git/list[1] front-page[2] threads[3] people[4] search[5] about
 

Re: [PATCH 2/3] setup: have the_repository use the_index

From
Junio C Hamano <gitster@pobox.com>
Date
Jul 18, 2017, 21:34 UTC
Message-ID
<xmqq379to2e7.fsf@gitster.mtv.corp.google.com>
In-Reply-To
<xmqqvamxz63i.fsf@gitster.mtv.corp.google.com>
Junio C Hamano <gitster@pobox.com> writes:
Show 11 quoted lines
> Jonathan Nieder <jrnieder@gmail.com> writes:
>
>>
>> All that said, I don't have a strong opinion on this.  Both the 1-word
>> approach (a pointer) and 24-word approach (embedding) are tolerable
>> and there are reasons to prefer each.
>
> I do not care too much about 24-word wastage.  If this were not "a
> pointer pretending to be embedded object", the fix in 1/3 wouldn't
> have been necessary.  I am worried about this being an invitations
> for such unnecesasry bugs.

Another thing I noticed that you already pointed out was this bit in your review message:

Show 21 quoted lines
> I wonder if this can be done sooner.  For example, does the following
> work?  This way, 'the_repository->index == &the_index' would be an
> invariant that always holds, even in the early setup stage before
> setup_git_directory_gently has run completely.
> 
> Thanks,
> Jonathan
> 
> diff --git i/repository.c w/repository.c
> index edca907404..bdc1f93282 100644
> --- i/repository.c
> +++ w/repository.c
> @@ -4,7 +4,7 @@
>  #include "submodule-config.h"
>  
>  /* The main repository */
> -static struct repository the_repo;
> +static struct repository the_repo = { .index = &the_index };
>  struct repository *the_repository = &the_repo;
>  
>  static char *git_path_from_env(const char *envvar, const char *git_dir,

With a pointer that can point at a random instance of index_state, the current "struct repository" allows two or more instances of it to share the same index_state. I do not think that is a designed and a desirable "feature" but an invitation for a mistake.

Embedding the real instance in it would solve that, too.

So, after saying "I am not (yet) telling you to fix the design" and then hearing what a potential advanage could be (and none of that was a convincing one), I am inclined to say that this eventually needs to be fixed, preferrably before too much code starts relying on it and making it more work to fix it later.

