Commit Graph

325 Commits

Author SHA1 Message Date
Junio C Hamano
76b620d816 Merge branch 'nd/exclusion-regression-fix'
The ignore mechanism saw a few regressions around untracked file
listing and sparse checkout selection areas in 2.7.0; the change
that is responsible for the regression has been reverted.

* nd/exclusion-regression-fix:
  Revert "dir.c: don't exclude whole dir prematurely if neg pattern may match"
2016-01-20 11:43:33 -08:00
Junio C Hamano
7a450b48e7 Merge branch 'nd/dir-exclude-cleanup'
The "exclude_list" structure has the usual "alloc, nr" pair of
fields to be used by ALLOC_GROW(), but clear_exclude_list() forgot
to reset 'alloc' to 0 when it cleared 'nr'to discard the managed
array.

* nd/dir-exclude-cleanup:
  dir.c: clean the entire struct in clear_exclude_list()
2016-01-20 11:43:24 -08:00
Nguyễn Thái Ngọc Duy
8c722360d1 Revert "dir.c: don't exclude whole dir prematurely if neg pattern may match"
This reverts commit 57534ee77d. The
feature added in that commit requires that patterns behave the same way
from anywhere. But some patterns can behave differently depending on
current "working" directory. The conditions to catch and avoid these
patterns are too loose. The untracked listing[1] and sparse-checkout
selection[2] can become incorrect as a result.

  [1] http://article.gmane.org/gmane.comp.version-control.git/283520
  [2] http://article.gmane.org/gmane.comp.version-control.git/283532

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-01-08 11:24:14 -08:00
Nguyễn Thái Ngọc Duy
2653a8c6fa dir.c: clean the entire struct in clear_exclude_list()
Make sure "el" can be reuseable again. The problem was el->alloc is
not cleared and may cause segfaults next time because add_exclude()
thinks el->excludes (being NULL) has enough space. Just clear the
entire struct to be safe.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-12-28 12:48:27 -08:00
Junio C Hamano
69fe31887b Merge branch 'dt/name-hash-dir-entry-fix'
The name-hash subsystem that is used to cope with case insensitive
filesystems keeps track of directories and their on-filesystem
cases for all the paths in the index by holding a pointer to a
randomly chosen cache entry that is inside the directory (for its
ce->ce_name component).  This pointer was not updated even when the
cache entry was removed from the index, leading to use after free.
This was fixed by recording the path for each directory instead of
borrowing cache entries and restructuring the API somewhat.

* dt/name-hash-dir-entry-fix:
  name-hash: don't reuse cache_entry in dir_entry
2015-10-29 13:59:19 -07:00
David Turner
41284eb0f9 name-hash: don't reuse cache_entry in dir_entry
Stop reusing cache_entry in dir_entry; doing so causes a
use-after-free bug.

During merges, we free entries that we no longer need in the
destination index.  But those entries might have also been stored in
the dir_entry cache, and when a later call to add_to_index found them,
they would be used after being freed.

To prevent this, change dir_entry to store a copy of the name instead
of a pointer to a cache_entry.  This entails some refactoring of code
that expects the cache_entry.

Keith McGuigan <kmcguigan@twitter.com> diagnosed this bug and wrote
the initial patch, but this version does not use any of Keith's code.

Helped-by: Keith McGuigan <kmcguigan@twitter.com>
Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-10-21 12:47:38 -07:00
Junio C Hamano
78891795df Merge branch 'jk/war-on-sprintf'
Many allocations that is manually counted (correctly) that are
followed by strcpy/sprintf have been replaced with a less error
prone constructs such as xstrfmt.

Macintosh-specific breakage was noticed and corrected in this
reroll.

