def divide_changes_to_group()

in core/lib/payload/copy.py [0:0]

• 24 lines of code
• 8 McCabe index (conditional complexity)

    def divide_changes_to_group(self, chg_rows):
        """
        Put consecutive changes with the same type into a group so that we can
        execute them in a single query to speed up replay

        @param chg_rows:  list of rows returned from _chg select query
        @type  chg_rows:  list[dict]
        """
        id_group = []
        type_now = None
        for idx, chg in enumerate(chg_rows):
            # Start of the current group
            if type_now is None:
                type_now = chg[self.DMLCOLNAME]
            id_group.append(chg[self.IDCOLNAME])

            # Dump when we are at the end of the changes
            if idx == len(chg_rows) - 1:
                yield type_now, id_group
                return
            # update type cannot be grouped
            elif type_now == self.DML_TYPE_UPDATE:
                yield type_now, id_group
                type_now = None
                id_group = []
            # The next change is a different type, dump what we have now
            elif chg_rows[idx + 1][self.DMLCOLNAME] != type_now:
                yield type_now, id_group
                type_now = None
                id_group = []
            # Reach the max group size, let's submit the query for now
            elif len(id_group) >= self.replay_group_size:
                yield type_now, id_group
                type_now = None
                id_group = []
            # The next element will be the same as what we are now
            else:
                continue