diff --git a/include/input/RingBuffer.h b/include/input/RingBuffer.h
new file mode 100644
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+++ b/include/input/RingBuffer.h
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+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <algorithm>
+#include <compare>
+#include <cstddef>
+#include <iterator>
+#include <memory>
+#include <type_traits>
+#include <utility>
+
+#include <android-base/logging.h>
+#include <android-base/stringprintf.h>
+
+namespace android {
+
+// A fixed-size ring buffer of elements.
+//
+// Elements can only be removed from the front/back or added to the front/back, but with O(1)
+// performance. Elements from the opposing side are evicted when new elements are pushed onto a full
+// buffer.
+template <typename T>
+class RingBuffer {
+public:
+    using value_type = T;
+    using size_type = size_t;
+    using difference_type = ptrdiff_t;
+    using reference = value_type&;
+    using const_reference = const value_type&;
+    using pointer = value_type*;
+    using const_pointer = const value_type*;
+
+    template <typename U>
+    class Iterator;
+    using iterator = Iterator<T>;
+    using const_iterator = Iterator<const T>;
+
+    // Creates an empty ring buffer that can hold some capacity.
+    explicit RingBuffer(size_type capacity)
+          : mBuffer(std::allocator<value_type>().allocate(capacity)), mCapacity(capacity) {}
+
+    // Creates a full ring buffer holding a fixed number of elements initialised to some value.
+    explicit RingBuffer(size_type count, const_reference value) : RingBuffer(count) {
+        while (count) {
+            pushBack(value);
+            --count;
+        }
+    }
+
+    RingBuffer(const RingBuffer& other) : RingBuffer(other.capacity()) {
+        for (const auto& element : other) {
+            pushBack(element);
+        }
+    }
+
+    RingBuffer(RingBuffer&& other) noexcept { *this = std::move(other); }
+
+    ~RingBuffer() {
+        if (mBuffer) {
+            clear();
+            std::allocator<value_type>().deallocate(mBuffer, mCapacity);
+        }
+    }
+
+    RingBuffer& operator=(const RingBuffer& other) { return *this = RingBuffer(other); }
+
+    RingBuffer& operator=(RingBuffer&& other) noexcept {
+        if (this == &other) {
+            return *this;
+        }
+        if (mBuffer) {
+            clear();
+            std::allocator<value_type>().deallocate(mBuffer, mCapacity);
+        }
+        mBuffer = std::move(other.mBuffer);
+        mCapacity = other.mCapacity;
+        mBegin = other.mBegin;
+        mSize = other.mSize;
+        other.mBuffer = nullptr;
+        other.mCapacity = 0;
+        other.mBegin = 0;
+        other.mSize = 0;
+        return *this;
+    }
+
+    iterator begin() { return {*this, 0}; }
+    const_iterator begin() const { return {*this, 0}; }
+    iterator end() { return {*this, mSize}; }
+    const_iterator end() const { return {*this, mSize}; }
+
+    reference operator[](size_type i) { return mBuffer[bufferIndex(i)]; }
+    const_reference operator[](size_type i) const { return mBuffer[bufferIndex(i)]; }
+
+    // Removes all elements from the buffer.
+    void clear() {
+        std::destroy(begin(), end());
+        mSize = 0;
+    }
+
+    // Removes and returns the first element from the buffer.
+    value_type popFront() {
+        value_type element = mBuffer[mBegin];
+        std::destroy_at(std::addressof(mBuffer[mBegin]));
+        mBegin = next(mBegin);
+        --mSize;
+        return element;
+    }
+
+    // Removes and returns the last element from the buffer.
+    value_type popBack() {
+        size_type backIndex = bufferIndex(mSize - 1);
+        value_type element = mBuffer[backIndex];
+        std::destroy_at(std::addressof(mBuffer[backIndex]));
+        --mSize;
+        return element;
+    }
+
+    // Adds an element to the front of the buffer.
+    void pushFront(const value_type& element) { pushFront(value_type(element)); }
+    void pushFront(value_type&& element) {
+        mBegin = previous(mBegin);
+        if (size() == capacity()) {
+            mBuffer[mBegin] = std::forward<value_type>(element);
+        } else {
+            // The space at mBuffer[mBegin] is uninitialised.
+            // TODO: Use std::construct_at when it becomes available.
+            new (std::addressof(mBuffer[mBegin])) value_type(std::forward<value_type>(element));
+            ++mSize;
+        }
+    }
+
+    // Adds an element to the back of the buffer.