* jk/war-on-sprintf: (70 commits)
  name-rev: use strip_suffix to avoid magic numbers
  use strbuf_complete to conditionally append slash
  fsck: use for_each_loose_file_in_objdir
  Makefile: drop D_INO_IN_DIRENT build knob
  fsck: drop inode-sorting code
  convert strncpy to memcpy
  notes: document length of fanout path with a constant
  color: add color_set helper for copying raw colors
  prefer memcpy to strcpy
  help: clean up kfmclient munging
  receive-pack: simplify keep_arg computation
  avoid sprintf and strcpy with flex arrays
  use alloc_ref rather than hand-allocating "struct ref"
  color: add overflow checks for parsing colors
  drop strcpy in favor of raw sha1_to_hex
  use sha1_to_hex_r() instead of strcpy
  daemon: use cld->env_array when re-spawning
  stat_tracking_info: convert to argv_array
  http-push: use an argv_array for setup_revisions
  fetch-pack: use argv_array for index-pack / unpack-objects
  ...
2015-10-20 15:24:01 -07:00
Junio C Hamano
6652939ce8 Merge branch 'js/icase-wt-detection'
On a case insensitive filesystems, setting GIT_WORK_TREE variable
using a random cases that does not agree with what the filesystem
thinks confused Git that it wasn't inside the working tree.

* js/icase-wt-detection:
  setup: fix "inside work tree" detection on case-insensitive filesystems
2015-10-15 15:43:39 -07:00
Junio C Hamano
506d8f1b39 Merge branch 'nd/ignore-then-not-ignore'
Allow a later "!/abc/def" to override an earlier "/abc" that
appears in the same .gitignore file to make it easier to express
"everything in /abc directory is ignored, except for ...".

* nd/ignore-then-not-ignore:
  dir.c: don't exclude whole dir prematurely if neg pattern may match
  dir.c: make last_exclude_matching_from_list() run til the end
2015-10-07 13:38:17 -07:00
Jeff King
00b6c178c3 use strbuf_complete to conditionally append slash
When working with paths in strbufs, we frequently want to
ensure that a directory contains a trailing slash before
appending to it. We can shorten this code (and make the
intent more obvious) by calling strbuf_complete.

Most of these cases are trivially identical conversions, but
there are two things to note:

  - in a few cases we did not check that the strbuf is
    non-empty (which would lead to an out-of-bounds memory
    access). These were generally not triggerable in
    practice, either from earlier assertions, or typically
    because we would have just fed the strbuf to opendir(),
    which would choke on an empty path.

  - in a few cases we indexed the buffer with "original_len"
    or similar, rather than the current sb->len, and it is
    not immediately obvious from the diff that they are the
    same. In all of these cases, I manually verified that
    the strbuf does not change between the assignment and
    the strbuf_complete call.

This does not convert cases which look like:

  if (sb->len && !is_dir_sep(sb->buf[sb->len - 1]))
	  strbuf_addch(sb, '/');

as those are obviously semantically different. Some of these
cases arguably should be doing that, but that is out of
scope for this change, which aims purely for cleanup with no
behavior change (and at least it will make such sites easier
to find and examine in the future, as we can grep for
strbuf_complete).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-10-05 11:08:06 -07:00
Johannes Schindelin
63ec5e1fec setup: fix "inside work tree" detection on case-insensitive filesystems
Git has a config variable to indicate that it is operating on a file
system that is case-insensitive: core.ignoreCase. But the
`dir_inside_of()` function did not respect that. As a result, if Git's
idea of the current working directory disagreed in its upper/lower case
with the `GIT_WORK_TREE` variable (e.g. `C:\test` vs `c:\test`) the
user would be greeted by the error message

	fatal: git-am cannot be used without a working tree.

when trying to run a rebase.

This fixes https://github.com/git-for-windows/git/issues/402 (reported by
Daniel Harding).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-09-28 10:49:06 -07:00
Nguyễn Thái Ngọc Duy
57534ee77d dir.c: don't exclude whole dir prematurely if neg pattern may match
If there is a pattern "!foo/bar", this patch makes it not exclude "foo"
right away. This gives us a chance to examine "foo" and re-include
"foo/bar".

In order for it to detect that the directory under examination should
not be excluded right away, in other words it is a parent directory of a
negative pattern, the "directory path" of the negative pattern must be
literal. Patterns like "!f?o/bar" can't stop "foo" from being excluded.

