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// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package stats provides support for recording telemetry statistics.
// It acts as a coordination point between things that want to record stats,
// and things that want to aggregate and report stats.
package stats
import (
"context"
)
// Int64Measure is used to record integer values.
type Int64Measure struct {
name string
description string
unit Unit
subscribers []Int64Subscriber
}
// Int64Measure is used to record floating point values.
type Float64Measure struct {
name string
description string
unit Unit
subscribers []Float64Subscriber
}
// Int64Subscriber is the type for functions that want to listen to
// integer statistic events.
type Int64Subscriber func(context.Context, *Int64Measure, int64)
// Float64Subscriber is the type for functions that want to listen to
// floating point statistic events.
type Float64Subscriber func(context.Context, *Float64Measure, float64)
// Unit is used to specify the units for a given measure.
// This is can used for display purposes.
type Unit int
const (
// UnitDimensionless indicates that a measure has no specified units.
UnitDimensionless = Unit(iota)
// UnitBytes indicates that that a measure is recording number of bytes.
UnitBytes
// UnitMilliseconds indicates that a measure is recording a duration in milliseconds.
UnitMilliseconds
)
// Int64 creates a new Int64Measure and prepares it for use.
func Int64(name string, description string, unit Unit) *Int64Measure {
return &Int64Measure{
name: name,
description: description,
unit: unit,
}
}
// Float64 creates a new Float64Measure and prepares it for use.
func Float64(name string, description string, unit Unit) *Float64Measure {
return &Float64Measure{
name: name,
description: description,
unit: unit,
}
}
// Name returns the name this measure was given on construction.
func (m *Int64Measure) Name() string { return m.name }
// Description returns the description this measure was given on construction.
func (m *Int64Measure) Description() string { return m.description }
// Unit returns the units this measure was given on construction.
func (m *Int64Measure) Unit() Unit { return m.unit }
// Subscribe adds a new subscriber to this measure.
func (m *Int64Measure) Subscribe(s Int64Subscriber) { m.subscribers = append(m.subscribers, s) }
// Record delivers a new value to the subscribers of this measure.
func (m *Int64Measure) Record(ctx context.Context, value int64) {
for _, s := range m.subscribers {
s(ctx, m, value)
}
}
// Name returns the name this measure was given on construction.
func (m *Float64Measure) Name() string { return m.name }
// Description returns the description this measure was given on construction.
func (m *Float64Measure) Description() string { return m.description }
// Unit returns the units this measure was given on construction.
func (m *Float64Measure) Unit() Unit { return m.unit }
// Subscribe adds a new subscriber to this measure.
func (m *Float64Measure) Subscribe(s Float64Subscriber) { m.subscribers = append(m.subscribers, s) }
// Record delivers a new value to the subscribers of this measure.
func (m *Float64Measure) Record(ctx context.Context, value float64) {
for _, s := range m.subscribers {
s(ctx, m, value)
}
}