Re: [GSoC] json helper functions

On Wed, May 30, 2018 at 12:42 AM, Charles Cui <charles.cui1984@gmail.com> wrote:
> Hi mentors and hackers,
>
>     I am working on providing a new plugin where creates new data type
> (thrift). What I am currently planning is to translate cstring to byte for
> thrift_in functions. The cstring should be json format. When I looking at
> json helper functions I find the header
>
> ./include/server/utils/json.h
>
> where all functions have the signature of Datum
> function(PG_FUNCTION_ARGS).This signature causes extra overhead when writing
> the code because I need to convert my intermediate variables to the required
> format. Wondering are there any json helpers that are used by postgresql and
> plugins can directly call?
>
>


See the DirectFunctionCall macros. There are lots of examples in the code.

cheers

andrew

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