Basename matching (i.e. "no slashes in the pattern") or must-be-dir
matching (i.e. "trailing slash in the pattern") does not work well with
this. For example, if we descend in "foo" and are examining "foo/abc",
current code for "foo/" pattern will check if path "foo/abc", not "foo",
is a directory. The same problem with basename matching. These may need
big code reorg to make it work.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-09-21 11:06:47 -07:00
Nguyễn Thái Ngọc Duy
e6efecc46a dir.c: make last_exclude_matching_from_list() run til the end
The next patch adds some post processing to the result value before it's
returned to the caller. Keep all branches reach the end of the function,
so we can do it all in one place.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-09-21 11:06:03 -07:00
Junio C Hamano
8833ccd7d0 Merge branch 'dt/untracked-subdir' into maint
The experimental untracked-cache feature were buggy when paths with
a few levels of subdirectories are involved.

* dt/untracked-subdir:
  untracked cache: fix entry invalidation
  untracked-cache: fix subdirectory handling
  t7063: use --force-untracked-cache to speed up a bit
  untracked-cache: support sparse checkout
2015-09-17 12:12:29 -07:00
Junio C Hamano
038226ebc6 Merge branch 'dt/untracked-subdir'
The experimental untracked-cache feature were buggy when paths with
a few levels of subdirectories are involved.

* dt/untracked-subdir:
  untracked cache: fix entry invalidation
  untracked-cache: fix subdirectory handling
2015-08-28 12:32:15 -07:00
Junio C Hamano
8c9155e031 Merge branch 'jk/git-path'
git_path() and mkpath() are handy helper functions but it is easy
to misuse, as the callers need to be careful to keep the number of
active results below 4.  Their uses have been reduced.

* jk/git-path:
  memoize common git-path "constant" files
  get_repo_path: refactor path-allocation
  find_hook: keep our own static buffer
  refs.c: remove_empty_directories can take a strbuf
  refs.c: avoid git_path assignment in lock_ref_sha1_basic
  refs.c: avoid repeated git_path calls in rename_tmp_log
  refs.c: simplify strbufs in reflog setup and writing
  path.c: drop git_path_submodule
  refs.c: remove extra git_path calls from read_loose_refs
  remote.c: drop extraneous local variable from migrate_file
  prefer mkpathdup to mkpath in assignments
  prefer git_pathdup to git_path in some possibly-dangerous cases
  add_to_alternates_file: don't add duplicate entries
  t5700: modernize style
  cache.h: complete set of git_path_submodule helpers
  cache.h: clarify documentation for git_path, et al
2015-08-19 14:48:56 -07:00
Junio C Hamano
b083703ce3 Merge branch 'cb/uname-in-untracked' into maint
An experimental "untracked cache" feature used uname(2) in a
slightly unportable way.

* cb/uname-in-untracked:
  untracked: fix detection of uname(2) failure
2015-08-19 14:41:28 -07:00
Nguyễn Thái Ngọc Duy
73f9145fbf untracked cache: fix entry invalidation
First, the current code in untracked_cache_invalidate_path() is wrong
because it can only handle paths "a" or "a/b", not "a/b/c" because
lookup_untracked() only looks for entries directly under the given
directory. In the last case, it will look for the entry "b/c" in
directory "a" instead. This means if you delete or add an entry in a
subdirectory, untracked cache may become out of date because it does not
invalidate properly. This is noticed by David Turner.

The second problem is about invalidation inside a fully untracked/excluded
directory. In this case we may have to invalidate back to root. See the
comment block for detail.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-08-19 10:40:55 -07:00
David Turner
2e5910f276 untracked-cache: fix subdirectory handling
Previously, some calls lookup_untracked would pass a full path.  But
lookup_untracked assumes that the portion of the path up to and
including to the untracked_cache_dir has been removed.  So
lookup_untracked would be looking in the untracked_cache for 'foo' for
'foo/bar' (instead of just looking for 'bar').  This would cause
untracked cache corruption.

Instead, treat_directory learns to track the base length of the parent
directory, so that only the last path component is passed to
lookup_untracked.

Helped-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-08-19 10:40:24 -07:00
Junio C Hamano
1c09276e34 Merge branch 'dt/untracked-sparse'
Allow untracked cache (experimental) to be used when sparse
checkout (experimental) is also in use.

