Re: PATCH: recursive json_populate_record()

On 25.01.2017 23:58, Tom Lane wrote:
> I think you need to take a second look at the code you're producing
> and realize that it's not so clean either. This extract from
> populate_record_field, for example, is pretty horrid:

But what if we introduce some helper macros like this:

#define JsValueIsNull(jsv) \
((jsv)->is_json ? !(jsv)->val.json.str \
: !(jsv)->val.jsonb || (jsv)->val.jsonb->type == jbvNull)

#define JsValueIsString(jsv) \
((jsv)->is_json ? (jsv)->val.json.type == JSON_TOKEN_STRING \
: (jsv)->val.jsonb && (jsv)->val.jsonb->type == jbvString)

/* prepare column metadata cache for the given type */
if (col->typid != typid || col->typmod != typmod)
prepare_column_cache(col, typid, typmod, mcxt, jsv->is_json);

*isnull = JsValueIsNull(jsv);

typcat = col->typcat;

/* try to convert json string to a non-scalar type through input function */
if (JsValueIsString(jsv) &&
(typcat == TYPECAT_ARRAY || typcat == TYPECAT_COMPOSITE))
typcat = TYPECAT_SCALAR;

/* we must perform domain checks for NULLs */
if (*isnull && typcat != TYPECAT_DOMAIN)
return (Datum) 0;

--
Nikita Glukhov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company