@NotNull
    private FetchDataResult buildFetchDataResult(final String feedName,
                                                 final String streamTypeName,
                                                 final Set<String> availableChildStreamTypes,
                                                 final Source streamSource,
                                                 final InputStreamProvider inputStreamProvider,
                                                 final FetchDataRequest fetchDataRequest,
                                                 final DataType dataType,
                                                 final RawResult rawResult,
                                                 final TaskContext taskContext) {

        String output;
        final DocRef pipeline = fetchDataRequest.getPipeline();
        // If we have a pipeline then we will try and use it.
        if (pipeline != null) {
            try {
                // If we have a pipeline then use it.
                output = usePipeline(
                        streamSource,
                        rawResult.getRawData(),
                        feedName,
                        pipeline,
                        inputStreamProvider,
                        taskContext);

            } catch (final RuntimeException e) {
                output = e.getMessage();
                if (output == null || output.length() == 0) {
                    output = e.toString();
                }
            }

        } else {
            output = rawResult.getRawData();
        }

        // Set the result.
        final String classification = feedProperties.getDisplayClassification(feedName);

        return new FetchDataResult(
                feedName,
                streamTypeName,
                classification,
                rawResult.getSourceLocation(),
                rawResult.getItemRange(),
                rawResult.getTotalItemCount(),
                rawResult.getTotalCharacterCount(),
                rawResult.getTotalBytes(),
                availableChildStreamTypes,
                output,
                fetchDataRequest.isShowAsHtml(),
                dataType,
                rawResult.getDisplayMode(),
                null);
    }
How big our buffers are. This should always be a multiple of 8.
stroom-data/stroom-data-store-impl/src/main/java/stroom/data/store/impl/DataFetcher.java