* dt/untracked-sparse:
  untracked-cache: support sparse checkout
2015-08-17 15:07:52 -07:00
Jeff King
f932729cc7 memoize common git-path "constant" files
One of the most common uses of git_path() is to pass a
constant, like git_path("MERGE_MSG"). This has two
drawbacks:

  1. The return value is a static buffer, and the lifetime
     is dependent on other calls to git_path, etc.

  2. There's no compile-time checking of the pathname. This
     is OK for a one-off (after all, we have to spell it
     correctly at least once), but many of these constant
     strings appear throughout the code.

This patch introduces a series of functions to "memoize"
these strings, which are essentially globals for the
lifetime of the program. We compute the value once, take
ownership of the buffer, and return the cached value for
subsequent calls.  cache.h provides a helper macro for
defining these functions as one-liners, and defines a few
common ones for global use.

Using a macro is a little bit gross, but it does nicely
document the purpose of the functions. If we need to touch
them all later (e.g., because we learned how to change the
git_dir variable at runtime, and need to invalidate all of
the stored values), it will be much easier to have the
complete list.

Note that the shared-global functions have separate, manual
declarations. We could do something clever with the macros
(e.g., expand it to a declaration in some places, and a
declaration _and_ a definition in path.c). But there aren't
that many, and it's probably better to stay away from
too-magical macros.

Likewise, if we abandon the C preprocessor in favor of
generating these with a script, we could get much fancier.
E.g., normalizing "FOO/BAR-BAZ" into "git_path_foo_bar_baz".
But the small amount of saved typing is probably not worth
the resulting confusion to readers who want to grep for the
function's definition.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-08-10 15:37:14 -07:00
Junio C Hamano
8e699cdb9f Merge branch 'cb/uname-in-untracked'
An experimental "untracked cache" feature used uname(2) in a
slightly unportable way.

* cb/uname-in-untracked:
  untracked: fix detection of uname(2) failure
2015-08-03 11:01:26 -07:00
David Turner
7687252f3f untracked-cache: support sparse checkout
Remove a check that would disable the untracked cache for sparse
checkouts.  Add tests that ensure that the untracked cache works with
sparse checkouts -- specifically considering the case that a file
foo/bar is checked out, but foo/.gitignore is not.

Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-07-31 10:56:18 -07:00
Charles Bailey
100e433741 untracked: fix detection of uname(2) failure
According to POSIX specification uname(2) must return -1 on failure
and a non-negative value on success.  Although many implementations
do return 0 on success it is valid to return any positive value for
success.  In particular, Solaris returns 1.

Signed-off-by: Charles Bailey <cbailey32@bloomberg.net>
Reviewed-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-07-17 14:39:59 -07:00
Junio C Hamano
4ba5bb5531 Merge branch 'rs/janitorial'
Code clean-up.

* rs/janitorial:
  dir: remove unused variable sb
  clean: remove unused variable buf
  use file_exists() to check if a file exists in the worktree
2015-06-01 12:45:15 -07:00
Junio C Hamano
38ccaf93bb Merge branch 'nd/untracked-cache'
Teach the index to optionally remember already seen untracked files
to speed up "git status" in a working tree with tons of cruft.

* nd/untracked-cache: (24 commits)
  git-status.txt: advertisement for untracked cache
  untracked cache: guard and disable on system changes
  mingw32: add uname()
  t7063: tests for untracked cache
  update-index: test the system before enabling untracked cache
  update-index: manually enable or disable untracked cache
  status: enable untracked cache
  untracked-cache: temporarily disable with $GIT_DISABLE_UNTRACKED_CACHE
  untracked cache: mark index dirty if untracked cache is updated
  untracked cache: print stats with $GIT_TRACE_UNTRACKED_STATS
  untracked cache: avoid racy timestamps
  read-cache.c: split racy stat test to a separate function
  untracked cache: invalidate at index addition or removal
  untracked cache: load from UNTR index extension
  untracked cache: save to an index extension
  ewah: add convenient wrapper ewah_serialize_strbuf()
  untracked cache: don't open non-existent .gitignore
  untracked cache: mark what dirs should be recursed/saved
  untracked cache: record/validate dir mtime and reuse cached output
  untracked cache: make a wrapper around {open,read,close}dir()
  ...
2015-05-26 13:24:46 -07:00
René Scharfe
22570b68e3 dir: remove unused variable sb
It had never been used.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-20 13:50:22 -07:00
Junio C Hamano
20cf8b548e Merge branch 'jc/gitignore-precedence'
core.excludesfile (defaulting to $XDG_HOME/git/ignore) is supposed
to be overridden by repository-specific .git/info/exclude file, but
the order was swapped from the beginning. This belatedly fixes it.

