git/diff.h

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/*
* Copyright (C) 2005 Junio C Hamano
*/
#ifndef DIFF_H
#define DIFF_H
#include "tree-walk.h"
#include "pathspec.h"
#include "object.h"
Log message printout cleanups On Sun, 16 Apr 2006, Junio C Hamano wrote: > > In the mid-term, I am hoping we can drop the generate_header() > callchain _and_ the custom code that formats commit log in-core, > found in cmd_log_wc(). Ok, this was nastier than expected, just because the dependencies between the different log-printing stuff were absolutely _everywhere_, but here's a patch that does exactly that. The patch is not very easy to read, and the "--patch-with-stat" thing is still broken (it does not call the "show_log()" thing properly for merges). That's not a new bug. In the new world order it _should_ do something like if (rev->logopt) show_log(rev, rev->logopt, "---\n"); but it doesn't. I haven't looked at the --with-stat logic, so I left it alone. That said, this patch removes more lines than it adds, and in particular, the "cmd_log_wc()" loop is now a very clean: while ((commit = get_revision(rev)) != NULL) { log_tree_commit(rev, commit); free(commit->buffer); commit->buffer = NULL; } so it doesn't get much prettier than this. All the complexity is entirely hidden in log-tree.c, and any code that needs to flush the log literally just needs to do the "if (rev->logopt) show_log(...)" incantation. I had to make the combined_diff() logic take a "struct rev_info" instead of just a "struct diff_options", but that part is pretty clean. This does change "git whatchanged" from using "diff-tree" as the commit descriptor to "commit", and I changed one of the tests to reflect that new reality. Otherwise everything still passes, and my other tests look fine too. Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-17 18:59:32 +00:00
struct rev_info;
struct diff_options;
struct diff_queue_struct;
struct strbuf;
struct diff_filespec;
struct userdiff_driver;
struct sha1_array;
struct commit;
tree-diff: rework diff_tree() to generate diffs for multiparent cases as well Previously diff_tree(), which is now named ll_diff_tree_sha1(), was generating diff_filepair(s) for two trees t1 and t2, and that was usually used for a commit as t1=HEAD~, and t2=HEAD - i.e. to see changes a commit introduces. In Git, however, we have fundamentally built flexibility in that a commit can have many parents - 1 for a plain commit, 2 for a simple merge, but also more than 2 for merging several heads at once. For merges there is a so called combine-diff, which shows diff, a merge introduces by itself, omitting changes done by any parent. That works through first finding paths, that are different to all parents, and then showing generalized diff, with separate columns for +/- for each parent. The code lives in combine-diff.c . There is an impedance mismatch, however, in that a commit could generally have any number of parents, and that while diffing trees, we divide cases for 2-tree diffs and more-than-2-tree diffs. I mean there is no special casing for multiple parents commits in e.g. revision-walker . That impedance mismatch *hurts* *performance* *badly* for generating combined diffs - in "combine-diff: optimize combine_diff_path sets intersection" I've already removed some slowness from it, but from the timings provided there, it could be seen, that combined diffs still cost more than an order of magnitude more cpu time, compared to diff for usual commits, and that would only be an optimistic estimate, if we take into account that for e.g. linux.git there is only one merge for several dozens of plain commits. That slowness comes from the fact that currently, while generating combined diff, a lot of time is spent computing diff(commit,commit^2) just to only then intersect that huge diff to almost small set of files from diff(commit,commit^1). That's because at present, to compute combine-diff, for first finding paths, that "every parent touches", we use the following combine-diff property/definition: D(A,P1...Pn) = D(A,P1) ^ ... ^ D(A,Pn) (w.r.t. paths) where D(A,P1...Pn) is combined diff between commit A, and parents Pi and D(A,Pi) is usual two-tree diff Pi..A So if any of that D(A,Pi) is huge, tracting 1 n-parent combine-diff as n 1-parent diffs and intersecting results will be slow. And usually, for linux.git and other topic-based workflows, that D(A,P2) is huge, because, if merge-base of A and P2, is several dozens of merges (from A, via first parent) below, that D(A,P2) will be diffing sum of merges from several subsystems to 1 subsystem. The solution is to avoid computing n 1-parent diffs, and to find changed-to-all-parents paths via scanning A's and all Pi's trees simultaneously, at each step comparing their entries, and based on that comparison, populate paths result, and deduce we could *skip* *recursing* into subdirectories, if at least for 1 parent, sha1 of that dir tree is the same as in A. That would save us from doing significant amount of needless work. Such approach is very similar to what diff_tree() does, only there we deal with scanning only 2 trees simultaneously, and for n+1 tree, the logic is a bit more complex: D(T,P1...Pn) calculation scheme ------------------------------- D(T,P1...Pn) = D(T,P1) ^ ... ^ D(T,Pn) (regarding resulting paths set) D(T,Pj) - diff between T..Pj D(T,P1...Pn) - combined diff from T to parents P1,...,Pn We start from all trees, which are sorted, and compare their entries in lock-step: T P1 Pn - - - |t| |p1| |pn| |-| |--| ... |--| imin = argmin(p1...pn) | | | | | | |-| |--| |--| |.| |. | |. | . . . . . . at any time there could be 3 cases: 1) t < p[imin]; 2) t > p[imin]; 3) t = p[imin]. Schematic deduction of what every case means, and what to do, follows: 1) t < p[imin] -> ∀j t ∉ Pj -> "+t" ∈ D(T,Pj) -> D += "+t"; t↓ 2) t > p[imin] 2.1) ∃j: pj > p[imin] -> "-p[imin]" ∉ D(T,Pj) -> D += ø; ∀ pi=p[imin] pi↓ 2.2) ∀i pi = p[imin] -> pi ∉ T -> "-pi" ∈ D(T,Pi) -> D += "-p[imin]"; ∀i pi↓ 3) t = p[imin] 3.1) ∃j: pj > p[imin] -> "+t" ∈ D(T,Pj) -> only pi=p[imin] remains to investigate 3.2) pi = p[imin] -> investigate δ(t,pi) | | v 3.1+3.2) looking at δ(t,pi) ∀i: pi=p[imin] - if all != ø -> ⎧δ(t,pi) - if pi=p[imin] -> D += ⎨ ⎩"+t" - if pi>p[imin] in any case t↓ ∀ pi=p[imin] pi↓ ~ For comparison, here is how diff_tree() works: D(A,B) calculation scheme ------------------------- A B - - |a| |b| a < b -> a ∉ B -> D(A,B) += +a a↓ |-| |-| a > b -> b ∉ A -> D(A,B) += -b b↓ | | | | a = b -> investigate δ(a,b) a↓ b↓ |-| |-| |.| |.| . . . . ~~~~~~~~ This patch generalizes diff tree-walker to work with arbitrary number of parents as described above - i.e. now there is a resulting tree t, and some parents trees tp[i] i=[0..nparent). The generalization builds on the fact that usual diff D(A,B) is by definition the same as combined diff D(A,[B]), so if we could rework the code for common case and make it be not slower for nparent=1 case, usual diff(t1,t2) generation will not be slower, and multiparent diff tree-walker would greatly benefit generating combine-diff. What we do is as follows: 1) diff tree-walker ll_diff_tree_sha1() is internally reworked to be a paths generator (new name diff_tree_paths()), with each generated path being `struct combine_diff_path` with info for path, new sha1,mode and for every parent which sha1,mode it was in it. 2) From that info, we can still generate usual diff queue with struct diff_filepairs, via "exporting" generated combine_diff_path, if we know we run for nparent=1 case. (see emit_diff() which is now named emit_diff_first_parent_only()) 3) In order for diff_can_quit_early(), which checks DIFF_OPT_TST(opt, HAS_CHANGES)) to work, that exporting have to be happening not in bulk, but incrementally, one diff path at a time. For such consumers, there is a new callback in diff_options introduced: ->pathchange(opt, struct combine_diff_path *) which, if set to !NULL, is called for every generated path. (see new compat ll_diff_tree_sha1() wrapper around new paths generator for setup) 4) The paths generation itself, is reworked from previous ll_diff_tree_sha1() code according to "D(A,P1...Pn) calculation scheme" provided above: On the start we allocate [nparent] arrays in place what was earlier just for one parent tree. then we just generalize loops, and comparison according to the algorithm. Some notes(*): 1) alloca(), for small arrays, is used for "runs not slower for nparent=1 case than before" goal - if we change it to xmalloc()/free() the timings get ~1% worse. For alloca() we use just-introduced xalloca/xalloca_free compatibility wrappers, so it should not be a portability problem. 2) For every parent tree, we need to keep a tag, whether entry from that parent equals to entry from minimal parent. For performance reasons I'm keeping that tag in entry's mode field in unused bit - see S_IFXMIN_NEQ. Not doing so, we'd need to alloca another [nparent] array, which hurts performance. 3) For emitted paths, memory could be reused, if we know the path was processed via callback and will not be needed later. We use efficient hand-made realloc-style path_appendnew(), that saves us from ~1-1.5% of potential additional slowdown. 