1
0
Fork 0
mirror of https://github.com/git/git.git synced 2024-10-31 06:17:56 +01:00
Commit graph

180 commits

Author SHA1 Message Date
Junio C Hamano
913e0e99b6 unpack_trees(): protect the handcrafted in-core index from read_cache()
unpack_trees() rebuilds the in-core index from scratch by allocating a new
structure and finishing it off by copying the built one to the final
index.

The resulting in-core index is Ok for most use, but read_cache() does not
recognize it as such.  The function is meant to be no-op if you already
have loaded the index, until you call discard_cache().

This change the way read_cache() detects an already initialized in-core
index, by introducing an extra bit, and marks the handcrafted in-core
index as initialized, to avoid this problem.

A better fix in the longer term would be to change the read_cache() API so
that it will always discard and re-read from the on-disk index to avoid
confusion.  But there are higher level API that have relied on the current
semantics, and they and their users all need to get converted, which is
outside the scope of 'maint' track.

An example of such a higher level API is write_cache_as_tree(), which is
used by git-write-tree as well as later Porcelains like git-merge, revert
and cherry-pick.  In the longer term, we should remove read_cache() from
there and add one to cmd_write_tree(); other callers expect that the
in-core index they prepared is what gets written as a tree so no other
change is necessary for this particular codepath.

The original version of this patch marked the index by pointing an
otherwise wasted malloc'ed memory with o->result.alloc, but this version
uses Linus's idea to use a new "initialized" bit, which is conceptually
much cleaner.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-23 18:09:27 -07:00
Junio C Hamano
c70115b4b1 Teach gitlinks to ie_modified() and ce_modified_check_fs()
The ie_modified() function is the workhorse for refresh_cache_entry(),
i.e. checking if an index entry that is stat-dirty actually has changes.

After running quicker check to compare cached stat information with
results from the latest lstat(2) to answer "has modification" early, the
code goes on to check if there really is a change by comparing the staged
data with what is on the filesystem by asking ce_modified_check_fs().
However, this function always said "no change" for any gitlinks that has a
directory at the corresponding path.  This made ie_modified() to miss
actual changes in the subproject.

The patch fixes this first by modifying an existing short-circuit logic
before calling the ce_modified_check_fs() function.  It knows that for any
filesystem entity to which ie_match_stat() says its data has changed, if
its cached size is nonzero then the contents cannot match, which is a
correct optimization only for blob objects.  We teach gitlink objects to
this special case, as we already know that any gitlink that
ie_match_stat() says is modified is indeed modified at this point in the
codepath.

With the above change, we could leave ce_modified_check_fs() broken, but
it also futureproofs the code by teaching it to use ce_compare_gitlink(),
instead of assuming (incorrectly) that any directory is unchanged.

Originally noticed by Alex Riesen on Cygwin.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-30 00:09:22 -07:00
Alex Riesen
1ce4790bf5 Make use of stat.ctime configurable
A new configuration variable 'core.trustctime' is introduced to
allow ignoring st_ctime information when checking if paths
in the working tree has changed, because there are situations where
it produces too much false positives.  Like when file system crawlers
keep changing it when scanning and using the ctime for marking scanned
files.

The default is to notice ctime changes.

Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-28 23:26:25 -07:00
Petr Baudis
81dc2307d0 git-mv: Keep moved index entries inact
The rewrite of git-mv from a shell script to a builtin was perhaps
a little too straightforward: the git add and git rm queues were
emulated directly, which resulted in a rather complicated code and
caused an inconsistent behaviour when moving dirty index entries;
git mv would update the entry based on working tree state,
except in case of overwrites, where the new entry would still have
sha1 of the old file.

This patch introduces rename_index_entry_at() into the index toolkit,
which will rename an entry while removing any entries the new entry
might render duplicate. This is then used in git mv instead
of all the file queues, resulting in a major simplification
of the code and an inevitable change in git mv -n output format.

Also the code used to refuse renaming overwriting symlink with a regular
file and vice versa; there is no need for that.

A few new tests have been added to the testsuite to reflect this change.

Signed-off-by: Petr Baudis <pasky@suse.cz>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-27 15:05:19 -07:00
Junio C Hamano
d14e7407b3 "needs update" considered harmful
"git update-index --refresh", "git reset" and "git add --refresh" have
reported paths that have local modifications as "needs update" since the
beginning of git.