* jc/gitignore-precedence:
  ignore: info/exclude should trump core.excludesfile
2015-05-19 13:17:51 -07:00
Junio C Hamano
8a1d89745d Merge branch 'cn/bom-in-gitignore' into maint
Teach the codepaths that read .gitignore and .gitattributes files
that these files encoded in UTF-8 may have UTF-8 BOM marker at the
beginning; this makes it in line with what we do for configuration
files already.

* cn/bom-in-gitignore:
  attr: skip UTF8 BOM at the beginning of the input file
  config: use utf8_bom[] from utf.[ch] in git_parse_source()
  utf8-bom: introduce skip_utf8_bom() helper
  add_excludes_from_file: clarify the bom skipping logic
  dir: allow a BOM at the beginning of exclude files
2015-05-13 14:05:51 -07:00
Junio C Hamano
558e5a8c40 Merge branch 'pt/xdg-config-path'
Code clean-up for xdg configuration path support.

* pt/xdg-config-path:
  path.c: remove home_config_paths()
  git-config: replace use of home_config_paths()
  git-commit: replace use of home_config_paths()
  credential-store.c: replace home_config_paths() with xdg_config_home()
  dir.c: replace home_config_paths() with xdg_config_home()
  attr.c: replace home_config_paths() with xdg_config_home()
  path.c: implement xdg_config_home()
2015-05-11 14:24:01 -07:00
Paul Tan
2845ce7ff1 dir.c: replace home_config_paths() with xdg_config_home()
Since only the xdg excludes file path is required, simplify the code by
replacing use of home_config_paths() with xdg_config_home().

Signed-off-by: Paul Tan <pyokagan@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-06 11:33:17 -07:00
Junio C Hamano
2e1dfd62dc Merge branch 'cn/bom-in-gitignore'
Teach the codepaths that read .gitignore and .gitattributes files
that these files encoded in UTF-8 may have UTF-8 BOM marker at the
beginning; this makes it in line with what we do for configuration
files already.

* cn/bom-in-gitignore:
  attr: skip UTF8 BOM at the beginning of the input file
  config: use utf8_bom[] from utf.[ch] in git_parse_source()
  utf8-bom: introduce skip_utf8_bom() helper
  add_excludes_from_file: clarify the bom skipping logic
  dir: allow a BOM at the beginning of exclude files
2015-05-05 21:00:34 -07:00
Junio C Hamano
099d2d86a8 ignore: info/exclude should trump core.excludesfile
$GIT_DIR/info/exclude and core.excludesfile (which falls back to
$XDG_HOME/git/ignore) are both ways to override the ignore pattern
lists given by the project in .gitignore files.  The former, which
is per-repository personal preference, should take precedence over
the latter, which is a personal preference default across different
repositories that are accessed from that machine.  The existing
documentation also agrees.

However, the precedence order was screwed up between these two from
the very beginning when 896bdfa2 (add: Support specifying an
excludes file with a configuration variable, 2007-02-27) introduced
core.excludesfile variable.

Noticed-by: Yohei Endo <yoheie@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-04-22 14:31:49 -07:00
Junio C Hamano
dde843e737 utf8-bom: introduce skip_utf8_bom() helper
With the recent change to ignore the UTF8 BOM at the beginning of
.gitignore files, we now have two codepaths that do such a skipping
(the other one is for reading the configuration files).

