This patch adds code to read a hash out of a specified file under
{GIT_DIR}/refs/, and to write such files atomically and optionally with an
compare and lock.
Signed-off-by: NDaniel Barkalow <barkalow@iabervon.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Only with gcc. It fixes some warnings for certain versions
of gcc, but not apparently all.

Add a "-u" flag to update the tree as a result of a merge.

Right now this code is way too anal about things, and fails merges it
shouldn't, but let me fix up the different cases and this will allow for
much smoother merging even in the presense of dirty data in the working
tree.

The merge stuff will want it soon, and we don't want to
duplicate all the work..

This adds sha1_file_size() helper function and uses it in the
rename/copy similarity estimator.  The helper function handles
deltified object as well.
Signed-off-by: NJunio C Hamano <junkio@cox.net>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

When a remote repository is deltified, we need to get the
objects that a deltified object we want to obtain is based upon.
The initial parts of each retrieved SHA1 file is inflated and
inspected to see if it is deltified, and its base object is
asked from the remote side when it is.  Since this partial
inflation and inspection has a small performance hit, it can
optionally be skipped by giving -d flag to git-*-pull commands.
This flag should be used only when the remote repository is
known to have no deltified objects.

Rsync transport does not have this problem since it fetches
everything the remote side has.
Signed-off-by: NJunio C Hamano <junkio@cox.net>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Make a separate helper for parsing the header of an object file
(really carefully) and for unpacking the rest. This means that
anybody who uses the "unpack_sha1_header()" interface can easily
look at the header and decide to unpack the rest too, without
doing any extra work.

It's for people who aren't necessarily interested in the whole
unpacked file, but do want to know the header information (size,
type, etc..)

For example, the delta code can use this to figure out whether
an object is already a delta object, and what it is a delta
against, without actually bothering to unpack all of the actual
data in the delta.

Add <limits.h> to the include files handled by "cache.h", and remove
extraneous #include directives from various .c files. The rule is that
"cache.h" gets all the basic stuff, so that we'll have as few system
dependencies as possible.

This one compares two pathnames that may be partial basenames, not
full paths. We need to get the path sorting right, since a directory
name will sort as if it had the final '/' at the end.

With -u flag, git-checkout-cache picks up the stat information
from newly created file and updates the cache.  This removes the
need to run git-update-cache --refresh immediately after running
git-checkout-cache.
Signed-off-by: NJunio C Hamano <junkio@cox.net>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

 - Raw hashes should be unsigned char.
 - String functions want signed char.
 - Hash and compress functions want unsigned char.

Signed-off By: Brian Gerst <bgerst@didntduck.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Comment in entry.h said that the cache contents is in the native CPU
byte format, which is really not true anymore for quite some time.

same_name -> ce_same_name()
remove_entry_at() -> remove_cache_entry_at()
Signed-off-by: NBrad Roberts <braddr@puremagic.com>
Signed-off-by: NPetr Baudis <pasky@ucw.cz>

Signed-off-by: NBrad Roberts <braddr@puremagic.com>
Signed-off-by: NPetr Baudis <pasky@ucw.cz>

xmalloc() and xrealloc() now take their sizes as size_t-type arguments.
Introduced complementary xcalloc().
Signed-off-by: NBrad Roberts <braddr@puremagic.com>
Signed-off-by: NPetr Baudis <pasky@ucw.cz>

It is kind of surprising that this was missed in the last round,
but the work tree scanner in git-ls-files was still deliberately
ignoring symlinks.  This patch fixes it, so that --others will
correctly report unregistered symlinks.
Signed-off-by: NJunio C Hamano <junkio@cox.net>
Signed-off-by: NPetr Baudis <pasky@ucw.cz>

This allows git to be built even with linkers which are not smart enough
to join those symbols, and makes this correct C. Pointed out by several
people.

During the mailing list discussion on renaming GIT_ environment
variables, people felt that having one environment that lets the
user (or Porcelain) specify both SHA1_FILE_DIRECTORY (now
GIT_OBJECT_DIRECTORY) and GIT_INDEX_FILE for the default layout
would be handy.  This change introduces GIT_DIR environment
variable, from which the defaults for GIT_INDEX_FILE and
GIT_OBJECT_DIRECTORY are derived.  When GIT_DIR is not defined,
it defaults to ".git".  GIT_INDEX_FILE defaults to
"$GIT_DIR/index" and GIT_OBJECT_DIRECTORY defaults to
"$GIT_DIR/objects".

Special thanks for ideas and discussions go to Petr Baudis and
Daniel Barkalow.  Bugs are mine ;-)
Signed-off-by: NJunio C Hamano <junkio@cox.net>

H. Peter Anvin mentioned that using SHA1_whatever as an
environment variable name is not nice and we should instead use
names starting with "GIT_" prefix to avoid conflicts.  Here is
what this patch does:

 * Renames the following environment variables:

    New name                           Old Name

    GIT_AUTHOR_DATE                    AUTHOR_DATE
    GIT_AUTHOR_EMAIL                   AUTHOR_EMAIL
    GIT_AUTHOR_NAME                    AUTHOR_NAME
    GIT_COMMITTER_EMAIL                COMMIT_AUTHOR_EMAIL
    GIT_COMMITTER_NAME                 COMMIT_AUTHOR_NAME
    GIT_ALTERNATE_OBJECT_DIRECTORIES   SHA1_FILE_DIRECTORIES
    GIT_OBJECT_DIRECTORY               SHA1_FILE_DIRECTORY

 * Introduces a compatibility macro, gitenv(), which does an
   getenv() and if it fails calls gitenv_bc(), which in turn
   picks up the value from old name while giving a warning about
   using an old name.

