Junio C Hamano <gitster@xxxxxxxxx> writes:
> Arnav Bhate <bhatearnav@xxxxxxxxx> writes:
>
>> -static int get_ours_cache_pos(const char *path, int pos)
>> +static int get_ours_cache_pos(const char *path, unsigned int inverted_pos)
>
> This renaming of parameter is not right.
>
> At this point when the value comes to this function, it *IS* the
> position, there is nothing inverted about it. It points at the
> position in the .cache[] array where an cache_entry at a higher
> stage would appear.
>
> It is perfectly fine to state that the value that is returned from
> index_name_pos() is potentially inverted. The function is given a
> path name (without any stage information) and
>
> - returns a non-negative number, the position in the .cache[] array,
> where a cache_entry at stage #0 (i.e. an entry for a path that does
> not require conflict resolution), or
>
> - returns a negative number, when there is no such cache_entry
> exists. The caller can "invert" the value to recover a position
> in the .cache[] array, where a cache_entry for the path at stage
> #0 _would_ _have_ been found, if existed. Due to the way the
> cache entries are sorted in the .cache[] array, when you are
> interested in finding cache entries for a path at higher stages,
> like this function is, you can start scanning at this point until
> you see an entry for a different path.
>
> Calling the parameter "pos" is the right thing to do. The value
> used to come here _could_ have been called "inverted", and the
> result of (-inverted_pos-1) can be assigned to "pos". But because
> the patch moves the inversion to the caller, what the code in the
> while loop sees is no longer "inverted".
My logic was that it was the inversion of the variable pos, but your
logic makes more sense. I'll make the change.
>> {
>> - int i = -pos - 1;
>> -
>> - while ((i < the_repository->index->cache_nr) && !strcmp(the_repository->index->cache[i]->name, path)) {
>> - if (ce_stage(the_repository->index->cache[i]) == 2)
>> - return i;
>> - i++;
>> + while ((inverted_pos < the_repository->index->cache_nr) && !strcmp(the_repository->index->cache[inverted_pos]->name, path)) {
>> + if (ce_stage(the_repository->index->cache[inverted_pos]) == 2)
>> + return inverted_pos;
>> + inverted_pos++;
>> }
>> return -1;
>> }
>> @@ -58,7 +55,7 @@ static void print_error_files(struct string_list *files_list,
>> int *errs)
>> {
>> if (files_list->nr) {
>> - int i;
>> + unsigned int i;
>> struct strbuf err_msg = STRBUF_INIT;
>>
>> strbuf_addstr(&err_msg, main_msg);
>> @@ -83,7 +80,7 @@ static void submodules_absorb_gitdir_if_needed(void)
>>
>> pos = index_name_pos(the_repository->index, name, strlen(name));
>> if (pos < 0) {
>
> Here is where the caller notices that index_name_pos() did not see a
> stage #0 entry. This caller wants to see "ours" entry at stage #2,
> so it "inverts" the returned value and asks the helper function if
> it sees such an entry in the .cache[] array.
>
> A handful of prerequisite pieces of knowledge to understand this
> code are:
>
> - The index (i.e. the .cache[] array) is sorted by full path name
> (down from the top level of the working tree).
>
> - The index can have at most one stage #0 entry for each path name.
> When a stage #0 entry exists for a path name, there cannot be
> higher stage entries (the path is called "resolved").
>
> - The cache entries in the .cache[] array for the same path name
> are sorted by their stage number.
>
> - There can be at most one stage #2 entry for each path name, which
> are called "ours". Entries at stage #1 are from common ancestor,
> entries at stage #3 are from "their" tree. These higher (i.e.
> more than zero) stage entries appear only for "conflicting"
> paths in the .cache[] array.
>
> With the understanding above, you can see why "our" position is
> computed only when index_name_pos() returns negative in this hunk.
Thanks for the explanation, I was not able to get this from the code.
>
>> - pos = get_ours_cache_pos(name, pos);
>> + pos = get_ours_cache_pos(name, -pos - 1);
>> if (pos < 0)
>> continue;
>> }
>> @@ -131,7 +128,7 @@ static int check_local_mod(struct object_id *head, int index_only)
>> * Skip unmerged entries except for populated submodules
>> * that could lose history when removed.
>> */
>> - pos = get_ours_cache_pos(name, pos);
>> + pos = get_ours_cache_pos(name, -pos - 1);
>> if (pos < 0)
>> continue;
>
> The above hunks are perfectly fine.
>
>> @@ -314,7 +311,7 @@ int cmd_rm(int argc,
>> if (pathspec_needs_expanded_index(the_repository->index, &pathspec))
>> ensure_full_index(the_repository->index);
>>
>> - for (i = 0; i < the_repository->index->cache_nr; i++) {
>> + for (unsigned int i = 0; i < the_repository->index->cache_nr; i++) {
>> const struct cache_entry *ce = the_repository->index->cache[i];
>>
>> if (!include_sparse &&
>
> OK.
>
> Thanks.
--
Regards,
Arnav Bhate
(He/Him)
