Horton

Re: [PATCH] Optimize json_lex_string by batching character copying

Nathan Bossart <nathandbossart@gmail.com>

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From: Nathan Bossart <nathandbossart@gmail.com>
To: John Naylor <john.naylor@enterprisedb.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: 2022-08-31T04:17:12Z
Lists: pgsql-hackers 
On Wed, Aug 31, 2022 at 10:50:39AM +0700, John Naylor wrote:
> Here's the final piece. I debated how many tests to add and decided it
> was probably enough to add one each for checking quotes and
> backslashes in the fast path. There is one cosmetic change in the
> code: Before, the vectorized less-equal check compared to 0x1F, but
> the byte-wise path did so with < 32. I made them both "less-equal 31"
> for consistency. I'll commit this by the end of the week unless anyone
> has a better idea about testing.

LGTM

-- 
Nathan Bossart
Amazon Web Services: https://aws.amazon.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