/**
* {@inheritDoc}
*
* <p>This routine is typically invoked by {@link IGangliaMetricsCollector}s. However, you can
* also simply invoke it directly.
*
* <p>Note: In order to get a nice metadata declaration for the record, the application should
* also register an {@link IGangliaMetadataFactory}.
*
* @param metricName The name of the metric.
* @param value The metric value.
* @see #getMetadataFactory()
*/
@Override
public void setMetric(final String metricName, final Object value) {
final GangliaSender sender = this.gangliaSender;
if (sender != null) {
try {
if (metricName == null) {
log.warn("Metric was emitted with no name.");
return;
}
if (value == null) {
log.warn("Metric was emitted with a null value: metricName=" + metricName);
return;
}
IGangliaMetadataMessage decl;
{
// Look for a pre-declared metric.
decl = gangliaState.getMetadata(metricName);
if (decl == null) {
// Obtain declaration.
decl = gangliaState.getMetadataFactory().newDecl(hostName, metricName, value);
if (decl == null) {
log.error("Could not declare: " + metricName);
return;
}
// Atomically declare/resolve.
decl = gangliaState.putIfAbsent(decl);
}
}
/*
* Lookup the current value for the metric.
*
* Note: At this point we are guaranteed that a metadata
* declaration exists so the return value must be non-null.
*/
final TimestampMetricValue tmv =
gangliaState.getMetric(getHostName(), decl.getMetricName());
// Return must be non-null since declaration exists.
assert tmv != null;
// Should be the same declaration reference.
assert decl == tmv.getMetadata();
if (tmv.getTimestamp() == 0L) {
/*
* Send metadata record.
*
* TODO Since the captured metadata record might have
* originated on another host, we should build a new
* metadata record either now (so we send out the record
* with our host name) or when we capture the record (as
* part of obtaining a richer metadata record object).
*/
sendMessage(tmv.getMetadata());
}
// Update the current metric value.
if (tmv.setValue(value)) {
/*
* Send the metric record.
*
* Note: Either the metric value has never been transmitted,
* or it has changed significantly, or TMax might expire if
* we do not retransmit it now.
*/
// update the timestamp when sending out the metric value.
tmv.update();
final IGangliaMetricMessage msg =
metricFactory.newMetricMessage(getHostName(), decl, false /* spoof */, value);
sendMessage(msg);
}
} catch (Throwable e) {
log.warn(e, e);
}
}
}
