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-rw-r--r--src/common/scratch_buffer.h95
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diff --git a/src/common/scratch_buffer.h b/src/common/scratch_buffer.h
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+// SPDX-FileCopyrightText: Copyright 2022 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include "common/make_unique_for_overwrite.h"
+
+namespace Common {
+
+/**
+ * ScratchBuffer class
+ * This class creates a default initialized heap allocated buffer for cases such as intermediate
+ * buffers being copied into entirely, where value initializing members during allocation or resize
+ * is redundant.
+ */
+template <typename T>
+class ScratchBuffer {
+public:
+ ScratchBuffer() = default;
+
+ explicit ScratchBuffer(size_t initial_capacity)
+ : last_requested_size{initial_capacity}, buffer_capacity{initial_capacity},
+ buffer{Common::make_unique_for_overwrite<T[]>(initial_capacity)} {}
+
+ ~ScratchBuffer() = default;
+
+ /// This will only grow the buffer's capacity if size is greater than the current capacity.
+ /// The previously held data will remain intact.
+ void resize(size_t size) {
+ if (size > buffer_capacity) {
+ auto new_buffer = Common::make_unique_for_overwrite<T[]>(size);
+ std::move(buffer.get(), buffer.get() + buffer_capacity, new_buffer.get());
+ buffer = std::move(new_buffer);
+ buffer_capacity = size;
+ }
+ last_requested_size = size;
+ }
+
+ /// This will only grow the buffer's capacity if size is greater than the current capacity.
+ /// The previously held data will be destroyed if a reallocation occurs.
+ void resize_destructive(size_t size) {
+ if (size > buffer_capacity) {
+ buffer_capacity = size;
+ buffer = Common::make_unique_for_overwrite<T[]>(buffer_capacity);
+ }
+ last_requested_size = size;
+ }
+
+ [[nodiscard]] T* data() noexcept {
+ return buffer.get();
+ }
+
+ [[nodiscard]] const T* data() const noexcept {
+ return buffer.get();
+ }
+
+ [[nodiscard]] T* begin() noexcept {
+ return data();
+ }
+
+ [[nodiscard]] const T* begin() const noexcept {
+ return data();
+ }
+
+ [[nodiscard]] T* end() noexcept {
+ return data() + last_requested_size;
+ }
+
+ [[nodiscard]] const T* end() const noexcept {
+ return data() + last_requested_size;
+ }
+
+ [[nodiscard]] T& operator[](size_t i) {
+ return buffer[i];
+ }
+
+ [[nodiscard]] const T& operator[](size_t i) const {
+ return buffer[i];
+ }
+
+ [[nodiscard]] size_t size() const noexcept {
+ return last_requested_size;
+ }
+
+ [[nodiscard]] size_t capacity() const noexcept {
+ return buffer_capacity;
+ }
+
+private:
+ size_t last_requested_size{};
+ size_t buffer_capacity{};
+ std::unique_ptr<T[]> buffer{};
+};
+
+} // namespace Common