36 lines
1014 B
C++
36 lines
1014 B
C++
#pragma once
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#include <cstddef>
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#include <cstdint>
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#include <span>
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// Bounds-checked sequential reader for byte streams. consume<T>() returns a
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// typed pointer into the underlying buffer or nullptr on underflow. Used to
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// walk packet headers in order without UB and without copies.
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class parse_buffer {
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const uint8_t* m_data;
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size_t m_remaining;
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public:
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parse_buffer(std::span<const uint8_t> data)
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: m_data(data.data()), m_remaining(data.size()) {}
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template <typename T>
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const T* consume() {
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if (m_remaining < sizeof(T)) return nullptr;
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auto* p = reinterpret_cast<const T*>(m_data);
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m_data += sizeof(T);
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m_remaining -= sizeof(T);
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return p;
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}
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bool skip(size_t len) {
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if (m_remaining < len) return false;
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m_data += len;
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m_remaining -= len;
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return true;
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}
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std::span<const uint8_t> remaining() const { return {m_data, m_remaining}; }
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size_t remaining_size() const { return m_remaining; }
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};
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