4) goto(s) are used in several places, as the code executes a little bit faster with lowered register pressure. Also - we should now check for FIND_COPIES_HARDER not only when two entries names are the same, and their hashes are equal, but also for a case, when a path was removed from some of all parents having it. The reason is, if we don't, that path won't be emitted at all (see "a > xi" case), and we'll just skip it, and FIND_COPIES_HARDER wants all paths - with diff or without - to be emitted, to be later analyzed for being copies sources. The new check is only necessary for nparent >1, as for nparent=1 case xmin_eqtotal always =1 =nparent, and a path is always added to diff as removal. ~~~~~~~~ Timings for # without -c, i.e. testing only nparent=1 case `git log --raw --no-abbrev --no-renames` before and after the patch are as follows: navy.git linux.git v3.10..v3.11 before 0.611s 1.889s after 0.619s 1.907s slowdown 1.3% 0.9% This timings show we did no harm to usual diff(tree1,tree2) generation. From the table we can see that we actually did ~1% slowdown, but I think I've "earned" that 1% in the previous patch ("tree-diff: reuse base str(buf) memory on sub-tree recursion", HEAD~~) so for nparent=1 case, net timings stays approximately the same. The output also stayed the same. (*) If we revert 1)-4) to more usual techniques, for nparent=1 case, we'll get ~2-2.5% of additional slowdown, which I've tried to avoid, as "do no harm for nparent=1 case" rule. For linux.git, combined diff will run an order of magnitude faster and appropriate timings will be provided in the next commit, as we'll be taking advantage of the new diff tree-walker for combined-diff generation there. P.S. and combined diff is not some exotic/for-play-only stuff - for example for a program I write to represent Git archives as readonly filesystem, there is initial scan with `git log --reverse --raw --no-abbrev --no-renames -c` to extract log of what was created/changed when, as a result building a map {} sha1 -> in which commit (and date) a content was added that `-c` means also show combined diff for merges, and without them, if a merge is non-trivial (merges changes from two parents with both having separate changes to a file), or an evil one, the map will not be full, i.e. some valid sha1 would be absent from it. That case was my initial motivation for combined diffs speedup. Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-04-06 21:46:26 +00:00
struct combine_diff_path;
typedef int (*pathchange_fn_t)(struct diff_options *options,
struct combine_diff_path *path);
typedef void (*change_fn_t)(struct diff_options *options,
unsigned old_mode, unsigned new_mode,
const unsigned char *old_sha1,
const unsigned char *new_sha1,
diff: do not use null sha1 as a sentinel value The diff code represents paths using the diff_filespec struct. This struct has a sha1 to represent the sha1 of the content at that path, as well as a sha1_valid member which indicates whether its sha1 field is actually useful. If sha1_valid is not true, then the filespec represents a working tree file (e.g., for the no-index case, or for when the index is not up-to-date). The diff_filespec is only used internally, though. At the interfaces to the diff subsystem, callers feed the sha1 directly, and we create a diff_filespec from it. It's at that point that we look at the sha1 and decide whether it is valid or not; callers may pass the null sha1 as a sentinel value to indicate that it is not. We should not typically see the null sha1 coming from any other source (e.g., in the index itself, or from a tree). However, a corrupt tree might have a null sha1, which would cause "diff --patch" to accidentally diff the working tree version of a file instead of treating it as a blob. This patch extends the edges of the diff interface to accept a "sha1_valid" flag whenever we accept a sha1, and to use that flag when creating a filespec. In some cases, this means passing the flag through several layers, making the code change larger than would be desirable. One alternative would be to simply die() upon seeing corrupted trees with null sha1s. However, this fix more directly addresses the problem (while bogus sha1s in a tree are probably a bad thing, it is really the sentinel confusion sending us down the wrong code path that is what makes it devastating). And it means that git is more capable of examining and debugging these corrupted trees. For example, you can still "diff --raw" such a tree to find out when the bogus entry was introduced; you just cannot do a "--patch" diff (just as you could not with any other corrupted tree, as we do not have any content to diff). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-07-28 15:03:01 +00:00
int old_sha1_valid, int new_sha1_valid,
const char *fullpath,
unsigned old_dirty_submodule, unsigned new_dirty_submodule);
typedef void (*add_remove_fn_t)(struct diff_options *options,
int addremove, unsigned mode,
const unsigned char *sha1,
diff: do not use null sha1 as a sentinel value The diff code represents paths using the diff_filespec struct. This struct has a sha1 to represent the sha1 of the content at that path, as well as a sha1_valid member which indicates whether its sha1 field is actually useful. If sha1_valid is not true, then the filespec represents a working tree file (e.g., for the no-index case, or for when the index is not up-to-date). The diff_filespec is only used internally, though. At the interfaces to the diff subsystem, callers feed the sha1 directly, and we create a diff_filespec from it. It's at that point that we look at the sha1 and decide whether it is valid or not; callers may pass the null sha1 as a sentinel value to indicate that it is not. We should not typically see the null sha1 coming from any other source (e.g., in the index itself, or from a tree). However, a corrupt tree might have a null sha1, which would cause "diff --patch" to accidentally diff the working tree version of a file instead of treating it as a blob. This patch extends the edges of the diff interface to accept a "sha1_valid" flag whenever we accept a sha1, and to use that flag when creating a filespec. In some cases, this means passing the flag through several layers, making the code change larger than would be desirable. One alternative would be to simply die() upon seeing corrupted trees with null sha1s. However, this fix more directly addresses the problem (while bogus sha1s in a tree are probably a bad thing, it is really the sentinel confusion sending us down the wrong code path that is what makes it devastating). And it means that git is more capable of examining and debugging these corrupted trees. For example, you can still "diff --raw" such a tree to find out when the bogus entry was introduced; you just cannot do a "--patch" diff (just as you could not with any other corrupted tree, as we do not have any content to diff). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-07-28 15:03:01 +00:00
int sha1_valid,
const char *fullpath, unsigned dirty_submodule);
typedef void (*diff_format_fn_t)(struct diff_queue_struct *q,
struct diff_options *options, void *data);
typedef struct strbuf *(*diff_prefix_fn_t)(struct diff_options *opt, void *data);
#define DIFF_FORMAT_RAW 0x0001
#define DIFF_FORMAT_DIFFSTAT 0x0002
#define DIFF_FORMAT_NUMSTAT 0x0004
#define DIFF_FORMAT_SUMMARY 0x0008
#define DIFF_FORMAT_PATCH 0x0010
#define DIFF_FORMAT_SHORTSTAT 0x0020
Add "--dirstat" for some directory statistics This adds a new form of overview diffstat output, doing something that I have occasionally ended up doing manually (and badly, because it's actually pretty nasty to do), and that I think is very useful for an project like the kernel that has a fairly deep and well-separated directory structure with semantic meaning. What I mean by that is that it's often interesting to see exactly which sub-directories are impacted by a patch, and to what degree - even if you don't perhaps care so much about the individual files themselves. What makes the concept more interesting is that the "impact" is often hierarchical: in the kernel, for example, something could either have a very localized impact to "fs/ext3/" and then it's interesting to see that such a patch changes mostly that subdirectory, but you could have another patch that changes some generic VFS-layer issue which affects _many_ subdirectories that are all under "fs/", but none - or perhaps just a couple of them - of the individual filesystems are interesting in themselves. So what commonly happens is that you may have big changes in a specific sub-subdirectory, but still also significant separate changes to the subdirectory leading up to that - maybe you have significant VFS-level changes, but *also* changes under that VFS layer in the NFS-specific directories, for example. In that case, you do want the low-level parts that are significant to show up, but then the insignificant ones should show up as under the more generic top-level directory. This patch shows all of that with "--dirstat". The output can be either something simple like commit 81772fe... Author: Thomas Gleixner <tglx@linutronix.de> Date: Sun Feb 10 23:57:36 2008 +0100 x86: remove over noisy debug printk pageattr-test.c contains a noisy debug printk that people reported. The condition under which it