Re: [PATCH] Add pretty-printed XML output option

On 09.02.23 08:23, Tom Lane wrote:
> Um ... why are you using PG_TRY here at all? It seems like
> you have full control of the actually likely error cases.
> The only plausible error out of the StringInfo calls is OOM,
> and you probably don't want to trap that at all.

My intention was to catch any unexpected error from
xmlDocDumpFormatMemory and handle it properly. But I guess you're right,
I can control the likely error cases by checking doc and nbytes.

You suggest something along these lines?

    xmlDocPtr  doc;
    xmlChar    *xmlbuf = NULL;
    text       *arg = PG_GETARG_TEXT_PP(0);
    StringInfoData buf;
    int nbytes;

    doc = xml_parse(arg, XMLOPTION_DOCUMENT, false,
GetDatabaseEncoding(), NULL);

    if(!doc)
        elog(ERROR, "could not parse the given XML document");

    xmlDocDumpFormatMemory(doc, &xmlbuf, &nbytes, 1);

    xmlFreeDoc(doc);

    if(!nbytes)
        elog(ERROR, "could not indent the given XML document");

    initStringInfo(&buf);
    appendStringInfoString(&buf, (const char *)xmlbuf);

    xmlFree(xmlbuf);

    PG_RETURN_XML_P(stringinfo_to_xmltype(&buf));

Thanks!

Best, Jim