histogram.go

// Copyright 2016 Circonus, Inc. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package circonusgometrics

import (
	"sync"
	"time"

	"github.com/openhistogram/circonusllhist"
	"github.com/pkg/errors"
)

// Histogram measures the distribution of a stream of values.
type Histogram struct {
	rw   sync.RWMutex
	hist *circonusllhist.Histogram
	name string
}

// TimingWithTags adds a value to a histogram metric with tags
func (m *CirconusMetrics) TimingWithTags(metric string, tags Tags, val float64) {
	m.SetHistogramValueWithTags(metric, tags, val)
}

// Timing adds a value to a histogram
func (m *CirconusMetrics) Timing(metric string, val float64) {
	m.SetHistogramValue(metric, val)
}

// RecordValueWithTags adds a value to a histogram metric with tags
func (m *CirconusMetrics) RecordValueWithTags(metric string, tags Tags, val float64) {
	m.SetHistogramValueWithTags(metric, tags, val)
}

// RecordValue adds a value to a histogram
func (m *CirconusMetrics) RecordValue(metric string, val float64) {
	m.SetHistogramValue(metric, val)
}

// RecordDurationWithTags adds a time.Duration to a histogram metric with tags
// (duration is normalized to time.Second, but supports nanosecond granularity).
func (m *CirconusMetrics) RecordDurationWithTags(metric string, tags Tags, val time.Duration) {
	m.SetHistogramDurationWithTags(metric, tags, val)
}

// RecordDuration adds a time.Duration to a histogram metric (duration is
// normalized to time.Second, but supports nanosecond granularity).
func (m *CirconusMetrics) RecordDuration(metric string, val time.Duration) {
	m.SetHistogramDuration(metric, val)
}

// RecordCountForValueWithTags adds count n for value to a histogram metric with tags
func (m *CirconusMetrics) RecordCountForValueWithTags(metric string, tags Tags, val float64, n int64) {
	m.RecordCountForValue(m.MetricNameWithStreamTags(metric, tags), val, n)
}

// RecordCountForValue adds count n for value to a histogram
func (m *CirconusMetrics) RecordCountForValue(metric string, val float64, n int64) {
	hist := m.NewHistogram(metric)

	m.hm.Lock()
	hist.rw.Lock()
	err := hist.hist.RecordValues(val, n)
	if err != nil {
		m.Log.Printf("error recording histogram values (%v)\n", err)
	}
	hist.rw.Unlock()
	m.hm.Unlock()
}

// SetHistogramValueWithTags adds a value to a histogram metric with tags
func (m *CirconusMetrics) SetHistogramValueWithTags(metric string, tags Tags, val float64) {
	m.SetHistogramValue(m.MetricNameWithStreamTags(metric, tags), val)
}

// SetHistogramValue adds a value to a histogram
func (m *CirconusMetrics) SetHistogramValue(metric string, val float64) {
	hist := m.NewHistogram(metric)

	m.hm.Lock()
	hist.rw.Lock()
	err := hist.hist.RecordValue(val)
	if err != nil {
		m.Log.Printf("error recording histogram value (%v)\n", err)
	}
	hist.rw.Unlock()
	m.hm.Unlock()
}

// SetHistogramDurationWithTags adds a value to a histogram with tags
func (m *CirconusMetrics) SetHistogramDurationWithTags(metric string, tags Tags, val time.Duration) {
	m.SetHistogramDuration(m.MetricNameWithStreamTags(metric, tags), val)
}

// SetHistogramDuration adds a value to a histogram
func (m *CirconusMetrics) SetHistogramDuration(metric string, val time.Duration) {
	hist := m.NewHistogram(metric)

	m.hm.Lock()
	hist.rw.Lock()
	err := hist.hist.RecordDuration(val)
	if err != nil {
		m.Log.Printf("error recording histogram duration (%v)\n", err)
	}
	hist.rw.Unlock()
	m.hm.Unlock()
}

// RemoveHistogramWithTags removes a histogram metric with tags
func (m *CirconusMetrics) RemoveHistogramWithTags(metric string, tags Tags) {
	m.RemoveHistogram(m.MetricNameWithStreamTags(metric, tags))
}

// RemoveHistogram removes a histogram
func (m *CirconusMetrics) RemoveHistogram(metric string) {
	m.hm.Lock()
	defer m.hm.Unlock()
	delete(m.histograms, metric)
}

// NewHistogramWithTags returns a histogram metric with tags instance
func (m *CirconusMetrics) NewHistogramWithTags(metric string, tags Tags) *Histogram {
	return m.NewHistogram(m.MetricNameWithStreamTags(metric, tags))
}

// NewHistogram returns a histogram instance.
func (m *CirconusMetrics) NewHistogram(metric string) *Histogram {
	m.hm.Lock()
	defer m.hm.Unlock()

	if hist, ok := m.histograms[metric]; ok {
		return hist
	}

	hist := &Histogram{
		name: metric,
		hist: circonusllhist.New(),
	}

	m.histograms[metric] = hist

	return hist
}

// GetHistogramTest returns the current value for a histogram. (note: it is a function specifically for "testing", disable automatic submission during testing.)
func (m *CirconusMetrics) GetHistogramTest(metric string) ([]string, error) {
	m.hm.Lock()
	defer m.hm.Unlock()

	if hist, ok := m.histograms[metric]; ok {
		hist.rw.Lock()
		defer hist.rw.Unlock()
		return hist.hist.DecStrings(), nil
	}

	return []string{""}, errors.Errorf("Histogram metric '%s' not found", metric)
}

// Name returns the name from a histogram instance
func (h *Histogram) Name() string {
	h.rw.Lock()
	defer h.rw.Unlock()
	return h.name
}

// RecordValue records the given value to a histogram instance
func (h *Histogram) RecordValue(v float64) {
	h.rw.Lock()
	defer h.rw.Unlock()
	_ = h.hist.RecordValue(v)
}

// RecordDuration records the given time.Duration to a histogram instance.
// RecordDuration normalizes the value to seconds.
func (h *Histogram) RecordDuration(v time.Duration) {
	h.rw.Lock()
	defer h.rw.Unlock()
	_ = h.hist.RecordDuration(v)
}