+    void pushBack(const value_type& element) { pushBack(value_type(element)); }
+    void pushBack(value_type&& element) {
+        if (size() == capacity()) {
+            mBuffer[mBegin] = std::forward<value_type>(element);
+            mBegin = next(mBegin);
+        } else {
+            // The space at mBuffer[...] is uninitialised.
+            // TODO: Use std::construct_at when it becomes available.
+            new (std::addressof(mBuffer[bufferIndex(mSize)]))
+                    value_type(std::forward<value_type>(element));
+            ++mSize;
+        }
+    }
+
+    bool empty() const { return mSize == 0; }
+    size_type capacity() const { return mCapacity; }
+    size_type size() const { return mSize; }
+
+    void swap(RingBuffer& other) noexcept {
+        using std::swap;
+        swap(mBuffer, other.mBuffer);
+        swap(mCapacity, other.mCapacity);
+        swap(mBegin, other.mBegin);
+        swap(mSize, other.mSize);
+    }
+
+    friend void swap(RingBuffer& lhs, RingBuffer& rhs) noexcept { lhs.swap(rhs); }
+
+    template <typename U>
+    class Iterator {
+    private:
+        using ContainerType = std::conditional_t<std::is_const_v<U>, const RingBuffer, RingBuffer>;
+
+    public:
+        using iterator_category = std::random_access_iterator_tag;
+        using size_type = ContainerType::size_type;
+        using difference_type = ContainerType::difference_type;
+        using value_type = std::remove_cv_t<U>;
+        using pointer = U*;
+        using reference = U&;
+
+        Iterator(ContainerType& container, size_type index)
+              : mContainer(container), mIndex(index) {}
+
+        Iterator(const Iterator&) = default;
+        Iterator& operator=(const Iterator&) = default;
+
+        Iterator& operator++() {
+            ++mIndex;
+            return *this;
+        }
+
+        Iterator operator++(int) {
+            Iterator iterator(*this);
+            ++(*this);
+            return iterator;
+        }
+
+        Iterator& operator--() {
+            --mIndex;
+            return *this;
+        }
+
+        Iterator operator--(int) {
+            Iterator iterator(*this);
+            --(*this);
+            return iterator;
+        }
+
+        Iterator& operator+=(difference_type n) {
+            mIndex += n;
+            return *this;
+        }
+
+        Iterator operator+(difference_type n) {
+            Iterator iterator(*this);
+            return iterator += n;
+        }
+
+        Iterator& operator-=(difference_type n) { return *this += -n; }
+
+        Iterator operator-(difference_type n) {
+            Iterator iterator(*this);
+            return iterator -= n;
+        }
+
+        difference_type operator-(const Iterator& other) { return mIndex - other.mIndex; }
+
+        bool operator==(const Iterator& rhs) const { return mIndex == rhs.mIndex; }
+
+        bool operator!=(const Iterator& rhs) const { return !(*this == rhs); }
+
+        friend auto operator<=>(const Iterator& lhs, const Iterator& rhs) {
+            return lhs.mIndex <=> rhs.mIndex;
+        }
+
+        reference operator[](difference_type n) { return *(*this + n); }
+
+        reference operator*() const { return mContainer[mIndex]; }
+        pointer operator->() const { return std::addressof(mContainer[mIndex]); }
+
+    private:
+        ContainerType& mContainer;
+        size_type mIndex = 0;
+    };
+
+private:
+    // Returns the index of the next element in mBuffer.
+    size_type next(size_type index) const {
+        if (index == capacity() - 1) {
+            return 0;
+        } else {
+            return index + 1;
+        }
+    }
+
+    // Returns the index of the previous element in mBuffer.
+    size_type previous(size_type index) const {
+        if (index == 0) {
+            return capacity() - 1;
+        } else {
+            return index - 1;
+        }
+    }
+
+    // Converts the index of an element in [0, size()] to its corresponding index in mBuffer.
+    size_type bufferIndex(size_type elementIndex) const {
+        CHECK_LE(elementIndex, size());
+        size_type index = mBegin + elementIndex;
+        if (index >= capacity()) {
+            index -= capacity();
+        }
+        CHECK_LT(index, capacity())
+                << android::base::StringPrintf("Invalid index calculated for element (%zu) "
+                                               "in buffer of size %zu",
+                                               elementIndex, size());
+        return index;
+    }
+
+    pointer mBuffer = nullptr;
+    size_type mCapacity = 0; // Total capacity of mBuffer.
+    size_type mBegin = 0;    // Index of the first initialised element in mBuffer.
+    size_type mSize = 0;     // Total number of initialised elements.
+};
+
+} // namespace android