kernel/git - git - PowerEL Git System

Author	SHA1	Message	Date
Linus Torvalds	a9ed376b15	xdiff: generate "anti-diffs" aka what is common to two files This fairly trivial patch adds a new XDL_EMIT_xxx flag to tell libxdiff that we don't want to generate the _diff_ between two files, we want to see the lines that are _common_ to two files. So when you set XDL_EMIT_COMMON, xdl_diff() will do everything exactly like it used to do, but the output records it generates just contain the lines that aren't part of the diff. This is for doing things like generating the common base case for a file that was added in both branches. Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>	19 years ago
Johannes Schindelin	0d21efa51c	Teach diff about -b and -w flags This adds -b (--ignore-space-change) and -w (--ignore-all-space) flags to diff. The main part of the patch is teaching libxdiff about it. [jc: renamed xdl_line_match() to xdl_recmatch() since the former is used for different purposes in xpatchi.c which is in the parts of the upstream source we do not use.] Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de> Signed-off-by: Junio C Hamano <junkio@cox.net>	19 years ago
Mark Wooding	acb7257729	xdiff: Show function names in hunk headers. The speed of the built-in diff generator is nice; but the function names shown by `diff -p' are /really/ nice. And I hate having to choose. So, we hack xdiff to find the function names and print them. xdiff has grown a flag to say whether to dig up the function names. The builtin_diff function passes this flag unconditionally. I suppose it could parse GIT_DIFF_OPTS, but it doesn't at the moment. I've also reintroduced the `function name' into the test suite, from which it was removed in commit `3ce8f089`. The function names are parsed by a particularly stupid algorithm at the moment: it just tries to find a line in the `old' file, from before the start of the hunk, whose first character looks plausible. Still, it's most definitely a start. Signed-off-by: Mark Wooding <mdw@distorted.org.uk> Signed-off-by: Junio C Hamano <junkio@cox.net>	19 years ago
Linus Torvalds	3443546f6e	Use a real built-in diff generator This uses a simplified libxdiff setup to generate unified diffs _without_ doing fork/execve of GNU "diff". This has several huge advantages, for example: Before: [torvalds@g5 linux]$ time git diff v2.6.16.. > /dev/null real 0m24.818s user 0m13.332s sys 0m8.664s After: [torvalds@g5 linux]$ time git diff v2.6.16.. > /dev/null real 0m4.563s user 0m2.944s sys 0m1.580s and the fact that this should be a lot more portable (ie we can ignore all the issues with doing fork/execve under Windows). Perhaps even more importantly, this allows us to do diffs without actually ever writing out the git file contents to a temporary file (and without any of the shell quoting issues on filenames etc etc). NOTE! THIS PATCH DOES NOT DO THAT OPTIMIZATION YET! I was lazy, and the current "diff-core" code actually will always write the temp-files, because it used to be something that you simply had to do. So this current one actually writes a temp-file like before, and then reads it into memory again just to do the diff. Stupid. But if this basic infrastructure is accepted, we can start switching over diff-core to not write temp-files, which should speed things up even further, especially when doing big tree-to-tree diffs. Now, in the interest of full disclosure, I should also point out a few downsides: - the libxdiff algorithm is different, and I bet GNU diff has gotten a lot more testing. And the thing is, generating a diff is not an exact science - you can get two different diffs (and you will), and they can both be perfectly valid. So it's not possible to "validate" the libxdiff output by just comparing it against GNU diff. - GNU diff does some nice eye-candy, like trying to figure out what the last function was, and adding that information to the "@@ .." line. libxdiff doesn't do that. - The libxdiff thing has some known deficiencies. In particular, it gets the "\No newline at end of file" case wrong. So this is currently for the experimental branch only. I hope Davide will help fix it. That said, I think the huge performance advantage, and the fact that it integrates better is definitely worth it. But it should go into a development branch at least due to the missing newline issue. Technical note: this is based on libxdiff-0.17, but I did some surgery to get rid of the extraneous fat - stuff that git doesn't need, and seriously cutting down on mmfile_t, which had much more capabilities than the diff algorithm either needed or used. In this version, "mmfile_t" is just a trivial <pointer,length> tuple. That said, I tried to keep the differences to simple removals, so that you can do a diff between this and the libxdiff origin, and you'll basically see just things getting deleted. Even the mmfile_t simplifications are left in a state where the diffs should be readable. Apologies to Davide, whom I'd love to get feedback on this all from (I wrote my own "fill_mmfile()" for the new simpler mmfile_t format: the old complex format had a helper function for that, but I did my surgery with the goal in mind that eventually we _should_ just do mmfile_t mf; buf = read_sha1_file(sha1, type, &size); mf->ptr = buf; mf->size = size; .. use "mf" directly .. which was really a nightmare with the old "helpful" mmfile_t, and really is that easy with the new cut-down interfaces). [ Btw, as any hawk-eye can see from the diff, this was actually generated with itself, so it is "self-hosting". That's about all the testing it has gotten, along with the above kernel diff, which eye-balls correctly, but shows the newline issue when you double-check it with "git-apply" ] Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>	19 years ago