event: constructors require metric description
Require a description in NewCounter, etc.
Also unexport MetricDescriptor.description for consistency with other
fields.
Change-Id: Id91279f89be9a65a528f3a3c9b4bde00ce622e54
Reviewed-on: https://go-review.googlesource.com/c/exp/+/326674
Trust: Jonathan Amsterdam <jba@google.com>
Run-TryBot: Jonathan Amsterdam <jba@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Cottrell <iancottrell@google.com>
diff --git a/event/bench/event_test.go b/event/bench/event_test.go
index 07d45a8..1e8e59c 100644
--- a/event/bench/event_test.go
+++ b/event/bench/event_test.go
@@ -68,7 +68,7 @@
},
}
- gauge = event.NewFloatGauge("gauge")
+ gauge = event.NewFloatGauge("gauge", "a gauge")
eventMetric = Hooks{
AStart: func(ctx context.Context, a int) context.Context {
event.To(ctx).With(aStat.Of(a)).Metric(gauge.Record(1))
diff --git a/event/builder_test.go b/event/builder_test.go
index 5e0174f..4f4166c 100644
--- a/event/builder_test.go
+++ b/event/builder_test.go
@@ -129,7 +129,7 @@
func TestTraceDuration(t *testing.T) {
// Verify that a trace can can emit a latency metric.
- dur := event.NewDuration("test")
+ dur := event.NewDuration("test", "")
want := 200 * time.Millisecond
check := func(t *testing.T, h *testTraceDurationHandler) {
@@ -171,7 +171,7 @@
func BenchmarkBuildContext(b *testing.B) {
// How long does it take to deliver an event from a nested context?
- c := event.NewCounter("c")
+ c := event.NewCounter("c", "")
for _, depth := range []int{1, 5, 7, 10} {
b.Run(fmt.Sprintf("depth %d", depth), func(b *testing.B) {
ctx := event.WithExporter(context.Background(), event.NewExporter(event.NopHandler{}, nil))
diff --git a/event/common_test.go b/event/common_test.go
index 4066f33..1fdfbd5 100644
--- a/event/common_test.go
+++ b/event/common_test.go
@@ -15,7 +15,7 @@
func TestCommon(t *testing.T) {
ctx, h := eventtest.NewCapture()
- m := event.NewCounter("m")
+ m := event.NewCounter("m", "")
const simple = "simple message"
const trace = "a trace"
diff --git a/event/event_test.go b/event/event_test.go
index 1656e56..4a01b72 100644
--- a/event/event_test.go
+++ b/event/event_test.go
@@ -23,9 +23,9 @@
l1 = keys.Int("l1").Of(1)
l2 = keys.Int("l2").Of(2)
l3 = keys.Int("l3").Of(3)
- counter = event.NewCounter("hits")
- gauge = event.NewFloatGauge("temperature")
- latency = event.NewDuration("latency")
+ counter = event.NewCounter("hits", "cache hits")
+ gauge = event.NewFloatGauge("temperature", "CPU board temperature in Celsius")
+ latency = event.NewDuration("latency", "how long it took")
)
func TestPrint(t *testing.T) {
diff --git a/event/metric.go b/event/metric.go
index 52b27ed..0c989ef 100644
--- a/event/metric.go
+++ b/event/metric.go
@@ -18,7 +18,7 @@
type MetricDescriptor struct {
namespace string
name string
- Description string
+ description string
// TODO: deal with units. Follow otel, or define Go types for common units.
// We don't need a time unit because we'll use time.Duration, and the only
// other unit otel currently defines (besides dimensionless) is bytes.
@@ -28,11 +28,11 @@
// The namespace defaults to the import path of the caller of NewMetricDescriptor.
// Use SetNamespace to provide a different one.
// Neither the name nor the namespace can be empty.
-func NewMetricDescriptor(name string) *MetricDescriptor {
- return newMetricDescriptor(name)
+func NewMetricDescriptor(name, description string) *MetricDescriptor {
+ return newMetricDescriptor(name, description)
}
-func newMetricDescriptor(name string) *MetricDescriptor {
+func newMetricDescriptor(name, description string) *MetricDescriptor {
if name == "" {
panic("name cannot be empty")
}
@@ -45,7 +45,8 @@
// 2 this function
// 3 caller of this function (one of the NewXXX methods in this package)
// 4 caller's caller
- namespace: importPath(4, nil),
+ namespace: importPath(4, nil),
+ description: description,
}
}
@@ -61,8 +62,9 @@
return fmt.Sprintf("Metric(\"%s/%s\")", m.namespace, m.name)
}
-func (m *MetricDescriptor) Name() string { return m.name }
-func (m *MetricDescriptor) Namespace() string { return m.namespace }
+func (m *MetricDescriptor) Name() string { return m.name }
+func (m *MetricDescriptor) Namespace() string { return m.namespace }
+func (m *MetricDescriptor) Description() string { return m.description }
// A MetricValue is a pair of a Metric and a Value.
type MetricValue struct {
@@ -76,8 +78,8 @@
}
// NewCounter creates a counter with the given name.
-func NewCounter(name string) *Counter {
- return &Counter{newMetricDescriptor(name)}
+func NewCounter(name, description string) *Counter {
+ return &Counter{newMetricDescriptor(name, description)}
}
// Descriptor returns the receiver's MetricDescriptor.
@@ -99,8 +101,8 @@
}
// NewFloatGauge creates a new FloatGauge with the given name.
-func NewFloatGauge(name string) *FloatGauge {
- return &FloatGauge{newMetricDescriptor(name)}
+func NewFloatGauge(name, description string) *FloatGauge {
+ return &FloatGauge{newMetricDescriptor(name, description)}
}
// Descriptor returns the receiver's MetricDescriptor.
@@ -122,8 +124,8 @@
}
// NewDuration creates a new Duration with the given name.
-func NewDuration(name string) *Duration {
- return &Duration{newMetricDescriptor(name)}
+func NewDuration(name, description string) *Duration {
+ return &Duration{newMetricDescriptor(name, description)}
}
// Descriptor returns the receiver's MetricDescriptor.
