feat: add histogram_add; update interface

collector.v

@@ -14,7 +14,7 @@ pub mut:
 }
 
 [heap]
-struct DefaultMetricsCollector {
+struct DefaultCollector {
 mut:
 	// The mutex for counters also applies to counter_indexes. Both data
 	// structuress are only ever updated together. Note that only registering a
@@ -25,15 +25,15 @@ mut:
 	histograms      shared map[string]HistogramEntry
 }
 
-pub fn new_default_metrics_collector() &DefaultMetricsCollector {
-	return &DefaultMetricsCollector{
+pub fn new_default_collector() &DefaultCollector {
+	return &DefaultCollector{
 		counters: []u64{}
 		counter_indexes: map[string]CounterEntry{}
 		histograms: map[string]HistogramEntry{}
 	}
 }
 
-pub fn (mut c DefaultMetricsCollector) counter_register(value u64, metric Metric) {
+pub fn (mut c DefaultCollector) counter_register(value u64, metric Metric) {
 	lock c.counters {
 		c.counters << value
 
@@ -44,7 +44,7 @@ pub fn (mut c DefaultMetricsCollector) counter_register(value u64, metric Metric
 	}
 }
 
-pub fn (mut c DefaultMetricsCollector) counter_increment(metric Metric) {
+pub fn (mut c DefaultCollector) counter_increment(metric Metric) {
 	rlock c.counters {
 		entry := c.counter_indexes[metric.str()]
 
@@ -52,7 +52,7 @@ pub fn (mut c DefaultMetricsCollector) counter_increment(metric Metric) {
 	}
 }
 
-pub fn (mut c DefaultMetricsCollector) counter_decrement(metric Metric) {
+pub fn (mut c DefaultCollector) counter_decrement(metric Metric) {
 	rlock c.counters {
 		entry := c.counter_indexes[metric.str()]
 
@@ -60,7 +60,7 @@ pub fn (mut c DefaultMetricsCollector) counter_decrement(metric Metric) {
 	}
 }
 
-pub fn (mut c DefaultMetricsCollector) counter_get(metric Metric) ?u64 {
+pub fn (mut c DefaultCollector) counter_get(metric Metric) ?u64 {
 	return rlock c.counters {
 		entry := c.counter_indexes[metric.str()] or { return none }
 
@@ -68,7 +68,7 @@ pub fn (mut c DefaultMetricsCollector) counter_get(metric Metric) ?u64 {
 	}
 }
 
-pub fn (mut c DefaultMetricsCollector) histogram_register(metric Metric) {
+pub fn (mut c DefaultCollector) histogram_register(metric Metric) {
 	lock c.histograms {
 		c.histograms[metric.str()] = HistogramEntry{
 			metric: metric
@@ -77,7 +77,7 @@ pub fn (mut c DefaultMetricsCollector) histogram_register(metric Metric) {
 	}
 }
 
-pub fn (mut c DefaultMetricsCollector) histogram_add(value f64, metric Metric) {
+pub fn (mut c DefaultCollector) histogram_add(value f64, metric Metric) {
 	entry := rlock c.histograms {
 		c.histograms[metric.str()]
 	}
@@ -86,3 +86,15 @@ pub fn (mut c DefaultMetricsCollector) histogram_add(value f64, metric Metric) {
 		entry.data << value
 	}
 }
+
+pub fn (mut c DefaultCollector) histogram_get(metric Metric) ?[]f64 {
+	entry := rlock c.histograms {
+		c.histograms[metric.str()] or { return none }
+	}
+
+	return rlock entry.data {
+		// Return a clone of the data to prevent user from altering
+		// internal structure
+		entry.data.clone()
+	}
+}

metrics.v

@@ -23,4 +23,8 @@ interface MetricsCollector {
 	counter_register(value u64, metric Metric)
 	counter_increment(metric Metric)
 	counter_decrement(metric Metric)
+	counter_get(metric Metric) ?u64
+	histogram_register(metric Metric)
+	histogram_add(value f64, metric Metric)
+	histogram_get(metric Metric) ?
 }