mirror of
https://github.com/logos-co/logos-protocol.git
synced 2026-08-30 05:21:07 +00:00
77 lines
2.3 KiB
C++
77 lines
2.3 KiB
C++
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#include "rpc_framing.h"
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#include <cstring>
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namespace logos::plain {
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namespace {
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void writeBe32(std::vector<uint8_t>& out, uint32_t n)
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{
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out.push_back(static_cast<uint8_t>((n >> 24) & 0xff));
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out.push_back(static_cast<uint8_t>((n >> 16) & 0xff));
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out.push_back(static_cast<uint8_t>((n >> 8) & 0xff));
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out.push_back(static_cast<uint8_t>( n & 0xff));
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}
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uint32_t readBe32(const uint8_t* p)
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{
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return (uint32_t(p[0]) << 24) | (uint32_t(p[1]) << 16)
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| (uint32_t(p[2]) << 8) | uint32_t(p[3]);
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}
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} // anonymous namespace
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std::vector<uint8_t>
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encodeFrame(MessageType tag, const std::vector<uint8_t>& payload)
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{
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// Total frame body length = 1 byte (tag) + payload bytes. The 4-byte
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// length prefix is not included in the length value it describes.
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const uint64_t bodyLen = 1u + payload.size();
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if (bodyLen > kMaxFrameLength)
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throw FramingError("frame too large");
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std::vector<uint8_t> out;
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out.reserve(4 + bodyLen);
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writeBe32(out, static_cast<uint32_t>(bodyLen));
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out.push_back(static_cast<uint8_t>(tag));
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out.insert(out.end(), payload.begin(), payload.end());
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return out;
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}
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std::vector<uint8_t>
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encodeFrame(IWireCodec& codec, const AnyMessage& msg)
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{
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return encodeFrame(messageTypeOf(msg), codec.encode(msg));
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}
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void FrameReader::append(const uint8_t* data, std::size_t len)
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{
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m_buf.insert(m_buf.end(), data, data + len);
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}
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bool FrameReader::next(MessageType& tag, std::vector<uint8_t>& payload)
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{
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// Need at least 4 bytes for the length prefix.
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if (m_buf.size() < 4) return false;
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const uint32_t bodyLen = readBe32(m_buf.data());
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if (bodyLen == 0) throw FramingError("zero-length frame");
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if (bodyLen > kMaxFrameLength) throw FramingError("frame length exceeds cap");
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const std::size_t total = 4u + bodyLen;
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if (m_buf.size() < total) return false;
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// Tag + payload.
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tag = static_cast<MessageType>(m_buf[4]);
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payload.assign(m_buf.begin() + 5, m_buf.begin() + total);
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// Drop the consumed bytes. erase from front is O(n) in buffer size;
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// acceptable while frames are small and rare. Can switch to a ring
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// buffer if profiling ever flags this.
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m_buf.erase(m_buf.begin(), m_buf.begin() + total);
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return true;
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}
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} // namespace logos::plain
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