prints (randomly tapping into a mem_map[] hole and not being able to c_p_a() there) is valid behavior and not interesting to report. Remove it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 100.0% arch/x86/mm/ or something much more complex like commit e231c2e... Author: David Howells <dhowells@redhat.com> Date: Thu Feb 7 00:15:26 2008 -0800 Convert ERR_PTR(PTR_ERR(p)) instances to ERR_CAST(p) 20.5% crypto/ 7.6% fs/afs/ 7.6% fs/fuse/ 7.6% fs/gfs2/ 5.1% fs/jffs2/ 5.1% fs/nfs/ 5.1% fs/nfsd/ 7.6% fs/reiserfs/ 15.3% fs/ 7.6% net/rxrpc/ 10.2% security/keys/ where that latter example is an example of significant work in some individual fs/*/ subdirectories (like the patches to reiserfs accounting for 7.6% of the whole), but then discounting those individual filesystems, there's also 15.3% other "random" things that weren't worth reporting on their oen left over under fs/ in general (either in that directory itself, or in subdirectories of fs/ that didn't have enough changes to be reported individually). I'd like to stress that the "15.3% fs/" mentioned above is the stuff that is under fs/ but that was _not_ significant enough to report on its own. So the above does _not_ mean that 15.3% of the work was under fs/ per se, because that 15.3% does *not* include the already-reported 7.6% of afs, 7.6% of fuse etc. If you want to enable "cumulative" directory statistics, you can use the "--cumulative" flag, which adds up percentages recursively even when they have been already reported for a sub-directory. That cumulative output is disabled if *all* of the changes in one subdirectory come from a deeper subdirectory, to avoid repeating subdirectories all the way to the root. For an example of the cumulative reporting, the above commit becomes commit e231c2e... Author: David Howells <dhowells@redhat.com> Date: Thu Feb 7 00:15:26 2008 -0800 Convert ERR_PTR(PTR_ERR(p)) instances to ERR_CAST(p) 20.5% crypto/ 7.6% fs/afs/ 7.6% fs/fuse/ 7.6% fs/gfs2/ 5.1% fs/jffs2/ 5.1% fs/nfs/ 5.1% fs/nfsd/ 7.6% fs/reiserfs/ 61.5% fs/ 7.6% net/rxrpc/ 10.2% security/keys/ in which the commit percentages now obviously add up to much more than 100%: now the changes that were already reported for the sub-directories under fs/ are then cumulatively included in the whole percentage of fs/ (ie now shows 61.5% as opposed to the 15.3% without the cumulative reporting). The default reporting limit has been arbitrarily set at 3%, which seems to be a pretty good cut-off, but you can specify the cut-off manually by giving it as an option parameter (eg "--dirstat=5" makes the cut-off be at 5% instead) NOTE! The percentages are purely about the total lines added and removed, not anything smarter (or dumber) than that. Also note that you should not generally expect things to add up to 100%: not only does it round down, we don't report leftover scraps (they add up to the top-level change count, but we don't even bother reporting that, it only reports subdirectories). Quite frankly, as a top-level manager this is really convenient for me, but it's going to be very boring for git itself since there are few subdirectories. Also, don't expect things to make tons of sense if you combine this with "-M" and there are cross-directory renames etc. But even for git itself, you can get some fun statistics. Try out git log --dirstat and see the occasional mentions of things like Documentation/, git-gui/, gitweb/ and gitk-git/. Or try out something like git diff --dirstat v1.5.0..v1.5.4 which does kind of git an overview that shows *something*. But in general, the output is more exciting for big projects with deeper structure, and doing a git diff --dirstat v2.6.24..v2.6.25-rc1 on the kernel is what I actually wrote this for! Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-12 21:26:31 +00:00
#define DIFF_FORMAT_DIRSTAT 0x0040
/* These override all above */
#define DIFF_FORMAT_NAME 0x0100
#define DIFF_FORMAT_NAME_STATUS 0x0200
#define DIFF_FORMAT_CHECKDIFF 0x0400
/* Same as output_format = 0 but we know that -s flag was given
* and we should not give default value to output_format.
*/
#define DIFF_FORMAT_NO_OUTPUT 0x0800
#define DIFF_FORMAT_CALLBACK 0x1000
#define DIFF_OPT_RECURSIVE (1 << 0)
#define DIFF_OPT_TREE_IN_RECURSIVE (1 << 1)
#define DIFF_OPT_BINARY (1 << 2)
#define DIFF_OPT_TEXT (1 << 3)
#define DIFF_OPT_FULL_INDEX (1 << 4)
#define DIFF_OPT_SILENT_ON_REMOVE (1 << 5)
#define DIFF_OPT_FIND_COPIES_HARDER (1 << 6)
#define DIFF_OPT_FOLLOW_RENAMES (1 << 7)
teach diffcore-rename to optionally ignore empty content Our rename detection is a heuristic, matching pairs of removed and added files with similar or identical content. It's unlikely to be wrong when there is actual content to compare, and we already take care not to do inexact rename detection when there is not enough content to produce good results. However, we always do exact rename detection, even when the blob is tiny or empty. It's easy to get false positives with an empty blob, simply because it is an obvious content to use as a boilerplate (e.g., when telling git that an empty directory is worth tracking via an empty .gitignore). This patch lets callers specify whether or not they are interested in using empty files as rename sources and destinations. The default is "yes", keeping the original behavior. It works by detecting the empty-blob sha1 for rename sources and destinations. One more flexible alternative would be to allow the caller to specify a minimum size for a blob to be "interesting" for rename detection. But that would catch small boilerplate files, not large ones (e.g., if you had the GPL COPYING file in many directories). A better alternative would be to allow a "-rename" gitattribute to allow boilerplate files to be marked as such. I'll leave the complexity of that solution until such time as somebody actually wants it. The complaints we've seen so far revolve around empty files, so let's start with the simple thing. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-03-22 22:52:13 +00:00
#define DIFF_OPT_RENAME_EMPTY (1 << 8)
/* (1 << 9) unused */
#define DIFF_OPT_HAS_CHANGES (1 << 10)
#define DIFF_OPT_QUICK (1 << 11)
#define DIFF_OPT_NO_INDEX (1 << 12)
#define DIFF_OPT_ALLOW_EXTERNAL (1 << 13)
#define DIFF_OPT_EXIT_WITH_STATUS (1 << 14)
#define DIFF_OPT_REVERSE_DIFF (1 << 15)
#define DIFF_OPT_CHECK_FAILED (1 << 16)
diff --relative: output paths as relative to the current subdirectory This adds --relative option to the diff family. When you start from a subdirectory: $ git diff --relative shows only the diff that is inside your current subdirectory, and without $prefix part. People who usually live in subdirectories may like it. There are a few things I should also mention about the change: - This works not just with diff but also works with the log family of commands, but the history pruning is not affected. In other words, if you go to a subdirectory, you can say: $ git log --relative -p but it will show the log message even for commits that do not touch the current directory. You can limit it by giving pathspec yourself: $ git log --relative -p . This originally was not a conscious design choice, but we have a way to affect diff pathspec and pruning pathspec independently. IOW "git log --full-diff -p ." tells it to prune history to commits that affect the current subdirectory but show the changes with full context. I think it makes more sense to leave pruning independent from --relative than the obvious alternative of always pruning with the current subdirectory, which would break the symmetry. - Because this works also with the log family, you could format-patch a single change, limiting the effect to your subdirectory, like so: $ cd gitk-git $ git format-patch -1 --relative 911f1eb But because that is a special purpose usage, this option will never become the default, with or without repository or user preference configuration. The risk of producing a partial patch and sending it out by mistake is too great if we did so. - This is inherently incompatible with --no-index, which is a bolted-on hack that does not have much to do with git itself. I didn't bother checking and erroring out on the combined use of the options, but probably I should. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-12 22:26:02 +00:00
#define DIFF_OPT_RELATIVE_NAME (1 << 17)
#define DIFF_OPT_IGNORE_SUBMODULES (1 << 18)
#define DIFF_OPT_DIRSTAT_CUMULATIVE (1 << 19)
#define DIFF_OPT_DIRSTAT_BY_FILE (1 << 20)
#define DIFF_OPT_ALLOW_TEXTCONV (1 << 21)
#define DIFF_OPT_DIFF_FROM_CONTENTS (1 << 22)
#define DIFF_OPT_SUBMODULE_LOG (1 << 23)
#define DIFF_OPT_DIRTY_SUBMODULES (1 << 24)
#define DIFF_OPT_IGNORE_UNTRACKED_IN_SUBMODULES (1 << 25)
#define DIFF_OPT_IGNORE_DIRTY_SUBMODULES (1 << 26)
