Function PLy_cursor_query

src/pl/plpython/plpy_cursorobject.c:77–139

static PyObject *
PLy_cursor_query(const char *query)
{
	PLyCursorObject *cursor;
	PLyExecutionContext *exec_ctx = PLy_current_execution_context();
	volatile MemoryContext oldcontext;
	volatile ResourceOwner oldowner;

	if ((cursor = PyObject_New(PLyCursorObject, &PLy_CursorType)) == NULL)
		return NULL;
	cursor->portalname = NULL;
	cursor->closed = false;
	cursor->mcxt = AllocSetContextCreate(TopMemoryContext,
										 "PL/Python cursor context",
										 ALLOCSET_DEFAULT_SIZES);

	/* Initialize for converting result tuples to Python */
	PLy_input_setup_func(&cursor->result, cursor->mcxt,
						 RECORDOID, -1,
						 exec_ctx->curr_proc);

	oldcontext = CurrentMemoryContext;
	oldowner = CurrentResourceOwner;

	if(!PLy_spi_subtransaction_begin(oldcontext, oldowner))
		return NULL;

	PG_TRY();
	{
		SPIPlanPtr	plan;
		Portal		portal;

		pg_verifymbstr(query, strlen(query), false);

		plan = SPI_prepare(query, 0, NULL);
		if (plan == NULL)
			elog(ERROR, "SPI_prepare failed: %s",
				 SPI_result_code_string(SPI_result));

		portal = SPI_cursor_open(NULL, plan, NULL, NULL,
								 exec_ctx->curr_proc->fn_readonly);
		SPI_freeplan(plan);

		if (portal == NULL)
			elog(ERROR, "SPI_cursor_open() failed: %s",
				 SPI_result_code_string(SPI_result));

		cursor->portalname = MemoryContextStrdup(cursor->mcxt, portal->name);

		PinPortal(portal);

		PLy_spi_subtransaction_commit(oldcontext, oldowner);
	}
	PG_CATCH();
	{
		PLy_spi_subtransaction_abort(oldcontext, oldowner);
		return NULL;
	}