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Diffstat (limited to 'src/hid_core/resources/ring_lifo.h')
-rw-r--r-- | src/hid_core/resources/ring_lifo.h | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/src/hid_core/resources/ring_lifo.h b/src/hid_core/resources/ring_lifo.h new file mode 100644 index 000000000..0816784e0 --- /dev/null +++ b/src/hid_core/resources/ring_lifo.h @@ -0,0 +1,53 @@ +// SPDX-FileCopyrightText: Copyright 2021 yuzu Emulator Project +// SPDX-License-Identifier: GPL-2.0-or-later + +#pragma once + +#include <array> + +#include "common/common_types.h" + +namespace Service::HID { + +template <typename State> +struct AtomicStorage { + s64 sampling_number; + State state; +}; + +template <typename State, std::size_t max_buffer_size> +struct Lifo { + s64 timestamp{}; + s64 total_buffer_count = static_cast<s64>(max_buffer_size); + s64 buffer_tail{}; + s64 buffer_count{}; + std::array<AtomicStorage<State>, max_buffer_size> entries{}; + + const AtomicStorage<State>& ReadCurrentEntry() const { + return entries[buffer_tail]; + } + + const AtomicStorage<State>& ReadPreviousEntry() const { + return entries[GetPreviousEntryIndex()]; + } + + std::size_t GetPreviousEntryIndex() const { + return static_cast<size_t>((buffer_tail + max_buffer_size - 1) % max_buffer_size); + } + + std::size_t GetNextEntryIndex() const { + return static_cast<size_t>((buffer_tail + 1) % max_buffer_size); + } + + void WriteNextEntry(const State& new_state) { + if (buffer_count < static_cast<s64>(max_buffer_size) - 1) { + buffer_count++; + } + buffer_tail = GetNextEntryIndex(); + const auto& previous_entry = ReadPreviousEntry(); + entries[buffer_tail].sampling_number = previous_entry.sampling_number + 1; + entries[buffer_tail].state = new_state; + } +}; + +} // namespace Service::HID |