Re: [PATCH 00/20] Read `packed-refs` using mmap()

> Following lots of work to extract the `packed_ref_store` into a
> separate module and decouple it from the `files_ref_store`, it is now
> possible to fundamentally change how the `packed-refs` file is read.
>
> * `mmap()` the whole file rather than `read()`ing it.
>
> * Instead of parsing the complete file at once into a `ref_cache`,
>   parse the references out of the file contents on demand.
>
> * Use a binary search to find, very quickly, the reference or group of
>   references that needs to be read. Parse *only* those references out
>   of the file contents, without creating in-memory data structures at
>   all.

> ...
> This branch applies on top of mh/packed-ref-transactions. It can also
> be obtained from my git fork [1] as branch `mmap-packed-refs`.
>
> Michael
>
> [1] https://github.com/mhagger/git