Submodules: Add the new "ignore" config option for diff and status The new "ignore" config option controls the default behavior for "git status" and the diff family. It specifies under what circumstances they consider submodules as modified and can be set separately for each submodule. The command line option "--ignore-submodules=" has been extended to accept the new parameter "none" for both status and diff. Users that chose submodules to get rid of long work tree scanning times might want to set the "dirty" option for those submodules. This brings back the pre 1.7.0 behavior, where submodule work trees were never scanned for modifications. By using "--ignore-submodules=none" on the command line the status and diff commands can be told to do a full scan. This option can be set to the following values (which have the same name and meaning as for the "--ignore-submodules" option of status and diff): "all": All changes to the submodule will be ignored. "dirty": Only differences of the commit recorded in the superproject and the submodules HEAD will be considered modifications, all changes to the work tree of the submodule will be ignored. When using this value, the submodule will not be scanned for work tree changes at all, leading to a performance benefit on large submodules. "untracked": Only untracked files in the submodules work tree are ignored, a changed HEAD and/or modified files in the submodule will mark it as modified. "none" (which is the default): Either untracked or modified files in a submodules work tree or a difference between the subdmodules HEAD and the commit recorded in the superproject will make it show up as changed. This value is added as a new parameter for the "--ignore-submodules" option of the diff family and "git status" so the user can override the settings in the configuration. Signed-off-by: Jens Lehmann <Jens.Lehmann@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-08-05 22:39:25 +00:00
#define DIFF_OPT_OVERRIDE_SUBMODULE_CONFIG (1 << 27)
New --dirstat=lines mode, doing dirstat analysis based on diffstat This patch adds an alternative implementation of show_dirstat(), called show_dirstat_by_line(), which uses the more expensive diffstat analysis (as opposed to show_dirstat()'s own (relatively inexpensive) analysis) to derive the numbers from which the --dirstat output is computed. The alternative implementation is controlled by the new "lines" parameter to the --dirstat option (or the diff.dirstat config variable). For binary files, the diffstat analysis counts bytes instead of lines, so to prevent binary files from dominating the dirstat results, the byte counts for binary files are divided by 64 before being compared to their textual/line-based counterparts. This is a stupid and ugly - but very cheap - heuristic. In linux-2.6.git, running the three different --dirstat modes: time git diff v2.6.20..v2.6.30 --dirstat=changes > /dev/null vs. time git diff v2.6.20..v2.6.30 --dirstat=lines > /dev/null vs. time git diff v2.6.20..v2.6.30 --dirstat=files > /dev/null yields the following average runtimes on my machine: - "changes" (default): ~6.0 s - "lines": ~9.6 s - "files": ~0.1 s So, as expected, there's a considerable performance hit (~60%) by going through the full diffstat analysis as compared to the default "changes" analysis (obviously, "files" is much faster than both). As such, the "lines" mode is probably only useful if you really need the --dirstat numbers to be consistent with the numbers returned from the other --*stat options. The patch also includes documentation and tests for the new dirstat mode. Improved-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Johan Herland <johan@herland.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-04-29 09:36:21 +00:00
#define DIFF_OPT_DIRSTAT_BY_LINE (1 << 28)
#define DIFF_OPT_FUNCCONTEXT (1 << 29)
#define DIFF_OPT_PICKAXE_IGNORE_CASE (1 << 30)
#define DIFF_OPT_DEFAULT_FOLLOW_RENAMES (1 << 31)
#define DIFF_OPT_TST(opts, flag) ((opts)->flags & DIFF_OPT_##flag)
#define DIFF_OPT_TOUCHED(opts, flag) ((opts)->touched_flags & DIFF_OPT_##flag)
#define DIFF_OPT_SET(opts, flag) (((opts)->flags |= DIFF_OPT_##flag),((opts)->touched_flags |= DIFF_OPT_##flag))
#define DIFF_OPT_CLR(opts, flag) (((opts)->flags &= ~DIFF_OPT_##flag),((opts)->touched_flags |= DIFF_OPT_##flag))
#define DIFF_XDL_TST(opts, flag) ((opts)->xdl_opts & XDF_##flag)
#define DIFF_XDL_SET(opts, flag) ((opts)->xdl_opts |= XDF_##flag)
#define DIFF_XDL_CLR(opts, flag) ((opts)->xdl_opts &= ~XDF_##flag)
#define DIFF_WITH_ALG(opts, flag) (((opts)->xdl_opts & ~XDF_DIFF_ALGORITHM_MASK) | XDF_##flag)
enum diff_words_type {
DIFF_WORDS_NONE = 0,
DIFF_WORDS_PORCELAIN,
DIFF_WORDS_PLAIN,
DIFF_WORDS_COLOR
};
struct diff_options {
const char *orderfile;
const char *pickaxe;
const char *single_follow;
const char *a_prefix, *b_prefix;
unsigned flags;
unsigned touched_flags;
/* diff-filter bits */
unsigned int filter;
int use_color;
int context;
int interhunkcontext;
int break_opt;
int detect_rename;
int irreversible_delete;
int skip_stat_unmatch;
int line_termination;
int output_format;
int pickaxe_opts;
int rename_score;
int rename_limit;
int needed_rename_limit;
int degraded_cc_to_c;
int show_rename_progress;
int dirstat_permille;
int setup;
int abbrev;
/* white-space error highlighting */
#define WSEH_NEW 1
#define WSEH_CONTEXT 2
#define WSEH_OLD 4
unsigned ws_error_highlight;
diff --relative: output paths as relative to the current subdirectory This adds --relative option to the diff family. When you start from a subdirectory: $ git diff --relative shows only the diff that is inside your current subdirectory, and without $prefix part. People who usually live in subdirectories may like it. There are a few things I should also mention about the change: - This works not just with diff but also works with the log family of commands, but the history pruning is not affected. In other words, if you go to a subdirectory, you can say: $ git log --relative -p but it will show the log message even for commits that do not touch the current directory. You can limit it by giving pathspec yourself: $ git log --relative -p . This originally was not a conscious design choice, but we have a way to affect diff pathspec and pruning pathspec independently. IOW "git log --full-diff -p ." tells it to prune history to commits that affect the current subdirectory but show the changes with full context. I think it makes more sense to leave pruning independent from --relative than the obvious alternative of always pruning with the current subdirectory, which would break the symmetry. - Because this works also with the log family, you could format-patch a single change, limiting the effect to your subdirectory, like so: $ cd gitk-git $ git format-patch -1 --relative 911f1eb But because that is a special purpose usage, this option will never become the default, with or without repository or user preference configuration. The risk of producing a partial patch and sending it out by mistake is too great if we did so. - This is inherently incompatible with --no-index, which is a bolted-on hack that does not have much to do with git itself. I didn't bother checking and erroring out on the combined use of the options, but probably I should. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-12 22:26:02 +00:00
const char *prefix;
int prefix_length;
const char *stat_sep;
long xdl_opts;
int stat_width;
int stat_name_width;
int stat_graph_width;
int stat_count;
const char *word_regex;
enum diff_words_type word_diff;
/* this is set by diffcore for DIFF_FORMAT_PATCH */
int found_changes;
/* to support internal diff recursion by --follow hack*/
int found_follow;
void (*set_default)(struct diff_options *);
FILE *file;
int close_file;
struct pathspec pathspec;
tree-diff: rework diff_tree() to generate diffs for multiparent cases as well Previously diff_tree(), which is now named ll_diff_tree_sha1(), was generating diff_filepair(s) for two trees t1 and t2, and that was usually used for a commit as t1=HEAD~, and t2=HEAD - i.e. to see changes a commit introduces. In Git, however, we have fundamentally built flexibility in that a commit can have many parents - 1 for a plain commit, 2 for a simple merge, but also more than 2 for merging several heads at once. For merges there is a so called combine-diff, which shows diff, a merge introduces by itself, omitting changes done by any parent. That works through first finding paths, that are different to all parents, and then showing generalized diff, with separate columns for +/- for each parent. The code lives in combine-diff.c . There is an impedance mismatch, however, in that a commit could generally have any number of parents, and that while diffing trees, we divide cases for 2-tree diffs and more-than-2-tree diffs. I mean there is no special casing for multiple parents commits in e.g. revision-walker . That impedance mismatch *hurts* *performance* *badly* for generating combined diffs - in "combine-diff: optimize combine_diff_path sets intersection" I've already removed some slowness from it, but from the timings provided there, it could be seen, that combined diffs still cost more than an order of magnitude more cpu time, compared to diff for usual commits, and that would only be an optimistic estimate, if we take into account that for e.g. linux.git there is only one merge for several dozens of plain commits. That slowness comes from the fact that currently, while generating combined diff, a lot of time is spent computing diff(commit,commit^2) just to only then intersect that huge diff to almost small set of files from diff(commit,commit^1). That's because at present, to compute combine-diff, for first finding paths, that "every parent touches", we use the following combine-diff property/definition: D(A,P1...Pn) = D(A,P1) ^ ... ^ D(A,Pn) (w.r.t. paths) where D(A,P1...Pn) is combined diff between commit A, and parents Pi and D(A,Pi) is usual two-tree diff Pi..A So if any of that D(A,Pi) is huge, tracting 1 n-parent combine-diff as n 1-parent diffs and intersecting results will be slow. And usually, for linux.git and other topic-based workflows, that D(A,P2) is huge, because, if merge-base of A and P2, is several dozens of merges (from A, via first parent) below, that D(A,P2) will be diffing sum of merges from several subsystems to 1 subsystem. The solution is to avoid computing n 1-parent diffs, and to find changed-to-all-parents paths via scanning A's and all Pi's trees simultaneously, at each step comparing their entries, and based on that comparison, populate paths result, and deduce we could *skip* *recursing* into subdirectories, if at least for 1 parent, sha1 of that dir tree is the same as in A. That would save us from doing significant amount of needless work. Such approach is very similar to what diff_tree() does, only there we deal with scanning only 2 trees simultaneously, and for n+1 tree, the logic is a bit more complex: D(T,P1...Pn) calculation scheme ------------------------------- D(T,P1...Pn) = D(T,P1) ^ ... ^ D(T,Pn) (regarding resulting paths set) D(T,Pj) - diff between T..Pj D(T,P1...Pn) - combined diff from T to parents P1,...,Pn We start from all trees, which are sorted, and compare their entries in lock-step: T P1 Pn - - - |t| |p1| |pn| |-| |--| ... |--| imin = argmin(p1...pn) | | | | | | |-| |--| |--| |.| |. | |. | . . . . . . at any time there could be 3 cases: 1) t < p[imin]; 2) t > p[imin]; 3) t = p[imin]. Schematic deduction of what every case means, and what to do, follows: 1) t < p[imin] -> ∀j t ∉ Pj -> "+t" ∈ D(T,Pj) -> D += "+t"; t↓ 2) t > p[imin] 2.1) ∃j: pj > p[imin] -> "-p[imin]" ∉ D(T,Pj) -> D += ø; ∀ pi=p[imin] pi↓ 2.2) ∀i pi = p[imin] -> pi ∉ T -> "-pi" ∈ D(T,Pi) -> D += "-p[imin]"; ∀i pi↓ 3) t = p[imin] 3.1) ∃j: pj > p[imin] -> "+t" ∈ D(T,Pj) -> only pi=p[imin] remains to investigate 3.2) pi = p[imin] -> investigate δ(t,pi) | | v 3.1+3.2) looking at δ(t,pi) ∀i: pi=p[imin] - if all != ø -> ⎧δ(t,pi) - if pi=p[imin] -> D += ⎨ ⎩"+t" - if pi>p[imin] in any case t↓ ∀ pi=p[imin] pi↓ ~ For comparison, here is how diff_tree() works: D(A,B) calculation scheme ------------------------- A B - - |a| |b| a < b -> a ∉ B -> D(A,B) += +a a↓ |-| |-| a > b -> b ∉ A -> D(A,B) += -b b↓ | | | | a = b -> investigate δ(a,b) a↓ b↓ |-| |-| |.| |.| . . . . ~~~~~~~~ This patch generalizes diff tree-walker to work with arbitrary number of parents as described above - i.e. now there is a resulting tree t, and some parents trees tp[i] i=[0..nparent). The generalization builds on the fact that usual diff D(A,B) is by definition the same as combined diff D(A,[B]), so if we could rework the code for common case and make it be not slower for nparent=1 case, usual diff(t1,t2) generation will not be slower, and multiparent diff tree-walker would greatly benefit generating combine-diff. What we do is as follows: 1) diff tree-walker ll_diff_tree_sha1() is internally reworked to be a paths generator (new name diff_tree_paths()), with each generated path being `struct combine_diff_path` with info for path, new sha1,mode and for every parent which sha1,mode it was in it. 2) From that info, we can still generate usual diff queue with struct diff_filepairs, via "exporting" generated combine_diff_path, if we know we run for nparent=1 case. (see emit_diff() which is now named emit_diff_first_parent_only()) 3) In order for diff_can_quit_early(), which checks DIFF_OPT_TST(opt, HAS_CHANGES)) to work, that exporting have to be happening not in bulk, but incrementally, one diff path at a time. For such consumers, there is a new callback in diff_options introduced: ->pathchange(opt, struct combine_diff_path *) which, if set to !NULL, is called for every generated path. (see new compat ll_diff_tree_sha1() wrapper around new paths generator for setup) 4) The paths generation itself, is reworked from previous ll_diff_tree_sha1() code according to "D(A,P1...Pn) calculation scheme" provided above: On the start we allocate [nparent] arrays in place what was earlier just for one parent tree. then we just generalize loops, and comparison according to the algorithm. Some notes(*): 1) alloca(), for small arrays, is used for "runs not slower for nparent=1 case than before" goal - if we change it to xmalloc()/free() the timings get ~1% worse. For alloca() we use just-introduced xalloca/xalloca_free compatibility wrappers, so it should not be a portability problem. 2) For every parent tree, we need to keep a tag, whether entry from that parent equals to entry from minimal parent. For performance reasons I'm keeping that tag in entry's mode field in unused bit - see S_IFXMIN_NEQ. Not doing so, we'd need to alloca another [nparent] array, which hurts performance. 3) For emitted paths, memory could be reused, if we know the path was processed via callback and will not be needed later. We use efficient hand-made realloc-style path_appendnew(), that saves us from ~1-1.5% of potential additional slowdown. 4) goto(s) are used in several places, as the code executes a little bit faster with lowered register pressure. Also - we should now check for FIND_COPIES_HARDER not only when two entries names are the same, and their hashes are equal, but also for a case, when a path was removed from some of all parents having it. The reason is, if we don't, that path won't be emitted at all (see "a > xi" case), and we'll just skip it, and FIND_COPIES_HARDER wants all paths - with diff or without - to be emitted, to be later analyzed for being copies sources. The new check is only necessary for nparent >1, as for nparent=1 case xmin_eqtotal always =1 =nparent, and a path is always added to diff as removal. ~~~~~~~~ Timings for # without -c, i.e. testing only nparent=1 case `git log --raw --no-abbrev --no-renames` before and after the patch are as follows: navy.git linux.git v3.10..v3.11 before 0.611s 1.889s after 0.619s 1.907s slowdown 1.3% 0.9% This timings show we did no harm to usual diff(tree1,tree2) generation. From the table we can see that we actually did ~1% slowdown, but I think I've "earned" that 1% in the previous patch ("tree-diff: reuse base str(buf) memory on sub-tree recursion", HEAD~~) so for nparent=1 case, net timings stays approximately the same. The output also stayed the same. (*) If we revert 1)-4) to more usual techniques, for nparent=1 case, we'll get ~2-2.5% of additional slowdown, which I've tried to avoid, as "do no harm for nparent=1 case" rule. For linux.git, combined diff will run an order of magnitude faster and appropriate timings will be provided in the next commit, as we'll be taking advantage of the new diff tree-walker for combined-diff generation there. P.S. and combined diff is not some exotic/for-play-only stuff - for example for a program I write to represent Git archives as readonly filesystem, there is initial scan with `git log --reverse --raw --no-abbrev --no-renames -c` to extract log of what was created/changed when, as a result building a map {} sha1 -> in which commit (and date) a content was added that `-c` means also show combined diff for merges, and without them, if a merge is non-trivial (merges changes from two parents with both having separate changes to a file), or an evil one, the map will not be full, i.e. some valid sha1 would be absent from it. That case was my initial motivation for combined diffs speedup. Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-04-06 21:46:26 +00:00
pathchange_fn_t pathchange;
change_fn_t change;
add_remove_fn_t add_remove;
diff_format_fn_t format_callback;
void *format_callback_data;
diff_prefix_fn_t output_prefix;
int output_prefix_length;
void *output_prefix_data;
int diff_path_counter;
};
enum color_diff {
DIFF_RESET = 0,
DIFF_CONTEXT = 1,
DIFF_METAINFO = 2,
DIFF_FRAGINFO = 3,
DIFF_FILE_OLD = 4,
DIFF_FILE_NEW = 5,
DIFF_COMMIT = 6,
DIFF_WHITESPACE = 7,
DIFF_FUNCINFO = 8
};
const char *diff_get_color(int diff_use_color, enum color_diff ix);
#define diff_get_color_opt(o, ix) \
diff_get_color((o)->use_color, ix)
const char *diff_line_prefix(struct diff_options *);
extern const char mime_boundary_leader[];