Although this is logically correct in that you need to update the index at
that path before you can commit that change, it is now becoming more and
more clear, especially with the continuous push for user friendliness
since 1.5.0 series, that the message is suboptimal.  After all, the change
may be something the user might want to get rid of, and "updating" would
be absolutely a wrong thing to do if that is the case.

I prepared two alternatives to solve this.  Both aim to reword the message
to more neutral "locally modified".

This patch is a more intrusive variant that changes the message for only
Porcelain commands ("add" and "reset") while keeping the plumbing
"update-index" intact.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-20 17:21:32 -07:00
Junio C Hamano
3bf0dd1f4e read-cache.c: typofix
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-16 18:48:58 -07:00
Miklos Vajna
e46bbcf6e8 Move read_cache_unmerged() to read-cache.c
builtin-read-tree has a read_cache_unmerged() which is useful for other
builtins, for example builtin-merge uses it as well. Move it to
read-cache.c to avoid code duplication.

Signed-off-by: Miklos Vajna <vmiklos@frugalware.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-06-30 22:45:51 -07:00
Junio C Hamano
159e639e5b Merge branch 'lt/racy-empty'
* lt/racy-empty:
  racy-git: an empty blob has a fixed object name
2008-06-22 14:34:20 -07:00
Linus Torvalds
f49c2c22fe racy-git: an empty blob has a fixed object name
We use size=0 as the magic token to say the entry is known to be racily
clean, but a sequence that does:

 - update the path with a non-empty blob and write the index;
 - update an unrelated path and write the index -- this smudges
   the above entry;
 - truncate the path to size zero.

would make both the size field for the path in the index and the size on
the filesystem zero.  We should not mistake it as a clean index entry.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-06-19 14:14:45 -07:00
Marius Storm-Olsen
aa9349d449 Add shortcut in refresh_cache_ent() for marked entries.
When a cache entry has been marked as CE_VALID, the user has
promised us that any change in the work tree does not matter.
Just mark the entry as up-to-date, and continue.

Signed-off-by: Marius Storm-Olsen <marius@trolltech.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-05-31 14:18:20 -07:00
Junio C Hamano
0166592495 Merge branch 'jc/add-n-u'
* jc/add-n-u:
  Make git add -n and git -u -n output consistent
  "git-add -n -u" should not add but just report

Conflicts:

	builtin-add.c
	builtin-mv.c
	cache.h
	read-cache.c
2008-05-25 14:03:50 -07:00
Junio C Hamano
7e83003029 Merge branch 'js/ignore-submodule'
* js/ignore-submodule:
  Ignore dirty submodule states during rebase and stash
  Teach update-index about --ignore-submodules
  diff options: Introduce --ignore-submodules
2008-05-25 13:37:08 -07:00
Junio C Hamano
38ed1d89f7 "git-add -n -u" should not add but just report
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-05-21 12:04:41 -07:00
Johannes Schindelin
5fdeacb0ca Teach update-index about --ignore-submodules
Like with the diff machinery, update-index should sometimes just
ignore submodules (e.g. to determine a clean state before a rebase).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-05-15 16:12:43 -07:00
Alex Riesen
960b8ad1b1 Make the exit code of add_file_to_index actually useful
Update the programs which used the function (as add_file_to_cache).

Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-05-12 20:54:46 -07:00
Linus Torvalds
d177cab048 Avoid some unnecessary lstat() calls
The commit sequence used to do

	if (file_exists(p->path))
		add_file_to_cache(p->path, 0);

where both "file_exists()" and "add_file_to_cache()" needed to do a
lstat() on the path to do their work.

This cuts down 'lstat()' calls for the partial commit case by two
for each path we know about (because we do this twice per path).

Just move the lstat() to the caller instead (that's all that
"file_exists()" really does), and pass the stat information down to the
add_to_cache() function.

This essentially makes 'add_to_index()' the core function that adds a path
to the index, getting the index pointer, the pathname and the stat
information as arguments. There are then shorthand helper functions that
use this core function:

 - 'add_to_cache()' is just 'add_to_index()' with the default index

 - 'add_file_to_cache/index()' is the same, but does the lstat() call
   itself, so you can pass just the pathname if you don't already have the
   stat information available.

