Horton

Re: [PATCH] Optimize json_lex_string by batching character copying

John Naylor <john.naylor@enterprisedb.com>

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From: John Naylor <john.naylor@enterprisedb.com>
To: Nathan Bossart <nathandbossart@gmail.com>
Cc: Andres Freund <andres@anarazel.de>, Tom Lane <tgl@sss.pgh.pa.us>, Jelte Fennema <Jelte.Fennema@microsoft.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>, Merlin Moncure <mmoncure@gmail.com>, Andrew Dunstan <andrew.dunstan@2ndquadrant.com>, Stephen Frost <sfrost@snowman.net>
Date: 2022-08-23T06:03:03Z
Lists: pgsql-hackers 
On Tue, Aug 23, 2022 at 10:32 AM Nathan Bossart
<nathandbossart@gmail.com> wrote:
>
> On Mon, Aug 22, 2022 at 02:22:29PM -0700, Nathan Bossart wrote:
> > On Mon, Aug 22, 2022 at 09:35:34AM +0700, John Naylor wrote:
> >> Not at all! However, the 32-bit-element changes are irrelevant for
> >> json, and make review more difficult. I would suggest keeping those in
> >> the other thread starting with whatever refactoring is needed. I can
> >> always rebase over that.
> >
> > Yeah, I'll remove those to keep this thread focused.
>
> Here's a new version of the patch with the 32-bit changes and calls to
> lfind() removed.

LGTM overall. My plan is to split out the json piece, adding tests for
that, and commit the infrastructure for it fairly soon. Possible
bikeshedding: Functions like vector8_eq() might be misunderstood as
comparing two vectors, but here we are comparing each lane with a
scalar. I wonder if vector8_eq_scalar() et al might be more clear.

-- 
John Naylor
EDB: http://www.enterprisedb.com

Commits

  1. Speed up lexing of long JSON strings

  2. Add optimized functions for linear search within byte arrays

  3. Build de-escaped JSON strings in larger chunks during lexing

  4. Simplify json lexing state