public Gauge gauge()

in geronimo-metrics-common/src/main/java/org/apache/geronimo/microprofile/metrics/common/RegistryImpl.java [201:215]

• 15 lines of code
• 4 McCabe index (conditional complexity)

    public <T, R extends Number> Gauge<R> gauge(final Metadata metadata, final T object, final Function<T, R> func, final Tag... tags) {
        final MetricID metricID = new MetricID(metadata.getName(), tags);
        Holder<? extends Metric> holder = metrics.get(metricID);
        if (holder == null) {
            holder = new Holder<>(new SimpleGaugeImpl<>(() -> func.apply(object)), enforceType(metadata, MetricType.GAUGE), metricID);
            final Holder<? extends Metric> existing = metrics.putIfAbsent(holder.metricID, holder);
            if (existing != null) {
                holder = existing;
            }
        }
        if (!Gauge.class.isInstance(holder.metric)) {
            throw new IllegalArgumentException(holder.metric + " is not a gauge");
        }
        return Gauge.class.cast(holder.metric);
    }