So old users of the 'add_file_to_xyzzy()' are essentially left unchanged,
and this just exposes the more generic helper function that can take
existing stat information into account.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-05-10 18:16:30 -07:00
Junio C Hamano
2855e70ad1 Merge branch 'py/diff-submodule'
* py/diff-submodule:
  is_racy_timestamp(): do not check timestamp for gitlinks
  diff-lib.c: rename check_work_tree_entity()
  diff: a submodule not checked out is not modified
  Add t7506 to test submodule related functions for git-status
  t4027: test diff for submodule with empty directory
2008-05-10 18:16:25 -07:00
Junio C Hamano
380a742679 Merge branch 'lt/case-insensitive'
* lt/case-insensitive:
  Make git-add behave more sensibly in a case-insensitive environment
  When adding files to the index, add support for case-independent matches
  Make unpack-tree update removed files before any updated files
  Make branch merging aware of underlying case-insensitive filsystems
  Add 'core.ignorecase' option
  Make hash_name_lookup able to do case-independent lookups
  Make "index_name_exists()" return the cache_entry it found
  Move name hashing functions into a file of its own
  Make unpack_trees_options bit flags actual bitfields
2008-05-10 18:14:28 -07:00
Junio C Hamano
050288d52d is_racy_timestamp(): do not check timestamp for gitlinks
Because we do not even check the timestamp to determie if a gitlink
is up to date or not, triggering the racy-timestamp check for gitlinks
does not make sense.

This fixes the recently added test in t7506.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-05-04 17:41:27 -07:00
Junio C Hamano
e06c43c795 write_index(): optimize ce_smudge_racily_clean_entry() calls with CE_UPTODATE
When writing the index out, we need to check the work tree again to see if
an entry whose timestamp indicates that it could be "racily clean", in
order to smudge it if it is stat-clean but with modified contents.

However, we can skip this step for entries marked with CE_UPTODATE,
which are known to be the really clean (i.e. the one we already have
checked when we prepared the index).  This will reduce lstat(2) calls
necessary in git-status.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-04-12 19:42:17 -07:00
Linus Torvalds
1102952b45 Make git-add behave more sensibly in a case-insensitive environment
This expands on the previous patch, and allows "git add" to sanely handle
a filename that has changed case, keeping the case in the index constant,
and avoiding aliases.

In particular, if you have an index entry called "File", but the
checked-out tree is case-corrupted and has an entry called "file"
instead, doing a

	git add .

(or naming "file" explicitly) will automatically notice that we have an
alias, and will replace the name "file" with the existing index
capitalization (ie "File").

However, if we actually have *both* a file called "File" and one called
"file", and they don't have the same lstat() information (ie we're on a
case-sensitive filesystem but have the "core.ignorecase" flag set), we
will error out if we try to add them both.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-04-09 01:22:25 -07:00
Linus Torvalds
6835550def When adding files to the index, add support for case-independent matches
This simplifies the matching case of "I already have this file and it is
up-to-date" and makes it do the right thing in the face of
case-insensitive aliases.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-04-09 01:22:25 -07:00
Linus Torvalds
96872bc200 Move name hashing functions into a file of its own
It's really totally separate functionality, and if we want to start
doing case-insensitive hash lookups, I'd rather do it when it's
separated out.

It also renames "remove_index_entry()" to "remove_name_hash()", because
that really describes the thing better. It doesn't actually remove the
index entry, that's done by "remove_index_entry_at()", which is something
very different, despite the similarity in names.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-04-09 01:22:25 -07:00
Linus Torvalds
d1f128b050 Add 'const' where appropriate to index handling functions
This is in an effort to make the source index of 'unpack_trees()' as
being const, and thus making the compiler help us verify that we only
access it for reading.

The constification also extended to some of the hashing helpers that get
called indirectly.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-03-09 00:43:48 -08:00
Linus Torvalds
0ab9e1e8cd Add 'df_name_compare()' helper function
This new helper is identical to base_name_compare(), except it compares
conflicting directory/file entries as equal in order to help handling DF
conflicts (thus the name).

Note that while a directory name compares as equal to a regular file
with the new helper, they then individually compare _differently_ to a
filename that has a dot after the basename (because '\0' < '.' < '/').

