83 lines
1.7 KiB
C++
83 lines
1.7 KiB
C++
// SPDX-License-Identifier: GPL-2.0-or-later
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// Copyright The Music Player Daemon Project
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#ifndef MPD_OPUS_READER_HXX
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#define MPD_OPUS_READER_HXX
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#include <algorithm>
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#include <cstdint>
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#include <string_view>
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#include <string.h>
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class OpusReader {
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const uint8_t *p, *const end;
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public:
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constexpr OpusReader(const void *_p, size_t size) noexcept
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:p((const uint8_t *)_p), end(p + size) {}
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constexpr bool Skip(size_t length) noexcept {
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p += length;
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return p <= end;
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}
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constexpr const void *Read(size_t length) noexcept {
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const uint8_t *result = p;
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return Skip(length)
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? result
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: nullptr;
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}
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bool Expect(const void *value, size_t length) noexcept {
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const void *data = Read(length);
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return data != nullptr && memcmp(value, data, length) == 0;
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}
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constexpr bool ReadByte(uint8_t &value_r) noexcept {
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if (p >= end)
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return false;
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value_r = *p++;
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return true;
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}
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constexpr bool ReadShort(uint16_t &value_r) noexcept {
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const uint8_t *value = (const uint8_t *)Read(sizeof(value_r));
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if (value == nullptr)
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return false;
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value_r = value[0] | (value[1] << 8);
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return true;
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}
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constexpr bool ReadWord(uint32_t &value_r) noexcept {
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const uint8_t *value = (const uint8_t *)Read(sizeof(value_r));
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if (value == nullptr)
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return false;
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value_r = value[0] | (value[1] << 8)
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| (value[2] << 16) | (value[3] << 24);
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return true;
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}
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constexpr bool SkipString() noexcept {
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uint32_t length;
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return ReadWord(length) && Skip(length);
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}
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constexpr std::string_view ReadString() noexcept {
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uint32_t length;
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if (!ReadWord(length))
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return {};
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const char *src = (const char *)Read(length);
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if (src == nullptr)
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return {};
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return {src, length};
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}
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};
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#endif
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