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2010-09-30diff: avoid repeated scanning while looking for funcnameLibravatar René Scharfe1-24/+14
For each hunk, xdl_find_func searches the preimage for a function name until the beginning of the file. If the file does not contain any function names, this search has complexity O(n^2) in the number of hunks n. Instead, inline xdl_find_func() and keep track of up to which line we have scanned already and the contents of the last funcname line that we have found. Noticed and a different approach proposed by Clemens Buchacher. This alternative solution was done by René Scharfe. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-03-15Fix various dead stores found by the clang static analyzerLibravatar Benjamin Kramer1-1/+1
http-push.c::finish_request(): request is initialized by the for loop index-pack.c::free_base_data(): b is initialized by the for loop merge-recursive.c::process_renames(): move compare to narrower scope, and remove unused assignments to it remove unused variable renames2 xdiff/xdiffi.c::xdl_recs_cmp(): remove unused variable ec xdiff/xemit.c::xdl_emit_diff(): xche is always overwritten Signed-off-by: Benjamin Kramer <benny.kra@googlemail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-12-29diff: add option to show context between close hunksLibravatar René Scharfe1-1/+2
Merge two hunks if there is only the specified number of otherwise unshown context between them. For --inter-hunk-context=1, the resulting patch has the same number of lines but shows uninterrupted context instead of a context header line in between. Patches generated with this option are easier to read but are also more likely to conflict if the file to be patched contains other changes. This patch keeps the default for this option at 0. It is intended to just make the feature available in order to see its advantages and downsides. Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-10-25Allow alternate "low-level" emit function from xdl_diffLibravatar Brian Downing1-2/+1
For some users (e.g. git blame), getting textual patch output is just extra work, as they can get all the information they need from the low- level diff structures. Allow for an alternate low-level emit function to be defined to allow bypassing the textual patch generation; set xemitconf_t's emit_func member to enable this. The (void (*)()) type is pretty ugly, but the alternative would be to include most of the private xdiff headers in xdiff.h to get the types required for the "proper" function prototype. Also, a (void *) won't work, as ANSI C doesn't allow a function pointer to be cast to an object pointer. Signed-off-by: Brian Downing <bdowning@lavos.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-07-06Per-path attribute based hunk header selection.Libravatar Junio C Hamano1-14/+23
This makes"diff -p" hunk headers customizable via gitattributes mechanism. It is based on Johannes's earlier patch that allowed to define a single regexp to be used for everything. The mechanism to arrive at the regexp that is used to define hunk header is the same as other use of gitattributes. You assign an attribute, funcname (because "diff -p" typically uses the name of the function the patch is about as the hunk header), a simple string value. This can be one of the names of built-in pattern (currently, "java" is defined) or a custom pattern name, to be looked up from the configuration file. (in .gitattributes) *.java funcname=java *.perl funcname=perl (in .git/config) [funcname] java = ... # ugly and complicated regexp to override the built-in one. perl = ... # another ugly and complicated regexp to define a new one. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-06-08Missing statics.Libravatar Pierre Habouzit1-2/+2
Signed-off-by: Pierre Habouzit <madcoder@debian.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-06-07War on whitespaceLibravatar Junio C Hamano1-1/+0
This uses "git-apply --whitespace=strip" to fix whitespace errors that have crept in to our source files over time. There are a few files that need to have trailing whitespaces (most notably, test vectors). The results still passes the test, and build result in Documentation/ area is unchanged. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2006-11-23Increase length of function name bufferLibravatar Andy Parkins1-1/+1
In xemit.c:xdl_emit_diff() a buffer for showing the function name as commentary is allocated; this buffer was 40 characters. This is a bit small; particularly for C++ function names where there is often an identical prefix (like void LongNamespace::LongClassName) on multiple functions, which makes the context the same everywhere. In other words the context is useless. This patch increases that buffer to 80 characters - which may still not be enough, but is better Signed-off-by: Andy Parkins <andyparkins@gmail.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-10-25xdiff: Match GNU diff behaviour when deciding hunk comment worthiness of linesLibravatar Petr Baudis1-2/+1
This removes the '#' and '(' tests and adds a '$' test instead although I have no idea what it is actually good for - but hey, if that's what GNU diff does... Pasky only went and did as Junio sayeth. Signed-off-by: Petr Baudis <pasky@suse.cz> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-10-23xdiff/xemit.c (xdl_find_func): Elide trailing white space in a context header.Libravatar Jim Meyering1-1/+1
This removes trailing blanks from git-generated diff headers the same way a similar patch did that for GNU diff: http://article.gmane.org/gmane.comp.gnu.utils.bugs/13839 That is, it removes trailing blanks on the hunk header line that shows the function name. Signed-off-by: Jim Meyering <jim@meyering.net> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-06-28xdiff: generate "anti-diffs" aka what is common to two filesLibravatar Linus Torvalds1-0/+18
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>
2006-03-27xdiff: Show function names in hunk headers.Libravatar Mark Wooding1-1/+40
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>
2006-03-25Use a *real* built-in diff generatorLibravatar Linus Torvalds1-0/+141
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>