So a directory called "foo/" will compare equal to a file "foo", even
though "foo.c" will compare after "foo" and before "foo/"

This will be used by routines that want to traverse the git namespace
but then handle conflicting entries together when possible.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-03-09 00:43:46 -08:00
Junio C Hamano
5a4d707a6d Merge branch 'db/checkout'
* db/checkout: (21 commits)
  checkout: error out when index is unmerged even with -m
  checkout: show progress when checkout takes long time while switching branches
  Add merge-subtree back
  checkout: updates to tracking report
  builtin-checkout.c: Remove unused prefix arguments in switch_branches path
  checkout: work from a subdirectory
  checkout: tone down the "forked status" diagnostic messages
  Clean up reporting differences on branch switch
  builtin-checkout.c: fix possible usage segfault
  checkout: notice when the switched branch is behind or forked
  Build in checkout
  Move code to clean up after a branch change to branch.c
  Library function to check for unmerged index entries
  Use diff -u instead of diff in t7201
  Move create_branch into a library file
  Build-in merge-recursive
  Add "skip_unmerged" option to unpack_trees.
  Discard "deleted" cache entries after using them to update the working tree
  Send unpack-trees debugging output to stderr
  Add flag to make unpack_trees() not print errors.
  ...

Conflicts:

	Makefile
2008-02-27 12:53:26 -08:00
Linus Torvalds
d070e3a31b Name hash fixups: export (and rename) remove_hash_entry
This makes the name hash removal function (which really just sets the
bit that disables lookups of it) available to external routines, and
makes read_cache_unmerged() use it when it drops an unmerged entry from
the index.

It's renamed to remove_index_entry(), and we drop the (unused) 'istate'
argument.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-22 21:24:47 -08:00
Linus Torvalds
a22c637124 Fix name re-hashing semantics
We handled the case of removing and re-inserting cache entries badly,
which is something that merging commonly needs to do (removing the
different stages, and then re-inserting one of them as the merged
state).

We even had a rather ugly special case for this failure case, where
replace_index_entry() basically turned itself into a no-op if the new
and the old entries were the same, exactly because the hash routines
didn't handle it on their own.

So what this patch does is to not just have the UNHASHED bit, but a
HASHED bit too, and when you insert an entry into the name hash, that
involves:

 - clear the UNHASHED bit, because now it's valid again for lookup
   (which is really all that UNHASHED meant)

 - if we're being lazy, we're done here (but we still want to clear the
   UNHASHED bit regardless of lazy mode, since we can become unlazy
   later, and so we need the UNHASHED bit to always be set correctly,
   even if we never actually insert the entry into the hash list)

 - if it was already hashed, we just leave it on the list

 - otherwise mark it HASHED and insert it into the list

this all means that unhashing and rehashing a name all just works
automatically.  Obviously, you cannot change the name of an entry (that
would be a serious bug), but nothing can validly do that anyway (you'd
have to allocate a new struct cache_entry anyway since the name length
could change), so that's not a new limitation.

The code actually gets simpler in many ways, although the lazy hashing
does mean that there are a few odd cases (ie something can be marked
unhashed even though it was never on the hash in the first place, and
isn't actually marked hashed!).

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-22 21:24:47 -08:00
Daniel Barkalow
94a5728cfb Library function to check for unmerged index entries
It's small, but it was in three places already, so it should be in the
library.

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
2008-02-09 23:16:51 -08:00
Junio C Hamano
9cb76b8cdc lazy index hashing
This delays the hashing of index names until it becomes necessary for
the first time.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-01-22 23:01:13 -08:00
Linus Torvalds
cf558704fb Create pathname-based hash-table lookup into index
This creates a hash index of every single file added to the index.
Right now that hash index isn't actually used for much: I implemented a
"cache_name_exists()" function that uses it to efficiently look up a
filename in the index without having to do the O(logn) binary search,
but quite frankly, that's not why this patch is interesting.

No, the whole and only reason to create the hash of the filenames in the
index is that by modifying the hash function, you can fairly easily do
things like making it always hash equivalent names into the same bucket.

That, in turn, means that suddenly questions like "does this name exist
in the index under an _equivalent_ name?" becomes much much cheaper.

