[PATCH v2 0/9] Store submodules in a hash, not a linked list

This is v2 of the patch series, considerably reorganized but not that different codewise. Thanks to Stefan, Junio, and Peff for their feedback about v1 [1]. I think I have addressed all of your comments.

Changes since v1:

* Rebase from `master` onto `maint` (to match Junio).

* Reorder some commits to make the presentation more logical.

* Added an explicit preparatory commit that just reorders some
  function definitions, because it makes the diff for the subsequent
  commit a lot easier to read.

* Make some preexisting functions private:
  * lookup_ref_store()
  * ref_store_init()

* Remove some unnecessary handling of `submodule == ""` when it is
  already known to have been converted to `NULL`. (Some of the
  purported handling also happened to be broken.)

* Introduce function `register_ref_store()` in a separate step, before
  switching to hashmaps.

* Don't initialize hashmap in `lookup_ref_store()`. (Just return
  `NULL`; the hashmap will be initialized in `register_ref_store()` a
  moment later.)

* Make code in `submodule_hash_cmp()` clearer.

* Use `FLEX_ALLOC_STR()` in `alloc_submodule_hash_entry()`.

* Don't specify an initial size for the submodule hashmap (the default
  is OK).

This patch series is also available from my fork on GitHub [2] as branch "submodule-hash".

Michael

[1] http://public-inbox.org/git/cover.1486629195.git.mhagger@alum.mit.edu/T/#u [2] https://github.com/mhagger/git

Michael Haggerty (9):
  refs: reorder some function definitions
  refs: make some ref_store lookup functions private
  refs: remove some unnecessary handling of submodule == ""
  register_ref_store(): new function
  refs: store submodule ref stores in a hashmap
  refs: push the submodule attribute down
  base_ref_store_init(): remove submodule argument
  files_ref_store::submodule: use NULL for the main repository
  read_loose_refs(): read refs using resolve_ref_recursively()

 refs.c               | 107 +++++++++++++++++++++++++++++++++++----------------
 refs/files-backend.c |  77 +++++++++++++++++++++---------------
 refs/refs-internal.h |  48 ++++-------------------
 3 files changed, 127 insertions(+), 105 deletions(-)