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2008-08-24unpack_trees(): protect the handcrafted in-core index from read_cache()Junio C Hamano
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>
2008-08-23discard_cache: reset lazy name_hash bitJunio C Hamano
We forgot to reset name_hash_initialized bit when discarding the in-core index. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-17index: future proof for "extended" index entriesJunio C Hamano
We do not have any more bits in the on-disk index flags word, but we would need to have more in the future. Use the last remaining bits as a signal to tell us that the index entry we are looking at is an extended one. Since we do not understand the extended format yet, we will just error out when we see it. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-30Teach gitlinks to ie_modified() and ce_modified_check_fs()Junio C Hamano
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>
2008-07-29Make use of stat.ctime configurableAlex Riesen
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>
2008-07-27git-mv: Keep moved index entries inactPetr Baudis
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>
2008-07-26builtin-add.c: restructure the code for maintainabilityJunio C Hamano
A private function add_files_to_cache() in builtin-add.c was borrowed by checkout and commit re-implementors without getting properly refactored to more library-ish place. This does the refactoring. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-21"needs update" considered harmfulJunio C Hamano
"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>
2008-07-17read-cache.c: typofixJunio C Hamano
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-01Move read_cache_unmerged() to read-cache.cMiklos Vajna
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>
2008-06-22Merge branch 'lt/racy-empty'Junio C Hamano
* lt/racy-empty: racy-git: an empty blob has a fixed object name
2008-06-19racy-git: an empty blob has a fixed object nameLinus Torvalds
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>
2008-05-31Add shortcut in refresh_cache_ent() for marked entries.Marius Storm-Olsen
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>
2008-05-25Merge branch 'jc/add-n-u'Junio C Hamano
* 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
2008-05-25Merge branch 'js/ignore-submodule'Junio C Hamano
* js/ignore-submodule: Ignore dirty submodule states during rebase and stash Teach update-index about --ignore-submodules diff options: Introduce --ignore-submodules
2008-05-21"git-add -n -u" should not add but just reportJunio C Hamano
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-05-15Teach update-index about --ignore-submodulesJohannes Schindelin
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>
2008-05-13Make the exit code of add_file_to_index actually usefulAlex Riesen
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>
2008-05-11Avoid some unnecessary lstat() callsLinus Torvalds
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>
2008-05-11Merge branch 'py/diff-submodule'Junio C Hamano
* 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
2008-05-11Merge branch 'lt/case-insensitive'Junio C Hamano
* 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
2008-05-05is_racy_timestamp(): do not check timestamp for gitlinksJunio C Hamano
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>
2008-04-13write_index(): optimize ce_smudge_racily_clean_entry() calls with CE_UPTODATEJunio C Hamano
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>
2008-04-09Make git-add behave more sensibly in a case-insensitive environmentLinus Torvalds
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>
2008-04-09When adding files to the index, add support for case-independent matchesLinus Torvalds
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>
2008-04-09Move name hashing functions into a file of its ownLinus Torvalds
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>
2008-03-09Add 'const' where appropriate to index handling functionsLinus Torvalds
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>
2008-03-09Add 'df_name_compare()' helper functionLinus Torvalds
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>
2008-02-27Merge branch 'db/checkout'Junio C Hamano
* 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
2008-02-23Name hash fixups: export (and rename) remove_hash_entryLinus Torvalds
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>
2008-02-23Fix name re-hashing semanticsLinus Torvalds
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>
2008-02-10Library function to check for unmerged index entriesDaniel Barkalow
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>
2008-01-23lazy index hashingJunio C Hamano
This delays the hashing of index names until it becomes necessary for the first time. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-01-23Create pathname-based hash-table lookup into indexLinus Torvalds
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>
2008-01-23read-cache.c: introduce is_racy_timestamp() helperJunio C Hamano
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>
2008-01-23read-cache.c: fix a couple more CE_REMOVE conversionJunio C Hamano
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>
2008-01-21Make on-disk index representation separate from in-core oneLinus Torvalds
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>
2008-01-21Avoid running lstat(2) on the same cache entry.Junio C Hamano
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>
2008-01-21index: be careful when handling long namesJunio C Hamano
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>
2007-11-14Merge branch 'jc/maint-add-sync-stat'Junio C Hamano
* 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
2007-11-10git-add: make the entry stat-clean after re-adding the same contentsJunio C Hamano
Earlier in commit 0781b8a9b2fe760fc4ed519a3a26e4b9bd6ccffe (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>
2007-11-10ce_match_stat, run_diff_files: use symbolic constants for readabilityJunio C Hamano
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>
2007-10-18Merge branch 'maint'Shawn O. Pearce
* 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
2007-10-18git-blame shouldn't crash if run in an unmerged treeLinus Torvalds
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>
2007-09-26Move make_cache_entry() from merge-recursive.c into read-cache.cCarlos Rica
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>
2007-09-26Small cache_tree_write refactor.Pierre Habouzit
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>
2007-09-14Merge branch 'jc/cachetree' into cr/resetJunio C Hamano
* 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.
2007-09-14Simplify cache APIJunio C Hamano
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>
2007-09-12Move make_cache_entry() from merge-recursive.c into read-cache.cCarlos Rica
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>
2007-08-13git-add: Add support for --refresh option.Alexandre Julliard
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>