Guiding principles behind this patch:

 - it shouldn't be too costly. In fact, my primary goal here was to
   actually speed up "git commit" with a fully populated kernel tree, by
   being faster at checking whether a file already existed in the index. I
   did succeed, but only barely:

	Best before:
		[torvalds@woody linux]$ time git commit > /dev/null
		real    0m0.255s
		user    0m0.168s
		sys     0m0.088s

	Best after:

		[torvalds@woody linux]$ time ~/git/git commit > /dev/null
		real    0m0.233s
		user    0m0.144s
		sys     0m0.088s

   so some things are actually faster (~8%).

   Caveat: that's really the best case. Other things are invariably going
   to be slightly slower, since we populate that index cache, and quite
   frankly, few things really use it to look things up.

   That said, the cost is really quite small. The worst case is probably
   doing a "git ls-files", which will do very little except puopulate the
   index, and never actually looks anything up in it, just lists it.

	Before:
		[torvalds@woody linux]$ time git ls-files > /dev/null
		real    0m0.016s
		user    0m0.016s
		sys     0m0.000s

	After:
		[torvalds@woody linux]$ time ~/git/git ls-files > /dev/null
		real    0m0.021s
		user    0m0.012s
		sys     0m0.008s

   and while the thing has really gotten relatively much slower, we're
   still talking about something almost unmeasurable (eg 5ms). And that
   really should be pretty much the worst case.

   So we lose 5ms on one "benchmark", but win 22ms on another. Pick your
   poison - this patch has the advantage that it will _likely_ speed up
   the cases that are complex and expensive more than it slows down the
   cases that are already so fast that nobody cares. But if you look at
   relative speedups/slowdowns, it doesn't look so good.

 - It should be simple and clean

   The code may be a bit subtle (the reasons I do hash removal the way I
   do etc), but it re-uses the existing hash.c files, so it really is
   fairly small and straightforward apart from a few odd details.

Now, this patch on its own doesn't really do much, but I think it's worth
looking at, if only because if done correctly, the name hashing really can
make an improvement to the whole issue of "do we have a filename that
looks like this in the index already". And at least it gets real testing
by being used even by default (ie there is a real use-case for it even
without any insane filesystems).

NOTE NOTE NOTE! The current hash is a joke. I'm ashamed of it, I'm just
not ashamed of it enough to really care. I took all the numbers out of my
nether regions - I'm sure it's good enough that it works in practice, but
the whole point was that you can make a really much fancier hash that
hashes characters not directly, but by their upper-case value or something
like that, and thus you get a case-insensitive hash, while still keeping
the name and the index itself totally case sensitive.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-01-22 21:46:30 -08:00
Junio C Hamano
6d91da6d3c read-cache.c: introduce is_racy_timestamp() helper
This moves a common boolean expression into a helper function,
and makes the comparison between filesystem timestamp and index
timestamp done in the function in line with the other places.
st.st_mtime should be casted to (unsigned int) when compared to
an index timestamp ce_mtime.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-01-22 21:26:40 -08:00
Junio C Hamano
077c48df8a read-cache.c: fix a couple more CE_REMOVE conversion
It is a D/F conflict if you want to add "foo/bar" to the index
when "foo" already exists.  Also it is a conflict if you want to
add a file "foo" when "foo/bar" exists.

An exception is when the existing entry is there only to mark "I
used to be here but I am being removed".  This is needed for
operations such as "git read-tree -m -u" that update the index
and then reflect the result to the work tree --- we need to
remember what to remove somewhere, and we use the index for
that.  In such a case, an existing file "foo" is being removed
and we can create "foo/" directory and hang "bar" underneath it
without any conflict.

We used to use (ce->ce_mode == 0) to mark an entry that is being
removed, but (CE_REMOVE & ce->ce_flags) is used for that purpose
these days.  An earlier commit forgot to convert the logic in
the code that checks D/F conflict condition.

The old code knew that "to be removed" entries cannot be at
higher stage and actively checked that condition, but it was an
unnecessary check.  This patch removes the extra check as well.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-01-22 21:24:21 -08:00
Junio C Hamano
eadb583134 Avoid running lstat(2) on the same cache entry.
Aside from the lstat(2) done for work tree files, there are
quite many lstat(2) calls in refname dwimming codepath.  This
patch is not about reducing them.

