[PATCH v2 00/43] lmdb ref backend

This version rebases on top of pu. Mainly, this just moves a couple of methods to the backend.

I added support for long symrefs to the lmdb backend. Peff added this to the files backend in pu, and there's a test for it.

I cleaned up some formatting (long lines), and moved one patch to put it closer to its related patches. I added a comment to a bit I found confusing when re-reading the patch (in the lmdb backend patch).

I re-ran the tests under lmdb, and everything that passed last time passes this time.

David Turner (24):
  refs: make repack_without_refs and is_branch public
  refs-be-files.c: add method for for_each_reftype_...
  refs-be-files.c: add do_for_each_per_worktree_ref
  refs.c: move refname_is_safe to the common code
  refs.h: document make refname_is_safe and add it to header
  refs.c: move copy_msg to the common code
  refs.c: move peel_object to the common code
  refs.c: move should_autocreate_reflog to common code
  refs.c: add ref backend init function
  refs.c: add methods for reflog
  refs-be-files.c: add method to expire reflogs
  refs.c: add method for initial ref transaction commit
  initdb: move safe_create_dir into common code
  refs.c: add method for initializing refs db
  refs.c: make struct ref_transaction generic
  refs-be-files.c: add method to rename refs
  run-command: track total number of commands run
  refs: move some defines from refs-be-files.c to refs.h
  refs: make some files backend functions public
  refs: break out a ref conflict check
  refs: allow ref backend to be set for clone
  refs: add register_refs_backend
  refs: add LMDB refs backend
  refs: tests for db backend

Ronnie Sahlberg (19):
  refs.c: create a public version of verify_refname_available
  refs-be-files.c: rename refs to refs-be-files
  refs.c: add a new refs.c file to hold all common refs code
  refs.c: move update_ref to refs.c
  refs.c: move delete_ref and delete_refs to the common code
  refs.c: move read_ref_at to the common refs file
  refs.c: move the hidden refs functions to the common code
  refs.c: move dwim and friend functions to the common refs code
  refs.c: move warn_if_dangling_symref* to the common code
  refs.c: move read_ref, read_ref_full and ref_exists to the common code
  refs.c: move resolve_refdup to common
  refs.c: move check_refname_format to the common code
  refs.c: move is_branch to the common code
  refs.c: move prettify_refname to the common code
  refs.c: move ref iterators to the common code
  refs.c: move head_ref_namespaced to the common code
  refs-be-files.c: add a backend method structure with transaction
    functions
  refs-be-files.c: add methods for misc ref operations
  refs-be-files.c: add methods for the ref iterators

 .gitignore                               |    1 +
 Documentation/git-clone.txt              |    4 +
 Documentation/git-init-db.txt            |    2 +-
 Documentation/git-init.txt               |    6 +
 Documentation/technical/refs-be-lmdb.txt |   39 +
 Makefile                                 |   13 +
 builtin/clone.c                          |   27 +-
 builtin/init-db.c                        |   39 +-
 builtin/submodule--helper.c              |    5 +-
 cache.h                                  |   13 +
 config.c                                 |   27 +
 configure.ac                             |   33 +
 contrib/workdir/git-new-workdir          |    2 +
 environment.c                            |    1 +
 path.c                                   |   12 +
 refs-be-files.c                          | 3757 +++++++++++++++++++++
 refs-be-lmdb.c                           | 1984 +++++++++++
 refs.c                                   | 5329 ++++++------------------------
 refs.h                                   |  282 +-
 run-command.c                            |    2 +
 run-command.h                            |    1 +
 setup.c                                  |   28 +-
 t/t1460-refs-be-db.sh                    | 1103 +++++++
 t/t1470-refs-be-db-reflog.sh             |  353 ++
 test-refs-be-lmdb.c                      |   68 +
 25 files changed, 8716 insertions(+), 4415 deletions(-)
 create mode 100644 Documentation/technical/refs-be-lmdb.txt
 create mode 100644 refs-be-files.c
 create mode 100644 refs-be-lmdb.c
 create mode 100755 t/t1460-refs-be-db.sh
 create mode 100755 t/t1470-refs-be-db-reflog.sh
 create mode 100644 test-refs-be-lmdb.c