Introduce utf8_bom[] constant string and skip_utf8_bom() helper
and teach .gitignore code how to use it.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-04-16 11:35:06 -07:00
Junio C Hamano
cb0abea870 add_excludes_from_file: clarify the bom skipping logic
Even though the previous step shifts where the "entry" begins, we
still iterate over the original buf[], which may begin with the
UTF-8 BOM we are supposed to be skipping.  At the end of the first
line, the code grabs the contents of it starting at "entry", so
there is nothing wrong per-se, but the logic looks really confused.

Instead, move the buf pointer and shrink its size, to truly
pretend that UTF-8 BOM did not exist in the input.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-04-16 11:26:29 -07:00
Carlos Martín Nieto
245e1c196d dir: allow a BOM at the beginning of exclude files
Some text editors like Notepad or LibreOffice write an UTF-8 BOM in
order to indicate that the file is Unicode text rather than whatever the
current locale would indicate.

If someone uses such an editor to edit a gitignore file, we are left
with those three bytes at the beginning of the file. If we do not skip
them, we will attempt to match a filename with the BOM as prefix, which
won't match the files the user is expecting.

Signed-off-by: Carlos Martín Nieto <cmn@elego.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-04-16 10:17:04 -07:00
Junio C Hamano
ab0fb57aac Merge branch 'jc/report-path-error-to-dir' into maint
Code clean-up.

* jc/report-path-error-to-dir:
  report_path_error(): move to dir.c
2015-03-31 14:53:08 -07:00
Junio C Hamano
574ee8ae86 Merge branch 'jc/report-path-error-to-dir'
Code clean-up.

* jc/report-path-error-to-dir:
  report_path_error(): move to dir.c
2015-03-26 11:57:13 -07:00
Junio C Hamano
777c55a616 report_path_error(): move to dir.c
The expected call sequence is for the caller to use match_pathspec()
repeatedly on a set of pathspecs, accumulating the "hits" in a
separate array, and then call this function to diagnose a pathspec
that never matched anything, as that can indicate a typo from the
command line, e.g. "git commit Maekfile".

Many builtin commands use this function from builtin/ls-files.c,
which is not a very healthy arrangement.  ls-files might have been
the first command to feel the need for such a helper, but the need
is shared by everybody who uses the "match and then report" pattern.

Move it to dir.c where match_pathspec() is defined.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-24 14:12:10 -07:00
Nguyễn Thái Ngọc Duy
1e8fef609e untracked cache: guard and disable on system changes
If the user enables untracked cache, then

 - move worktree to an unsupported filesystem
 - or simply upgrade OS
 - or move the whole (portable) disk from one machine to another
 - or access a shared fs from another machine

there's no guarantee that untracked cache can still function properly.
Record the worktree location and OS footprint in the cache. If it
changes, err on the safe side and disable the cache. The user can
'update-index --untracked-cache' again to make sure all conditions are
met.

This adds a new requirement that setup_git_directory* must be called
before read_cache() because we need worktree location by then, or the
cache is dropped.

This change does not cover all bases, you can fool it if you try
hard. The point is to stop accidents.

Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Helped-by: brian m. carlson <sandals@crustytoothpaste.net>
Helped-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-12 13:45:18 -07:00
Nguyễn Thái Ngọc Duy
76e6b090a0 untracked-cache: temporarily disable with $GIT_DISABLE_UNTRACKED_CACHE
This can be used to double check if results with untracked cache are
correctly, compared to vanilla version. Untracked cache remains in
index, but not used.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-12 13:45:17 -07:00
Nguyễn Thái Ngọc Duy
1bbb3dba3f untracked cache: mark index dirty if untracked cache is updated
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-12 13:45:17 -07:00
Nguyễn Thái Ngọc Duy
c9ccb5d327 untracked cache: print stats with $GIT_TRACE_UNTRACKED_STATS
This could be used to verify correct behavior in tests

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-12 13:45:17 -07:00
Nguyễn Thái Ngọc Duy
ed4efab1b1 untracked cache: avoid racy timestamps
When a directory is updated within the same second that its timestamp
is last saved, we cannot realize the directory has been updated by
checking timestamps. Assume the worst (something is update). See
29e4d36 (Racy GIT - 2005-12-20) for more information.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-12 13:45:17 -07:00
Nguyễn Thái Ngọc Duy
e931371a8f untracked cache: invalidate at index addition or removal
Ideally we should implement untracked_cache_remove_from_index() and
untracked_cache_add_to_index() so that they update untracked cache
right away instead of invalidating it and wait for read_directory()
next time to deal with it. But that may need some more work in
unpack-trees.c. So stay simple as the first step.

