Horton

Re: making the backend's json parser work in frontend code

Andrew Dunstan <andrew.dunstan@2ndquadrant.com>

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From: Andrew Dunstan <andrew.dunstan@2ndquadrant.com>
To: Mark Dilger <mark.dilger@enterprisedb.com>
Cc: Robert Haas <robertmhaas@gmail.com>, David Steele <david@pgmasters.net>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2020-01-27T01:09:53Z
Lists: pgsql-hackers 
On Mon, Jan 27, 2020 at 5:54 AM Mark Dilger
<mark.dilger@enterprisedb.com> wrote:
>
>
>
> > On Jan 22, 2020, at 10:53 AM, Robert Haas <robertmhaas@gmail.com> wrote:
> >
> > 0004 is a substantially cleaned up version of the patch to make the
> > JSON parser return a result code rather than throwing errors. Names
> > have been fixed, interfaces have been tidied up, and the thing is
> > better integrated with the surrounding code. I would really like
> > comments, if anyone has them, on whether this approach is acceptable.
> >
> > 0005 builds on 0004 by moving three functions from jsonapi.c to
> > jsonfuncs.c. With that done, jsonapi.c has minimal remaining
> > dependencies on the backend environment. It would still need a
> > substitute for elog(ERROR, "some internal thing is broken"); I'm
> > thinking of using pg_log_fatal() for that case. It would also need a
> > fix for the problem that pg_mblen() is not available in the front-end
> > environment. I don't know what to do about that yet exactly, but it
> > doesn't seem unsolvable. The frontend environment just needs to know
> > which encoding to use, and needs a way to call PQmblen() rather than
> > pg_mblen().
>
> I have completed the work in the attached 0006 and 0007 patches.
> These are intended to apply after your 0004 and 0005; they won’t
> work directly on master which, as of this writing, only contains your
> 0001-0003 patches.
>
> 0006 finishes moving the json parser to src/include/common and src/common.
>
> 0007 adds testing.
>
> I would appreciate somebody looking at the portability issues for 0007
> on Windows.
>

We'll need at a minimum something added to src/tools/msvc to build the
test program, maybe some other stuff too. I'll take a look.

cheers

andrew


-- 
Andrew Dunstan                https://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services

Commits

  1. Add jsonapi.c to Mkvcbuild.pm's @pgcommonallfiles.

  2. Move jsonapi.c and jsonapi.h to src/common.

  3. Move some code from jsonapi.c to jsonfuncs.c.

  4. Adjust pg_parse_json() so that it does not directly ereport().

  5. Remove jsonapi.c's lex_accept().

  6. Split JSON lexer/parser from 'json' data type support.

  7. Rationalize code placement between wchar.c, encnames.c, and mbutils.c.

  8. Move wchar.c and encnames.c to src/common/.

  9. Update header comments for wchar.c and encnames.c.

  10. Make StringInfo available to frontend code.

  11. Use SASLprep to normalize passwords for SCRAM authentication.