tree-diff: rework diff_tree() to generate diffs for multiparent cases as well Previously diff_tree(), which is now named ll_diff_tree_sha1(), was generating diff_filepair(s) for two trees t1 and t2, and that was usually used for a commit as t1=HEAD~, and t2=HEAD - i.e. to see changes a commit introduces. In Git, however, we have fundamentally built flexibility in that a commit can have many parents - 1 for a plain commit, 2 for a simple merge, but also more than 2 for merging several heads at once. For merges there is a so called combine-diff, which shows diff, a merge introduces by itself, omitting changes done by any parent. That works through first finding paths, that are different to all parents, and then showing generalized diff, with separate columns for +/- for each parent. The code lives in combine-diff.c . There is an impedance mismatch, however, in that a commit could generally have any number of parents, and that while diffing trees, we divide cases for 2-tree diffs and more-than-2-tree diffs. I mean there is no special casing for multiple parents commits in e.g. revision-walker . That impedance mismatch *hurts* *performance* *badly* for generating combined diffs - in "combine-diff: optimize combine_diff_path sets intersection" I've already removed some slowness from it, but from the timings provided there, it could be seen, that combined diffs still cost more than an order of magnitude more cpu time, compared to diff for usual commits, and that would only be an optimistic estimate, if we take into account that for e.g. linux.git there is only one merge for several dozens of plain commits. That slowness comes from the fact that currently, while generating combined diff, a lot of time is spent computing diff(commit,commit^2) just to only then intersect that huge diff to almost small set of files from diff(commit,commit^1). That's because at present, to compute combine-diff, for first finding paths, that "every parent touches", we use the following combine-diff property/definition: D(A,P1...Pn) = D(A,P1) ^ ... ^ D(A,Pn) (w.r.t. paths) where D(A,P1...Pn) is combined diff between commit A, and parents Pi and D(A,Pi) is usual two-tree diff Pi..A So if any of that D(A,Pi) is huge, tracting 1 n-parent combine-diff as n 1-parent diffs and intersecting results will be slow. And usually, for linux.git and other topic-based workflows, that D(A,P2) is huge, because, if merge-base of A and P2, is several dozens of merges (from A, via first parent) below, that D(A,P2) will be diffing sum of merges from several subsystems to 1 subsystem. The solution is to avoid computing n 1-parent diffs, and to find changed-to-all-parents paths via scanning A's and all Pi's trees simultaneously, at each step comparing their entries, and based on that comparison, populate paths result, and deduce we could *skip* *recursing* into subdirectories, if at least for 1 parent, sha1 of that dir tree is the same as in A. That would save us from doing significant amount of needless work. Such approach is very similar to what diff_tree() does, only there we deal with scanning only 2 trees simultaneously, and for n+1 tree, the logic is a bit more complex: D(T,P1...Pn) calculation scheme ------------------------------- D(T,P1...Pn) = D(T,P1) ^ ... ^ D(T,Pn) (regarding resulting paths set) D(T,Pj) - diff between T..Pj D(T,P1...Pn) - combined diff from T to parents P1,...,Pn We start from all trees, which are sorted, and compare their entries in lock-step: T P1 Pn - - - |t| |p1| |pn| |-| |--| ... |--| imin = argmin(p1...pn) | | | | | | |-| |--| |--| |.| |. | |. | . . . . . . at any time there could be 3 cases: 1) t < p[imin]; 2) t > p[imin]; 3) t = p[imin]. Schematic deduction of what every case means, and what to do, follows: 1) t < p[imin] -> ∀j t ∉ Pj -> "+t" ∈ D(T,Pj) -> D += "+t"; t↓ 2) t > p[imin] 2.1) ∃j: pj > p[imin] -> "-p[imin]" ∉ D(T,Pj) -> D += ø; ∀ pi=p[imin] pi↓ 2.2) ∀i pi = p[imin] -> pi ∉ T -> "-pi" ∈ D(T,Pi) -> D += "-p[imin]"; ∀i pi↓ 3) t = p[imin] 3.1) ∃j: pj > p[imin] -> "+t" ∈ D(T,Pj) -> only pi=p[imin] remains to investigate 3.2) pi = p[imin] -> investigate δ(t,pi) | | v 3.1+3.2) looking at δ(t,pi) ∀i: pi=p[imin] - if all != ø -> ⎧δ(t,pi) - if pi=p[imin] -> D += ⎨ ⎩"+t" - if pi>p[imin] in any case t↓ ∀ pi=p[imin] pi↓ ~ For comparison, here is how diff_tree() works: D(A,B) calculation scheme ------------------------- A B - - |a| |b| a < b -> a ∉ B -> D(A,B) += +a a↓ |-| |-| a > b -> b ∉ A -> D(A,B) += -b b↓ | | | | a = b -> investigate δ(a,b) a↓ b↓ |-| |-| |.| |.| . . . . ~~~~~~~~ This patch generalizes diff tree-walker to work with arbitrary number of parents as described above - i.e. now there is a resulting tree t, and some parents trees tp[i] i=[0..nparent). The generalization builds on the fact that usual diff D(A,B) is by definition the same as combined diff D(A,[B]), so if we could rework the code for common case and make it be not slower for nparent=1 case, usual diff(t1,t2) generation will not be slower, and multiparent diff tree-walker would greatly benefit generating combine-diff. What we do is as follows: 1) diff tree-walker ll_diff_tree_sha1() is internally reworked to be a paths generator (new name diff_tree_paths()), with each generated path being `struct combine_diff_path` with info for path, new sha1,mode and for every parent which sha1,mode it was in it. 2) From that info, we can still generate usual diff queue with struct diff_filepairs, via "exporting" generated combine_diff_path, if we know we run for nparent=1 case. (see emit_diff() which is now named emit_diff_first_parent_only()) 3) In order for diff_can_quit_early(), which checks DIFF_OPT_TST(opt, HAS_CHANGES)) to work, that exporting have to be happening not in bulk, but incrementally, one diff path at a time. For such consumers, there is a new callback in diff_options introduced: ->pathchange(opt, struct combine_diff_path *) which, if set to !NULL, is called for every generated path. (see new compat ll_diff_tree_sha1() wrapper around new paths generator for setup) 4) The paths generation itself, is reworked from previous ll_diff_tree_sha1() code according to "D(A,P1...Pn) calculation scheme" provided above: On the start we allocate [nparent] arrays in place what was earlier just for one parent tree. then we just generalize loops, and comparison according to the algorithm. Some notes(*): 1) alloca(), for small arrays, is used for "runs not slower for nparent=1 case than before" goal - if we change it to xmalloc()/free() the timings get ~1% worse. For alloca() we use just-introduced xalloca/xalloca_free compatibility wrappers, so it should not be a portability problem. 2) For every parent tree, we need to keep a tag, whether entry from that parent equals to entry from minimal parent. For performance reasons I'm keeping that tag in entry's mode field in unused bit - see S_IFXMIN_NEQ. Not doing so, we'd need to alloca another [nparent] array, which hurts performance. 3) For emitted paths, memory could be reused, if we know the path was processed via callback and will not be needed later. We use efficient hand-made realloc-style path_appendnew(), that saves us from ~1-1.5% of potential additional slowdown. 4) goto(s) are used in several places, as the code executes a little bit faster with lowered register pressure. Also - we should now check for FIND_COPIES_HARDER not only when two entries names are the same, and their hashes are equal, but also for a case, when a path was removed from some of all parents having it. The reason is, if we don't, that path won't be emitted at all (see "a > xi" case), and we'll just skip it, and FIND_COPIES_HARDER wants all paths - with diff or without - to be emitted, to be later analyzed for being copies sources. The new check is only necessary for nparent >1, as for nparent=1 case xmin_eqtotal always =1 =nparent, and a path is always added to diff as removal. ~~~~~~~~ Timings for # without -c, i.e. testing only nparent=1 case `git log --raw --no-abbrev --no-renames` before and after the patch are as follows: navy.git linux.git v3.10..v3.11 before 0.611s 1.889s after 0.619s 1.907s slowdown 1.3% 0.9% This timings show we did no harm to usual diff(tree1,tree2) generation. From the table we can see that we actually did ~1% slowdown, but I think I've "earned" that 1% in the previous patch ("tree-diff: reuse base str(buf) memory on sub-tree recursion", HEAD~~) so for nparent=1 case, net timings stays approximately the same. The output also stayed the same. (*) If we revert 1)-4) to more usual techniques, for nparent=1 case, we'll get ~2-2.5% of additional slowdown, which I've tried to avoid, as "do no harm for nparent=1 case" rule. For linux.git, combined diff will run an order of magnitude faster and appropriate timings will be provided in the next commit, as we'll be taking advantage of the new diff tree-walker for combined-diff generation there. P.S. and combined diff is not some exotic/for-play-only stuff - for example for a program I write to represent Git archives as readonly filesystem, there is initial scan with `git log --reverse --raw --no-abbrev --no-renames -c` to extract log of what was created/changed when, as a result building a map {} sha1 -> in which commit (and date) a content was added that `-c` means also show combined diff for merges, and without them, if a merge is non-trivial (merges changes from two parents with both having separate changes to a file), or an evil one, the map will not be full, i.e. some valid sha1 would be absent from it. That case was my initial motivation for combined diffs speedup. Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-04-06 21:46:26 +00:00
extern struct combine_diff_path *diff_tree_paths(
struct combine_diff_path *p, const unsigned char *sha1,
const unsigned char **parent_sha1, int nparent,
struct strbuf *base, struct diff_options *opt);
extern int diff_tree_sha1(const unsigned char *old, const unsigned char *new,
const char *base, struct diff_options *opt);
extern int diff_root_tree_sha1(const unsigned char *new, const char *base,
struct diff_options *opt);
struct combine_diff_path {
struct combine_diff_path *next;
char *path;
unsigned int mode;
struct object_id oid;
struct combine_diff_parent {
char status;
