Function ExplainXMLTag

src/backend/commands/explain.c:5981–5999

* Emit opening or closing XML tag. * * "flags" must contain X_OPENING, X_CLOSING, or X_CLOSE_IMMEDIATE. * Optionally, OR in X_NOWHITESPACE to suppress the whitespace we'd normally * add. * * XML restricts tag names more than our other output formats, eg they can't * contain white space or slashes. Replace invalid characters with dashes, * so that for example "I/O Read Time" becomes "I-O-R

 * so that for example "I/O Read Time" becomes "I-O-Read-Time".
 */
static void
ExplainXMLTag(const char *tagname, int flags, ExplainState *es)
{
	const char *s;
	const char *valid = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_.";

	if ((flags & X_NOWHITESPACE) == 0)
		appendStringInfoSpaces(es->str, 2 * es->indent);
	appendStringInfoCharMacro(es->str, '<');
	if ((flags & X_CLOSING) != 0)
		appendStringInfoCharMacro(es->str, '/');
	for (s = tagname; *s; s++)
		appendStringInfoChar(es->str, strchr(valid, *s) ? *s : '-');
	if ((flags & X_CLOSE_IMMEDIATE) != 0)
		appendStringInfoString(es->str, " /");
	appendStringInfoCharMacro(es->str, '>');
	if ((flags & X_NOWHITESPACE) == 0)
		appendStringInfoCharMacro(es->str, '\n');
}

/*
 * Indent a text-format line.