Function createLinkIterator

tempodb/encoding/vparquet4/block_traceql.go:1826–1903

(makeIter, makeNilIter makeIterFn, conditions []traceql.Condition, allConditions, selectAll bool)

}

func createLinkIterator(makeIter, makeNilIter makeIterFn, conditions []traceql.Condition, allConditions, selectAll bool) (parquetquery.Iterator, error) {
	if len(conditions) == 0 {
		return nil, nil
	}

	linkIters := make([]parquetquery.Iterator, 0, len(conditions))
	var genericConditions []traceql.Condition

	for _, cond := range conditions {
		switch cond.Attribute.Intrinsic {
		case traceql.IntrinsicLinkTraceID:
			pred, err := createBytesPredicate(cond.Op, cond.Operands, false)
			if err != nil {
				return nil, err
			}
			linkIters = append(linkIters, makeIter(columnPathLinkTraceID, pred, columnPathLinkTraceID))
			continue

		case traceql.IntrinsicLinkSpanID:
			pred, err := createBytesPredicate(cond.Op, cond.Operands, true)
			if err != nil {
				return nil, err
			}
			linkIters = append(linkIters, makeIter(columnPathLinkSpanID, pred, columnPathLinkSpanID))
			continue
		}

		if cond.Op == traceql.OpNotExists {
			// Generic attr doesn't exist
			pred := parquetquery.NewIncludeNilStringEqualPredicate([]byte(cond.Attribute.Name))
			linkIters = append(linkIters, makeNilIter(columnPathLinkAttrKey, pred, cond.Attribute.Name))
			continue
		}

		genericConditions = append(genericConditions, cond)
	}

	attrIter, err := createAttributeIterator(makeIter, genericConditions, DefinitionLevelResourceSpansILSSpanLinkAttrs,
		columnPathLinkAttrKey, columnPathLinkAttrString, columnPathLinkAttrInt, columnPathLinkAttrDouble, columnPathLinkAttrBool, allConditions, selectAll)
	if err != nil {
		return nil, fmt.Errorf("creating link attribute iterator: %w", err)
	}

	if attrIter != nil {
		linkIters = append(linkIters, attrIter)
	}

	var required []parquetquery.Iterator
	minCount := 0

	if allConditions {
		// The final number of expected attributes.
		distinct := map[string]struct{}{}
		for _, cond := range conditions {
			distinct[cond.Attribute.Name] = struct{}{}
		}
		minCount = len(distinct)
	}