 * Changes all users of the environment variable to fetch
   environment variable with the new name using gitenv().

 * Updates the documentation and scripts shipped with Linus GIT
   distribution.

The transition plan is as follows:

 * We will keep the backward compatibility list used by gitenv()
   for now, so the current scripts and user environments
   continue to work as before.  The users will get warnings when
   they have old name but not new name in their environment to
   the stderr.

 * The Porcelain layers should start using new names.  However,
   just in case it ends up calling old Plumbing layer
   implementation, they should also export old names, taking
   values from the corresponding new names, during the
   transition period.

 * After a transition period, we would drop the compatibility
   support and drop gitenv().  Revert the callers to directly
   call getenv() but keep using the new names.

   The last part is probably optional and the transition
   duration needs to be set to a reasonable value.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

When "path" exists as a file or a symlink in the index, an
attempt to add "path/file" is refused because it results in file
vs directory conflict.  Similarly when "path/file1",
"path/file2", etc. exist, an attempt to add "path" as a file or
a symlink is refused.  With git-update-cache --replace, these
existing entries that conflict with the entry being added are
automatically removed from the cache, with warning messages.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

SHA1_FILE_DIRECTORIES environment variable is a colon separated paths
used when looking for SHA1 files not found in the usual place for
reading.  Creating a new SHA1 file does not use this alternate object
database location mechanism.  This is useful to archive older, rarely
used objects into separate directories.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

Now all the users have gone.
Signed-off-by: NJunio C Hamano <junkio@cox.net>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

It didn't properly mark all cache updates as being dirty, and
causes merge errors due to that. In particular, it didn't notice
when a file was force-removed.

Besides, it was ugly as hell. I've put in place a slightly cleaner
version, but I've not enabled the optimization because I don't
want to be burned again.

Kind of like ctime(), but not as broken.

We really always want to have S_IFREG there for non-symlinks,
otherwise we create corrupt index files.

Allow to store and track symlink in the repository. A symlink is stored
the same way as a regular file, only with the appropriate mode bits set.
The symlink target is therefore stored in a blob object.
This will hopefully make our udev repository fully functional. :)
Signed-off-by: NKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Make it much safer: we write to a temporary file, and then link that
temporary file to the final destination. This avoids all the nasty
races if several people write the same object at the same time.

It should also result in nicer on-disk layout, since it means that
objects all get created in the same subdirectory. That makes a lot
of block allocation algorithms happier, since the objects will now
be allocated from the same zone.

A new command, git-write-blob, is introduced.  This registers
the contents of any file on the filesystem as a blob in the
object database and reports its SHA1 to the standard output.
To implement it, the patch promotes index_fd() from a static
function in update-cache.c to extern and moves it to a library
source, sha1_file.c.

This command is used to update git-merge-one-file-script so that
it does not smudge the work tree.
Signed-off-by: NJunio C Hamano <junkio@cox.net>

This allows the programs to use various simplified versions of
the SHA1 names, eg just say "HEAD" for the SHA1 pointed to by
the .git/HEAD file etc.

For example, this commit has been done with

	git-commit-tree $(git-write-tree) -p HEAD

instead of the traditional "$(cat .git/HEAD)" syntax.

Not everybody has "d_type".

Older zlib's don't have deflateBound()

...since everything out there is either strange (libc mktime has issues
with timezones) or introduces unnecessary dependencies for people (libcurl).

This goes back to the old date parsing, but moves it out into a file of
its own, and does the "struct tm" to "seconds since epoch" handling by
hand. 

I grepped through the tz-database and it seems there's one "country"
left that has non-60-minute DST: Lord Howe Island.  All others dropped
that before 1970. 

This patch renames read_tree_with_tree_or_commit_sha1() to
read_object_with_reference() and extends it to automatically
dereference not just "commit" objects but "tag" objects.  With
this patch, you can say e.g.:

    ls-tree $tag
    read-tree -m $(merge-base $tag $HEAD) $tag $HEAD
    diff-cache $tag
    diff-tree $tag $HEAD
Signed-off-by: NJunio C Hamano <junkio@cox.net>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Introduce xmalloc and xrealloc to die gracefully with a descriptive
message when out of memory, rather than taking a SIGSEGV. 

Signed-off-by: Christopher Li<chrislgit@chrisli.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Use "unsigned long" for the size, like we do everywhere else.

The write function now adds the header to the file by itself, so there
is no reason to duplicate it among all the users any more.

This adds two functions: one to check if an object is present in the local
database, and one to add an object to the local database by reading it
from a file descriptor and checking its hash.
Signed-Off-By: NDaniel Barkalow <barkalow@iabervon.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This one is about a million times simpler, and much more likely to be
correct too.

Instead of trying to match up a tree object against the index, we just
read in the tree object side-by-side into the index, and just walk the
resulting index file. This was what all the read-tree cleanups were
all getting to.

Next step: make "diff-cache" use it.