tasks/common/metrics/noop_impl.go

// The MIT License
//
// Copyright (c) 2020 Temporal Technologies Inc.  All rights reserved.
//
// Copyright (c) 2020 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

package metrics

import (
	"time"

	"go.temporal.io/server/common/log"
)

var (
	NoopReporter       Reporter       = newNoopReporter()
	NoopClient         Client         = newNoopClient()
	NoopScope          Scope          = newNoopScope()
	NoopUserScope      UserScope      = newNoopUserScope()
	NoopStopwatch      Stopwatch      = newNoopStopwatch()
	NoopMetricsHandler MetricsHandler = newNoopMetricsHandler()
)

type (
	noopReporterImpl     struct{}
	noopClientImpl       struct{}
	noopMetricsUserScope struct{}
	noopStopwatchImpl    struct{}
	noopScopeImpl        struct{}
	noopMetricsHandler   struct{}
)

func newNoopReporter() *noopReporterImpl {
	return &noopReporterImpl{}
}

func (*noopReporterImpl) MetricsHandler() MetricsHandler {
	return NoopMetricsHandler
}

func (*noopReporterImpl) Stop(logger log.Logger) {}

func (*noopReporterImpl) UserScope() UserScope {
	return NoopUserScope
}

func newNoopUserScope() *noopMetricsUserScope {
	return &noopMetricsUserScope{}
}

func (n *noopMetricsUserScope) IncCounter(counter string) {}

func (n *noopMetricsUserScope) AddCounter(counter string, delta int64) {}

func (n *noopMetricsUserScope) StartTimer(timer string) Stopwatch {
	return NoopStopwatch
}

func (n *noopMetricsUserScope) RecordTimer(timer string, d time.Duration) {}

func (n *noopMetricsUserScope) RecordDistribution(id string, unit MetricUnit, d int) {}

func (n *noopMetricsUserScope) UpdateGauge(gauge string, value float64) {}

func (n *noopMetricsUserScope) Tagged(tags map[string]string) UserScope {
	return n
}

func newNoopClient() *noopClientImpl {
	return &noopClientImpl{}
}

func (m *noopClientImpl) IncCounter(scope int, counter int) {}

func (m *noopClientImpl) AddCounter(scope int, counter int, delta int64) {}

func (m *noopClientImpl) StartTimer(scope int, timer int) Stopwatch {
	return NoopStopwatch
}

func (m *noopClientImpl) RecordTimer(scope int, timer int, d time.Duration) {}

func (m *noopClientImpl) RecordDistribution(scope int, timer int, d int) {}

func (m *noopClientImpl) UpdateGauge(scope int, gauge int, value float64) {}

func (m *noopClientImpl) Scope(scope int, tags ...Tag) Scope {
	return NoopScope
}

// NoopScope returns a noop scope of metrics
func newNoopScope() *noopScopeImpl {
	return &noopScopeImpl{}
}

func (n *noopScopeImpl) AddCounterInternal(name string, delta int64) {
}

func (n *noopScopeImpl) StartTimerInternal(timer string) Stopwatch {
	return NoopStopwatch
}

func (n *noopScopeImpl) RecordTimerInternal(timer string, d time.Duration) {
}

func (n *noopScopeImpl) RecordDistributionInternal(id string, unit MetricUnit, d int) {
}

func (n *noopScopeImpl) IncCounter(counter int) {}

func (n *noopScopeImpl) AddCounter(counter int, delta int64) {}

func (n *noopScopeImpl) StartTimer(timer int) Stopwatch {
	return NoopStopwatch
}

func (n *noopScopeImpl) RecordTimer(timer int, d time.Duration) {}

func (n *noopScopeImpl) RecordDistribution(id int, d int) {}

func (n *noopScopeImpl) UpdateGauge(gauge int, value float64) {}

func (n *noopScopeImpl) Tagged(tags ...Tag) Scope {
	return n
}

// NopStopwatch return a fake tally stop watch
func newNoopStopwatch() *noopStopwatchImpl {
	return &noopStopwatchImpl{}
}

func (n *noopStopwatchImpl) Stop()                       {}
func (n *noopStopwatchImpl) Subtract(nsec time.Duration) {}

func newNoopMetricsHandler() *noopMetricsHandler { return &noopMetricsHandler{} }

// WithTags creates a new MetricProvder with provided []Tag
// Tags are merged with registered Tags from the source MetricsHandler
func (n *noopMetricsHandler) WithTags(...Tag) MetricsHandler {
	return n
}

// Counter obtains a counter for the given name and MetricOptions.
func (*noopMetricsHandler) Counter(string) CounterMetric {
	return CounterMetricFunc(func(i int64, t ...Tag) {})
}

// Gauge obtains a gauge for the given name and MetricOptions.
func (*noopMetricsHandler) Gauge(string) GaugeMetric {
	return GaugeMetricFunc(func(f float64, t ...Tag) {})
}

// Timer obtains a timer for the given name and MetricOptions.
func (*noopMetricsHandler) Timer(string) TimerMetric {
	return TimerMetricFunc(func(d time.Duration, t ...Tag) {})
}

// Histogram obtains a histogram for the given name and MetricOptions.
func (*noopMetricsHandler) Histogram(string, MetricUnit) HistogramMetric {
	return HistogramMetricFunc(func(i int64, t ...Tag) {})
}

func (*noopMetricsHandler) Stop(log.Logger) {}