[PATCH 1 of 9 V6] exchange: add `_getbookmarks()` function

[Pierre-Yves David]

On 10/11/2016 06:25 PM, Stanislau Hlebik wrote:
> # HG changeset patch
> # User Stanislau Hlebik <stash at fb.com>
> # Date 1476195835 25200
> #      Tue Oct 11 07:23:55 2016 -0700
> # Node ID 55e997127023d7208488c593adb933a1bfb23312
> # Parent  b85fa6bf298be07804a74d8fdec0d19fdbc6d740
> exchange: add `_getbookmarks()` function

I was thinking about the various in-flight series and it made me 
realized that the various important point about this bookmarks series 
are spread in various emails and might be a bit hard to follow.

Since I still had them in my head I've made a summary of the important 
point that needs to be addressed or discussed. Since the 4.0 feature 
freeze is Tuesday, this will probably not reach conclusion this cycle.

- Do not go through pushkey to list the bookmarks
   (using a function from mercurial.bookmarks seems the way to go),

- either drop the dedicated  exception classes (BookmarksEncodeError and 
BookmarksDecodeError) or make it clear why we need them,

- write internal documentations about the new parts and the process 
around them in mercurial/helps/internals/,

- double check the binary encoding with Greg. I personnaly think we 
should drop the optional 'nodeid' and include one in all case,

- introduce a new attributes on the unbundle2 to pass "inputs" around 
(instead of our previous approach of using dedicated attributes for each)

(there is also a small number of various questions and comments inline 
but they seems less important)

Cheers,

-- 
Pierre-Yves David