1 // Copyright 2020 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 package metrics 6 7 // Float64Histogram represents a distribution of float64 values. 8 type Float64Histogram struct { 9 // Counts contains the weights for each histogram bucket. 10 // 11 // Given N buckets, Count[n] is the weight of the range 12 // [bucket[n], bucket[n+1]), for 0 <= n < N. 13 Counts []uint64 14 15 // Buckets contains the boundaries of the histogram buckets, in increasing order. 16 // 17 // Buckets[0] is the inclusive lower bound of the minimum bucket while 18 // Buckets[len(Buckets)-1] is the exclusive upper bound of the maximum bucket. 19 // Hence, there are len(Buckets)-1 counts. Furthermore, len(Buckets) != 1, always, 20 // since at least two boundaries are required to describe one bucket (and 0 21 // boundaries are used to describe 0 buckets). 22 // 23 // Buckets[0] is permitted to have value -Inf and Buckets[len(Buckets)-1] is 24 // permitted to have value Inf. 25 // 26 // For a given metric name, the value of Buckets is guaranteed not to change 27 // between calls until program exit. 28 // 29 // This slice value is permitted to alias with other Float64Histograms' Buckets 30 // fields, so the values within should only ever be read. If they need to be 31 // modified, the user must make a copy. 32 Buckets []float64 33 } 34