Add structures for simple metrics.

Author: vmarmol

info/v2/metric.go

@@ -0,0 +1,69 @@
+// Copyright 2015 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package v2
+
+import (
+	"time"
+)
+
+// Type of metric being exported.
+type MetricType string
+
+const (
+	// Instantaneous value. May increase or decrease.
+	MetricGauge MetricType = "gauge"
+
+	// A counter-like value that is only expected to increase.
+	MetricCumulative = "cumulative"
+
+	// Rate over a time period.
+	MetricDelta = "delta"
+)
+
+// An exported metric.
+type Metric struct {
+	// The name of the metric.
+	Name string `json:"name"`
+
+	// Type of the metric.
+	Type MetricType `json:"type"`
+
+	// Metadata associated with this metric.
+	Labels map[string]string
+
+	// Value of the metric. Only one of these values will be
+	// available according to the output type of the metric.
+	// If no values are available, there are no data points.
+	IntPoints   []IntPoint   `json:"int_points,omitempty"`
+	FloatPoints []FloatPoint `json:"float_points,omitempty"`
+}
+
+// An integer metric data point.
+type IntPoint struct {
+	// Time at which the metric was queried
+	Timestamp time.Time `json:"timestamp"`
+
+	// The value of the metric at this point.
+	Value int64 `json:"value"`
+}
+
+// A float metric data point.
+type FloatPoint struct {
+	// Time at which the metric was queried
+	Timestamp time.Time `json:"timestamp"`
+
+	// The value of the metric at this point.
+	Value float64 `json:"value"`
+}