Delta indices, at least on 64-bit platforms, tend to be larger than
the actual uncompressed data. As such, keeping track of this storage
is important if you want to successfully limit the memory size of your
pack window.
Squirrel away the total allocation size inside the delta_index struct,
and add an accessor "sizeof_delta_index" to access it.
Signed-off-by: Brian Downing <bdowning@lavos.net>
Acked-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Avoid creating a delta index for objects with maximum depth since they
are not going to be used as delta base anyway. This also reduce peak
memory usage slightly as the current object's delta index is not useful
until the next object in the loop is considered for deltification. This
saves a bit more than 1% on CPU usage.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This patch splits the diff-delta interface into index creation and delta
generation. A wrapper is provided to preserve the diff-delta() call.
This will allow for an optimization in pack-objects.c where the source
object could be fixed and a full window of objects tentatively tried
against
that same source object without recomputing the source index each time.
This patch only restructure things, plus a couple cleanups for good
measure. There is no performance change yet.
Signed-off-by: Nicolas Pitre <nico@cam.org>
My kernel work habit made me look at the generated assembly for the
delta code, and one obvious albeit small improvement is this patch.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This is a wrap-up patch including all the cleanups I've done to the
delta code and its usage. The most important change is the
factorization of the delta header handling code.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Packed delta files created by git-pack-objects seems to be the
way to go, and existing "delta" object handling code has exposed
the object representation details to too many places. Remove it
while we refactor code to come up with a proper interface in
sha1_file.c.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Anything that generates a delta to see if two objects are close usually
isn't interested in the delta ends up being bigger than some specified
size, and this allows us to stop delta generation early when that
happens.
Make 'sha1' parameters const where possible
Signed-off-by: Jason McMullan <jason.mcmullan@timesys.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This adds knowledge of delta objects to fsck-cache and various object
parsing code. A new switch to git-fsck-cache is provided to display the
maximum delta depth found in a repository.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds the basic library functions to create and replay delta
information. Also included is a test-delta utility to validate the
code.
diff-delta was based on LibXDiff written by Davide Libenzi
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
