Re: Question About Sorting the Index

From: Jon Forrest <nobozo@gmail.com>
Date: May 27, 2025, 16:38 UTC
Message-ID: <9befdb3e-ff6e-4416-8735-1eea99dbbf01@gmail.com>
In-Reply-To: <xmqqfrh3qe2w.fsf@gitster.g>

On 5/17/25 11:36 AM, Junio C Hamano wrote:

> For example, the fact that the index is first read into core, each
> entry is represented as a cache_entry in-core structure, and the
> code accesses them via an array active_cache[], and that array is
> sorted per pathnames, haven't changed.

I had a thought. What if the in-memory cache were stored in a hash, where the pathname is the key? That way nothing would have to be sorted in order to lookup a particular file.

The on-disk index could be in any order.

I don't know how the overhead of creating the hash when a git program starts compares to that of creating the cache_entry struct and then later doing the sorting. This seems like the key question.

Jon