| // 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 |

| } |