Don't send steps to frontend if they haven't changed since last poll

[timja]

What feature do you want to see added?

see #993

Ideally we would send an If-Modified-Since or If-None-Match header and avoid sending all those bytes over the wire when nothing changed since the last poll. Something for another day.

Upstream changes

see similar implementation for list of runs:

pipeline-graph-view-plugin/src/main/java/io/jenkins/plugins/pipelinegraphview/multipipelinegraphview/MultiPipelineGraphViewAction.java

Lines 88 to 92 in ce1c59e

	String etag = etagBuilder.getEtag();
	String header = req.getHeader("If-None-Match");
	if (etag != null && etag.equals(header)) {
	rsp.setStatus(HttpServletResponse.SC_NOT_MODIFIED);
	return;

Are you interested in contributing this feature?

No response

[timja]

fyi @das7pad