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: 2022-08-22T21:22:29Z
Lists: pgsql-hackers 
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.

> - I like the idea of simplifying the assertions, but I can't get
> behind using platform lfind to do it, since it has a different API,
> requires new functions we don't need, and possibly has portability
> issues. A simple for-loop is better for assertions.

My main goal with this was improving readability, which is likely possible
without lfind().  I'll see what I can do.

> - A runtime elog is not appropriate for a compile time check -- use
> #error instead.

Will do.

-- 
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