Method collectRequired

pkg/parquetquery/iters.go:1504–1571

(rowNumber RowNumber)

}

func (j *LeftJoinIterator) collectRequired(rowNumber RowNumber) (err error) {
	// First iterator is broken out because it is treated a little differently,
	// and being on the hot path this is requiredfor best performance.
iter0:
	for j.peeksRequired[0] != nil {
		j.collector.Collect(j.peeksRequired[0], j.paramsRequired[0])

		j.peeksRequired[0], err = j.required[0].Next()
		if err != nil {
			return
		}
		if j.peeksRequired[0] == nil {
			break iter0
		}

		// For the driver we check after because we already know
		// entering this loop that it was pointed at the row.
		for k := j.defLevelsRequired[0]; k >= 0; k-- {
			if j.peeksRequired[0].RowNumber[k] != rowNumber[k] {
				break iter0
			}
		}
	}

iters:
	for i := 1; i < len(j.required); i++ {
		if i > 0 {
			if EqualRowNumber(j.defLevelsRequired[i], j.collectedThroughRequired[i], rowNumber) {
				// Already collected
				continue
			}
		}

		// First iterator (driver) is pointing at the next row to collect.
		// Collect from it while at the same level as the desired definition level
		// or until exhausted.
		for j.peeksRequired[i] != nil {

			// Before collecting ensure we are at the same row.
			// For the driver we already know entering this loop that it s pointed at the row.
			// So this early check is only for later iterators.
			if i > 0 {
				// Interned version of EqualRowNumber
				// Compare in reverse order because most row number activity
				// occurs at the deeper definition levels.
				for k := j.defLevelsRequired[i]; k >= 0; k-- {
					if j.peeksRequired[i].RowNumber[k] != rowNumber[k] {
						continue iters
					}
				}
			}

			j.collector.Collect(j.peeksRequired[i], j.paramsRequired[i])

			// Optimization: we don't need to save the row number
			// for the primary iterator (driver).
			if i > 0 {
				j.collectedThroughRequired[i] = j.peeksRequired[i].RowNumber