 * It adds a new ce_flag, CE_UPTODATE, that is meant to mark the
   cache entries that record a regular file blob that is up to
   date in the work tree.  If somebody later walks the index and
   wants to see if the work tree has changes, they do not have
   to be checked with lstat(2) again.

 * fill_stat_cache_info() marks the cache entry it just added
   with CE_UPTODATE.  This has the effect of marking the paths
   we write out of the index and lstat(2) immediately as "no
   need to lstat -- we know it is up-to-date", from quite a lot
   fo callers:

    - git-apply --index
    - git-update-index
    - git-checkout-index
    - git-add (uses add_file_to_index())
    - git-commit (ditto)
    - git-mv (ditto)

 * refresh_cache_ent() also marks the cache entry that are clean
   with CE_UPTODATE.

 * write_index is changed not to write CE_UPTODATE out to the
   index file, because CE_UPTODATE is meant to be transient only
   in core.  For the same reason, CE_UPDATE is not written to
   prevent an accident from happening.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-21 12:44:31 -08:00
Junio C Hamano
7fec10b7f4 index: be careful when handling long names
We currently use lower 12-bit (masked with CE_NAMEMASK) in the
ce_flags field to store the length of the name in cache_entry,
without checking the length parameter given to
create_ce_flags().  This can make us store incorrect length.

Currently we are mostly protected by the fact that many
codepaths first copy the path in a variable of size PATH_MAX,
which typically is 4096 that happens to match the limit, but
that feels like a bug waiting to happen.  Besides, that would
not allow us to shorten the width of CE_NAMEMASK to use the bits
for new flags.

This redefines the meaning of the name length stored in the
cache_entry.  A name that does not fit is represented by storing
CE_NAMEMASK in the field, and the actual length needs to be
computed by actually counting the bytes in the name[] field.
This way, only the unusually long paths need to suffer.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-21 12:44:31 -08:00
Linus Torvalds
7a51ed66f6 Make on-disk index representation separate from in-core one
This converts the index explicitly on read and write to its on-disk
format, allowing the in-core format to contain more flags, and be
simpler.

In particular, the in-core format is now host-endian (as opposed to the
on-disk one that is network endian in order to be able to be shared
across machines) and as a result we can dispense with all the
htonl/ntohl on accesses to the cache_entry fields.

This will make it easier to make use of various temporary flags that do
not exist in the on-disk format.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-21 12:44:31 -08:00
Junio C Hamano
c78a24986d Merge branch 'jc/maint-add-sync-stat'
* jc/maint-add-sync-stat:
  t2200: test more cases of "add -u"
  git-add: make the entry stat-clean after re-adding the same contents
  ce_match_stat, run_diff_files: use symbolic constants for readability

Conflicts:

	builtin-add.c
2007-11-14 14:15:40 -08:00
Junio C Hamano
fb63d7f889 git-add: make the entry stat-clean after re-adding the same contents
Earlier in commit 0781b8a9b2
(add_file_to_index: skip rehashing if the cached stat already
matches), add_file_to_index() were taught not to re-add the path
if it already matches the index.

The change meant well, but was not executed quite right.  It
used ie_modified() to see if the file on the work tree is really
different from the index, and skipped adding the contents if the
function says "not modified".

This was wrong.  There are three possible comparison results
between the index and the file in the work tree:

 - with lstat(2) we _know_ they are different.  E.g. if the
   length or the owner in the cached stat information is
   different from the length we just obtained from lstat(2), we
   can tell the file is modified without looking at the actual
   contents.

 - with lstat(2) we _know_ they are the same.  The same length,
   the same owner, the same everything (but this has a twist, as
   described below).

 - we cannot tell from lstat(2) information alone and need to go
   to the filesystem to actually compare.

The last case arises from what we call 'racy git' situation,
that can be caused with this sequence:

    $ echo hello >file
    $ git add file
    $ echo aeiou >file ;# the same length

If the second "echo" is done within the same filesystem
timestamp granularity as the first "echo", then the timestamp
recorded by "git add" and the timestamp we get from lstat(2)
will be the same, and we can mistakenly say the file is not
modified.  The path is called 'racily clean'.  We need to
reliably detect racily clean paths are in fact modified.

