1 files changed, 82 insertions, 0 deletions
diff --git a/vendor/go.opentelemetry.io/otel/sdk/log/ring.go b/vendor/go.opentelemetry.io/otel/sdk/log/ring.go
new file mode 100644
index 000000000..5e84cb164
--- /dev/null
+++ b/vendor/go.opentelemetry.io/otel/sdk/log/ring.go
@@ -0,0 +1,82 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+// Copyright 2009 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 log // import "go.opentelemetry.io/otel/sdk/log"
+
+// A ring is an element of a circular list, or ring. Rings do not have a
+// beginning or end; a pointer to any ring element serves as reference to the
+// entire ring. Empty rings are represented as nil ring pointers. The zero
+// value for a ring is a one-element ring with a nil Value.
+//
+// This is copied from the "container/ring" package. It uses a Record type for
+// Value instead of any to avoid allocations.
+type ring struct {
+	next, prev *ring
+	Value      Record
+}
+
+func (r *ring) init() *ring {
+	r.next = r
+	r.prev = r
+	return r
+}
+
+// Next returns the next ring element. r must not be empty.
+func (r *ring) Next() *ring {
+	if r.next == nil {
+		return r.init()
+	}
+	return r.next
+}
+
+// Prev returns the previous ring element. r must not be empty.
+func (r *ring) Prev() *ring {
+	if r.next == nil {
+		return r.init()
+	}
+	return r.prev
+}
+
+// newRing creates a ring of n elements.
+func newRing(n int) *ring {
+	if n <= 0 {
+		return nil
+	}
+	r := new(ring)
+	p := r
+	for i := 1; i < n; i++ {
+		p.next = &ring{prev: p}
+		p = p.next
+	}
+	p.next = r
+	r.prev = p
+	return r
+}
+
+// Len computes the number of elements in ring r. It executes in time
+// proportional to the number of elements.
+func (r *ring) Len() int {
+	n := 0
+	if r != nil {
+		n = 1
+		for p := r.Next(); p != r; p = p.next {
+			n++
+		}
+	}
+	return n
+}
+
+// Do calls function f on each element of the ring, in forward order. The
+// behavior of Do is undefined if f changes *r.
+func (r *ring) Do(f func(Record)) {
+	if r != nil {
+		f(r.Value)
+		for p := r.Next(); p != r; p = p.next {
+			f(p.Value)
+		}
+	}
+}