Function TryCheckMetaScoreOrderBy

pg_documentdb/src/opclass/bson_text_gin.c:448–492

* Validates that the order by is for a text search * i.e. the document { "$meta": "textScore" } */

 * i.e. the document { "$meta": "textScore" }
 */
bool
TryCheckMetaScoreOrderBy(const bson_value_t *value)
{
	pgbsonelement metaOrderingElement = { 0 };

	if (value->value_type != BSON_TYPE_DOCUMENT)
	{
		return false;
	}

	if (TryGetBsonValueToPgbsonElement(value, &metaOrderingElement) &&
		metaOrderingElement.pathLength == 5 &&
		strncmp(metaOrderingElement.path, "$meta", 5) == 0)
	{
		if (metaOrderingElement.bsonValue.value_type != BSON_TYPE_UTF8)
		{
			ereport(ERROR, (errcode(ERRCODE_DOCUMENTDB_LOCATION31138),
							errmsg("Invalid use of $meta sort: $meta: \"%s\"",
								   BsonValueToJsonForLogging(
									   &metaOrderingElement.bsonValue))));
		}

		if (metaOrderingElement.bsonValue.value.v_utf8.len != 9 ||
			strncmp(metaOrderingElement.bsonValue.value.v_utf8.str, "textScore", 9) != 0)
		{
			ereport(ERROR, (errcode(ERRCODE_DOCUMENTDB_LOCATION31138),
							errmsg("$meta for sort only allows textScore not %s",
								   metaOrderingElement.bsonValue.value.v_utf8.str)));
		}

		bson_iter_t documentIterator;
		BsonValueInitIterator(value, &documentIterator);
		if (!TryGetSinglePgbsonElementFromBsonIterator(&documentIterator,
													   &metaOrderingElement))
		{
			ereport(ERROR, (errcode(ERRCODE_DOCUMENTDB_FAILEDTOPARSE),
							errmsg(
								"Additional keys are not permitted within a $meta sort specification.")));
		}

		return true;
	}

	return false;
}


/*