diff options
Diffstat (limited to 'src/core/hle/service/hid/ring_lifo.h')
-rw-r--r-- | src/core/hle/service/hid/ring_lifo.h | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/src/core/hle/service/hid/ring_lifo.h b/src/core/hle/service/hid/ring_lifo.h new file mode 100644 index 000000000..1cc2a194f --- /dev/null +++ b/src/core/hle/service/hid/ring_lifo.h @@ -0,0 +1,54 @@ +// Copyright 2021 yuzu Emulator Project +// Licensed under GPLv2 or any later version +// Refer to the license.txt file included + +#pragma once + +#include "common/common_types.h" +#include "common/swap.h" + +namespace Service::HID { +constexpr std::size_t max_entry_size = 17; + +template <typename State> +struct AtomicStorage { + s64_le sampling_number; + State state; +}; + +template <typename State> +struct Lifo { + s64_le timestamp{}; + s64_le total_entry_count = max_entry_size; + s64_le last_entry_index{}; + s64_le entry_count{}; + std::array<AtomicStorage<State>, max_entry_size> entries{}; + + const AtomicStorage<State>& ReadCurrentEntry() const { + return entries[last_entry_index]; + } + + const AtomicStorage<State>& ReadPreviousEntry() const { + return entries[GetPreviuousEntryIndex()]; + } + + std::size_t GetPreviuousEntryIndex() const { + return (last_entry_index + total_entry_count - 1) % total_entry_count; + } + + std::size_t GetNextEntryIndex() const { + return (last_entry_index + 1) % total_entry_count; + } + + void WriteNextEntry(const State& new_state) { + if (entry_count < total_entry_count - 1) { + entry_count++; + } + last_entry_index = GetNextEntryIndex(); + const auto& previous_entry = ReadPreviousEntry(); + entries[last_entry_index].sampling_number = previous_entry.sampling_number + 1; + entries[last_entry_index].state = new_state; + } +}; + +} // namespace Service::HID |