To solve this problem, when we write out the index, we mark the
index entry that has the same timestamp as the index file itself
(that is the time from the point of view of the filesystem) to
tell any later code that does the lstat(2) comparison not to
trust the cached stat info, and ie_modified() then actually goes
to the filesystem to compare the contents for such a path.

That's all good, but it should not be used for this "git add"
optimization, as the goal of "git add" is to actually update the
path in the index and make it stat-clean.  With the false
optimization, we did _not_ cause any data loss (after all, what
we failed to do was only to update the cached stat information),
but it made the following sequence leave the file stat dirty:

    $ echo hello >file
    $ git add file
    $ echo hello >file ;# the same contents
    $ git add file

The solution is not to use ie_modified() which goes to the
filesystem to see if it is really clean, but instead use
ie_match_stat() with "assume racily clean paths are dirty"
option, to force re-adding of such a path.

There was another problem with "git add -u".  The codepath
shares the same issue when adding the paths that are found to be
modified, but in addition, it asked "git diff-files" machinery
run_diff_files() function (which is "git diff-files") to list
the paths that are modified.  But "git diff-files" machinery
uses the same ie_modified() call so that it does not report
racily clean _and_ actually clean paths as modified, which is
not what we want.

The patch allows the callers of run_diff_files() to pass the
same "assume racily clean paths are dirty" option, and makes
"git-add -u" codepath to use that option, to discover and re-add
racily clean _and_ actually clean paths.

We could further optimize on top of this patch to differentiate
the case where the path really needs re-adding (i.e. the content
of the racily clean entry was indeed different) and the case
where only the cached stat information needs to be refreshed
(i.e. the racily clean entry was actually clean), but I do not
think it is worth it.

This patch applies to maint and all the way up.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-11-10 00:37:39 -08:00
Junio C Hamano
4bd5b7dacc ce_match_stat, run_diff_files: use symbolic constants for readability
ce_match_stat() can be told:

 (1) to ignore CE_VALID bit (used under "assume unchanged" mode)
     and perform the stat comparison anyway;

 (2) not to perform the contents comparison for racily clean
     entries and report mismatch of cached stat information;

using its "option" parameter.  Give them symbolic constants.

Similarly, run_diff_files() can be told not to report anything
on removed paths.  Also give it a symbolic constant for that.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-11-10 00:24:51 -08:00
Shawn O. Pearce
e75c55844f Merge branch 'maint'
* maint:
  Yet more 1.5.3.5 fixes mentioned in release notes
  cvsserver: Use exit 1 instead of die when req_Root fails.
  git-blame shouldn't crash if run in an unmerged tree
  git-config: print error message if the config file cannot be read
  fixing output of non-fast-forward output of post-receive-email
2007-10-18 03:11:17 -04:00
Linus Torvalds
cd8ae20195 git-blame shouldn't crash if run in an unmerged tree
If we are in the middle of resolving a merge conflict there may be
one or more files whose entries in the index represent an unmerged
state (index entries in the higher-order stages).

Attempting to run git-blame on any file in such a working directory
resulted in "fatal: internal error: ce_mode is 0" as we use the magic
marker for an unmerged entry is 0 (set up by things like diff-lib.c's
do_diff_cache() and builtin-read-tree.c's read_tree_unmerged())
and the ce_match_stat_basic() function gets upset about this.

I'm not entirely sure that the whole "ce_mode = 0" case is a good
idea to begin with, and maybe the right thing to do is to remove
that horrid freakish special case, but removing the internal error
seems to be the simplest fix for now.

                Linus

[sp: Thanks to Björn Steinbrink for the test case]

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-10-18 02:31:30 -04:00
Carlos Rica
102c2338da Move make_cache_entry() from merge-recursive.c into read-cache.c
The function make_cache_entry() is too useful to be hidden away in
merge-recursive.  So move it to libgit.a (exposing it via cache.h).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-09-26 13:42:10 -07:00
Pierre Habouzit
1dffb8fa80 Small cache_tree_write refactor.
This function cannot fail, make it void. Also make write_one act on a
const char* instead of a char*.

