61 lines
1.8 KiB
C++
61 lines
1.8 KiB
C++
/**
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******************************************************************************
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* Xenia : Xbox 360 Emulator Research Project *
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******************************************************************************
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* Copyright 2015 Ben Vanik. All rights reserved. *
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* Released under the BSD license - see LICENSE in the root for more details. *
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******************************************************************************
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*/
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#include "xenia/base/ring_buffer.h"
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#include <algorithm>
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#include <cstring>
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namespace xe {
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RingBuffer::RingBuffer(uint8_t* buffer, size_t capacity)
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: buffer_(buffer), capacity_(capacity), read_offset_(0), write_offset_(0) {}
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size_t RingBuffer::Read(uint8_t* buffer, size_t count) {
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count = std::min(count, capacity_);
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if (!count) {
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return 0;
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}
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if (read_offset_ + count < capacity_) {
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std::memcpy(buffer, buffer_ + read_offset_, count);
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read_offset_ += count;
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} else {
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size_t left_half = capacity_ - read_offset_;
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size_t right_half = count - left_half;
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std::memcpy(buffer, buffer_ + read_offset_, left_half);
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std::memcpy(buffer + left_half, buffer_, right_half);
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read_offset_ = right_half;
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}
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return count;
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}
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size_t RingBuffer::Write(uint8_t* buffer, size_t count) {
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count = std::min(count, capacity_);
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if (!count) {
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return 0;
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}
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if (write_offset_ + count < capacity_) {
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std::memcpy(buffer_ + write_offset_, buffer, count);
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write_offset_ += count;
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} else {
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size_t left_half = capacity_ - write_offset_;
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size_t right_half = count - left_half;
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std::memcpy(buffer_ + write_offset_, buffer, left_half);
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std::memcpy(buffer_, buffer + left_half, right_half);
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write_offset_ = right_half;
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}
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return count;
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}
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} // namespace xe
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