unsigned int mode;
struct object_id oid;
} parent[FLEX_ARRAY];
};
#define combine_diff_path_size(n, l) \
(sizeof(struct combine_diff_path) + \
sizeof(struct combine_diff_parent) * (n) + (l) + 1)
Log message printout cleanups On Sun, 16 Apr 2006, Junio C Hamano wrote: > > In the mid-term, I am hoping we can drop the generate_header() > callchain _and_ the custom code that formats commit log in-core, > found in cmd_log_wc(). Ok, this was nastier than expected, just because the dependencies between the different log-printing stuff were absolutely _everywhere_, but here's a patch that does exactly that. The patch is not very easy to read, and the "--patch-with-stat" thing is still broken (it does not call the "show_log()" thing properly for merges). That's not a new bug. In the new world order it _should_ do something like if (rev->logopt) show_log(rev, rev->logopt, "---\n"); but it doesn't. I haven't looked at the --with-stat logic, so I left it alone. That said, this patch removes more lines than it adds, and in particular, the "cmd_log_wc()" loop is now a very clean: while ((commit = get_revision(rev)) != NULL) { log_tree_commit(rev, commit); free(commit->buffer); commit->buffer = NULL; } so it doesn't get much prettier than this. All the complexity is entirely hidden in log-tree.c, and any code that needs to flush the log literally just needs to do the "if (rev->logopt) show_log(...)" incantation. I had to make the combined_diff() logic take a "struct rev_info" instead of just a "struct diff_options", but that part is pretty clean. This does change "git whatchanged" from using "diff-tree" as the commit descriptor to "commit", and I changed one of the tests to reflect that new reality. Otherwise everything still passes, and my other tests look fine too. Signed-off-by: Linus Torvalds <torvalds@osdl.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-04-17 18:59:32 +00:00
extern void show_combined_diff(struct combine_diff_path *elem, int num_parent,
int dense, struct rev_info *);
extern void diff_tree_combined(const unsigned char *sha1, const struct sha1_array *parents, int dense, struct rev_info *rev);
extern void diff_tree_combined_merge(const struct commit *commit, int dense, struct rev_info *rev);
diff-tree -c: show a merge commit a bit more sensibly. A new option '-c' to diff-tree changes the way a merge commit is displayed when generating a patch output. It shows a "combined diff" (hence the option letter 'c'), which looks like this: $ git-diff-tree --pretty -c -p fec9ebf1 | head -n 18 diff-tree fec9ebf... (from parents) Merge: 0620db3... 8a263ae... Author: Junio C Hamano <junkio@cox.net> Date: Sun Jan 15 22:25:35 2006 -0800 Merge fixes up to GIT 1.1.3 diff --combined describe.c @@@ +98,7 @@@ return (a_date > b_date) ? -1 : (a_date == b_date) ? 0 : 1; } - static void describe(char *arg) - static void describe(struct commit *cmit, int last_one) ++ static void describe(char *arg, int last_one) { + unsigned char sha1[20]; + struct commit *cmit; There are a few things to note about this feature: - The '-c' option implies '-p'. It also implies '-m' halfway in the sense that "interesting" merges are shown, but not all merges. - When a blob matches one of the parents, we do not show a diff for that path at all. For a merge commit, this option shows paths with real file-level merge (aka "interesting things"). - As a concequence of the above, an "uninteresting" merge is not shown at all. You can use '-m' in addition to '-c' to show the commit log for such a merge, but there will be no combined diff output. - Unlike "gitk", the output is monochrome. A '-' character in the nth column means the line is from the nth parent and does not appear in the merge result (i.e. removed from that parent's version). A '+' character in the nth column means the line appears in the merge result, and the nth parent does not have that line (i.e. added by the merge itself or inherited from another parent). The above example output shows that the function signature was changed from either parents (hence two "-" lines and a "++" line), and "unsigned char sha1[20]", prefixed by a " +", was inherited from the first parent. The code as sent to the list was buggy in few corner cases, which I have fixed since then. It does not bother to keep track of and show the line numbers from parent commits, which it probably should. Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-01-24 09:22:04 +00:00
void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b);
extern int diff_can_quit_early(struct diff_options *);
extern void diff_addremove(struct diff_options *,
int addremove,
unsigned mode,
const unsigned char *sha1,
diff: do not use null sha1 as a sentinel value The diff code represents paths using the diff_filespec struct. This struct has a sha1 to represent the sha1 of the content at that path, as well as a sha1_valid member which indicates whether its sha1 field is actually useful. If sha1_valid is not true, then the filespec represents a working tree file (e.g., for the no-index case, or for when the index is not up-to-date). The diff_filespec is only used internally, though. At the interfaces to the diff subsystem, callers feed the sha1 directly, and we create a diff_filespec from it. It's at that point that we look at the sha1 and decide whether it is valid or not; callers may pass the null sha1 as a sentinel value to indicate that it is not. We should not typically see the null sha1 coming from any other source (e.g., in the index itself, or from a tree). However, a corrupt tree might have a null sha1, which would cause "diff --patch" to accidentally diff the working tree version of a file instead of treating it as a blob. This patch extends the edges of the diff interface to accept a "sha1_valid" flag whenever we accept a sha1, and to use that flag when creating a filespec. In some cases, this means passing the flag through several layers, making the code change larger than would be desirable. One alternative would be to simply die() upon seeing corrupted trees with null sha1s. However, this fix more directly addresses the problem (while bogus sha1s in a tree are probably a bad thing, it is really the sentinel confusion sending us down the wrong code path that is what makes it devastating). And it means that git is more capable of examining and debugging these corrupted trees. For example, you can still "diff --raw" such a tree to find out when the bogus entry was introduced; you just cannot do a "--patch" diff (just as you could not with any other corrupted tree, as we do not have any content to diff). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-07-28 15:03:01 +00:00
int sha1_valid,
const char *fullpath, unsigned dirty_submodule);
extern void diff_change(struct diff_options *,
unsigned mode1, unsigned mode2,
const unsigned char *sha1,
const unsigned char *sha2,
diff: do not use null sha1 as a sentinel value The diff code represents paths using the diff_filespec struct. This struct has a sha1 to represent the sha1 of the content at that path, as well as a sha1_valid member which indicates whether its sha1 field is actually useful. If sha1_valid is not true, then the filespec represents a working tree file (e.g., for the no-index case, or for when the index is not up-to-date). The diff_filespec is only used internally, though. At the interfaces to the diff subsystem, callers feed the sha1 directly, and we create a diff_filespec from it. It's at that point that we look at the sha1 and decide whether it is valid or not; callers may pass the null sha1 as a sentinel value to indicate that it is not. We should not typically see the null sha1 coming from any other source (e.g., in the index itself, or from a tree). However, a corrupt tree might have a null sha1, which would cause "diff --patch" to accidentally diff the working tree version of a file instead of treating it as a blob. This patch extends the edges of the diff interface to accept a "sha1_valid" flag whenever we accept a sha1, and to use that flag when creating a filespec. In some cases, this means passing the flag through several layers, making the code change larger than would be desirable. One alternative would be to simply die() upon seeing corrupted trees with null sha1s. However, this fix more directly addresses the problem (while bogus sha1s in a tree are probably a bad thing, it is really the sentinel confusion sending us down the wrong code path that is what makes it devastating). And it means that git is more capable of examining and debugging these corrupted trees. For example, you can still "diff --raw" such a tree to find out when the bogus entry was introduced; you just cannot do a "--patch" diff (just as you could not with any other corrupted tree, as we do not have any content to diff). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-07-28 15:03:01 +00:00
int sha1_valid,
int sha2_valid,
const char *fullpath,
unsigned dirty_submodule1, unsigned dirty_submodule2);
extern struct diff_filepair *diff_unmerge(struct diff_options *, const char *path);
#define DIFF_SETUP_REVERSE 1
#define DIFF_SETUP_USE_CACHE 2
#define DIFF_SETUP_USE_SIZE_CACHE 4
/*
* Poor man's alternative to parse-option, to allow both stuck form
* (--option=value) and separate form (--option value).
