[PATCH v2 00/20] Separate `ref_cache` into a separate module

This is v2 of this patch series. Thanks to Peff, Junio, Stefan and Ævar for their comments about v1 [1].

This version literally only contains a few commit message changes and one minor comment changes relative to v1. The code is identical. I wasn't sure whether it is even worth sending this patch series to the ML again; Junio, if you'd prefer I just send a link to a published branch in such cases, please let me know.

* I picked up the "area:" prefixes that Junio added to a couple of
  commit subject lines.

* I clarified the justification for keeping a pointer to the
  `ref_store` in `ref_dir`.

* I added a long blurb about the removal of an internal consistency
  check in the commit message for

      [18/20] commit_packed_refs(): use reference iteration

* I changed "loose refs cache" to "loose ref cache" in a comment in

      [19/20] files_pack_refs(): use reference iteration

This patch series is also available from my GitHub fork [2] as branch "separate-ref-cache". These patches depend on Duy's nd/files-backend-git-dir branch.

[1] http://public-inbox.org/git/cover.1490026594.git.mhagger@alum.mit.edu/ [2] https://github.com/mhagger/git

Michael Haggerty (20):
  get_ref_dir(): don't call read_loose_refs() for "refs/bisect"
  refs_read_raw_ref(): new function
  refs_ref_iterator_begin(): new function
  refs_verify_refname_available(): implement once for all backends
  refs_verify_refname_available(): use function in more places
  ref-cache: rename `add_ref()` to `add_ref_entry()`
  ref-cache: rename `find_ref()` to `find_ref_entry()`
  ref-cache: rename `remove_entry()` to `remove_entry_from_dir()`
  refs: split `ref_cache` code into separate files
  ref-cache: introduce a new type, ref_cache
  refs: record the ref_store in ref_cache, not ref_dir
  ref-cache: use a callback function to fill the cache
  refs: handle "refs/bisect/" in `loose_fill_ref_dir()`
  do_for_each_entry_in_dir(): eliminate `offset` argument
  get_loose_ref_dir(): function renamed from get_loose_refs()
  get_loose_ref_cache(): new function
  cache_ref_iterator_begin(): make function smarter
  commit_packed_refs(): use reference iteration
  files_pack_refs(): use reference iteration
  do_for_each_entry_in_dir(): delete function

 Makefile             |    1 +
 refs.c               |  111 ++++-
 refs.h               |    2 +-
 refs/files-backend.c | 1229 +++++++-------------------------------------------
 refs/ref-cache.c     |  523 +++++++++++++++++++++
 refs/ref-cache.h     |  267 +++++++++++
 refs/refs-internal.h |   22 +-
 7 files changed, 1066 insertions(+), 1089 deletions(-)
 create mode 100644 refs/ref-cache.c
 create mode 100644 refs/ref-cache.h