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Re: [PATCH 05/22] read-cache: add index reading api

From
Duy Nguyen <pclouds@gmail.com>
Date
Jul 8, 2013, 02:01 UTC
Message-ID
<CACsJy8A65JGUtdJnGuC20vUfQLQfrtDzj7Eb8pgP9RTqP1Po_w@mail.gmail.com>
In-Reply-To
<1373184720-29767-6-git-send-email-t.gummerer@gmail.com>
On Sun, Jul 7, 2013 at 3:11 PM, Thomas Gummerer <t.gummerer@gmail.com> wrote:
Show 30 quoted lines
> Add an api for access to the index file.  Currently there is only a very
> basic api for accessing the index file, which only allows a full read of
> the index, and lets the users of the data filter it.  The new index api
> gives the users the possibility to use only part of the index and
> provides functions for iterating over and accessing cache entries.
>
> This simplifies future improvements to the in-memory format, as changes
> will be concentrated on one file, instead of the whole git source code.
>
> Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
> ---
>  cache.h         |  57 +++++++++++++++++++++++++++++-
>  read-cache-v2.c |  96 +++++++++++++++++++++++++++++++++++++++++++++++--
>  read-cache.c    | 108 ++++++++++++++++++++++++++++++++++++++++++++++++++++----
>  read-cache.h    |  12 ++++++-
>  4 files changed, 263 insertions(+), 10 deletions(-)
>
> diff --git a/cache.h b/cache.h
> index 5082b34..d38dfbd 100644
> --- a/cache.h
> +++ b/cache.h
> @@ -127,7 +127,8 @@ struct cache_entry {
>         unsigned int ce_flags;
>         unsigned int ce_namelen;
>         unsigned char sha1[20];
> -       struct cache_entry *next;
> +       struct cache_entry *next; /* used by name_hash */
> +       struct cache_entry *next_ce; /* used to keep a list of cache entries */
>         char name[FLEX_ARRAY]; /* more */
>  };
>From what I read, doing
    ce = start;
    while (ce) { do(something); ce = next_cache_entry(ce); }
is the same as
    i = start_index;
    while (i < active_nr) { ce = active_cache[i]; do(something); i++; }

What's the advantage of using the former over the latter? Do you plan to eliminate the latter loop (by hiding "struct cache_entry **cache;" from public index_state structure? -- Duy

Previous: Thomas GummererNext: Thomas Gummerer
Message 7 of 51 in “Index v5”
  1. 00/22 Index v5Thomas Gummerer, Jul 7, 2013
  2. 01/22 t2104: Don't fail for index versions other than [23]Thomas Gummerer, Jul 7, 2013
  3. 02/22 read-cache: split index file version specific functionalityThomas Gummerer, Jul 7, 2013
  4. 03/22 read-cache: move index v2 specific functions to their own fileThomas Gummerer, Jul 7, 2013
  5. 04/22 read-cache: Re-read index if index file changedThomas Gummerer, Jul 7, 2013
  6. 05/22 read-cache: add index reading apiThomas Gummerer, Jul 7, 2013
  7. Duy NguyenJul 8, 2013
  8. Thomas GummererJul 8, 2013
  9. Duy NguyenJul 8, 2013
  10. Thomas GummererJul 8, 2013
  11. Duy NguyenJul 8, 2013
  12. Thomas GummererJul 8, 2013
  13. 5/22 Add documentation for the index apiThomas Gummerer, Jul 8, 2013
  14. Duy NguyenJul 9, 2013
  15. Thomas GummererJul 9, 2013
  16. Duy NguyenJul 10, 2013
  17. Thomas GummererJul 11, 2013
  18. Duy NguyenJul 11, 2013
  19. Duy NguyenJul 11, 2013
  20. Junio C HamanoJul 8, 2013
  21. Thomas GummererJul 8, 2013
  22. Junio C HamanoJul 8, 2013
  23. Thomas GummererJul 9, 2013
  24. 06/22 make sure partially read index is not changedThomas Gummerer, Jul 7, 2013
  25. Junio C HamanoJul 8, 2013
  26. Thomas GummererJul 8, 2013
  27. 07/22 dir.c: use index apiThomas Gummerer, Jul 7, 2013
  28. 08/22 tree.c: use index apiThomas Gummerer, Jul 7, 2013
  29. 09/22 name-hash.c: use index apiThomas Gummerer, Jul 7, 2013
  30. 10/22 grep.c: Use index apiThomas Gummerer, Jul 7, 2013
  31. 11/22 ls-files.c: use the index apiThomas Gummerer, Jul 7, 2013
  32. 12/22 read-cache: make read_blob_data_from_index use index apiThomas Gummerer, Jul 7, 2013
  33. 13/22 documentation: add documentation of the index-v5 file formatThomas Gummerer, Jul 7, 2013
  34. Duy NguyenJul 11, 2013
  35. Thomas GummererJul 11, 2013
  36. Duy NguyenJul 11, 2013
  37. Thomas GummererJul 11, 2013
  38. Duy NguyenJul 11, 2013
  39. 14/22 read-cache: make in-memory format aware of stat_crcThomas Gummerer, Jul 7, 2013
  40. 15/22 read-cache: read index-v5Thomas Gummerer, Jul 7, 2013
  41. Eric SunshineJul 7, 2013
  42. Thomas GummererJul 8, 2013
  43. 16/22 read-cache: read resolve-undo dataThomas Gummerer, Jul 7, 2013
  44. 17/22 read-cache: read cache-tree in index-v5Thomas Gummerer, Jul 7, 2013
  45. Eric SunshineJul 7, 2013
  46. 18/22 read-cache: write index-v5Thomas Gummerer, Jul 7, 2013
  47. Eric SunshineJul 7, 2013
  48. 19/22 read-cache: write index-v5 cache-tree dataThomas Gummerer, Jul 7, 2013
  49. 20/22 read-cache: write resolve-undo data for index-v5Thomas Gummerer, Jul 7, 2013
  50. 21/22 update-index.c: rewrite index when index-version is givenThomas Gummerer, Jul 7, 2013
  51. 22/22 p0003-index.sh: add perf test for the index formatsThomas Gummerer, Jul 7, 2013

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