Re: [PATCH v5 3/3] ls-files.c: add --deduplicate option

Junio C Hamano [off-list ref] 于2021年1月22日周五 上午4:45写道：

胡哲宁 [off-list ref] writes:

quoted

quoted

OK.  When show_stage is set, skipping_duplicates is automatically
turned off (and show_unmerged is automatically covered as it turns
show_stage on automatically).  So this feature has really become
"are we showing only names, and if so, did we show an entry of the
same name before?".

Yeah,showing only names,so I yesterday ask such question :)

quoted

quoted

                      if (!show_unmerged || ce_stage(ce))
                              show_ce(repo, dir, ce, fullname.buf,
                                      ce_stage(ce) ? tag_unmerged :
                                      (ce_skip_worktree(ce) ? tag_skip_worktree :
                                              tag_cached));
+                     if (show_cached && skipping_duplicates)
+                             last_shown_ce = ce;

The code that calls show_ce() belonging to a totally separate if()
statement makes my stomach hurt---how are we going to guarantee that
"last shown" really will keep track of what was shown last?

Shouldn't the above be more like this?

-                       if (!show_unmerged || ce_stage(ce))
+                       if (!show_unmerged || ce_stage(ce)) {
                                show_ce(repo, dir, ce, fullname.buf,
                                        ce_stage(ce) ? tag_unmerged :
                                        (ce_skip_worktree(ce) ? tag_skip_worktree :
                                                tag_cached));
+                               last_shown_ce = ce;
+                       }

well,I am also thinking about this question :"last_shown_ce" is not true
last shown ce,but may be If "last_shown_ce" truly seen every last shown
ce ,We may need more cumbersome logic to make the program correct.
I have tried the processing method of your above code before, but found
 that some errors may have occurred.

I think judicious use of "goto" without introducing the last_shown
would probably result in a much more maintainable code.  It may look
somewhat like so:

        for (i = 0; i < repo->index->cache_nr; i++) {
                const struct cache_entry *ce = repo->index->cache[i];
                struct stat st;
                int stat_err;

                construct_fullname(&fullname, repo, ce);

                if ((dir->flags & DIR_SHOW_IGNORED) &&
                        !ce_excluded(dir, repo->index, fullname.buf, ce))
                        continue;
                if (ce->ce_flags & CE_UPDATE)
                        continue;
                if ((show_cached || show_stage) &&
                    (!show_unmerged || ce_stage(ce))) {
                        show_ce(repo, dir, ce, fullname.buf,
                                ce_stage(ce) ? tag_unmerged :
                                (ce_skip_worktree(ce) ? tag_skip_worktree :
                                 tag_cached));
                        if (skip_duplicates)
                                goto skip_to_next_name;
                }

                if (!show_deleted && !show_modified)
                        continue;
                if (ce_skip_worktree(ce))
                        continue;
                stat_err = lstat(fullname.buf, &st);
                if (stat_err && (errno != ENOENT && errno != ENOTDIR))
                        error_errno("cannot lstat '%s'", fullname.buf);

                if (show_deleted) {
                        show_ce(repo, dir, ce, fullname.buf, tag_removed);
                        if (skip_duplicates)
                                goto skip_to_next_name;
                }
                if (show_modified &&
                    (stat_err || ie_modified(repo->index, ce, &st, 0)))
                        show_ce(repo, dir, ce, fullname.buf, tag_modified);
                continue;

        skip_to_next_name:
                {
                        int j;
                        const struct cache_entry **cache = repo->index->cache;
                        for (j = i + 1; j < repo->index->cache_nr; j++)
                                if (strcmp(ce->ce_name, cache[j]->ce_name))
                                        break;
                        i = j - 1; /* compensate for outer for loop */
                }
        }

I have to admit that this is indeed a good way to skip with "goto".
Thanks for your help.
And should I still use gitgitgadget PR on my origin branch "dedup"or
send patch on branch "zh/ls-files-deduplicate"?