Adding upstream version 1.21.8.upstream/1.21.8

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 33 insertions, 0 deletions

diff --git a/src/runtime/metrics/histogram.go b/src/runtime/metrics/histogram.go
new file mode 100644
index 0000000..956422b
--- /dev/null
+++ b/src/runtime/metrics/histogram.go
@@ -0,0 +1,33 @@
+// 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
+}