*/
extern int parse_long_opt(const char *opt, const char **argv,
const char **optarg);
extern int git_diff_basic_config(const char *var, const char *value, void *cb);
extern int git_diff_ui_config(const char *var, const char *value, void *cb);
extern void diff_setup(struct diff_options *);
extern int diff_opt_parse(struct diff_options *, const char **, int);
extern void diff_setup_done(struct diff_options *);
#define DIFF_DETECT_RENAME 1
#define DIFF_DETECT_COPY 2
#define DIFF_PICKAXE_ALL 1
#define DIFF_PICKAXE_REGEX 2
#define DIFF_PICKAXE_KIND_S 4 /* traditional plumbing counter */
#define DIFF_PICKAXE_KIND_G 8 /* grep in the patch */
extern void diffcore_std(struct diff_options *);
unpack-trees.c: look ahead in the index This makes the traversal of index be in sync with the tree traversal. When unpack_callback() is fed a set of tree entries from trees, it inspects the name of the entry and checks if the an index entry with the same name could be hiding behind the current index entry, and (1) if the name appears in the index as a leaf node, it is also fed to the n_way_merge() callback function; (2) if the name is a directory in the index, i.e. there are entries in that are underneath it, then nothing is fed to the n_way_merge() callback function; (3) otherwise, if the name comes before the first eligible entry in the index, the index entry is first unpacked alone. When traverse_trees_recursive() descends into a subdirectory, the cache_bottom pointer is moved to walk index entries within that directory. All of these are omitted for diff-index, which does not even want to be fed an index entry and a tree entry with D/F conflicts. This fixes 3-way read-tree and exposes a bug in other parts of the system in t6035, test #5. The test prepares these three trees: O = HEAD^ 100644 blob e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 a/b-2/c/d 100644 blob e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 a/b/c/d 100644 blob e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 a/x A = HEAD 100644 blob e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 a/b-2/c/d 100644 blob e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 a/b/c/d 100644 blob 587be6b4c3f93f93c489c0111bba5596147a26cb a/x B = master 120000 blob a36b77384451ea1de7bd340ffca868249626bc52 a/b 100644 blob e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 a/b-2/c/d 100644 blob e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 a/x With a clean index that matches HEAD, running git read-tree -m -u --aggressive $O $A $B now yields 120000 a36b77384451ea1de7bd340ffca868249626bc52 3 a/b 100644 e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 0 a/b-2/c/d 100644 e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 1 a/b/c/d 100644 e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 2 a/b/c/d 100644 587be6b4c3f93f93c489c0111bba5596147a26cb 0 a/x which is correct. "master" created "a/b" symlink that did not exist, and removed "a/b/c/d" while HEAD did not do touch either path. Before this series, read-tree did not notice the situation and resolved addition of "a/b" and removal of "a/b/c/d" independently. If A = HEAD had another path "a/b/c/e" added, this merge should conflict but instead it silently resolved "a/b" and then immediately overwrote it to add "a/b/c/e", which was quite bogus. Tests in t1012 start to work with this. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-09-20 07:03:39 +00:00
extern void diffcore_fix_diff_index(struct diff_options *);
#define COMMON_DIFF_OPTIONS_HELP \
"\ncommon diff options:\n" \
" -z output diff-raw with lines terminated with NUL.\n" \
" -p output patch format.\n" \
" -u synonym for -p.\n" \
" --patch-with-raw\n" \
" output both a patch and the diff-raw format.\n" \
" --stat show diffstat instead of patch.\n" \
" --numstat show numeric diffstat instead of patch.\n" \
" --patch-with-stat\n" \
" output a patch and prepend its diffstat.\n" \
" --name-only show only names of changed files.\n" \
" --name-status show names and status of changed files.\n" \
" --full-index show full object name on index lines.\n" \
" --abbrev=<n> abbreviate object names in diff-tree header and diff-raw.\n" \
" -R swap input file pairs.\n" \
" -B detect complete rewrites.\n" \
" -M detect renames.\n" \
" -C detect copies.\n" \
" --find-copies-harder\n" \
" try unchanged files as candidate for copy detection.\n" \
" -l<n> limit rename attempts up to <n> paths.\n" \
" -O<file> reorder diffs according to the <file>.\n" \
" -S<string> find filepair whose only one side contains the string.\n" \
" --pickaxe-all\n" \
" show all files diff when -S is used and hit is found.\n" \
" -a --text treat all files as text.\n"
extern int diff_queue_is_empty(void);
extern void diff_flush(struct diff_options*);
extern void diff_warn_rename_limit(const char *varname, int needed, int degraded_cc);
/* diff-raw status letters */
#define DIFF_STATUS_ADDED 'A'
#define DIFF_STATUS_COPIED 'C'
#define DIFF_STATUS_DELETED 'D'
#define DIFF_STATUS_MODIFIED 'M'
#define DIFF_STATUS_RENAMED 'R'
#define DIFF_STATUS_TYPE_CHANGED 'T'
#define DIFF_STATUS_UNKNOWN 'X'
#define DIFF_STATUS_UNMERGED 'U'
/* these are not diff-raw status letters proper, but used by
* diffcore-filter insn to specify additional restrictions.
*/
#define DIFF_STATUS_FILTER_AON '*'
#define DIFF_STATUS_FILTER_BROKEN 'B'
extern const char *diff_unique_abbrev(const unsigned char *, int);
/* do not report anything on removed paths */
#define DIFF_SILENT_ON_REMOVED 01
git-add: make the entry stat-clean after re-adding the same contents Earlier in commit 0781b8a9b2fe760fc4ed519a3a26e4b9bd6ccffe (add_file_to_index: skip rehashing if the cached stat already matches), add_file_to_index() were taught not to re-add the path if it already matches the index. The change meant well, but was not executed quite right. It used ie_modified() to see if the file on the work tree is really different from the index, and skipped adding the contents if the function says "not modified". This was wrong. There are three possible comparison results between the index and the file in the work tree: - with lstat(2) we _know_ they are different. E.g. if the length or the owner in the cached stat information is different from the length we just obtained from lstat(2), we can tell the file is modified without looking at the actual contents. - with lstat(2) we _know_ they are the same. The same length, the same owner, the same everything (but this has a twist, as described below). - we cannot tell from lstat(2) information alone and need to go to the filesystem to actually compare. The last case arises from what we call 'racy git' situation, that can be caused with this sequence: $ echo hello >file $ git add file $ echo aeiou >file ;# the same length If the second "echo" is done within the same filesystem timestamp granularity as the first "echo", then the timestamp recorded by "git add" and the timestamp we get from lstat(2) will be the same, and we can mistakenly say the file is not modified. The path is called 'racily clean'. We need to reliably detect racily clean paths are in fact modified. To solve this problem, when we write out the index, we mark the index entry that has the same timestamp as the index file itself (that is the time from the point of view of the filesystem) to tell any later code that does the lstat(2) comparison not to trust the cached stat info, and ie_modified() then actually goes to the filesystem to compare the contents for such a path. That's all good, but it should not be used for this "git add" optimization, as the goal of "git add" is to actually update the path in the index and make it stat-clean. With the false optimization, we did _not_ cause any data loss (after all, what we failed to do was only to update the cached stat information), but it made the following sequence leave the file stat dirty: $ echo hello >file $ git add file $ echo hello >file ;# the same contents $ git add file The solution is not to use ie_modified() which goes to the filesystem to see if it is really clean, but instead use ie_match_stat() with "assume racily clean paths are dirty" option, to force re-adding of such a path. There was another problem with "git add -u". The codepath shares the same issue when adding the paths that are found to be modified, but in addition, it asked "git diff-files" machinery run_diff_files() function (which is "git diff-files") to list the paths that are modified. But "git diff-files" machinery uses the same ie_modified() call so that it does not report racily clean _and_ actually clean paths as modified, which is not what we want. The patch allows the callers of run_diff_files() to pass the same "assume racily clean paths are dirty" option, and makes "git-add -u" codepath to use that option, to discover and re-add racily clean _and_ actually clean paths. We could further optimize on top of this patch to differentiate the case where the path really needs re-adding (i.e. the content of the racily clean entry was indeed different) and the case where only the cached stat information needs to be refreshed (i.e. the racily clean entry was actually clean), but I do not think it is worth it. This patch applies to maint and all the way up. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2007-11-10 02:22:52 +00:00
/* report racily-clean paths as modified */
#define DIFF_RACY_IS_MODIFIED 02
extern int run_diff_files(struct rev_info *revs, unsigned int option);
extern int run_diff_index(struct rev_info *revs, int cached);
extern int do_diff_cache(const unsigned char *, struct diff_options *);
extern int diff_flush_patch_id(struct diff_options *, unsigned char *);
extern int diff_result_code(struct diff_options *, int);
extern void diff_no_index(struct rev_info *, int, const char **, const char *);
extern int index_differs_from(const char *def, int diff_flags);
extern size_t fill_textconv(struct userdiff_driver *driver,
struct diff_filespec *df,
char **outbuf);
extern struct userdiff_driver *get_textconv(struct diff_filespec *one);
extern int parse_rename_score(const char **cp_p);
extern long parse_algorithm_value(const char *value);
extern int print_stat_summary(FILE *fp, int files,
int insertions, int deletions);
extern void setup_diff_pager(struct diff_options *);
#endif /* DIFF_H */