feat: freeze typed metrics registry and bounded exemplars

2026-08-14 11:52:00 +03:00
parent 17c8e3a8f0
commit 8e709acea9
29 changed files with 1690 additions and 103 deletions
@@ -0,0 +1,100 @@
+use std::collections::BTreeSet;
+
+use crank_metrics::{
+    HTTP_ROUTE_DOMAIN, HttpRoute, MAX_LOGICAL_SERIES_PER_PROCESS, MAX_PRODUCT_LABELS_PER_FAMILY,
+    MAX_RENDERED_SERIES_PER_PROCESS, METRIC_SCHEMA_VERSION, metric_schema,
+    render_metric_schema_json, schema_budget, validate_budget,
+};
+
+#[test]
+fn schema_v1_is_complete_deterministic_and_inside_the_frozen_budget() {
+    assert_eq!(METRIC_SCHEMA_VERSION, 1);
+    assert_eq!(metric_schema().len(), 23);
+
+    let budget = schema_budget().expect("canonical schema must be valid");
+    assert!(budget.logical_series <= MAX_LOGICAL_SERIES_PER_PROCESS);
+    assert!(budget.rendered_series <= MAX_RENDERED_SERIES_PER_PROCESS);
+
+    for definition in metric_schema() {
+        assert!(!definition.description.trim().is_empty());
+        assert!(definition.labels.len() <= MAX_PRODUCT_LABELS_PER_FAMILY);
+        assert!(!definition.processes.is_empty());
+        assert_eq!(definition.labels.len(), definition.label_domains.len());
+        assert!(definition.label_domains.iter().all(|domain| {
+            !domain.values.is_empty()
+                && domain.values.iter().all(|value| !value.is_empty())
+                && domain.values.iter().copied().collect::<BTreeSet<_>>().len()
+                    == domain.values.len()
+        }));
+        if definition.kind.as_str() == "histogram" {
+            assert!(!definition.buckets.is_empty());
+            assert!(definition.buckets.windows(2).all(|pair| pair[0] < pair[1]));
+        } else {
+            assert!(definition.buckets.is_empty());
+        }
+    }
+
+    let first = render_metric_schema_json().expect("schema renders");
+    let second = render_metric_schema_json().expect("schema renders deterministically");
+    assert_eq!(first, second);
+    assert!(first.len() < 65_536);
+    assert!(!first.contains("trace_id"));
+    assert!(!first.contains("request_id"));
+}
+
+#[test]
+fn frozen_budget_edges_are_exact() {
+    assert!(validate_budget(4_999, 14_999).is_ok());
+    assert!(validate_budget(5_000, 15_000).is_ok());
+    assert!(validate_budget(5_001, 15_000).is_err());
+    assert!(validate_budget(5_000, 15_001).is_err());
+    assert_eq!(crank_metrics::max_exemplar_slots(), 9_170);
+}
+
+#[test]
+fn every_registered_route_round_trips_without_dynamic_segments() {
+    assert_eq!(HTTP_ROUTE_DOMAIN.len(), 57);
+    for route in HTTP_ROUTE_DOMAIN {
+        assert_eq!(HttpRoute::from_matched_path(route).as_str(), *route);
+        assert!(!route.contains("trace_id"));
+        assert!(!route.contains("request_id"));
+    }
+}
+
+#[test]
+fn canonical_schema_validation_reports_its_category() {
+    assert_eq!(
+        schema_budget(),
+        Ok(crank_metrics::SchemaBudget {
+            logical_series: 4_513,
+            rendered_series: 14_338
+        })
+    );
+}
+
+#[test]
+fn exact_budget_math_counts_histogram_bucket_sum_and_count_series() {
+    for definition in metric_schema() {
+        let logical = definition
+            .label_domains
+            .iter()
+            .map(|domain| domain.values.len())
+            .product::<usize>();
+        let logical = logical.max(1);
+        let rendered = if definition.kind.as_str() == "histogram" {
+            logical * (definition.buckets.len() + 3)
+        } else {
+            logical
+        };
+        assert_eq!(
+            definition.max_logical_series, logical,
+            "{}",
+            definition.name
+        );
+        assert_eq!(
+            definition.max_rendered_series, rendered,
+            "{}",
+            definition.name
+        );
+    }
+}