This patch optimizes "diff-cache -p --cached" by avoiding to
inflate blobs into temporary files when the blob recorded in the
cache matches the corresponding file in the work tree. The file
in the work tree is passed as the comparison source in such a
case instead.
This optimization kicks in only when we have already read the
cache this optimization and this is deliberate. Especially,
diff-tree does not use this code, because changes are contained
in small number of files relative to the project size most of
the time, and reading cache is so expensive for a large project
that the cost of reading it outweighs the savings by not
inflating blobs.
Also this patch cleans up the structure passed from diff clients
by removing one unused structure member.
Signed-off-by: Junio C Hamano <junkio@cox.net>
This introduces three public functions for diff-cache and friends can
use to call out to the GIT_EXTERNAL_DIFF program when they wish to.
A normal "add/remove/change" entry is turned into 7-parameter process
invocation of GIT_EXTERNAL_DIFF program as before. In addition, the
program can now be called with a single parameter when diff-cache and
friends want to report an unmerged path.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This reworks the diff-tree-helper and show-diff to further make external
diff command interface simpler.
These commands now honor GIT_EXTERNAL_DIFF environment variable which
can point at an arbitrary program that takes 7 parameters:
name file1 file1-sha1 file1-mode file2 file2-sha1 file2-mode
The parameters for an external diff command are as follows:
name this invocation of the command is to emit diff
for the named cache/tree entry.
file1 pathname that holds the contents of the first
file. This can be a file inside the working
tree, or a temporary file created from the blob
object, or /dev/null. The command should not
attempt to unlink it -- the temporary is
unlinked by the caller.
file1-sha1 sha1 hash if file1 is a blob object, or "."
otherwise.
file1-mode mode bits for file1, or "." for a deleted file.
If GIT_EXTERNAL_DIFF environment variable is not set, the
default is to invoke diff with the set of parameters old
show-diff used to use. This built-in implementation honors the
GIT_DIFF_CMD and GIT_DIFF_OPTS environment variables as before.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
With this patch, the non-core'ish part of show-diff command that
invokes an external "diff" comand to obtain patches is split
into a separate file. The next patch will introduce a new
command, diff-tree-helper, which uses this common diff interface
to format diff-tree and diff-cache output into a patch form.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
