From: Chris Torek <chris.torek@gmail.com>
Date: Tue, 21 Oct 2025 11:16:53 GMT
Subject: Re: [PATCH 5/9] xdiff: split xrecord_t.ha into line_hash and minimal_perfect_hash
Message-ID: <CAPx1Gvdd4KW=P=0te6ZeBXJPSp8NgyXnrEnJLb5g1uLcjNYnXQ@mail.gmail.com>
In-Reply-To: <a0711cfe-6e44-44d6-b66b-84a296e113d2@gmail.com>

On Tue, Oct 21, 2025 at 3:04 AM Phillip Wood <phillip.wood123@gmail.com> wrote:
...
> uint64_t. How much more memory do we end up using by adding second hash
> member to the struct?

As in any string-to-string algorithm of this sort, there's one per "symbol",
but in this case a "symbol" is a line in a file. So if files are M and N lines
long, there are M+N symbols. Take the difference of the size of the two
records and multiply by this.

Assuming "sane" input file sizes (under a million lines each) it's a few
megabytes maximum...

Chris