Re: [PATCH/GSoC/RFC] fetch: git fetch --deepen

>> -             if (starts_with(line, "deepen ")) {
>> +             if (starts_with(line, "depth ")) {
>>                       char *end;
>> -                     depth = strtol(line + 7, &end, 0);
>> -                     if (end == line + 7 || depth <= 0)
>> -                             die("Invalid deepen: %s", line);
>> +                     depth = strtol(line + 6, &end, 0);
>> +                     if (end == line + 6 || depth <= 0)
>> +                             die("Invalid depth: %s", line);
>>                       continue;
>>               }
>>               if (!starts_with(line, "want ") ||
>
> I do not quite understand this hunk.  What happens when this program
> is talking to an existing fetch-pack that requested "deepen"?

> @@ -317,7 +318,7 @@ static int find_common(struct fetch_pack_args *args,
>         if (is_repository_shallow())
>                 write_shallow_commits(&req_buf, 1, NULL);
>         if (args->depth > 0)
> -               packet_buf_write(&req_buf, "deepen %d", args->depth);
> +               packet_buf_write(&req_buf, "depth %d", args->depth);
>         packet_buf_flush(&req_buf);
>         state_len = req_buf.len;

> Dongcan Jiang <dongcan.jiang@gmail.com> writes:
>
>> This patch is just for discusstion. An option --deepen is added to
>> 'git fetch'. When it comes to '--deepen', git should fetch N more
>> commits ahead the local shallow commit, where N is indicated by
>> '--depth=N'. [1]
>>
>> e.g.
>>
>>>  (upstream)
>>>   ---o---o---o---A---B
>>>
>>>  (you)
>>>                  A---B
>>
>> After excuting "git fetch --depth=1 --deepen", (you) get one more
>> tip and it becomes
>>
>>>  (you)
>>>              o---A---B
>>
>> '--deepen' is designed to be a boolean option in this patch, which
>> is a little different from [1]. It's designed in this way, because
>> it can reuse '--depth' in the program, and just costs one more bit
>> in some data structure, such as fetch_pack_args,
>> git_transport_options.
>>
>> Of course, as a patch for discussion, it remains a long way to go
>> before being complete.
>>
>>       1) Documents should be completed.
>>       2) More test cases, expecially corner cases, should be added.
>>       3) No need to get remote refs when it comes to '--deepen' option.
>>       4) Validity on options combination should be checked.
>>       5) smart-http protocol remains to be supported. [2]
>>
>> Besides, I still have one question:
>> What does (you) exactly mean in [1]? The local branch or the local
>> remote ref?
>
> As this operation is not about moving _any_ refs, whether local
> branches or remote-tracking branches, any ref that used to point at
> commit B before you executed "fetch --deepen" would point at the
> same commit after the command finishes.
>
> The "you" does not explicitly depict any ref, because the picture is
> meant to illustrate _everything_ the repository at the receiving end
> of "fetch" has.  It used to have two commits, A and B (and the tree
> and blob objects necessary to complete these two commits).  After
> deepening the history by one commit, it then will have commit A^ and
> its trees and blobs.
>
>> diff --git a/upload-pack.c b/upload-pack.c
>> index b531a32..8004f2f 100644
>> --- a/upload-pack.c
>> +++ b/upload-pack.c
>> @@ -31,6 +31,7 @@ static const char upload_pack_usage[] = "git upload-pack [--strict] [--timeout=<
>>
>>  static unsigned long oldest_have;
>>
>> +static int depth_deepen;
>>  static int multi_ack;
>>  static int no_done;
>>  static int use_thin_pack, use_ofs_delta, use_include_tag;
>> @@ -563,11 +564,11 @@ static void receive_needs(void)
>>                       }
>>                       continue;
>>               }
>> -             if (starts_with(line, "deepen ")) {
>> +             if (starts_with(line, "depth ")) {
>>                       char *end;
>> -                     depth = strtol(line + 7, &end, 0);
>> -                     if (end == line + 7 || depth <= 0)
>> -                             die("Invalid deepen: %s", line);
>> +                     depth = strtol(line + 6, &end, 0);
>> +                     if (end == line + 6 || depth <= 0)
>> +                             die("Invalid depth: %s", line);
>>                       continue;
>>               }
>>               if (!starts_with(line, "want ") ||
>
> I do not quite understand this hunk.  What happens when this program
> is talking to an existing fetch-pack that requested "deepen"?
>
>> @@ -577,6 +578,8 @@ static void receive_needs(void)
>>
>>               features = line + 45;
>>
>> +             if (parse_feature_request(features, "depth_deepen"))
>> +                     depth_deepen = 1;
>>               if (parse_feature_request(features, "multi_ack_detailed"))
>>                       multi_ack = 2;
>>               else if (parse_feature_request(features, "multi_ack"))
>> @@ -631,6 +634,10 @@ static void receive_needs(void)
>>                               struct object *object = shallows.objects[i].item;
>>                               object->flags |= NOT_SHALLOW;
>>                       }
>> +             else if (depth_deepen)
>> +                     backup = result =
>> +                             get_shallow_commits(&shallows, depth + 1,
>> +                                                 SHALLOW, NOT_SHALLOW);
>>               else
>>                       backup = result =
>>                               get_shallow_commits(&want_obj, depth,
>> --
>> 2.3.1.253.gb3fd89e