Method Fetch

tempodb/encoding/vparquet4/wal_block.go:696–743

(ctx context.Context, req traceql.FetchSpansRequest, _ common.SearchOptions)

}

func (b *walBlock) Fetch(ctx context.Context, req traceql.FetchSpansRequest, _ common.SearchOptions) (traceql.FetchSpansResponse, error) {
	ctx, span := tracer.Start(ctx, "walBlock.Fetch")
	defer span.End()

	// todo: this same method is called in backendBlock.Fetch. is there anyway to share this?
	err := checkConditions(req.Conditions)
	if err != nil {
		return traceql.FetchSpansResponse{}, fmt.Errorf("conditions invalid: %w", err)
	}

	blockFlushes := b.readFlushes()
	// collect page readers to compute totalBytesRead
	readers := make([]*walReaderAt, 0, len(blockFlushes))
	iters := make([]traceql.SpansetIterator, 0, len(blockFlushes))
	for _, page := range blockFlushes {
		file, err := page.file(ctx)
		if err != nil {
			return traceql.FetchSpansResponse{}, fmt.Errorf("error opening file %s: %w", page.path, err)
		}

		pf := file.parquetFile

		iter, err := fetch(ctx, req, pf, pf.RowGroups(), b.meta.DedicatedColumns)
		if err != nil {
			return traceql.FetchSpansResponse{}, fmt.Errorf("creating fetch iter: %w", err)
		}

		wrappedIterator := &pageFileClosingIterator{iter: iter, pageFile: file}
		iters = append(iters, wrappedIterator)
		readers = append(readers, file.r)
	}

	// combine iters?
	return traceql.FetchSpansResponse{
		Results: &mergeSpansetIterator{
			iters: iters,
		},
		// FIXME: can this be simplified with the common.MetadataCallback?? and Metrics Collector??
		Bytes: func() uint64 {
			// read value when callback is called
			var totalBytesRead uint64
			for _, r := range readers {
				totalBytesRead += r.BytesRead()
			}
			return totalBytesRead
		},
	}, nil
}

func (b *walBlock) FetchSpans(_ context.Context, _ traceql.FetchSpansRequest, _ common.SearchOptions) (traceql.FetchSpansOnlyResponse, error) {
	return traceql.FetchSpansOnlyResponse{}, util.ErrUnsupported