From 9651f66c4cb68be3816c25df4e2aef488f1a31ea Mon Sep 17 00:00:00 2001
From: Moses Turner <moses@collabora.com>
Date: Tue, 14 Jun 2022 12:22:12 +0100
Subject: [PATCH] a/util: Add clear() method to HistoryBuffer

---
 src/xrt/auxiliary/util/u_template_historybuf.hpp      | 11 +++++++++++
 .../util/u_template_historybuf_impl_helpers.hpp       | 10 ++++++++++
 2 files changed, 21 insertions(+)

diff --git a/src/xrt/auxiliary/util/u_template_historybuf.hpp b/src/xrt/auxiliary/util/u_template_historybuf.hpp
index 73ae1bfef..c263b5e2d 100644
--- a/src/xrt/auxiliary/util/u_template_historybuf.hpp
+++ b/src/xrt/auxiliary/util/u_template_historybuf.hpp
@@ -178,6 +178,9 @@ public:
 	const T &
 	back() const;
 
+	void
+	clear();
+
 private:
 	// Make sure all valid indices can be represented in a signed integer of the same size
 	static_assert(MaxSize < (std::numeric_limits<size_t>::max() >> 1), "Cannot use most significant bit");
@@ -187,6 +190,14 @@ private:
 	detail::RingBufferHelper helper_{MaxSize};
 };
 
+
+template <typename T, size_t MaxSize>
+void
+HistoryBuffer<T, MaxSize>::clear()
+{
+	helper_.clear();
+}
+
 template <typename T, size_t MaxSize>
 inline bool
 HistoryBuffer<T, MaxSize>::empty() const noexcept
diff --git a/src/xrt/auxiliary/util/u_template_historybuf_impl_helpers.hpp b/src/xrt/auxiliary/util/u_template_historybuf_impl_helpers.hpp
index 0d12d39f6..1f3ebd631 100644
--- a/src/xrt/auxiliary/util/u_template_historybuf_impl_helpers.hpp
+++ b/src/xrt/auxiliary/util/u_template_historybuf_impl_helpers.hpp
@@ -113,6 +113,9 @@ public:
 	size_t
 	back_inner_index() const noexcept;
 
+	void
+	clear();
+
 private:
 	// Would be const, but that would mess up our ability to copy/move containers using this.
 	size_t capacity_;
@@ -135,6 +138,13 @@ private:
 };
 
 
+inline void
+RingBufferHelper::clear()
+{
+	this->latest_inner_idx_ = 0;
+	this->length_ = 0;
+}
+
 inline size_t
 RingBufferHelper::front_impl_() const noexcept
 {