The new call in add_index_entry_with_check() may look strange because
new calls usually stay close to cache_tree_invalidate_path(). We do it
a bit later than c_t_i_p() in this function because if it's about
replacing the entry with the same name, we don't care (but cache-tree
does).

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-12 13:45:16 -07:00
Nguyễn Thái Ngọc Duy
f9e6c64958 untracked cache: load from UNTR index extension
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-12 13:45:16 -07:00
Nguyễn Thái Ngọc Duy
83c094ad0d untracked cache: save to an index extension
Helped-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-12 13:45:16 -07:00
Nguyễn Thái Ngọc Duy
27b099ae87 untracked cache: don't open non-existent .gitignore
This cuts down a signficant number of open(.gitignore) because most
directories usually don't have .gitignore files.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-12 13:45:16 -07:00
Nguyễn Thái Ngọc Duy
26cb0182b8 untracked cache: mark what dirs should be recursed/saved
If we redo this thing in a functional style, we would have one struct
untracked_dir as input tree and another as output. The input is used
for verification. The output is a brand new tree, reflecting current
worktree.

But that means recreate a lot of dir nodes even if a lot could be
shared between input and output trees in good cases. So we go with the
messy but efficient way, combining both input and output trees into
one. We need a way to know which node in this combined tree belongs to
the output. This is the purpose of this "recurse" flag.

"valid" bit can't be used for this because it's about data of the node
except the subdirs. When we invalidate a directory, we want to keep
cached data of the subdirs intact even though we don't really know
what subdir still exists (yet). Then we check worktree to see what
actual subdir remains on disk. Those will have 'recurse' bit set
again. If cached data for those are still valid, we may be able to
avoid computing exclude files for them. Those subdirs that are deleted
will have 'recurse' remained clear and their 'valid' bits do not
matter.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-12 13:45:16 -07:00
Nguyễn Thái Ngọc Duy
91a2288b5f untracked cache: record/validate dir mtime and reuse cached output
The main readdir loop in read_directory_recursive() is replaced with a
new one that checks if cached results of a directory is still valid.

If a file is added or removed from the index, the containing directory
is invalidated (but not its subdirs). If directory's mtime is changed,
the same happens. If a .gitignore is updated, the containing directory
and all subdirs are invalidated recursively. If dir_struct#flags or
other conditions change, the cache is ignored.

If a directory is invalidated, we opendir/readdir/closedir and run the
exclude machinery on that directory listing as usual. If untracked
cache is also enabled, we'll update the cache along the way. If a
directory is validated, we simply pull the untracked listing out from
the cache. The cache also records the list of direct subdirs that we
have to recurse in. Fully excluded directories are seen as "untracked
files".

In the best case when no dirs are invalidated, read_directory()
becomes a series of

  stat(dir), open(.gitignore), fstat(), read(), close() and optionally
  hash_sha1_file()

For comparison, standard read_directory() is a sequence of

  opendir(), readdir(), open(.gitignore), fstat(), read(), close(), the
  expensive last_exclude_matching() and closedir().

We already try not to open(.gitignore) if we know it does not exist,
so open/fstat/read/close sequence does not apply to every
directory. The sequence could be reduced further, as noted in
prep_exclude() in another patch. So in theory, the entire best-case
read_directory sequence could be reduced to a series of stat() and
nothing else.

This is not a silver bullet approach. When you compile a C file, for
example, the old .o file is removed and a new one with the same name
created, effectively invalidating the containing directory's cache
(but not its subdirectories). If your build process touches every
directory, this cache adds extra overhead for nothing, so it's a good
idea to separate generated files from tracked files.. Editors may use
the same strategy for saving files. And of course you're out of luck
running your repo on an unsupported filesystem and/or operating system.

Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-03-12 13:45:15 -07:00