Method KeepGroup

tempodb/encoding/vparquet4/block_traceql.go:3338–3427

KeepGroup applies resource-level data and filtering to the spans yielded from the span-level iterators. It updates the spans in-place in the OtherEntries slice. Creation of the spanset is delayed until the traceCollector.

(res *parquetquery.IteratorResult)

// the span-level iterators.  It updates the spans in-place in the OtherEntries slice.
// Creation of the spanset is delayed until the traceCollector.
func (c *batchCollector) KeepGroup(res *parquetquery.IteratorResult) bool {
	// First pass over spans and attributes from the AttributeCollector
	spans := res.OtherEntries[:0]
	c.resAttrs = c.resAttrs[:0]

	for _, kv := range res.OtherEntries {
		switch v := kv.Value.(type) {
		case *span:
			spans = append(spans, kv)
		case traceql.Static:
			c.resAttrs = append(c.resAttrs, attrVal{newResAttr(kv.Key), v})
		}
	}
	res.OtherEntries = spans

	// Throw out batches without any candidate spans
	if len(res.OtherEntries) == 0 {
		return false
	}

	// Gather Attributes from dedicated resource-level columns
	for _, e := range res.Entries {
		switch e.Value.Kind() {
		case parquet.Int64:
			c.resAttrs = append(c.resAttrs, attrVal{newResAttr(e.Key), traceql.NewStaticInt(int(e.Value.Int64()))})
		case parquet.ByteArray:
			c.resAttrs = append(c.resAttrs, attrVal{newResAttr(e.Key), traceql.NewStaticString(unsafeToString(e.Value.Bytes()))})
		default:
			// This is a null value, indicating the attribute doesn't exist
			if e.Value.IsNull() {
				c.resAttrs = append(c.resAttrs, attrVal{newResAttr(e.Key), traceql.NewStaticString("nil")})
			}
		}
	}

	if c.minAttributes > 0 {
		if len(c.resAttrs) < c.minAttributes {
			return false
		}
	}

	// Second pass. Update and further filter the spans
	if len(c.resAttrs) > 0 || c.requireAtLeastOneMatchOverall {
		mightFilter := c.requireAtLeastOneMatchOverall

		// If we might filter, then rebuild the slice of kept
		// spans, in place with the same underlying buffer.
		// If not filtering, then skip this work.
		var spans []struct {
			Key   string
			Value interface{}
		}
		if mightFilter {
			spans = res.OtherEntries[:0]
		}

		for _, e := range res.OtherEntries {
			span, ok := e.Value.(*span)