Method MakeCursor

storage/connect/cmgoconn.cpp:354–516

/ MakeCursor: make the cursor used to retrieve documents. */ /

/*  MakeCursor: make the cursor used to retrieve documents.            */
/***********************************************************************/
bool CMgoConn::MakeCursor(PGLOBAL g)
{
	const char *p;
	bool  id, all = false;
	PCSZ  options = Pcg->Options;
	PTDB  tp = Pcg->Tdbp;
	PCOL  cp;
	PSTRG s = NULL;
	PFIL  filp = tp->GetFilter();

	id = (tp->GetMode() == MODE_UPDATE || tp->GetMode() == MODE_DELETE);

	if (options && !stricmp(options, "all")) {
		options = NULL;
		all = true;
	} else for (cp = tp->GetColumns(); cp && !all; cp = cp->GetNext())
		if (cp->GetFmt() && !strcmp(cp->GetFmt(), "*") && !options)
			all = true;
		else if (!id)
			id = !strcmp(cp->GetFmt() ? cp->GetFmt() : cp->GetName(), "_id");

	if (Pcg->Pipe) {
		if (trace(1))
			htrc("Pipeline: %s\n", options);

		p = strrchr(options, ']');

		if (!p) {
			snprintf(g->Message, sizeof(g->Message), "Missing ] in pipeline");
			return true;
		} else
			*(char*)p = 0;

		s = new(g) STRING(g, 1023, (PSZ)options);

		if (filp) {
			s->Append(",{\"$match\":");

			if (MakeSelector(g, filp, s)) {
				snprintf(g->Message, sizeof(g->Message), "Failed making selector");
				return true;
			} else
				s->Append('}');

			tp->SetFilter(NULL);   // Not needed anymore
		} // endif To_Filter

		if (tp->GetColumns() && !strstr(s->GetStr(), "$project")) {
			// Project list
			s->Append(",{\"$project\":{\"");

			if (!id)
				s->Append("_id\":0,\"");

			Project(g, s);
			s->Append("}}");
		} // endif all