Function CopyReadAttributesText

src/backend/commands/copyfromparse.c:1305–1545

* Parse the current line into separate attributes (fields), * performing de-escaping as needed. * * The input is in line_buf. We use attribute_buf to hold the result * strings. cstate->raw_fields[k] is set to point to the k'th attribute * string, or NULL when the input matches the null marker string. * This array is expanded as necessary. * * (Note that the caller cannot check for nulls

 * The return value is the number of fields actually read.
 */
int
CopyReadAttributesText(CopyFromState cstate, int stop_processing_at_field)
{
	char		delimc = cstate->opts.delim[0];
	char		escapec = cstate->opts.escape[0];
	bool		delim_off = cstate->opts.delim_off;
	int			fieldno;
	char	   *output_ptr;
	char	   *cur_ptr;
	char	   *line_end_ptr;

	/*
	 * We need a special case for zero-column tables: check that the input
	 * line is empty, and return.
	 */
	if (cstate->max_fields <= 0)
	{
		if (cstate->line_buf.len != 0)
			ereport(ERROR,
					(errcode(ERRCODE_BAD_COPY_FILE_FORMAT),
					 errmsg("extra data after last expected column")));
		return 0;
	}

	resetStringInfo(&cstate->attribute_buf);

	/*
	 * The de-escaped attributes will certainly not be longer than the input
	 * data line, so we can just force attribute_buf to be large enough and
	 * then transfer data without any checks for enough space.  We need to do
	 * it this way because enlarging attribute_buf mid-stream would invalidate
	 * pointers already stored into cstate->raw_fields[].
	 */
	if (cstate->attribute_buf.maxlen <= cstate->line_buf.len)
		enlargeStringInfo(&cstate->attribute_buf, cstate->line_buf.len);
	output_ptr = cstate->attribute_buf.data;

	/* set pointer variables for loop */
	cur_ptr = cstate->line_buf.data + cstate->line_buf.cursor;
	line_end_ptr = cstate->line_buf.data + cstate->line_buf.len;

	/* Outer loop iterates over fields */
	fieldno = 0;
	for (;;)
	{
		bool		found_delim = false;
		char	   *start_ptr;
		char	   *end_ptr;
		int			input_len;
		bool		saw_non_ascii = false;

		/*
		 * In QD, stop once we have processed the last field we need in the QD.
		 */
		if (fieldno == stop_processing_at_field)
		{
			cstate->stopped_processing_at_delim = true;
			break;