Previous: Junio C HamanoNext: Brandon Williams
Message 16 of 68 in “Convert grep to recurse in-process”
  1. 0/3 Convert grep to recurse in-processBrandon Williams, Jul 11, 2017
  2. 1/3 repo_read_index: don't discard the indexBrandon Williams, Jul 11, 2017
  3. Jonathan NiederJul 11, 2017
  4. Brandon WilliamsJul 12, 2017
  5. Stefan BellerJul 11, 2017
  6. Brandon WilliamsJul 12, 2017
  7. 2/3 setup: have the_repository use the_indexBrandon Williams, Jul 11, 2017
  8. Jonathan NiederJul 12, 2017
  9. Stefan BellerJul 12, 2017
  10. Brandon WilliamsJul 12, 2017
  11. Junio C HamanoJul 12, 2017
  12. Brandon WilliamsJul 12, 2017
  13. Junio C HamanoJul 12, 2017
  14. Jonathan NiederJul 12, 2017
  15. Junio C HamanoJul 12, 2017
  16. Junio C HamanoJul 18, 2017
  17. 3/3 grep: recurse in-process using 'struct repository'Brandon Williams, Jul 11, 2017
  18. Jacob KellerJul 11, 2017
  19. Brandon WilliamsJul 12, 2017
  20. Stefan BellerJul 12, 2017
  21. Brandon WilliamsJul 12, 2017
  22. Jonathan NiederJul 12, 2017
  23. Brandon WilliamsJul 12, 2017
  24. Jeff KingJul 12, 2017
  25. Brandon WilliamsJul 12, 2017
  26. Jeff KingJul 12, 2017
  27. Jonathan NiederJul 12, 2017
  28. Jeff KingJul 12, 2017
  29. Jonathan NiederJul 12, 2017
  30. Stefan BellerJul 12, 2017
  31. Jeff KingJul 12, 2017
  32. 0/3 Convert grep to recurse in-processBrandon Williams, Jul 14, 2017
  33. 1/3 repo_read_index: don't discard the indexBrandon Williams, Jul 14, 2017
  34. 2/3 repository: have the_repository use the_indexBrandon Williams, Jul 14, 2017
  35. 3/3 grep: recurse in-process using 'struct repository'Brandon Williams, Jul 14, 2017
  36. 00/10 Convert grep to recurse in-processBrandon Williams, Jul 18, 2017
  37. 01/10 repo_read_index: don't discard the indexBrandon Williams, Jul 18, 2017
  38. 02/10 repository: have the_repository use the_indexBrandon Williams, Jul 18, 2017
  39. 04/10 config: add config_from_gitmodulesBrandon Williams, Jul 18, 2017
  40. 03/10 cache.h: add GITMODULES_FILE macroBrandon Williams, Jul 18, 2017
  41. convert any hard coded .gitmodules file string to the MACROStefan Beller, Jul 31, 2017
  42. Jeff HostetlerAug 1, 2017
  43. Stefan BellerAug 1, 2017
  44. Junio C HamanoAug 1, 2017
  45. Brandon WilliamsAug 2, 2017
  46. Brandon WilliamsAug 2, 2017
  47. 08/10 submodule: check for unmerged .gitmodules outside of config parsingBrandon Williams, Jul 18, 2017
  48. 09/10 submodule: merge repo_read_gitmodules and gitmodules_configBrandon Williams, Jul 18, 2017
  49. 10/10 grep: recurse in-process using 'struct repository'Brandon Williams, Jul 18, 2017
  50. 05/10 submodule: remove submodule.fetchjobs from submodule-config parsingBrandon Williams, Jul 18, 2017
  51. 06/10 submodule: remove fetch.recursesubmodules from submodule-config parsingBrandon Williams, Jul 18, 2017
  52. 07/10 submodule: check for unstaged .gitmodules outside of config parsingBrandon Williams, Jul 18, 2017
  53. Stefan BellerJul 31, 2017
  54. Brandon WilliamsAug 2, 2017
  55. Brandon WilliamsAug 2, 2017
  56. Junio C HamanoJul 18, 2017
  57. Brandon WilliamsJul 18, 2017
  58. 00/10 Convert grep to recurse in-processBrandon Williams, Aug 2, 2017
  59. 01/10 repo_read_index: don't discard the indexBrandon Williams, Aug 2, 2017
  60. 02/10 repository: have the_repository use the_indexBrandon Williams, Aug 2, 2017
  61. 04/10 config: add config_from_gitmodulesBrandon Williams, Aug 2, 2017
  62. 06/10 submodule: remove fetch.recursesubmodules from submodule-config parsingBrandon Williams, Aug 2, 2017
  63. 03/10 cache.h: add GITMODULES_FILE macroBrandon Williams, Aug 2, 2017
  64. 08/10 submodule: check for unmerged .gitmodules outside of config parsingBrandon Williams, Aug 2, 2017
  65. 09/10 submodule: merge repo_read_gitmodules and gitmodules_configBrandon Williams, Aug 2, 2017
  66. 10/10 grep: recurse in-process using 'struct repository'Brandon Williams, Aug 2, 2017
  67. 05/10 submodule: remove submodule.fetchjobs from submodule-config parsingBrandon Williams, Aug 2, 2017
  68. 07/10 submodule: check for unstaged .gitmodules outside of config parsingBrandon Williams, Aug 2, 2017

Read the whole thread, see it on lore, or plain text.

$ cat FOOTERMessages come from the public archive at lore.kernel.org/git, fetched every hour. The front page is chosen and written each morning by an AI editor and can be wrong; the threads themselves are the record. About and API. For agents: an MCP server at https://gitlist.dev/mcp, and any thread, story or person page as Markdown by adding .md to its URL (or sending Accept: text/markdown). Details in /llms.txt.