category:status, path   = "STDIN"
    category:status, result = "ok" | "reject"

Status will fallback and run a normal status scan when a "reject"
is reported (unless "--deserialize-wait=fail").  If "ok" is reported,
status was able to use the status cache and avoid scanning the workdir.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
…uded

Add check to see if a directory is included in the virtualfilesystem
before checking the directory hashmap. This allows a directory entry
like foo/ to find all untracked files in subdirectories.
When studying the performance of 'git push' we would like to know
how much time is spent at various parts of the command. One area
that could cause performance trouble is 'git pack-objects'.

Add trace2 regions around the three main actions taken in this
command:

1. Enumerate objects.
2. Prepare pack.
3. Write pack-file.

Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
(Experimental) Trace2 base plus GVFS extensions
William Baker reported that the non-built-in rebase and stash fail to
run the post-command hook (which is important for VFS for Git, though).

The reason is that an `exec()` will replace the current process by the
newly-exec'ed one (our Windows-specific emulation cannot do that, and
does not even try, so this is only an issue on Linux/macOS). As a
consequence, not even the atexit() handlers are run, including the
one running the post-command hook.

To work around that, let's spawn the legacy rebase/stash and exit with
the reported exit code.
We want to make `git push` faster, but we need to know where the time is going!

There are likely four places where the time is going:

1. The info/refs call and force-update checking at the beginning.
2. The `git pack-objects` call that creates a pack-file to send to the server.
3. Sending the data to the server.
4. Waiting for the server to verify the pack-file.

This PR adds `trace2_region_` calls inside `git pack-objects` so we can track the time in item (2). The rest could be interpreted from the start and end time of the entire command after we know this region. The server-side verification is something we can track using server telemetry.
…tash`

William Baker reported that the non-built-in rebase and stash fail to
run the post-command hook (which is important for VFS for Git, though).

The reason is that an `exec()` will replace the current process by the
newly-exec'ed one (our Windows-specific emulation cannot do that, and
does not even try, so this is only an issue on Linux/macOS). As a
consequence, not even the atexit() handlers are run, including the
one running the post-command hook.

To work around that, let's spawn the legacy rebase/stash and exit with
the reported exit code.
This includes commits that fixup!-revert all the midx-related commits from our GVFS branch and replaces them with the exact commits that are being merged upstream. This should automatically remove the commits during our next version rebase-and-merge action.

Changes upstream:
- The builtin is called 'git multi-pack-index'.
- The command-line takes a 'write' verb and an '--object-dir' parameter.
- We no longer have a 'midx-head' or '*.midx' files.
- Instead, we have a 'multi-pack-index' file in the pack-dir.
- It no longer makes sense to specify '--update-head'
@dscho dscho force-pushed the tentative/gvfs-2.20.0-rc1 branch from 9c7b3c3 to 29870a0 Compare November 26, 2018 18:27
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dscho commented Dec 2, 2018

Closing in favor of #81.

@dscho dscho closed this Dec 2, 2018
@dscho dscho deleted the tentative/gvfs-2.20.0-rc1 branch February 8, 2019 15:43
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9 participants