Re: [PATCH 05/22] read-cache: add index reading api

[Junio C Hamano <gitster@pobox.com>]

Thomas Gummerer <t.gummerer@gmail.com> writes:

>> The reader often needs to rewind the read-pointer partially while
>> walking the index (e.g. next_cache_entry() in unpack-trees.c and how
>> the o->cache_bottom position is used throughout the subsystem).  I
>> am not sure if this singly-linked list is a good way to go.
>
> I'm not very familiar with the unpack-trees code, but from a quick look
> the pointer (or position in the cache) is always only moved forward.

I am more worried about o->cache_bottom processing, where it
currently is an index into an array.

With your ce->next_in_list_of_read_entries change, a natural rewrite
would be to point at the ce with o->cache_bottom, but then that
would mean you cannot in-place replace the entries like we used to
be able to in an array based implementation.

But your series does not seem to touch unpack-trees yet, so I may be
worried too much before it becomes necessary.