Signed-off-by: Pierre Habouzit <madcoder@debian.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-09-26 02:27:06 -07:00
Junio C Hamano
58f6fb53dd Merge branch 'jc/cachetree' into cr/reset
* jc/cachetree:
  Simplify cache API
  git-format-patch --in-reply-to: accept <message@id> with angle brackets
  git-add -u: do not barf on type changes
  Remove duplicate note about removing commits with git-filter-branch
  git-clone: improve error message if curl program is missing or not executable
  git.el: Allow the add and remove commands to be applied to ignored files.
  git.el: Allow selecting whether to display uptodate/unknown/ignored files.
  git.el: Keep the status buffer sorted by filename.
  hooks--update: Explicitly check for all zeros for a deleted ref.
2007-09-14 01:19:30 -07:00
Junio C Hamano
09d5dc32fb Simplify cache API
Earlier, add_file_to_index() invalidated the path in the cache-tree
but remove_file_from_cache() did not, and the user of the latter
needed to invalidate the entry himself.  This led to a few bugs due to
missed invalidate calls already.  This patch makes the management of
cache-tree less error prone by making more invalidate calls from lower
level cache API functions.

The rules are:

 - If you are going to write the index, you should either maintain
   cache_tree correctly.

   - If you cannot, alternatively you can remove the entire cache_tree
     by calling cache_tree_free() before you call write_cache().

   - When you modify the index, cache_tree_invalidate_path() should be
     called with the path you are modifying, to discard the entry from
     the cache-tree structure.

 - The following cache API functions exported from read-cache.c (and
   the macro whose names have "cache" instead of "index")
   automatically call cache_tree_invalidate_path() for you:

   - remove_file_from_index();
   - add_file_to_index();
   - add_index_entry();

   You can modify the index bypassing the above API functions
   (e.g. find an existing cache entry from the index and modify it in
   place).  You need to call cache_tree_invalidate_path() yourself in
   such a case.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-09-14 01:02:21 -07:00
Carlos Rica
6640f88165 Move make_cache_entry() from merge-recursive.c into read-cache.c
The function make_cache_entry() is too useful to be hidden away in
merge-recursive.  So move it to libgit.a (exposing it via cache.h).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-09-12 13:25:07 -07:00
Alexandre Julliard
d616813d75 git-add: Add support for --refresh option.
This allows to refresh only a subset of the project files, based on
the specified pathspecs.

Signed-off-by: Alexandre Julliard <julliard@winehq.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-08-13 12:58:38 -07:00
Junio C Hamano
af3785dc5a Optimize "diff --cached" performance.
The read_tree() function is called only from the call chain to
run "git diff --cached" (this includes the internal call made by
git-runstatus to run_diff_index()).  The function vacates stage
without any funky "merge" magic.  The caller then goes and
compares stage #1 entries from the tree with stage #0 entries
from the original index.

When adding the cache entries this way, it used the general
purpose add_cache_entry().  This function looks for an existing
entry to replace or if there is none to find where to insert the
new entry, resolves D/F conflict and all the other things.

For the purpose of reading entries into an empty stage, none of
that processing is needed.  We can instead append everything and
then sort the result at the end.

This commit changes read_tree() to first make sure that there is
no existing cache entries at specified stage, and if that is the
case, it runs add_cache_entry() with ADD_CACHE_JUST_APPEND flag
(new), and then sort the resulting cache using qsort().

This new flag tells add_cache_entry() to omit all the checks
such as "Does this path already exist?  Does adding this path
remove other existing entries because it turns a directory to a
file?" and instead append the given cache entry straight at the
end of the active cache.  The caller of course is expected to
sort the resulting cache at the end before using the result.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-08-10 11:44:23 -07:00
Junio C Hamano
0781b8a9b2 add_file_to_index: skip rehashing if the cached stat already matches
An earlier commit 366bfcb6 broke git-add by moving read_cache()
call down, because it wanted the directory walking code to grab
paths that are already in the index.  The change serves its
purpose, but introduces a regression because the responsibility
of avoiding unnecessary reindexing by matching the cached stat
is shifted nowhere.

This makes it the job of add_file_to_index() function.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-07-30 17:49:50 -07:00
Johannes Schindelin
2031427167 git add: respect core.filemode with unmerged entries
When a merge left unmerged entries, git add failed to pick up the
file mode from the index, when core.filemode == 0. If more than one
unmerged entry is there, the order of stage preference is 2, 1, 3.

Noticed by Johannes Sixt.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-07-01 13:26:05 -07:00