| // Copyright 2020 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 metrics | |
| // Float64Histogram represents a distribution of float64 values. | |
| type Float64Histogram struct { | |
| // Counts contains the weights for each histogram bucket. | |
| // | |
| // Given N buckets, Count[n] is the weight of the range | |
| // [bucket[n], bucket[n+1]), for 0 <= n < N. | |
| Counts []uint64 | |
| // Buckets contains the boundaries of the histogram buckets, in increasing order. | |
| // | |
| // Buckets[0] is the inclusive lower bound of the minimum bucket while | |
| // Buckets[len(Buckets)-1] is the exclusive upper bound of the maximum bucket. | |
| // Hence, there are len(Buckets)-1 counts. Furthermore, len(Buckets) != 1, always, | |
| // since at least two boundaries are required to describe one bucket (and 0 | |
| // boundaries are used to describe 0 buckets). | |
| // | |
| // Buckets[0] is permitted to have value -Inf and Buckets[len(Buckets)-1] is | |
| // permitted to have value Inf. | |
| // | |
| // For a given metric name, the value of Buckets is guaranteed not to change | |
| // between calls until program exit. | |
| // | |
| // This slice value is permitted to alias with other Float64Histograms' Buckets | |
| // fields, so the values within should only ever be read. If they need to be | |
| // modified, the user must make a copy. | |
| Buckets []float64 | |
| } | |