[PATCH v3 0/5] pack-write: cleanup usage of global variables

This is a small series to remove global variable usage from `pack-write.c`. Mostly it bubble's up the usage of global variables to upper layers. The only exception is in `write-midx.c`, which was cleaned of global variable usage, so there, we use the repo that is in available in the context.

This series is based on fbe8d3079d (Git 2.48, 2025-01-10) with 'ps/more-sign-compare' and 'ps/the-repository' merged in.

There are no conflicts with topics in 'next', however there is a conflict with 'tb/incremental-midx-part-2' in 'seen', the fix is simple but happy to merge that in too if necessary.

Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
---
Changes in v3:
- Fix the ambiguous commit message in the last commit.
- Link to v2: https://lore.kernel.org/r/20250117-kn-the-repo-cleanup-v2-0-a7fdc19688f5@gmail.com

Changes in v2:
- Fixes to the commit messages to:
  - Fix copy-paste error s/the_hash_algo/the_repository
  - Mention why certain functions are modified
  - Small cleanups
- Link to v1: https://lore.kernel.org/r/20250116-kn-the-repo-cleanup-v1-0-a2f4c8e1c4c3@gmail.com

---
Karthik Nayak (5):
      pack-write: pass hash_algo to `fixup_pack_header_footer()`
      pack-write: pass repository to `index_pack_lockfile()`
      pack-write: pass hash_algo to `write_idx_file()`
      pack-write: pass hash_algo to `write_rev_file()`
      pack-write: pass hash_algo to internal functions

 builtin/fast-import.c  | 11 +++---
 builtin/index-pack.c   | 11 +++---
 builtin/pack-objects.c | 12 +++---
 builtin/receive-pack.c |  2 +-
 bulk-checkin.c         |  7 ++--
 fetch-pack.c           |  4 +-
 midx-write.c           |  4 +-
 pack-write.c           | 99 +++++++++++++++++++++++++++-----------------------
 pack.h                 | 30 ++++++++++++---
 9 files changed, 106 insertions(+), 74 deletions(-)
---

Range-diff versus v2:

1:  d3812f88e6 ! 1:  5f646111d0 pack-write: pass hash_algo to `fixup_pack_header_footer()`
    @@ Commit message
     
         The `fixup_pack_header_footer()` function uses the global
         `the_hash_algo` variable to access the repository's hash function. To
    -    avoid global variable usage, pass the hash function from the layers
    -    above.
    +    avoid global variable usage, pass a hash_algo from the layers above.
     
    -    Altough the layers above could have access to the hash function
    -    internally, simply pass in `the_hash_algo`. This avoids any
    -    compatibility issues and bubbles up global variable usage to upper
    -    layers which can be eventually resolved.
    +    Altough the layers above could have access to the hash_algo internally,
    +    simply pass in `the_hash_algo`. This avoids any compatibility issues and
    +    bubbles up global variable usage to upper layers which can be eventually
    +    resolved.
     
         Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
     
2:  89255a4822 = 2:  696e991823 pack-write: pass repository to `index_pack_lockfile()`
3:  5ccf220732 ! 3:  21fefb8279 pack-write: pass hash_algo to `write_idx_file()`
    @@ Commit message
         pack-write: pass hash_algo to `write_idx_file()`
     
         The `write_idx_file()` function uses the global `the_hash_algo` variable
    -    to access the repository's hash function. To avoid global variable
    -    usage, pass the hash function from the layers above.
    +    to access the repository's hash_algo. To avoid global variable usage,
    +    pass a hash_algo from the layers above.
     
         Since `stage_tmp_packfiles()` also resides in 'pack-write.c' and calls
    -    `write_idx_file()`, update it to accept `the_hash_algo` as a parameter
    -    and pass it through to the callee.
    +    `write_idx_file()`, update it to accept a `struct git_hash_algo` as a
    +    parameter and pass it through to the callee.
     
    -    Altough the layers above could have access to the hash function
    -    internally, simply pass in `the_hash_algo`. This avoids any
    -    compatibility issues and bubbles up global variable usage to upper
    -    layers which can be eventually resolved.
    +    Altough the layers above could have access to the hash_algo internally,
    +    simply pass in `the_hash_algo`. This avoids any compatibility issues and
    +    bubbles up global variable usage to upper layers which can be eventually
    +    resolved.
     
         Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
     
4:  95b1f784e2 ! 4:  3f730b26d1 pack-write: pass hash_algo to `write_rev_file()`
    @@ Commit message
         pack-write: pass hash_algo to `write_rev_file()`
     
         The `write_rev_file()` function uses the global `the_hash_algo` variable
    -    to access the repository's hash function. To avoid global variable
    -    usage, let's pass the hash function from the layers above. Also modify
    -    children functions `write_rev_file_order()` and `write_rev_header()` to
    -    accept 'the_hash_algo'.
    +    to access the repository's hash_algo. To avoid global variable usage,
    +    pass a hash_algo from the layers above. Also modify children functions
    +    `write_rev_file_order()` and `write_rev_header()` to accept
    +    'the_hash_algo'.
     
    -    Altough the layers above could have access to the hash function
    -    internally, simply pass in `the_hash_algo`. This avoids any
    -    compatibility issues and bubbles up global variable usage to upper
    -    layers which can be eventually resolved.
    +    Altough the layers above could have access to the hash_algo internally,
    +    simply pass in `the_hash_algo`. This avoids any compatibility issues and
    +    bubbles up global variable usage to upper layers which can be eventually
    +    resolved.
     
         However, in `midx-write.c`, since all usage of global variables is
         removed, don't reintroduce them and instead use the `repo` available in
5:  50da9bf405 ! 5:  7d1d42ca67 pack-write: pass hash_algo to internal functions
    @@ Commit message
         The internal functions `write_rev_trailer()`, `write_rev_trailer()`,
         `write_mtimes_header()` and write_mtimes_trailer()` use the global
         `the_hash_algo` variable to access the repository's hash function. Pass
    -    the hash from down as we've added made them available in the previous
    -    few commits.
    +    the hash_algo down from callers, all of which already have access to the
    +    variable.
     
         This removes all global variables from the 'pack-write.c' file, so
         remove the 'USE_THE_REPOSITORY_VARIABLE' macro.

---

base-commit: 8b2efc058aaa3d1437678616bccf7c5f7ce1f92b change-id: 20250110-kn-the-repo-cleanup-44144fa42dc3

Thanks
- Karthik