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: 2022-08-19T08:11:36Z
Lists: pgsql-hackers

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On Tue, Aug 16, 2022 at 4:23 AM Nathan Bossart <nathandbossart@gmail.com> wrote:
>
> On Mon, Aug 15, 2022 at 08:33:21PM +0700, John Naylor wrote:
> > +#ifdef USE_SSE2
> > +             chunk = _mm_loadu_si128((const __m128i *) &base[i]);
> > +#else
> > +             memcpy(&chunk, &base[i], sizeof(chunk));
> > +#endif                                                       /* USE_SSE2 */
>
> Perhaps there should be a macro or inline function for loading a vector so
> that these USE_SSE2 checks can be abstracted away, too.

This is done. Also:
- a complete overhaul of the pg_lfind8* tests
- using a typedef for the vector type
- some refactoring, name changes and other cleanups (a few of these
could also be applied to the 32-byte element path, but that is left
for future work)

TODO: json-specific tests of the new path

--
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