package pg

// BatchSize is the default number of DB records to access in one batch
const BatchSize uint = 1000

// BatchFunc is the function to execute on each batch of records, should return the count of records affected
type BatchFunc func(offset, limit uint) (count uint, err error)

// Batch is an iterator for batches of records
func Batch(cb BatchFunc) error {
	offset := uint(0)
	limit := BatchSize

	for {
		count, err := cb(offset, limit)
		if err != nil {
			return err
		}

		if count < limit {
			return nil
		}

		offset += limit
	}
}