When a reference buffer is used multiple times then its index can be
computed only once and reused multiple times. This patch adds an extra
pointer to a pointer argument (from_index) to diff_delta() for this.
If from_index is NULL then everything is like before.
If from_index is non NULL and *from_index is NULL then the index is
created and its location stored to *from_index. In this case the caller
has the responsibility to free the memory pointed to by *from_index.
If from_index and *from_index are non NULL then the index is reused as
is.
This currently saves about 10% of CPU time to repack the git archive.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
All usage strings are now declared as static const char [].
This is carried over from my old git-pb branch.
Signed-off-by: Petr Baudis <pasky@ucw.cz>
Signed-off-by: Junio C Hamano <junkio@cox.net>
I have reviewed all occurrences of mmap() in git and fixed three types
of errors/defects:
1) The result is not checked.
2) The file descriptor is closed if mmap() succeeds, but not when it
fails.
3) Various casts applied to -1 are used instead of MAP_FAILED, which is
specifically defined to check mmap() return value.
[jc: This is a second round of Pavel's patch. He fixed up the problem
that close() potentially clobbering the errno from mmap, which
the first round had.]
Signed-off-by: Pavel Roskin <proski@gnu.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
If we prefer 0 as maxsize for diff_delta() to say "unlimited", let's be
consistent about it.
This patch also fixes type mismatch in a call to get_delta_hdr_size()
from packed_delta_info().
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.
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>
