From: Junio C Hamano <gitster@pobox.com>
Date: Wed, 26 Oct 2016 16:14:56 GMT
Subject: Re: [PATCH v1 00/19] Add configuration options for split-index
Message-ID: <xmqqeg33ccjj.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <CACsJy8Ba0BY=pZwrKf5rcD5AaZ3YyKh9=ENKkj7hHpTqh00OnA@mail.gmail.com>

Duy Nguyen <pclouds@gmail.com> writes:

> On Wed, Oct 26, 2016 at 12:21 AM, Junio C Hamano <gitster@pobox.com> wrote:
>
> Even if we ignore user index files (by forcing them all to be stored
> in one piece), there is a problem with the special temporary file
> index.lock, which must use split-index because it will become the new
> index. Handling race conditions could be tricky with ref counting.
> Timestamps help in this regard.

I actually think using the split-index only for the $GIT_DIR/index,
the primary one, and using the full index for others is a bad idea,
as we use temporary index ourselves when making partial commits,
which happens quite often.

So time-based GC it is.

I actually do not think index.lock is a problem, but is a solution,
if we only limit the split-index to the primary one (we can have at
most one, so we can GC the stale shared ones while holding the
lock).

But that is no longer important.