/histogram.go
http://github.com/rcrowley/go-metrics · Go · 202 lines · 98 code · 46 blank · 58 comment · 5 complexity · d76284bee710901f90fd45e4e54a8e9e MD5 · raw file
- package metrics
- // Histograms calculate distribution statistics from a series of int64 values.
- type Histogram interface {
- Clear()
- Count() int64
- Max() int64
- Mean() float64
- Min() int64
- Percentile(float64) float64
- Percentiles([]float64) []float64
- Sample() Sample
- Snapshot() Histogram
- StdDev() float64
- Sum() int64
- Update(int64)
- Variance() float64
- }
- // GetOrRegisterHistogram returns an existing Histogram or constructs and
- // registers a new StandardHistogram.
- func GetOrRegisterHistogram(name string, r Registry, s Sample) Histogram {
- if nil == r {
- r = DefaultRegistry
- }
- return r.GetOrRegister(name, func() Histogram { return NewHistogram(s) }).(Histogram)
- }
- // NewHistogram constructs a new StandardHistogram from a Sample.
- func NewHistogram(s Sample) Histogram {
- if UseNilMetrics {
- return NilHistogram{}
- }
- return &StandardHistogram{sample: s}
- }
- // NewRegisteredHistogram constructs and registers a new StandardHistogram from
- // a Sample.
- func NewRegisteredHistogram(name string, r Registry, s Sample) Histogram {
- c := NewHistogram(s)
- if nil == r {
- r = DefaultRegistry
- }
- r.Register(name, c)
- return c
- }
- // HistogramSnapshot is a read-only copy of another Histogram.
- type HistogramSnapshot struct {
- sample *SampleSnapshot
- }
- // Clear panics.
- func (*HistogramSnapshot) Clear() {
- panic("Clear called on a HistogramSnapshot")
- }
- // Count returns the number of samples recorded at the time the snapshot was
- // taken.
- func (h *HistogramSnapshot) Count() int64 { return h.sample.Count() }
- // Max returns the maximum value in the sample at the time the snapshot was
- // taken.
- func (h *HistogramSnapshot) Max() int64 { return h.sample.Max() }
- // Mean returns the mean of the values in the sample at the time the snapshot
- // was taken.
- func (h *HistogramSnapshot) Mean() float64 { return h.sample.Mean() }
- // Min returns the minimum value in the sample at the time the snapshot was
- // taken.
- func (h *HistogramSnapshot) Min() int64 { return h.sample.Min() }
- // Percentile returns an arbitrary percentile of values in the sample at the
- // time the snapshot was taken.
- func (h *HistogramSnapshot) Percentile(p float64) float64 {
- return h.sample.Percentile(p)
- }
- // Percentiles returns a slice of arbitrary percentiles of values in the sample
- // at the time the snapshot was taken.
- func (h *HistogramSnapshot) Percentiles(ps []float64) []float64 {
- return h.sample.Percentiles(ps)
- }
- // Sample returns the Sample underlying the histogram.
- func (h *HistogramSnapshot) Sample() Sample { return h.sample }
- // Snapshot returns the snapshot.
- func (h *HistogramSnapshot) Snapshot() Histogram { return h }
- // StdDev returns the standard deviation of the values in the sample at the
- // time the snapshot was taken.
- func (h *HistogramSnapshot) StdDev() float64 { return h.sample.StdDev() }
- // Sum returns the sum in the sample at the time the snapshot was taken.
- func (h *HistogramSnapshot) Sum() int64 { return h.sample.Sum() }
- // Update panics.
- func (*HistogramSnapshot) Update(int64) {
- panic("Update called on a HistogramSnapshot")
- }
- // Variance returns the variance of inputs at the time the snapshot was taken.
- func (h *HistogramSnapshot) Variance() float64 { return h.sample.Variance() }
- // NilHistogram is a no-op Histogram.
- type NilHistogram struct{}
- // Clear is a no-op.
- func (NilHistogram) Clear() {}
- // Count is a no-op.
- func (NilHistogram) Count() int64 { return 0 }
- // Max is a no-op.
- func (NilHistogram) Max() int64 { return 0 }
- // Mean is a no-op.
- func (NilHistogram) Mean() float64 { return 0.0 }
- // Min is a no-op.
- func (NilHistogram) Min() int64 { return 0 }
- // Percentile is a no-op.
- func (NilHistogram) Percentile(p float64) float64 { return 0.0 }
- // Percentiles is a no-op.
- func (NilHistogram) Percentiles(ps []float64) []float64 {
- return make([]float64, len(ps))
- }
- // Sample is a no-op.
- func (NilHistogram) Sample() Sample { return NilSample{} }
- // Snapshot is a no-op.
- func (NilHistogram) Snapshot() Histogram { return NilHistogram{} }
- // StdDev is a no-op.
- func (NilHistogram) StdDev() float64 { return 0.0 }
- // Sum is a no-op.
- func (NilHistogram) Sum() int64 { return 0 }
- // Update is a no-op.
- func (NilHistogram) Update(v int64) {}
- // Variance is a no-op.
- func (NilHistogram) Variance() float64 { return 0.0 }
- // StandardHistogram is the standard implementation of a Histogram and uses a
- // Sample to bound its memory use.
- type StandardHistogram struct {
- sample Sample
- }
- // Clear clears the histogram and its sample.
- func (h *StandardHistogram) Clear() { h.sample.Clear() }
- // Count returns the number of samples recorded since the histogram was last
- // cleared.
- func (h *StandardHistogram) Count() int64 { return h.sample.Count() }
- // Max returns the maximum value in the sample.
- func (h *StandardHistogram) Max() int64 { return h.sample.Max() }
- // Mean returns the mean of the values in the sample.
- func (h *StandardHistogram) Mean() float64 { return h.sample.Mean() }
- // Min returns the minimum value in the sample.
- func (h *StandardHistogram) Min() int64 { return h.sample.Min() }
- // Percentile returns an arbitrary percentile of the values in the sample.
- func (h *StandardHistogram) Percentile(p float64) float64 {
- return h.sample.Percentile(p)
- }
- // Percentiles returns a slice of arbitrary percentiles of the values in the
- // sample.
- func (h *StandardHistogram) Percentiles(ps []float64) []float64 {
- return h.sample.Percentiles(ps)
- }
- // Sample returns the Sample underlying the histogram.
- func (h *StandardHistogram) Sample() Sample { return h.sample }
- // Snapshot returns a read-only copy of the histogram.
- func (h *StandardHistogram) Snapshot() Histogram {
- return &HistogramSnapshot{sample: h.sample.Snapshot().(*SampleSnapshot)}
- }
- // StdDev returns the standard deviation of the values in the sample.
- func (h *StandardHistogram) StdDev() float64 { return h.sample.StdDev() }
- // Sum returns the sum in the sample.
- func (h *StandardHistogram) Sum() int64 { return h.sample.Sum() }
- // Update samples a new value.
- func (h *StandardHistogram) Update(v int64) { h.sample.Update(v) }
- // Variance returns the variance of the values in the sample.
- func (h *StandardHistogram) Variance() float64 { return h.sample.Variance() }